• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Nanostructured materials with localized surface plasmon resonance for photocatalysis

    2022-06-18 10:52:24JunLiZizhuLouBojunLi
    Chinese Chemical Letters 2022年3期

    Jun Li,Zizhu Lou,b,?,Bojun Li

    a Institute of Nanophotonics,Jinan University,Guangzhou 511443,China

    b State Key Laboratory for Crystal Materials,Shandong University,Ji’nan 250100,China

    Keywords:Localized surface plasmon resonance Plasmonic photocatalysis Plasmonic semiconductor Hot electrons Solar energy harvesting

    ABSTRACT Localized surface plasmon resonance (LSPR) enhanced photocatalysis has fascinated much interest and considerable efforts have been devoted toward the development of plasmonic photocatalysts.In the past decades,noble metal nanoparticles (Au and Ag) with LSPR feature have found wide applications in solar energy conversion.Numerous metal-based photocatalysts have been proposed including metal/semiconductor heterostructures and plasmonic bimetallic or multimetallic nanostructures.However,high cost and scarce reserve of noble metals largely limit their further practical use,which drives the focus gradually shift to low-cost and abundant nonmetallic nanostructures.Recently,various heavily doped semiconductors (such as WO3-x,MoO3-x,Cu2–xS,TiN) have emerged as potential alternatives to costly noble metals for efficient photocatalysis due to their strong LSPR property in visible-near infrared region.This review starts with a brief introduction to LSPR property and LSPR-enhanced photocatalysis,the following highlights recent advances of plasmonic photocatalysts from noble metal to semiconductorbased plasmonic nanostructures.Their synthesis methods and promising applicability in plasmon-driven photocatalytic reactions such as water splitting,CO2 reduction and pollution decomposition are also summarized in details.This review is expected to give guidelines for exploring more efficient plasmonic systems and provide a perspective on development of plasmonic photocatalysis.

    1.Introduction

    Evoked by present dilemma of energy shortage and environmental pollution,developing renewable energy is highly urgent.Solar energy as one of “green” energy resources has attracted worldwide attention,but its efficient utilization is a significant challenge.Photocatalysis,an emerging “green technology”,can convert solar energy to chemical fuels to address current global environmental and energy crisis [1–3].Since the discovery of Honda-Fujishima effect on TiO2photoelectrode in 1972 [4],semiconductor photocatalysis has dominated the research area for several decades[5–7].However,intrinsic wide band gaps (>3.1 eV) render the conventional semiconductors (TiO2,ZnO) solely responsive to ultraviolet (UV) light,accounting for only 4% of solar energy.Other visiblelight responsive semiconductors likeα-Fe2O3,are inherited with short charge-carrier diffusion lengths and suffer from poor charge separation efficiency,significantly hampering their applications in photocatalysis [8].In order to enhance the photoactivities of semiconductors,various methods have been proposed,such as doping external elements to tune their band structures for a broad optical response [9,10],constructing suitable heterostructure to retard the charge recombination [11,12],engineering surface architectures for more active sites [13,14]etc.Nevertheless,weak photoresponse and low quantum efficiency are still two major bottlenecks for largescale application of semiconductor photocatalysts.

    Fig.1.Schematic illustration of LSPR excitation on metallic NPs.

    Along with semiconductor photocatalysis,localized surface plasmon resonance (LSPR) mediated photocatalysis has fascinated much attention in solar energy conversion [15–19].LSPR is one physical phenomenon of free electrons oscillation of with incident photons confined on noble metallic nanoparticles (NPs) surface.Plasmonic metallic NPs (Au,Ag) were initially used to sensitize semiconductors and improve their photoelectric response by constructing noble metal/semiconductor hybrids [20–22].Owing to LSPR effect,plasmonic NPs can transfer solar energy to adjacent semiconductors to drive chemical reactions.Intriguingly,apart from acting as light absorber,plasmonic NPs themselves can also serve as active sites to directly induce catalysis.Plasmon-induced active hot charge carriers,electrons and holes can drive surface catalytic reaction and modulate the reaction path [23–26].LSPR excitation induces strong light harvesting,hot electron generation and localized heating effect,all of which could be beneficial for photochemical reactions [27–30].Although plasmonic noble metals exhibit favorable advantages over traditional semiconductors,high cost and scarce reserve significantly inhibit their practical applications in photocatalysis.Moreover,LSPR of noble metallic NPs mostly localize in visible light region and near-infrared light accounting for more than 50% of solar energy failed to be wellutilized.Note that non-noble metals like Al and Cu also exhibit LSPR properties,which are considered as strong competitors to noble metals in term of their optical response.While both Al and Cu are cost-effective,their wide applicability for photocatalysis is largely hindered by the instability under ambient conditions.For example,Al has an inherent tendency to form oxides upon exposure to air due to high reduction potential (1.66 V).Cu NPs are also prone to oxidation and lead to the formation of Cu2O or CuO.

    Developing nonmetallic plasmonic nanostructures that enable broad-spectrum solar harvesting as potential substitutes of noble metals is of significance to sustainable and energy-efficient plasmonic photocatalysis.Recently,various semiconductors with heavy doping (WO3-x,Cu2–xS,MoO3-x,etc.) have emerged as a burgeoning research hotspot due to their strong LSPR absorption in visiblenear infrared (vis-NIR) region [31–38].There has been debate as to whether defect absorption or SPR is responsible for strong absorption of heavily-doped semiconductors.Alivisatos and Manthiram theoretically proved that the intense absorption of WO3-xis arised from the unique property of their outer-dvalence electrons,providing theoretical support for non-metallic LSPR effect[39].Since then,numerous nonmetallic plasmonic nanostructures have springed up as active photocatalysts and opened a new route for the development of photocatalysis [40–45].In this review,we introduce recent advances of plasmonic photocatalysts from noble metal to semiconductor-based plasmonic nanostructures and further discuss their characterization and photocatalytic applications(water splitting,artificial photosynthesis,pollution decompositionetc.) in detail.Finally,we also present an outlook for the development of plasmonic photocatalysts and provide guidelines for optimizing the existing plasmonic systems.

    2.Localized surface plasmon resonance

    2.1.LSPR property

    LSPR is an intriguing phenomenon associated with collective oscillations of free electrons with incident light Fig.1).The extent of interaction between materials and light can be described by a complex dielectric function based on the Drude-Lorentz model as follows (Eqs.1–4):

    whereεpis dielectric function of materials,εrandεiare real and imaginary parts,respectively.ε∞is the high frequency dielectric constant of materials,ωpis plasma frequency,ωis light frequency,γis the damping constant that represents free carriers scattering,Nis free carriers density,meis the effective mass of free carriers,e is elementary charge andε0is the permittivity of vacuum.εris determined by electric field induced polarization,whereasεibasically corresponds to damping and energy loss upon absorption at NPs surface [46].As light irradiates on metallic NPs (Au,Ag,Cu),the associated electric field induces polarization of electrons density to one surface.At plasmon wavelength,electrons on NPs surface occur resonant oscillation to exhibit a strong LSPR absorption[47–49].

    The LSPR wavelength of metallic NPs largely depends on the metal nature,morphology and dielectric constants of the surrounding media (Fig.2).For example,by varying the geometry of Ag NPs from spheres to wires or cubes,both LSPR modes and wavelength are changed [18].Moreover,LSPR wavelength also changes with the surrounding media due to variation in dielectric constant.The LSPR wavelengths of Ag nanocubes were found to red shift as the surrounding refractive index of solvents increased [50].The longitudinal plasmon wavelength of Au nanorods (NRs) exhibits a nearly linear relation with aspect ratio as well as refractive index of surrounding solvents [47,51].By tailoring these parameters,the corresponding photoresponse of metallic NPs can be finely manipulated,which is expected to improve the solar utilization.

    The LSPR phenomenon is not restricted to metallic NPs and could also be observed in semiconductors with high free carrier density.Similar to noble metals,LSPR in semiconductors are originated from resonant interaction of free carriers and incident light,as described by the complex dielectric function.However,unlike metals,LSPR in semiconductors can be induced by free electrons or holes depending on the dopant nature,which are labeled as n-type or p-type plasmonic semiconductors,respectively [52].Besides,LSPR wavelength in semiconductors is largely up to free carrier density.Luther et al.investigated the effect of free carrier density on LSPR frequency (wavelength).For NPs size in the range of 2–12 nm,carrier density of 1019–1022cm?3generates LSPR in infrared range while carrier density below 1019cm?3is too low to support one LSPR mode [32].Due to lower carrier density in comparison to noble metals,semiconductors usually exhibit LSPR in broad Vis-NIR region.For example,p-type self-doped copper chalcogenide (Cu2-xX,X=S,Se,Te) nanocrystals (NCs) exhibit LSPR absorption in NIR region generated by free holes oscillation(Figs.3a–c) [53].Control over dopant type and extent can impact the free carrier density,leading to different LSPR energies and spectral shapes within the same host material.Fanget al.reported that for the same doping level,LSPR is at lower energy and has a smaller bandwidth for Ti-doped than Sb-doped In2O3NCs,indicating lower free carrier density due to the formation of deep defect states within Ti:In2O3band gap [54].Similar phenomena have been widely reported across several metal oxides.The plasmonic behavior of Cu2-xS NCs also can be tunedviachanging the composition with different Cu+doping extent.By a versatile postsynthesis reaction,the Cu/S ratio in NCs could be gradually increased from 1.1:1 to 2:1 while preserving their size and morphology.With increasing incorporation of Cu,the LSPR band of covellite Cu2-xS NCs red-shifted and decreased in intensity until it vanished for NCs with Cu2S composition.It is mainly attributed to the decrease of free carrier density in NCs due to the increase in Cu stoichiometry [55].A similar red shift and an increase in full-width at half maximum of LSPR band were also observed with increasing of Cu/S feed ratios,ascribing to the change of free carriers density induced by phase transformation [56].In addition to free carrier density modulation,the shape parameters and crystal structure also greatly influence the LSPR of semiconductor NCs.The Cu2?xX exhibits a diverse crystal phases and morphology,which have a huge impact on their plasmonic response.The djurleite Cu1.94S nanodisks display two LSPR peaks in NIR and Mid-IR regions,while both roxbyite Cu1.8S and covellite CuS have only one peak in NIR region [33](Fig.3d).Cu2–xS nanodisks have two planes labeled as “in-plane” and “out-of-plane”,where each plane corresponds to one LSPR mode.The characteristic LSPR wavelengths vary with the aspect ratio (diametervs.thickness) and carrier density of nanodisks [57].Increasing the aspect ratio induces out-ofplane plasmon to blue-shift and in-plane to red-shift,consistent well with Mie scattering theory (Fig.3e).As only hole carrier density is increased,both out-of-plane and in-plane plasmon are expected to blue-shift according to Drude theory (Fig.3f).These results above indicate that both morphology (size,shape,aspect ratio etc.) and the free-carriers density (related to composition and phase) should be carefully considered to achieve dynamic tailoring for LSPR characteristics of semiconductor NCs.

    Fig.2.The plasmonic resonant wavelength dependence of metallic NPs on their (a) metal species,morphology of (b) shape and (c) size.Reproduced with permission [18].Copyright 2011,Nature Publishing Group.

    Fig.3.(a–c) Extinction spectra and TEM images of Cu2-xS (x=0–0.03,a),Cu2-xSe (x=0–0.2,b) and Cu2-xTe (x=0.6,c) NCs.Reproduced with permission [53].Copyright 2011,American Chemical Society.(d) Shape-dependent extinction spectra of Cu2–xS NCs with sphere and nanodisks.Reproduced with permission [33].Copyright 2011,American Chemical Society.The LSPR dependence of Cu2–xS nanodisks on (e) aspect ratio and (f) free carrier density.Reproduced with permission [57].Copyright 2012,American Chemical Society.

    Fig.4.(a) LSPR undergo decay by either radiative photons emission or nonradiative relaxation to generate hot electrons.(b) Hot electrons with a wide distribution range in energy.(c) Hot electrons with large energy can be injected to CB of adjacent semiconductors.Reproduced with permission [58].Copyright 2011,Nature Publishing Group.

    2.2.LSPR-enhanced photocatalysis

    The LSPR enables significant electric field enhancement on metallic NPs surface,known as near-field enhancement,which is beneficial for efficient light absorption and charge-carrier generation [58–60].This near-field enhancement attenuates exponentially with the distance away from metal NPs surface and spatially limited to nanoscale “hot spots” region around the surface.The excited LSPR undergo decay by either radiative photons emission or nonradiative relaxation (Fig.4),and the latter forms the basis of photocatalytic applications.The hot electrons are generated during the nonradiative decay through intra- or inter-band electrons transition.For Au and Ag NPs,owing to their fairly low-lyingdband below Fermi level,hot electrons generate primarily via intraband transitions within conduction band (CB) and the energies exhibit a wide distribution range of 1–4 eV [18,59,61].Ultrafast measurements have shown that these hot electrons rapidly thermalize in isolated NPs,and the lifetime is extremely short in the range of 1–100 ps [58].However,as metallic NPs are married with semiconductors,hot electrons with sufficient energy can be injected to CB of adjacent semiconductors across interfacial Schottky barrier to impede the decay,greatly altering their dynamics[59,62,63].Similar to conventional electron transfer,hot electron injection is manipulated by the heterostructural interfacial contact and band alignment [25,59,64,65].Therefore,elaborate structural engineering is highly needed for a fast hot electron injection to avoid the decay.For plasmonic semiconductors,LSPR-excited hot carriers (electrons or holes) also exhibit a similar ultrafast dynamic with that of metallic NPs.

    During plasmonic photocatalytic process,plasmon-induced hot electrons can be transferred to adjacent semiconductor or directly interact with molecules adsorbed on plasmonic NPs surface[24,66–68].The extracted hot electrons can activate specific chemical bonds of reactants and modify the reaction pathway,making a big difference to products selectivity [69].Besides,hot electrons enable accelerated desorption of certain surface-adsorbed species,further promoting the catalytic activity and simultaneously prolong the stability of plasmonic NPs [70].The hot electrons have been demonstrated to play dominant role in various plasmon-enhanced chemical reactions including CO2reduction [71–73],H2evolution[74–76]etc.However,compared to widely studied photochemistry driven by hot electrons,the ones that driven by plasmonic hot holes have received less attention,probably due to much shorter lifetime of hot holes than hot electrons [77].The hot carriers that do not participate in reaction could subsequently dissipate their energy to lattice phononviaelectron-phonon scattering,inducing considerable photothermal effect (heating),which is also favorable for chemical conversion since both reaction rates and routes are closely related to temperature [78–81].The photothermal heating is an effective driving force to accelerate the reaction by promoting the adsorption-desorption of surface adsorbent and shifting chemical equilibria toward higher products yield [82,83].In plasmonic photocatalysis,by structural design of plasmonic catalysts,hot carrier driven reactant activation and photothermal effect could coexist and synergistically make positive contributions to enhance plasmonic catalytic efficiency [84–87].

    The electric near-field enhancement,plasmonic hot carriers and thermal effect are representative features of LSPR,which are mostly investigated in plasmonic photocatalysis and offer guidelines for developing efficient photocatalysts.To date,based on these plasmonic effects,various plasmonic nanostructures have been reported as active photocatalysts and herein is primarily divided into two big categories of noble metal-based and nonmetallic plasmonic photocatalysts according to the components.The synthesis,LSPR property and photocatalytic applications of these photocatalysts are discussed in details below.

    3.Noble metal based plasmonic photocatalysts

    3.1.Metal-semiconductor composites as plasmonic photocatalysts

    For conventional semiconductor photocatalysts,narrow photoresponse range and low quantum efficiency are two major challenges for their practical applications.The controlled integration of semiconductor with plasmonic noble metals (Au,Ag) has been considered as an effective route to improve the situation.In 2008,Awazu group deposited TiO2on Ag/SiO2core-shell structures and initially proposed the concept of “plasmonic photocatalysis”.The enhanced electric field on Ag NPs surface was pioneered to afford better photocatalytic performance for decomposition of methylene blue (MB) [20].The same year,Huang group proposed a stable plasmonic photocatalyst of Ag@AgCl with strong absorption in visible region for efficient degradation of organic dyes [21].Compared with spherical NPs with only one LSPR mode,anisotropic metallic NPs with multipolar LSPR modes could achieve broader vis-NIR light harvesting.Liuet al.prepared Au NRs loaded TiO2phototcatalysts and found that both transversal and longitudinal plasma of Au NRs (with tunable adsorption from 630 nm to 810 nm) could induce photocatalytic 2-propanol oxidation [88].The adjustable light adsorption caused by tunability of Au NRs aspect ratio is benefit to developing photocatalyst with specific light harvesting.Moreover,Au NRs and metal NPs (Au,Ag or Pt) co-decorated CdS nanowires(NWs) ensemble with tunable and progressive harvesting of vis-NIR light (λ >570 nm) has also been reported for distinctly boosting photoreduction of 4-nitroaniline and water splitting to H2[89].The results show that finely progressive control over a series of factors,including interfacial interaction,morphology optimization and cocatalyst addition in metal-semiconductor (Au NRs-CdS) heterostructures,can lead to tunable and improved performance for vis-NIR driven plasmonic photocatalysis.

    Fig.5.(a) SEM images and (b,c) HRTEM images of Au/MesoTiO2.(d) Kinetic linear fitting curves for photocatalytic MB degradation over different samples under 460–700 nm light irradiation.(e) Time-resolved DRS observed after 530 nm laser flash photolysis of Au/MesoTiO2.Reproduced with permission [90].Copyright 2013,American Chemical Society.

    In plasmonic metal-semiconductor photocatalyst,plasmoninduced hot electrons can be injected into CB of nearby semiconductors across interfacial Schottky barriers,dominantly driving the photocatalytic redox reaction.Bianet al.successfully deposited Au NPs on TiO2mesocrystals by a simple impregnation method (Fig.5) [90].The diffuse reflectance spectroscopy (DRS)measurements demonstrate that LSPR-induced hot electrons are injected from Au NPs to TiO2mesocrystals,directionally migrate from basal surfaces to the edges of plate-like TiO2nanocrystal.Such anisotropic electron flow significantly retarded the charge recombination of hot carriers in Au NPs,thereby improving visiblelight driven photocatalytic organic-pollutant degradation.

    Plasmon-induced hot electron injection in metal-semiconductor system provides a promising avenue to improve the efficiency of photocatalysis.To this end,the metal-semiconductor interface is of significance and should be elaborately engineered to facilitate rapid hot electron injection that is competitive with ultrafast hot electron relaxation.Apart from surface decoration,core-shell geometry is favorable in view of its maximized contact and optimal configuration for efficient charge transfer.Yadong Li group produced core-shell structures of Au@MS (M=Cd,Zn) with controllable shapes and unique atomically organized interfacesviaaqueous cation exchange-facilitated nonepitaxial growth.Beneficial from interfacial- and structural-optimization,Au@MS enables improved hot electron injection with an estimated quantum yield of~48% for boosting plasmon-enhanced photocatalytic H2evolution[74].Recently,various Au NR@ZnO core-shell photocatalysts with tunable shell thickness were also successfully prepared to achieve solar-driven CO2conversion to CH4,further demonstrating the redox reactivity of plasmonic hot electrons.With ZnO shell acting as electron acceptor,the hot electrons prolonged the lifetime,which are more conducive to being captured by absorbed molecules to participate in the reaction.Both of Au core and ZnO shell are coexcited by solar light,synergistically contributing to significant enhancement of CO2photoreduction [91].

    The coupling manners between metal and semiconductor are also crucial for photocatalytic performance of plasmonic metalsemiconductor photocatalysts.Instead of depositing metallic NPs onto semiconductor,anisotropic growth of semiconductor onto Au NPs afford better interfacial contact between them.Besides,anisotropic metallic NPs with high-curvature sites such as nanocubes corners and nanocones tips,are found to be locations for maximum electric field distribution compared with spherical NPs [92].Because of the lightning rod effect and decreased radiative damping,anisotropic metallic NPs with high-curvature sites concentrate the incident energy and largely facilitate plasmonic hot electrons generation and transfer,which play significant roles for activating surface chemical reaction [93].Therefore,controlled selective overgrowth of semiconductors at high-curvature sites of metallic NPs is valid strategy to obtain active plasmonic photocatalysts.Au triangular nanoprisms (Au TNPs) with unique anisotropic structures and multipolar LSPR modes,offer diverse sites of corner,edge and surface for coupling with semiconductors to construct various plasmonic photocatalysts.Lou et al.constructed anisotropic Ag2S-edged Au TNPs by controlling preferential overgrowth (Fig.6).Under vis-NIR light irradiation,Ag2S-edged Au TNPs achieve maximum H2generation rate (796 μmol h?1g?1),almost four times higher than those of Ag2S-covered Au TNPs (216 μmol h?1g?1)and pure Au TNPs (none).Single-particle photoluminescence (PL)measurements have been performed and an obvious PL quenching in Ag2S-edged Au TNPs demonstrates SPR-induced hot electron transfer from Au-TNPs to Ag2S for boosting H2generation[75].Plasmonic hot electrons have been demonstrated to play a vital role in photocatalysis.However,only a few hot electrons with high energy can cross the as-formed Schottky barrier between metal and semiconductor for photocatalysis.The photocatalytic efficiency of plasmonic metal-semiconductor heterostructure is still challenged by slow charge mobility,inefficient hot electrons utilization and lack of active sites for redox reactions.

    3.2.Bimetallic/multimetallic composites as plasmonic photocatalysts

    Due to fast electrons transfer between metallic parts,bimetallic/multimetallic NPs are expected to show unique performance in photocatalysis.Various bimetallic NPs with enhanced charge separation have been developed,including Au-Pt,Au-Pd,Au-Cu,etc.[94–97].In order to achieve efficient light utilization and high catalytic activity simultaneously,the intimate integration of plasmonic and catalytic metals is strongly desirable [98].Majima group developed anisotropic Pt/Pd-tipped Au NRs,which simultaneously act as light absorber and catalytic active site to boost H2evolution from water splitting [94]and formic acid dehydrogenation [95],respectively (Fig.7).Both PL quenching and light scattering from single Pt/Pd-tipped Au NRs confirmed hot electron transfer from excited Au to Pt/Pd.To further promote generation and transfer of hot electrons,Tanget al.reported freestanding heterosuperstructures of Au NRs@Pd (Au@Pd SSs),where ordered Pd nanoarrays are precisely grown on AuNRs surfacesviaseed-mediated approach.With help of strong antenna effect in ordered Pd nanoarrays,plasmonic AuNRs engender abundant hot electrons to promote molecular oxygen activation;while vertical organization of Pd on Au NRs with small contact not only exposes rich active sites for reactants but also prolongs hot electron lifetime,largely enhancing C?C coupling reaction [99].

    Fig.6.(a) TEM,(b) High-angle annular dark-field scanning TEM and (c) HRTEM images of Ag2S-edged Au TNPs.(d) Average H2 generation rates over Ag2S-covered,Ag2Sedged,pure Au TNPs and Ag2S photocatalysts under Vis-NIR light irradiation.(e,f) Single-particle PL image and spectra of Ag2S-edged Au TNPs.Reproduced with permission[75].Copyright 2018,Wiley-VCH.

    Fig.7.Single-particle PL study of (a) Pt-tipped Au NRs for plasmon-enhanced water splitting and (b) Pd-tipped Au NRs for plasmon-enhanced HCOOH dehydrogenation.Reproduced with permission [94,95].Copyright 2014,American Chemical Society.

    Apart from 1D NRs,2D Au TNPs are also promising components for bimetallic plasmonic photocatalysis,which have multiple SPR modes including in-plane dipole SPR (DSPR),multipole SPR (MSPR)and out-of-plane SPR in visible-NIR region.Louet al.synthesized three types of anisotropic Pt-covered,Pt-edged,and Pt-tipped Au TNPs by seed and subsequently controlling overgrowth,as shown in Figs.8a–f.With intense electric field and more interface contact,Pt-edged Au TNPs facilitates hot electron transfer,leading to superior photocatalytic activity for H2generation than the other two.By single-particle PL spectra,in-plane DSPR mode of Au TNPs was demonstrated as the dominant channel for hot electrons transfer to edged Pt [100].Byin situetching of single Au TNP,2D Au obtuse TNP (O-TNP) and nanodisk were obtained to construct various anisotropic Pt-Au heterostructures as plasmonic photocatalysts[101].The Pt-edged Au O-TNP with larger tip area and electric field enhancement is beneficial for hot electron transfer and charge separation,resulting in higher efficiency in photocatalytic H2generation (Figs.8g–i).To improve charge separation,reduced graphene oxide (rGO) with high conductivity was introduced to facilitate hot electrons transfer from plasmonic to catalytic metals.Ternary 2D Au-TNP/rGO/Pt nanoframe (NF) as plasmonic photocatalysts are preferable for boosting H2generation under vis-NIR light.The hot electrons generated on Au TNP are quickly transferred to rGO and further collected by loaded Pt NF cocatalyst,leading to efficient charge separation for high photocatalytic activity [102].Recently,Huanget al.reported multimetallic heterostructure of Pd-dotted Ag@Au hexagonal nanoplates (HNPs),where plasmonic core-shell Ag@Au structure act as an ideal light absorber and Pd nanodots provide more catalytic active sites [103].The heterostructure exhibits an excellent catalytic activity for formic acid (HCOOH) dehydrogenation even at 0 °C with turnover frequency of 1062 h?1,due to plasmon-induced hot electron transfer from Ag@Au HNPs to Pd dots.

    By analyzing the relaxation path,most hot carriers may undergo further thermalizationviaelectron-phonon scattering and lead to photothermal heating,which is also an effective driving force for accelerating surface reaction.However,the two plasmonic effects of hot-electrons and photothermal conversion are usually entangled,making it hard to quantify their individual contribution to chemical reactions.To distinctly differentiate these two effects,Huang and co-workers reported a bar-shaped core-shell Au@Pd system toward Vis-NIR light-driven catalytic styrene hydrogenation,since that hot electrons have been considered as detrimental to hydrogenation [104].Intriguingly,the Pd shell thickness could serve as a knob to maneuver the processes of hot-electron transfer and photothermal conversion,building a platform for unraveling their roles in catalytic reactions.As Pd shell thickness was tuned to 14 atomic layers precisely,photothermal heating effi-ciency was maximized while the side effect of plasmonic hot electrons was suppressed.Consequently,owing to plasmonic thermal effect,Au@Pd achieved high conversion yield of 76% in photocatalytic styrene hydrogenation to ethylbenzene,comparable to that achieved via thermally driven process at 80 °C.For most chemical reactions,both hot electrons and photothermal effect make positive contributions,synergistically enhance plasmonic catalytic effi-ciency.

    Fig.8.TEM images of (a) Pt-covered,(b) Pt-edged and (c) Pt-tipped Au TNPs.(d) H2 evolution over different photocatalysts.(e) Schematic diagram of plasmon radiative decay in Au TNPs.(f) Single-particle PL spectra.Reproduced with permission [100].Copyright 2016,American Chemical Society.(g) TEM image,(h) H2 generation rates and(i) Single-particle PL spectra of Pt-edged Au O-TNPs.Reproduced with permission [101].Copyright 2017,American Chemical Society.

    There are several distinct features of hot carrier contribution to chemical reaction that can be used to experimentally differentiate from photothermal effect including: (1) Linear dependence of reaction rate on light intensity due to the fact that hot carrier generation rate increases linearly with photon flux [105],(2) a higher kinetic isotope effect or modified products selectivity in chemical reaction compared with that driven by thermal energy at same reaction temperature [106],(3) similar tendency of apparent quantum efficiency (AQE) with LSPR absorption spectrum of plasmonic NPs [73].A clear separation of these two effects facilitates the rational design of plasmonic photocatalysts for efficient photochemical applications and solar energy utilization.

    4.Nonmetallic materials as plasmonic photocatalysts

    Recently,various nonmetallic nanomaterials have emerged as potential LSPR hosts and can be classified based on the origin of their LSPR properties.The ones that would be discussed in this review are heavily doped metal oxides (MoO3-x,WO3-x,NiO),metal chalcogenides (Cu2-xS,Cu2-xSe),and other semiconductors(TiN,Bi2WO6,BP)etc.We will highlight the development of these plasmonic semiconductors regarding on their synthesis methods and their promising applicability in plasmon enhanced photoredox catalysis such as H2evolution,CO2reduction,nitrogen reduction,pollution decomposition.

    4.1.Plasmonic metal oxides

    Plasmonic metal oxides with rich oxygen vacancies (OVs) have drawn tremendous interest in photocatalysis owing to their abundant reserve,facile synthetic method and good electrochemical stability.The OVs,basically a type of intrinsic defects,can serve as electron donor sites to modulate optical properties of a material [107].Introduction of rich OVs is an effective strategy to increase free electrons density in semiconductors,inducing strong LSPR properties.In addition,OVs also facilitate charge transfer between semiconductor and adsorbed intermediates,thereby leading to enhanced photoredox reaction.Mostly reported metal oxides with OVs-induced LSPR are WO3-xand MoO3-x,which have been widely used for plasmonic photocatalysis.

    Fig.9.(a) UV–Vis absorption spectra,(b) XRD patterns,(c) TEM image and (d) schematic photocatalytic H2 evolution from ammonia borane over WO3?x NWs.Reproduced with permission [112].Copyright 2015,WILEY-VCH.(e) TEM image and (f) schematic photocatalytic Suzuki coupling reactions over Pd/WO3?x NWs.Reproduced with permission [113].Copyright 2015,Elsevier B.V.(g) Photoelectron and hot electron generation in self Z-scheme heterostructure of WO3?x under UV-Vis irradiation.Reproduced with permission [114].Copyright 2019,the Royal Society of Chemistry.

    4.1.1.Tungsten trioxide

    Tungsten trioxide (WO3-x),an electrochromic material with suitable band gap of 2.6 eV,exhibits great potential in photocatalytic solar conversion.By removing oxygen atoms,disorder structure is formed in WO3lattice with large amounts of oxygen vacancies.The low valence state of W5+are generated,forming different non-stoichiometric oxides such as W20O58,W18O49and W24O68[108].With more introduction of OVs,the properties of WO3-xare changed from semiconductor to metal,exhibiting strong LSPR in vis-NIR region.Various methods have been reported to synthesize WO3-xwith abundant OVs for enhanced photocatalysis.For instance,by annealing pristine WO3under H2atmosphere or vacuum at different high temperatures,WO3-xsamples with controlled OVs has been prepared successfully,displaying an improved photocurrent density [109,110].Wanget al.tailored the amount and distribution of OVs on surface or bulk by tuning H2concentration during thermal treatment [111].The amounts of bulk OVs on WO3monotonically rise with increasing of H2concentration,while that of surface OVs presents a volcano-type variation tendency.The WO3sample thermal-treated in 20% H2(WO3-H2O) contains the largest amount of surface OVs,which play more decisive role to achieve higher charge-carriers separation efficiency and photocatalytic O2evolution from water splitting.

    One mostly used method to synthesize WO3-xis simple surfactant-free solvothermal treatment.Louet al.synthesized WO3-xNWs via one-step solvothermal treatment using WCl6or W(CO)6as precursors and absolute ethanol as solvents.Owing to rich OVs on surface,WO3-xNWs exhibit strong LSPR absorption in vis-NIR region and greatly promote H2generation from ammonia borane and Suzuki coupling reactions (Figs.9a–f) [112,113].Louet al.found that under UV–vis irradiation,the unique electronic band structure of plasmonic WO3?xcan act as a self Zscheme heterostructure (Fig.9g).UV-excited photoelectrons are injected into conduction band of WO3?x,stabilizing free electron density and accelerating plasmonic hot electron generation for photocatalytic ethanol dehydrogenation to aldehyde [114].Moreover,both morphology and crystalline phase of WO3-xwere affected by species/concentration of precursors and solvents,temperature and time in solvothermal reaction [115].Interestingly,NIR light excited plasmonic photothermal effect can make a big difference to the products selectivity.Under UV-vis-NIR irradiation,the synthesized WO3?xNWs with abundant OVs selectively promote ethanol dehydration,yielding a remarkable ethylene generation rate of 16.9 mmol g?1h?1.Besides,plasmonic WO3?xwith thin amorphous surface was obtained using simple hydrochloric acid-assisted solvothermal method and also exhibits superior photocatalytic performance on CO2reduction reaction [116].Intermediates detection indicates that the adjacent OVs around W4+on amorphous surface of WO3-xact as active sites for C?C coupling,leading to high-selective ethylene generation.

    4.1.2.Molybdenum trioxide

    Similar to WO3-x,Molybdenum trioxide (MoO3-x) is another reported metal oxide with OV-induced LSPR properties for solardriven photocatalysis.Yamashitaet al.firstly reported that plasmonic MoO3-xnanosheets display an enhanced H2production from ammonia borane under visible light [40](Figs.10a–c).To date,plasmonic MoO3?xhas been successfully synthesizedvialiquid exfoliation approach,solvothermal method,soft template synthesis method,CO2assisted approach [117–121]etc.For example,Liuet al.reported to obtain amorphous plasmonic MoO3?xnanosheets by MoS2oxidation and subsequent supercritical CO2-treatment[117].Etmanet al.report the synthesis of MoO3?xnanosheetsviaa liquid exfoliation approach to achieve efficient photocatalytic dye degradation [118].Liet al.synthesized MoO3?xnanobelts by a simple solvothermal method,which are utilized for photocatalytic N2fixation [119].The surface OVs of MoO3?xwas found to chemisorb N2molecule and reduce its activation energy,playing a critical role in photocatalytic N2reduction to NH3(Figs.10d–f).The obtained MoO3-xviasolvothermal method also exhibit high activity for photo-thermal synergistic CO2reduction under UV–vis-NIR irradiation.OVs-induced LSPR in MoO3-xenables intense absorption in NIR region,leading to a strong thermal effect.Besides,OVs also improves CO2adsorption on the defective surface,decreases the barrier of CO2hydrogenation and carrier recombination during catalytic CO2conversion [121].

    Apart from WO3-xand MoO3-x,Li group recently synthesized a new plasmonic semiconductor Bi2O3-xwith rich OVs by oxidizing commercial bismuth powder in atmosphere at 453.15 K (Figs.10g–i).The OVs induce LSPR in Bi2O3-xacross the wavelength range of 600–1400 nm and enhance CO2molecules adsorption,which enable efficient photocatalytic CO2reduction to CO (100% selectivity)under low-intensity NIR irradiation.Similar to noble metals,the photocatalytic CO generation rate over Bi2O3-xshows a nearly linear dependence on light intensity and temperature,which suggests that catalytic performance originates from the synergetic effect between light irradiation and heating [122].

    Fig.10.(a) SEM image,(b) TEM image and (c) UV-vis-NIR DRS of MoO3-x nanosheets.Reproduced with permission [40].Copyright 2014,Wiley-VCH.(d) HAADF STEM image and (e) Atomic scale HAADF image showing ordered OVs in MoO3?x nanobelts.(f) Electron transfer process during OVs-mediated N2 fixation.Reproduced with permission[119].Copyright 2019,the Royal Society of Chemistry.(g) Absorption spectra,(h) Schematic illustration of LSPR excitation and (i) possible pathway for photocatalytic CO2 reduction over Bi2O3?x.Reproduced with permission [122].Copyright 2020,Wiley-VCH.

    4.1.3.Other metal oxides

    Nickel oxide (NiO) with superior electrochemical stability has been widely studied in photoelectrocatalysis.Nevertheless,as a ptype semiconductor with intrinsic hole doping and carrier selftrapping of amorphous nature,NiO NCs fail to act as individual photocatalyst to offer electrons for reduction reaction.Linet al.reported 2D amorphous NiO nanostructure as a plasmonic photocatalyst for solar H2evolution without any cocatalysts [123].They prepared 2D plasmonic amorphous NiO nanoflakes (2DPA) by laser ablation of bulk crystalline NiO powders in methanol solution.The 2D architecture can suppress the self-trapping induced carrier recombination and introduce LSPR property in NiO by increasing the electron doping.The solar H2evolution rate over 2DPA photocatalyst was improved by a factor of 19.4 owing to plasmon-mediated charge releasing.Another metal oxide indium oxide (In2O3) has also attracted interest for tunable LSPR that occurs in near- to mid-NIR region by aliovalent ion doping.Two plasmonic systems of Ti and Sb doped In2O3NCs have been reported,which allow for a significant expansion and tunability of plasmon band [54].By a self-assembly technique,In2O3was encapsulated into bundled TiO2NW arrays,displaying broadband LSPR absorption of 84% in range of 400–2500 nm.This plasmonic photocatalyst achieved an improved catalytic activity for methyl orange degradation arising from LSPR effect of the In2O3membrane,which extends light response and excites hot carriers [124].

    4.1.4.Metal oxides heterostructures

    The OVs are easily removed in aqueous solution,leading to unstable LSPR effect and decreased catalytic efficiency.In addition,excited hot electrons on the surface can react with the adsorbates and the associated free electron density decrease,which further weaken the LSPR effect and hot electron generation.To solve this problem,Louet al.proposed the concept of electron injection to maintain free carrier density and stabilize LSPR effect of OVsdoped semiconductors by constructing heterostructures with other semiconductors [76].Heterostructural CdS/WO3?xNWs were synthesized byin-situsolvothermal growth of WO3?xon CdS NWs,which exhibit superior activity than WO3?xand CdS alone for photocatalytic H2generation.Single-particle PL study demonstrated that photogenerated electrons in CdS NWs are injected into conduction band of WO3?x,which stabilizes its LSPR effect and boosts continuous hot electrons generation for efficient photocatalysis(Figs.11a–c).Plasmonic heterostructure TiO2-mesocrystals/WO3?xNWs (TiO2-MCs/WO3?xNWs) were also constructedviaa simple solvothermal procedure,and used for photocatalytic CO2reduction [125].The obtained heterostructure exhibits much higher activity and selectivity (16.3 μmol g?1h?1,83%) than TiO2-MCs(3.5 μmol g?1h?1,42%) and WO3?xNWs (8.0 μmol g?1h?1,64%)for CH4generation (Figs.11d–f).The PL study demonstrates the photoelectron injection from TiO2to WO3?xboosting hot electron generation,which plays a great role in highly selective CH4generation from CO2reduction.For efficient photoelectron injection,Liet al.recently proposed to construct atom-sharing heterostructure of MoS2/MoO3–xwith good interfacial contact via light-inducedin situpartial oxidation of MoS2nanosheets [126].The OVs induce intense LSPR of MoO3–xand promote photoelectron injection from MoS2into MoO3–x,leading to stable LSPR and continuous hot electron generation for enhanced photocatalysis.An enhanced CO generation rate of 32.4 μmol g?1h?1with high selectivity of 94.1% was achieved over the heterostructure under UV–vis-NIR irradiation (Figs.11g–i).Wei group synthesized flexible MoS2@MoO3core-shell nanowires with tunable plasmon resonance using a twostep method,realizing broadband light absorption and improved interfacial contact for better carrier transport [127].The plasmonic MoS2@MoO3exhibits good stability and flexibility in photocatalytic water splitting and yields an optimized H2evolution rate of 841.4 μmol h?1g?1.

    Fig.11.(a) TEM image of CdS/WO3?x.(b) Single-particle PL spectra and (c) schematic diagram showing the electrons injection from CdS to WO3?x.Reproduced with permission [76].Copyright 2017,Elsevier B.V.(d) STEM image of TiO2-MCs/WO3?x NWs.(e) Absorption spectra and (f) CH4 evolution over the as-prepared photocatalysts.Reproduced with permission [125].Copyright 2019,Wiley-VCH.(g) TEM images,(h) CO evolution and (i) excitation and electron transfer over MoS2/MoO3-x heterostructure.Reproduced with permission [127].Copyright 2021,American Chemical Society.

    Similar to metals,plasmon-induced hot electrons are expected to play great roles on promoting catalytic reaction.By constructing semiconductor heterostructures,LSPR effect can be stabilizedviaphotogenerated carrier injection maintained free carrier concentration.However,currently reported semiconductor heterostructures still suffer from fast recombination of hot carriers,which hinders commercial application of plasmonic catalyst.Besides,single plasmonic semiconductor fail to meet the required potential to driven reduction reaction.A valid strategy to overcome these restrictions is to integrate plasmonic catalysts with appropriate active semiconductors for constructing a new generation of plasmonic heterostructures.Zhanget al.constructed a plasmonic Zscheme photocatalyst by solvothermally integrating 1D plasmonic W18O49nanograsses onto exfoliated 2D graphitic carbon nitride(g-C3N4) nanosheets [128].The plasmon-excited hot electrons of W18O49nanograsses can be injected into neighboring g-C3N4that possesses abundant active sites and strong redox capacity,boosting long-lived hot electron generation for improved photocatalytic protons reduction.Almost a full-spectrum-driven H2evolution effi-ciently was achieved over W18O49/g-C3N4heterostructure through the synergistic effect between Z-scheme charge-carriers separation and plasmon induced hot electrons injection (Figs.12a and b).They also fabricated W18O49/TiO2branched heterostructure via solvothermal growth of plasmonic W18O49NWs branches onto TiO2nanofiber backbones [129].Using ultrafast transient absorption spectroscopy combined with FDTD simulations,plasmonic hot electrons were demonstrated to transfer from W18O49branches to TiO2backbones within a very short timescale of 200 fs,much faster than the relaxation process (7–9 ps).Such an ultrafast transfer effectively improves the generation and separation of plasmonic hot electrons,thereby leading to an enhanced IR-driven catalytic activity for H2generation from ammonia borane (Figs.12c and d).By pulsed laser deposition and plasma sputtering reaction deposition,plasmonic Z-scheme core-shell W18O49/g-C3N4nanocone arrays were also successfully prepared to achieve more efficient plasmon-excited hot electron injection,spatial carriers separation and carrier lifetime extension [130].Besides,Z-scheme heterostructure photocatalyst of W18O49/CdS was also synthesized byin-situanchoring 0D W18O49quantum dots on the surface of 1D CdS NRs [131].Both bulk and surface photo-induced carriers are separated efficiently,achieving an improved photocatalytic H2evolution performance (Figs.12e–g).A Z-scheme BiO2-x/Bi2O2.75heterostructure photocatalysts with rich OVs was preparedviaa simple low-temperature hydrothermal method [132].The Zscheme interfacial heterojunction boosts the separation and migration of photoinduced charge carrier as well as improves the redox ability.Consequently,the as-prepared BiO2-x/Bi2O2.75exhibits an enhanced photocatalytic activity in RhB degradation compared to pure BiO2-x,ascribing to the synergistic effects of OVs-induced LSPR and Z-scheme heterogeneous interface.In addition to band alignment,steering an electron flow is of significance for developing efficient plasmonic catalysts.Wenet al.prepared plasmonic catalyst by coating ZIF-8 (zeolitic imidazolate frameworks) on plasmonic MoO3-xsurface and subsequent depositing Pd NPs on ZIF-8 (Pd/MoO3-x@ZIF-8) [133].Plasmon-induced hot electrons in MoO3-xare injected into ZIF-8 and further transferred to Pd active sites through a Schottky junction,which greatly accelerating plasmon-induced electron transfer from MoO3-xto Pd active sites.The heterostructure formed effectively retards the recombination of hot electron-hole pairs in MoO3-x,leading to a higher catalytic activities for nitroaromatics hydrogenation.

    Fig.12.(a) TEM and elemental mapping images,(b) energy band and photoinduced charge-carriers transfer process of W18O49/g-C3N4 heterostructure.Reproduced with permission [128].Copyright 2017,Wiley-VCH.(c) TEM and corresponding elemental mapping images,(d) schematic kinetics process of plasmon hot electrons for H2 generation from NH3BH3 over W18O49/TiO2 branched heterostructure.Reproduced with permission [129].Copyright 2018,Wiley-VCH.(e) TEM images of W18O49/CdS heterostructure and corresponding HRTEM image of (010) plane of W18O49 component (inset).(f) Transient photocurrent response and (g) Illustration of H2 evolution mechanism over W18O49/CdS NRs.Reproduced with permission [131].Copyright 2021,Elsevier B.V.

    4.2.Plasmonic metal chalcogenides

    Metal chalcogenides with narrow bandgaps are one of potential candidates for photocatalytic applications.Similar to metal oxides,plasmonic property in chalcogenides also can be induced by introduction of vacancies.However,contrary to metal oxides,LSPR property in chalcogenides arises due to collective oscillation of cation vacancy-induced free holes in valence band (VB) rather than free electrons.Metal chalcogenides can be obtained by binding ligand-coordinated chalcogenide species to metal precursors.By changing metal-chalcogen ratios,tunable stoichiometric ratios and cation vacancies are achieved [52].An emerging class of copper chalcogenide materials for plasmonic photocatalysis will be discussed in this section.

    Self-doped copper chalcogenide (Cu2-xX: X=S,Se,Te) have drawn great attention due to their LSPR absorption in NIR region,which is generated by the oscillation of Cu vacancy induced free holes.Various approaches have been reported to synthesize Cu2?xX with tunable crystal phase,stoichiometry and morphology,including solvothermal,hot-injection,wet chemical and templated method [134–138].Shaoet al.prepared a range of vacancydoped Cu2?xS NCs (Cu1.2S,Cu1.4S,Cu1.75S and Cu1.94S) with size of ~10 nm through a hot injection method [138].By varying the injection volume of sulfur powder-oleic acid,the doping level of samples were manipulated to finely tune the LSPR wavelength.The obtained Cu1.94S NCs with the highest LSPR energy exhibited superior photocatalytic activity in dye degradation due to Cu vacancies induced high density of free holes.Ganet al.prepared Cu2?xSe NCsviaa hot injection method and observed plasmon-driven chemical reaction of 4-nitrobenzenethiol dimerization on Cu2?xSe surfaces with considerable yields [136].

    The Cu2?xX-based heterostructures have attracted extensive attention because they can inhibit the photogenerated carriers recombination for improved photocatalysis.Plasmonic Cu2-xS nanodots were successfully deposited on two-dimensional (2D) g-C3N4nanosheets by one-step hydrothermal growth method [139].With efficient charge separation and strong light absorption,the 0D/2D plasmonic Cu2-xS/g-C3N4nanosheets achieved 100% degradation rate in 20 min for typical antibiotic pollutant,showing excellent catalytic degradation effect under UV–vis-NIR broad spectrum.Lianet al.synthesized CdS/Cu7S4heterostructured NCs by a seeded growth reaction of disk-shaped Cu7S4NCs and a subsequent partial cation exchange with Cd2+[140].The CdS/Cu7S4NCs achieved efficient photocatalytic H2evolution driven by nearto shortwave-IR light (up to 2500 nm) irradiation.The apparent quantum yield reached 3.8% at 1100 nm,which exceeds most IRlight energy conversion systems reported.Spectroscopic results revealed the plasmon-induced hot electron injection and long-lived charge separation (>273 μs) at p?n heterojunction of CdS/Cu7S4NCs,which contributes to efficient IR light to hydrogen conversion (Figs.13a–d).Moreover,a hollow sandwich-layered octahedral structure of Cu2?xS/CdS/Bi2S3with p?n?p type tandem heterojunctions was constructed via continuous growth deposition method [141].This unique structure provides large surface area,rich reaction sites and improved separation and transfer of photogenerated carriers.Under Vis-NIR irradiation,Cu2?xS/CdS/Bi2S3as photocatalyst displays a high H2production rate (8012 μmol h?1g?1),and 2,4-dichlorophenol is almost degraded completely in 150 min.Though Cu2?xS primarily produce hot holes,the electrons of hot electron?hole pairs appear to be more active to drive chemical reactions in Cu2?xS-based photocatalysts above,possibly due to the shorter lifetime of holes compared with electrons.From the kinetic perspective,it is difficult to achieve sufficient collection of hot holes for photocatalysis.Hot holes transfer has been proposed as a possible mechanism for contributing to photocatalytic activity by constructing heterostructured nanocrystals (HNCs) composed of plasmonic Cu2?xS and other semiconductors acting as acceptor.Lianet al.elucidate LSPR-induced hot holes transfer in CdS/CuS HNCs using time-resolved infrared (TR-IR) spectroscopy(Figs.13e–h) [142].The spectroscopic results provide an insight into a novel multi-step holes transfer mechanism named plasmoninduced transit carrier transfer (PITCT),in which the excited hot holes were not directly injected into CdS phase,but transferred stepwise through the carrier trapping state.Schematic decay processes of hot holes generated in CuS and CdS/CuS HNCs are shown in Fig.13h.For single CuS,the generated hot holes decayedviaphonon–hole scattering (1),hole trapping to the shallow state (2)or deep state (3),followed by relaxation to intrinsic hole state.For CdS/CuS HNCs,the holes in deep state transferred to VB of CdS(4,PITCT) and then the holes in CdS moved to trapping state,displaying structureless absorption in vis-region and recombination to the initial state.The PITCT of CdS/CuS HNCs realizes high quantum yield of 19% and longlived charge separation (9.2 μs),contributing to a superior oxidation catalytic activity for MB dye than those of CuS or CdS NCs alone under NIR irradiation.

    Fig.13.(a) TEM image,(b) bright-field scanning TEM image and (c) absorption spectrum and AQY for H2 evolution reaction over CdS/Cu7S4 HNCs.(d) Hot-electron injection of plasmonic p–n CdS/Cu7S4 HNCs upon IR light excitation.Reproduced with permission [140].Copyright 2018,American Chemical Society.(e) TEM image and (f) HRTEM image of CdS/CuS HNCs.Scale bars: 10 nm.(g) Decay profiles of CuS and CdS/CuS HNCs at 560 nm,in which the rising part corresponds to the trapped holes of CdS in CdS/CuS HNCs.(h) Schematic illustration of LSPR-induced holes transfer [142].Copyright 2018,Nature Publishing Group.

    4.3.Other plasmonic semiconductors

    In addition to oxides and sulfides,transition metal nitrides(TMNs) is also a type of material with a significant prospect for extensive photocatalytic applications due to their distinct physical,electronic properties and metal-like properties.Recently,Chenget al.systematically discussed and summarized different roles of TMNs materials in photocatalytic systems including semiconductor active components,co-catalysts,LSPR components,etc[143].To date,TiN and WN have been applied for photocatalysis through LSPR effect,which is verified by both theoretical and experimental results.For example,plasmonic nanohybrid of plasmonic TiN nanocubes decorated with Pt NCs has been reported to efficiently drive H2evolution from NH3BH3dehydrogenation.The apparent quantum yield reaches 120% under resonant light at 700 nm driven by hot electrons only.Under solar irradiation,the activity of TiN?Pt nanohybrids is enhanced by one order owing to the synergistic effect of plasmonic hot electrons and photothermal heating [84].Heterostructures comprised of plasmonic TiN and other semiconductors have been proved to exhibit higher photocatalytic activity due to hot electron injection.Boltassevaet al.synthesized core–shell TiN@TiO2NPs with broad LSPR in red-NIR region.Under 700 nm fs-pulsed laser illumination,TiN@TiO2NPs effectively converts ground-state oxygen into singlet oxygen,driven primarily by hot electrons transferred from plasmonic TiN core to TiO2shell.Analytical calculations also reveal the unique advantages of TiN@TiO2heterostructures in hot-electron driven photocatalysis [144].Another TMN of tungsten nitride (WN) with strong LSPR in NIR region has also been employed as photocatalyst for overall water splitting operated at red-light up to 765 nm [145].Huanget al.proved the NIR-driven photocatalytic performance of plasmonic cubic-phase WN in effective reactive oxygen species activation by both density functional theory (DFT) calculation and experimental observation [146].

    Apart from widely reported semiconductors above,several novel semiconductors with LSPR in vis-NIR region also have been developed as plasmonic photocatalysts.Luet al.successfully constructed plasmonic Bi2WO6with strong LSPR around 500–1500 nm region by electron doping [147].Two types of OVs on W-O-W (V1)and Bi-O-Bi (V2) sites are precisely controlled by chemical methods,obtaining Bi2WO6-V1 with LSPR and Bi2WO6-V2 with defect absorption across Vis-NIR region separately.The DFT calculations indicate that V1 induced energy states have a small energy range of 0.25 eV and are close to conduction band,which facilitates photoelectron transfer and trapping for a long lifetime,leading to LSPR in Bi2WO6.A 93% PL quenching on Bi2WO6-V1 was observed by single-particle PL microscopy,demonstrating the photoelectron trapping on V1 sites.Plasmonic Bi2WO6-V1 boosts high-selective CH4generation with a rate of 9.95 μmol g?1h?1from photocatalytic CO2reduction,which is 26-fold higher than 0.37 μmol g?1h?1of Bi2WO6-V2 under UV–vis irradiation (Figs.14a–d).Both DFT-simulation andin situFourier transform infrared spectra on Bi2WO6surface prove that V1 sites facilitate CH4generation.The results imply the possibility of electron accumulations on the state to generate high carrier density and LSPR property.Introducing a doping electronic state to trap electrons is an effective strategy to modulate LSPR effect in semiconductors.Moreover,boron phosphide (BP) containing abundant III-V elements with strong covalent bonding exhibits indirect band gap of ~2.0 eV,excellent charge mobility and thermal stability (>1000 °C),is potential to be a promising photocatalytic material [148,149].Recently,Tianet al.reported a metal-free plasmonic core-shell BP@g-C3N4photocatalyst with LSPR effect derived from free electrons collective oscillation on BP surface induced by abundant P-vacancies formed under high temperature [150].The BP@C3N4catalyst exhibits excellent solar energy utilization efficiency in UV–vis-NIR region and shows a remarkable photocatalytic activity for water splitting even under 730 nm illumination.The H2production rate can reach up to 31.5 μmol g?1h?1under visible light irradiation,which is 112.6 and 34.3 times higher than that of C3N4and Pt/C3N4,respectively.The BP LSPR can facilitate generation and separation of charge carriers near the surface of C3N4,and plasmon-induced hot electrons transfer to CB of C3N4for significantly improved water reduction reaction (Figs.14e–h).

    Fig.14.(a) Crystal structure and (b) DFT-calculated band structure of Bi2WO6 with OVs on W-O-W sites.(c) UV-vis-NIR DRS with color images and (d) CH4 generation over different Bi2WO6 samples.Reproduced with permission [147].Copyright 2021,American Chemical Society.(e) TEM (HRTEM) images and (f) UV-vis absorption of BP@C3N4.(g) Photocatalytic H2 generation and (h) proposed mechanism over metal-free plasmonic BP@C3N4 composite.Reproduced with permission [148].Copyright 2021,Elsevier B.V.

    5.Conclusions and future prospects

    Plasmonic photocatalysis has emerged as a promising technology to address the energy and environmental crisis.Owing to intriguing optical-electrical features such as intense light absorption,improved charge carrier separation,hot carriers generation and photothermal effect,plasmonic photocatalysts have effectively made their way to solar energy conversion applications including water splitting,CO2reduction,pollution decompositionetc.Although considerable progress has been made in plasmonic metalbased photocatalysts,high-cost and poor absorption in NIR region inhibited their large-scale practical applications,and also inspired the exploration of alternate plasmonic materials.Recently,heavily-doped semiconductors like nonstoichiometric oxides,sulfides,etc.have gained significant attention for the construction of LSPR with abundant oxygen/cation vacancies induced large free carrier density.By tuning the geometry and free carrier density,these semiconductors enable broadband solar energy harvesting across UV-vis-NIR range,highly desired for efficient photocatalysis.Even though recent efforts have been devoted to the development of novel plasmonic semiconductors for plasmon-driven photoredox reactions,there remain challenges accompanying them such as low utilization of hot carriers,obscure mechanism of hot carrier-driven reactions and unclear plasmon-related photochemical and physical process,etc.To realize full potential of plasmonic materials for development of efficient photocatalytic systems,prospective studies are still highly necessary towards the following regards.

    5.1.Exploration of novel nonmetallic plasmonic materials

    Heavily doped semiconductors exhibit great potential in photocatalysis due to their low cost,abundant reserve and strong LSPR in vis-NIR region.However,single plasmonic semiconductor still suffer from the low utilization of hot carriers,especially for hot hole in p-type semiconductors.Construction of asymmetric heterostructures of plasmonic and catalytic semiconductors with suitable potential position is an effective approach,where hot carrier transfer boosts long-lived hot carrier generation and separation for efficient photocatalysis.Besides,Millironet al.discussed the presence of depletion layer near semiconductors surface that have a dramatically decreased free carrier density,largely damping LSPR effect.Therefore,developing plasmonic semiconductors with thin depletion layers is highly desirable,which also facilitates hot carriers separation for photocatalysis.Since the efficiency of plasmonic photocatalysts depends on geometry,configuration of plasmonic nanostructures should be specifically engineered with consideration of many design trade-offs.For example,2D ordered plasmonic semiconductors or porous structure with distinct optical features,ease decoration and more active sites,might be a promising candidate for plasmonic photocatalysis.Generally,high-efficiency plasmonic photocatalysts possess features including stable LSPR effect,efficient charge carrier separation,suitable potential position and abundant active sites.

    5.2.Uncover the mechanism of hot carrier-driven reactions

    Plasmonic hot carriers have been demonstrated to play critical role in photocatalysis,but the underlying reaction mechanism still needs to be systematically studied.In contrast to progress of n-type plasmonic photocatalysts based on plasmon-induced hot electron transfer,there are few reports on hot holes transfer process regardless of its importance.The unclear behavior of hot holes remained an obstacle for the comprehensive understanding of hot carrier-drive reactions.An in-depth understanding of photochemical-physical process of hot carrier generation,transfer and recombination would clarify the role of hot carriers contributing the photocatalytic activity,and also beneficial to developing efficient plasmonic photocatalysts for high selectivity of anticipated products with zero side reactions.Recently,advanced experimental techniques including time-resolved infrared spectroscopy,singleparticle PL spectroscopy,etc.have been employed to study the relaxation and transfer processes of hot carriers.However,there are still much processes left in fuzziness,and more techniques,especially the ones with high temporal-spatial resolutions,need to be introduced in research of plasmonic photocatalysis.

    5.3.Insights into plasmon-related physicochemical process

    Despite numerous efforts have been devoted to LSPR-driven catalytic reactions,there is still big room for the investigation of new processes,especially plasmonic photo-thermocatalysis.An insight into plasmon-related physicochemical processes should refer the knowledge from both plasmonic photocatalysis and photothermocatalysis to give a comprehensive description of the catalytic reactions.In situcharacterization and temperature monitoring of plasmonic photocatalyst experimentally would be helpful to establish an in-depth understanding of detailed plasmon-related physicochemical process.Moreover,modeling and simulated studies could also be conducted to give insights into the underlying photocatalytic reaction mechanisms,such as thermal transfer,electronic transitions and interfacial charge transfer behaviors,which are expected to offer guideline for optimization of plasmonic photocatalysts.

    Declaration of competing interest

    The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

    Acknowledgments

    This work was supported by the National Natural Science Foundation of China (Nos.11904133,51872125),Guangdong Natural Science Funds for Distinguished Young Scholar (No.2018B030306004)and GDUPS (2018),the Fundamental Research Funds for the Central Universities (No.21619322) and Regional Joint Foundation in Guangdong Province (No.2019A1515110210).

    亚洲精品色激情综合| 国产综合懂色| 国产伦一二天堂av在线观看| 国产午夜精品久久久久久一区二区三区| 少妇的逼好多水| 欧美成人a在线观看| 成人鲁丝片一二三区免费| 国产日韩欧美在线精品| av天堂中文字幕网| 国产精品久久久久久精品电影| 久久精品久久精品一区二区三区| 韩国高清视频一区二区三区| 亚洲性久久影院| 久久久亚洲精品成人影院| 丰满人妻一区二区三区视频av| 日日干狠狠操夜夜爽| a级毛色黄片| 小蜜桃在线观看免费完整版高清| 亚洲精品日韩在线中文字幕| 国产精品精品国产色婷婷| 亚洲av免费高清在线观看| 国产在线一区二区三区精 | 国产爱豆传媒在线观看| 精品久久久久久久久av| 99热6这里只有精品| 免费观看精品视频网站| 男的添女的下面高潮视频| 亚洲精品色激情综合| 欧美xxxx黑人xx丫x性爽| 91精品国产九色| 麻豆一二三区av精品| 三级国产精品欧美在线观看| 久久精品影院6| 午夜福利视频1000在线观看| 成人一区二区视频在线观看| 日韩人妻高清精品专区| 成人漫画全彩无遮挡| 51国产日韩欧美| 国产探花在线观看一区二区| 成人毛片a级毛片在线播放| 黑人高潮一二区| 国语对白做爰xxxⅹ性视频网站| 亚洲美女搞黄在线观看| 最近中文字幕2019免费版| 美女国产视频在线观看| 久久久色成人| 久久这里有精品视频免费| 我的老师免费观看完整版| 爱豆传媒免费全集在线观看| av女优亚洲男人天堂| 99热这里只有是精品50| 在线观看av片永久免费下载| a级毛片免费高清观看在线播放| 成人av在线播放网站| 国产日韩欧美在线精品| 亚洲精品aⅴ在线观看| 中文精品一卡2卡3卡4更新| 亚洲精品国产av成人精品| 国产av一区在线观看免费| 国语自产精品视频在线第100页| 色噜噜av男人的天堂激情| 69人妻影院| 一级av片app| 欧美+日韩+精品| 村上凉子中文字幕在线| 九九热线精品视视频播放| 韩国av在线不卡| 18+在线观看网站| 亚洲av中文av极速乱| 丰满乱子伦码专区| 欧美3d第一页| 网址你懂的国产日韩在线| 久久久久精品久久久久真实原创| 91在线精品国自产拍蜜月| 国产一级毛片在线| .国产精品久久| 日韩制服骚丝袜av| 日韩高清综合在线| 啦啦啦观看免费观看视频高清| 国内精品美女久久久久久| 五月玫瑰六月丁香| 人妻系列 视频| 国产亚洲精品av在线| 日本五十路高清| 99九九线精品视频在线观看视频| 老司机福利观看| 九草在线视频观看| 亚州av有码| 亚洲av免费高清在线观看| 免费观看精品视频网站| 91aial.com中文字幕在线观看| 偷拍熟女少妇极品色| 日本黄色片子视频| 国产精品一区二区在线观看99 | 精品午夜福利在线看| 欧美色视频一区免费| 天堂av国产一区二区熟女人妻| 亚洲av中文av极速乱| 18禁在线播放成人免费| 嘟嘟电影网在线观看| 亚洲最大成人中文| 美女黄网站色视频| 99在线视频只有这里精品首页| 免费人成在线观看视频色| 成人毛片a级毛片在线播放| 九九热线精品视视频播放| 色视频www国产| 欧美+日韩+精品| 少妇丰满av| 18禁在线无遮挡免费观看视频| 99久久成人亚洲精品观看| 国产av码专区亚洲av| 亚洲精品色激情综合| 能在线免费观看的黄片| 欧美激情国产日韩精品一区| 午夜a级毛片| 精品久久久久久久末码| 最近最新中文字幕大全电影3| 国产免费一级a男人的天堂| 国产成人福利小说| 晚上一个人看的免费电影| 亚洲色图av天堂| 亚洲美女视频黄频| 乱系列少妇在线播放| 色5月婷婷丁香| av国产免费在线观看| 久久韩国三级中文字幕| 一级爰片在线观看| av播播在线观看一区| 欧美激情在线99| videos熟女内射| 午夜福利高清视频| 精品免费久久久久久久清纯| 国产 一区 欧美 日韩| 国产精品一区二区性色av| 精品久久国产蜜桃| 亚洲av电影不卡..在线观看| 亚洲av日韩在线播放| 中文字幕熟女人妻在线| 亚洲美女搞黄在线观看| 尾随美女入室| 精品人妻偷拍中文字幕| 看非洲黑人一级黄片| 18禁在线播放成人免费| 18禁裸乳无遮挡免费网站照片| 中文字幕精品亚洲无线码一区| 男女那种视频在线观看| 久久久久国产网址| 亚洲真实伦在线观看| 国产成年人精品一区二区| 一级二级三级毛片免费看| 大香蕉97超碰在线| 国产免费又黄又爽又色| av福利片在线观看| 91aial.com中文字幕在线观看| 精品午夜福利在线看| 91在线精品国自产拍蜜月| 免费黄色在线免费观看| 又爽又黄a免费视频| 少妇熟女aⅴ在线视频| 亚洲乱码一区二区免费版| 五月玫瑰六月丁香| 色播亚洲综合网| 少妇熟女欧美另类| 黄色欧美视频在线观看| 国产免费又黄又爽又色| 欧美日韩综合久久久久久| 纵有疾风起免费观看全集完整版 | .国产精品久久| 只有这里有精品99| 国产成人免费观看mmmm| 日日干狠狠操夜夜爽| 国产精品嫩草影院av在线观看| 色尼玛亚洲综合影院| 内射极品少妇av片p| 中文字幕av成人在线电影| 亚洲一级一片aⅴ在线观看| 免费搜索国产男女视频| 成人av在线播放网站| 欧美高清性xxxxhd video| 赤兔流量卡办理| 寂寞人妻少妇视频99o| 色综合亚洲欧美另类图片| 亚洲精品影视一区二区三区av| 国产精品国产三级国产专区5o | 国产极品天堂在线| 亚洲av男天堂| 精品免费久久久久久久清纯| 少妇熟女欧美另类| 成人美女网站在线观看视频| 久久久久国产网址| 神马国产精品三级电影在线观看| 日韩精品有码人妻一区| 一级毛片久久久久久久久女| 精品一区二区三区视频在线| 嘟嘟电影网在线观看| 伦精品一区二区三区| 亚洲av中文av极速乱| 噜噜噜噜噜久久久久久91| 久久人人爽人人片av| 看片在线看免费视频| 免费av不卡在线播放| 日本与韩国留学比较| 中文字幕熟女人妻在线| 一级黄片播放器| 成人欧美大片| 国产女主播在线喷水免费视频网站 | 日日摸夜夜添夜夜添av毛片| 亚洲精品乱码久久久久久按摩| 五月玫瑰六月丁香| 好男人在线观看高清免费视频| 高清毛片免费看| kizo精华| 精品人妻偷拍中文字幕| 国产欧美另类精品又又久久亚洲欧美| 91精品伊人久久大香线蕉| 美女高潮的动态| 久久久久免费精品人妻一区二区| ponron亚洲| 国产精品日韩av在线免费观看| 亚洲欧美日韩高清专用| 国产在视频线在精品| 少妇的逼水好多| 日韩人妻高清精品专区| 有码 亚洲区| 国产麻豆成人av免费视频| 一级爰片在线观看| 国产av码专区亚洲av| 美女xxoo啪啪120秒动态图| 别揉我奶头 嗯啊视频| 国产高清不卡午夜福利| 亚洲av男天堂| 久久久久九九精品影院| 国产69精品久久久久777片| 欧美97在线视频| 色网站视频免费| 九九久久精品国产亚洲av麻豆| 久久6这里有精品| 在线免费观看不下载黄p国产| 国产精品电影一区二区三区| 国产免费福利视频在线观看| 国产成人免费观看mmmm| 99久久无色码亚洲精品果冻| 极品教师在线视频| 少妇高潮的动态图| 男人舔女人下体高潮全视频| 毛片一级片免费看久久久久| 精品久久久久久久久久久久久| 国产精品国产高清国产av| 纵有疾风起免费观看全集完整版 | 在线观看av片永久免费下载| 麻豆国产97在线/欧美| 熟女人妻精品中文字幕| 亚洲欧美日韩东京热| 午夜福利网站1000一区二区三区| 搡老妇女老女人老熟妇| 看黄色毛片网站| 亚州av有码| 成人亚洲精品av一区二区| 一区二区三区高清视频在线| 亚洲av免费高清在线观看| 伦理电影大哥的女人| 亚洲国产精品专区欧美| 国内精品宾馆在线| 国产色爽女视频免费观看| ponron亚洲| 一级毛片久久久久久久久女| 亚洲av不卡在线观看| 国产精品乱码一区二三区的特点| 国产真实伦视频高清在线观看| 精品免费久久久久久久清纯| 又爽又黄无遮挡网站| 伊人久久精品亚洲午夜| 亚洲成人中文字幕在线播放| 最后的刺客免费高清国语| 搞女人的毛片| 精品久久国产蜜桃| 男人狂女人下面高潮的视频| 网址你懂的国产日韩在线| 草草在线视频免费看| 18禁在线无遮挡免费观看视频| 日韩欧美国产在线观看| 我的老师免费观看完整版| 九九热线精品视视频播放| 色视频www国产| 少妇高潮的动态图| 美女黄网站色视频| 在线免费观看不下载黄p国产| 亚洲,欧美,日韩| 久久热精品热| 国产精品爽爽va在线观看网站| 非洲黑人性xxxx精品又粗又长| 日日摸夜夜添夜夜添av毛片| 免费观看a级毛片全部| 精品免费久久久久久久清纯| 天堂影院成人在线观看| 在线a可以看的网站| 日韩三级伦理在线观看| 国产真实乱freesex| 欧美日韩国产亚洲二区| av免费观看日本| av视频在线观看入口| 老师上课跳d突然被开到最大视频| 国产免费福利视频在线观看| 综合色av麻豆| 久久人人爽人人片av| 久久久久久久久久成人| 久久久成人免费电影| 欧美成人a在线观看| 久久人妻av系列| 日韩人妻高清精品专区| 日本av手机在线免费观看| 国产久久久一区二区三区| 亚洲中文字幕一区二区三区有码在线看| 91久久精品国产一区二区三区| 建设人人有责人人尽责人人享有的 | 97热精品久久久久久| 十八禁国产超污无遮挡网站| 精品国产露脸久久av麻豆 | 2021天堂中文幕一二区在线观| 性插视频无遮挡在线免费观看| 亚洲av成人精品一区久久| 天堂中文最新版在线下载 | 又爽又黄无遮挡网站| 少妇高潮的动态图| 免费不卡的大黄色大毛片视频在线观看 | 亚洲国产精品专区欧美| 两个人视频免费观看高清| 亚洲久久久久久中文字幕| 亚洲欧美精品自产自拍| 欧美一区二区亚洲| 老司机福利观看| 插逼视频在线观看| 天堂√8在线中文| 精品无人区乱码1区二区| 欧美日韩国产亚洲二区| 精华霜和精华液先用哪个| 国产成人a∨麻豆精品| 少妇的逼水好多| 国产国拍精品亚洲av在线观看| 国产久久久一区二区三区| 男人舔奶头视频| 欧美成人a在线观看| 大又大粗又爽又黄少妇毛片口| 日韩一本色道免费dvd| 亚洲av一区综合| 精品久久久久久成人av| 日本黄大片高清| 成人漫画全彩无遮挡| 亚洲国产精品国产精品| 天天躁夜夜躁狠狠久久av| 视频中文字幕在线观看| 一级爰片在线观看| 免费电影在线观看免费观看| 久久精品国产鲁丝片午夜精品| 亚洲成人精品中文字幕电影| 99久国产av精品| 亚洲国产精品sss在线观看| 日本黄色片子视频| 免费观看a级毛片全部| 蜜桃亚洲精品一区二区三区| 久久精品国产自在天天线| 国产69精品久久久久777片| 国产老妇女一区| 日本免费a在线| 欧美高清性xxxxhd video| 一区二区三区高清视频在线| 中文字幕熟女人妻在线| 国产精品久久久久久久久免| 久久精品91蜜桃| 国产视频首页在线观看| 国产久久久一区二区三区| 日本免费一区二区三区高清不卡| 一级二级三级毛片免费看| 国产乱人偷精品视频| 永久免费av网站大全| 一区二区三区四区激情视频| 亚洲丝袜综合中文字幕| 亚洲自拍偷在线| videossex国产| kizo精华| 国产一区亚洲一区在线观看| 精品久久久久久成人av| 91午夜精品亚洲一区二区三区| 好男人在线观看高清免费视频| 精品一区二区三区人妻视频| 国产真实乱freesex| 人妻制服诱惑在线中文字幕| 国产私拍福利视频在线观看| 青春草国产在线视频| 精品国产露脸久久av麻豆 | 国产一区二区三区av在线| 亚洲av免费高清在线观看| 国产精品.久久久| 一级毛片我不卡| 不卡视频在线观看欧美| 天堂√8在线中文| 18禁动态无遮挡网站| 又粗又爽又猛毛片免费看| 一区二区三区免费毛片| 日日摸夜夜添夜夜添av毛片| 免费播放大片免费观看视频在线观看 | av国产久精品久网站免费入址| 国产欧美日韩精品一区二区| 久久这里只有精品中国| 又爽又黄无遮挡网站| 成人毛片a级毛片在线播放| 日韩欧美精品免费久久| 国产亚洲精品av在线| 草草在线视频免费看| 久久精品国产99精品国产亚洲性色| 久久99蜜桃精品久久| 狂野欧美白嫩少妇大欣赏| 亚洲精品乱码久久久久久按摩| 一本久久精品| 国产成人一区二区在线| 久久精品久久久久久噜噜老黄 | 国产午夜福利久久久久久| 国产精华一区二区三区| 国产精品综合久久久久久久免费| 日韩av在线大香蕉| 中国美白少妇内射xxxbb| 亚洲自偷自拍三级| 亚洲国产精品国产精品| 国产三级在线视频| 国产人妻一区二区三区在| 三级经典国产精品| 青春草亚洲视频在线观看| av专区在线播放| 久久久久久久久久黄片| 免费看日本二区| 亚洲精品日韩在线中文字幕| 一级毛片我不卡| 久久久久国产网址| 18禁裸乳无遮挡免费网站照片| 精品一区二区三区人妻视频| 国产精品国产三级国产专区5o | 国产精品久久电影中文字幕| 日日撸夜夜添| 久久精品国产99精品国产亚洲性色| 国产极品天堂在线| 精品人妻熟女av久视频| 日本-黄色视频高清免费观看| 亚洲综合精品二区| 一区二区三区高清视频在线| 欧美3d第一页| 国产成人91sexporn| 亚洲在线自拍视频| 99在线人妻在线中文字幕| 国产 一区 欧美 日韩| 国产三级在线视频| 51国产日韩欧美| 亚洲精品aⅴ在线观看| 亚洲精品国产av成人精品| 久久久欧美国产精品| 99热网站在线观看| 蜜桃久久精品国产亚洲av| 欧美日韩在线观看h| 久久精品久久久久久久性| 只有这里有精品99| 久久久久性生活片| 日韩av在线免费看完整版不卡| 最近手机中文字幕大全| 全区人妻精品视频| 亚洲人与动物交配视频| eeuss影院久久| 直男gayav资源| 又粗又硬又长又爽又黄的视频| 国产高清三级在线| 亚洲av.av天堂| 成年av动漫网址| 欧美bdsm另类| 国产精品蜜桃在线观看| 自拍偷自拍亚洲精品老妇| 亚洲成人久久爱视频| 欧美精品一区二区大全| 久久国内精品自在自线图片| 小说图片视频综合网站| 一级毛片久久久久久久久女| 亚洲经典国产精华液单| 1024手机看黄色片| 中文欧美无线码| 久久久久久久久久久丰满| 高清av免费在线| 国产精品99久久久久久久久| 午夜免费激情av| 亚洲精品日韩在线中文字幕| 亚洲精品乱码久久久v下载方式| 国产精品一区二区三区四区久久| 免费观看精品视频网站| 高清av免费在线| 青春草视频在线免费观看| 国产精品国产三级国产av玫瑰| 级片在线观看| 亚洲欧洲国产日韩| 精品99又大又爽又粗少妇毛片| 看非洲黑人一级黄片| 午夜福利成人在线免费观看| 3wmmmm亚洲av在线观看| 国产一级毛片在线| 久久久久久久久久黄片| 国产伦一二天堂av在线观看| 亚洲综合精品二区| 国产精品久久久久久久电影| 国产在视频线精品| 天堂中文最新版在线下载 | 亚洲伊人久久精品综合 | 午夜福利在线观看免费完整高清在| 亚洲va在线va天堂va国产| 精品不卡国产一区二区三区| 好男人视频免费观看在线| 人体艺术视频欧美日本| 国产亚洲av嫩草精品影院| 小说图片视频综合网站| 女人十人毛片免费观看3o分钟| 国产伦在线观看视频一区| 午夜亚洲福利在线播放| 91精品一卡2卡3卡4卡| АⅤ资源中文在线天堂| 国产日韩欧美在线精品| 久久人人爽人人爽人人片va| 亚洲在线观看片| 长腿黑丝高跟| 青春草视频在线免费观看| 亚洲av福利一区| 99热精品在线国产| 久久精品影院6| 啦啦啦韩国在线观看视频| 国产精品一区二区三区四区久久| 99热这里只有是精品50| 一本—道久久a久久精品蜜桃钙片 精品乱码久久久久久99久播 | 国产一区二区在线观看日韩| 一卡2卡三卡四卡精品乱码亚洲| 免费观看a级毛片全部| 成人鲁丝片一二三区免费| 国产精品福利在线免费观看| 免费黄网站久久成人精品| 国产精品三级大全| 一个人看的www免费观看视频| 国产美女午夜福利| 午夜a级毛片| a级一级毛片免费在线观看| 男女视频在线观看网站免费| 国产三级中文精品| 级片在线观看| 我要看日韩黄色一级片| 国产伦一二天堂av在线观看| 偷拍熟女少妇极品色| 国产伦理片在线播放av一区| av视频在线观看入口| 三级经典国产精品| 在线免费观看不下载黄p国产| 久久久成人免费电影| 国产成人a区在线观看| 国产国拍精品亚洲av在线观看| 免费av观看视频| 超碰av人人做人人爽久久| 97超碰精品成人国产| 一级二级三级毛片免费看| 两性午夜刺激爽爽歪歪视频在线观看| av视频在线观看入口| 亚洲av二区三区四区| 性色avwww在线观看| 亚洲中文字幕一区二区三区有码在线看| 简卡轻食公司| 国产极品天堂在线| 午夜激情福利司机影院| 久久99蜜桃精品久久| 午夜福利成人在线免费观看| 亚洲怡红院男人天堂| 亚洲在线观看片| 国产精品日韩av在线免费观看| 中国美白少妇内射xxxbb| 菩萨蛮人人尽说江南好唐韦庄 | 大香蕉久久网| 日韩欧美精品免费久久| 亚洲av日韩在线播放| 最近的中文字幕免费完整| 国产精品福利在线免费观看| 成人亚洲精品av一区二区| 亚洲av男天堂| 大又大粗又爽又黄少妇毛片口| 我要看日韩黄色一级片| 日本熟妇午夜| 午夜老司机福利剧场| 亚洲精品aⅴ在线观看| 三级国产精品片| 久久久久久久久大av| 伦精品一区二区三区| 亚洲国产色片| 久久亚洲精品不卡| 日韩成人伦理影院| 免费观看的影片在线观看| 国产不卡一卡二| 国产欧美日韩精品一区二区| 综合色丁香网| 精品国产一区二区三区久久久樱花 | 97在线视频观看| 久久久久久久久久成人| 国产精品嫩草影院av在线观看| 国产精品无大码| 高清在线视频一区二区三区 | 一级黄片播放器| 男人舔女人下体高潮全视频| 久久久久久久亚洲中文字幕| 男女国产视频网站| 成人高潮视频无遮挡免费网站| 午夜老司机福利剧场| 纵有疾风起免费观看全集完整版 | videossex国产| 边亲边吃奶的免费视频| 久久99热6这里只有精品| 日本wwww免费看| 可以在线观看毛片的网站| 乱人视频在线观看|