Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely bee...Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely been produced through the modulation of their structure and composition.In this study,a series of bimetallic nickel-iron phosphide(Ni_(x)Fe_(2-x)P,where 0<x<2)cocatalysts with controllable structures and overpotentials were designed by adjusting the atomic ratio of Ni/Fe onto nonmetallic elemental red phosphorus(RP)for the photocatalytic selective oxidation of benzyl alcohol(BA)coupled with hydrogen production.The catalysts exhibited an outstanding photocatalytic activity for benzaldehyde and a high H_(2)yield.The RP regulated by bimetallic phosphide cocatalysts(Ni_(x)Fe_(2-x)P)demonstrated higher photocatalytic oxidation-reduction activity than that regulated by monometallic phosphide cocatalysts(Ni_(2)P and Fe2P).In particular,the RP regulated by Ni_(1.25)Fe_(0.75)P exhibited the best photocatalytic performance.In addition,experimental and theoretical calculations further illustrated that Ni_(1.25)Fe_(0.75)P,with the optimized electronic structure,possessed good electrical conductivity and provided strong adsorption and abundant active sites,thereby accelerating electron migration and lowering the reaction energy barrier of RP.This finding offers valuable insights into the rational design of highly effective cocatalysts aimed at optimizing the photocatalytic activity of composite photocatalysts.展开更多
The development of stable and efficient non-noble metal cocatalysts has arisen as a promising yet challenging endeavor in the context of photocatalytic overall water splitting.In this study,NiCo alloy cocatalysts were...The development of stable and efficient non-noble metal cocatalysts has arisen as a promising yet challenging endeavor in the context of photocatalytic overall water splitting.In this study,NiCo alloy cocatalysts were synthesized with nickel/cobalt metal organic framework(NiCo-MOF)as source of nickel and cobalt.Systematic characterization results demonstrate the successful deposition of alloy cocatalysts onto the surface of SrTiO_(3).The prepared SrTiO_(3)loaded NiCo-alloy can generate hydrogen and oxygen in a stoichiometric ratio for photocatalytic overall water splitting,achieving an apparent quantum yield of 11.9%at 350±10 nm.Theoretical calculations indicate that the introduction of cobalt has a beneficial regulatory effect on the hydrogen evolution sites of Ni,reducing the free energy of H adsorption.The synergistic catalytic effect of bimetallic catalysts contributes to enhancing photocatalytic activity and stability.This study offers constructive insights for the development of high-efficiency and cost-effective cocatalyst systems.展开更多
Negatively charged open-framework metal sulfides(NOSs),taking advantages of the characteristics of excellent visible light absorption,easily exchanged cations,and abundant active sites,hold significant promise as high...Negatively charged open-framework metal sulfides(NOSs),taking advantages of the characteristics of excellent visible light absorption,easily exchanged cations,and abundant active sites,hold significant promise as highly efficient photocatalysts for hydrogen evolution.However,their applications in photocatalytic hydrogen evolution(PHE)are infrequently documented and the corresponding photocatalytic mechanism has not yet been explored.Herein,we excavated a novel NOS photocatalyst of(Me_(2)NH_(2))_(6)In_(10)S_(18)(MIS)with a three-dimensional(3D)structure,and successfully incorporated divalent Co(Ⅱ)and metal Co(0)into its cavities via the convenient cation exchange-assisted approach to regulate the critical steps of photocatalytic reactions.As the introduced Co(0)allows for more efficient light utilization and adroitly surficial hydrogen desorption,and meanwhile acts as the‘electron pump’for rapid charge transfer,Co(0)-modified MIS delivers a surprising PHE activity in the initial stage of photocatalysis.With the prolonging of illumination,metal Co(0)gradually escapes from MIS framework,resulting in the decline of PHE performance.By stark contrast,the incorporated Co(Ⅱ)can establish a strong interaction with MIS framework,and simultaneously capture photogenerated electrons from MIS to produce Co(0),which constructs a stable photocatalytic system as well as provides additional channels for spatially separating photogenerated carriers.Thus,Co(Ⅱ)-modified MIS exhibits a robust and highly stable PHE activity of~4944μmol/g/h during the long-term photocatalytic reactions,surpassing most of the previously reported In–S framework photocatalysts.This work represents a breakthrough in the study of PHE performance and mechanism of NOS-based photocatalysts,and sheds light on the design of vip confined NOS-based photocatalysts towards high-efficiency solar-to-chemical energy conversion.展开更多
Photocatalysts are essential for the preparation of wanted fine chemical and biomedical intermediates via visible photocatalysis,but existing photocatalysts with low catalytic efficiency limit their wide applications....Photocatalysts are essential for the preparation of wanted fine chemical and biomedical intermediates via visible photocatalysis,but existing photocatalysts with low catalytic efficiency limit their wide applications.Herein,CdS/Ti_(3)C2T_(x)/MBI nanocomposites have been successfully fabricated through anchoring reduction cocatalyst Ti_(3)C_(2)T_(x) with electron-drawing ability and oxidation cocatalyst 2-mercaptobenzimidazole(MBI)with hole-capturing capacity on CdS nanoparticles.The Ti_(3)C_(2)T_(x) and MBI of CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites can extract electrons and holes from CdS nanoparticles to come true electron-hole separation,respectively.Moreover,the electron-drawing and hole-capturing abilities of the CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites depend on Ti_(3)C_(2)T_(x) and MBI contents,and the quantifiable electron and hole transfers finally determine photocatalytic efficiency of the CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites.The transient photocurrent density of the CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites is 6-fold higher than that of the CdS nanoparticles.The CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites with strong electron-hole separation capability exhibit outstanding visible photocatalytic organic transformation properties.The CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites produce(E)-N-benzyl-1-phenylmethylimine in~96%yield(~8000μmol·g^(-1)·h^(-1)),which is 3-fold higher than the CdS nanoparticles(~2500μmol·g^(-1)·h^(-1),30%).This work provides a new strategy for constructing efficient and stable photocatalysts that can be used for efficient visible light-driven organic transformations.展开更多
Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) ...Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) production,cocatalyst modification is commonly employed to provide active sites for the hydrogen evolution reaction(HER)[4,5].In this context,the kinetics of hydrogen adsorption and desorption at these active sites play a crucial role in enhancing overall photocatalytic H_(2) production efficiency.However,the H adsorption/desorption kinetics often exhibit a trade-off,presenting a significant challenge in achieving an optimal equilibrium between Hads and Hdes in many cocatalyst systems.Therefore,fine-tuning the active sites to optimize the H_(2) evolution kinetics is essential for improving photocatalytic activity[6].展开更多
BiVO_(4)is an ideal photocatalysts for H_(2)O_(2)generation due to its suitable band edge.In practice,however,the photocatalytic performance of BiVO_(4)is substantially low owing to the slow kinetics of 2e^(-)O_(2)red...BiVO_(4)is an ideal photocatalysts for H_(2)O_(2)generation due to its suitable band edge.In practice,however,the photocatalytic performance of BiVO_(4)is substantially low owing to the slow kinetics of 2e^(-)O_(2)reduction(2e^(-)ORR)and water oxidation(WOR)processes.To solve the problems,in this work,the AuPd alloy cocatalyst and the NiOOH cocatalys were modified on the electron(010)facets and the(110)hole facet of BiVO_(4)by photodeposition method.The designed AuPd/BiVO_(4)/NiOOH(0.5%)photocatalyst showed prominent photocatalytic H_(2)O_(2)production activity of 289.3μmmol_·L^(-1)with an AQE value of 0.89%at 420 nm,which was increased by 40 times compared with the BiVO_(4)sample(7.1μmmol_?L^(-1)).The outstanding photocatalytic activity of the AuPd/BiVO_(4)/NiOOH photocatalyst can be attributed to the synergistic effect of AuPd and NiOOH cocatalysts,which promoted the kinetics of oxygen reduction and water oxidation,and concurrently facilitated the charge separation.The present strategy of dual-cocatalyst rational assembly on different facets of BiVO_(4)provides an insight into explore efficient BiVO_(4)-based materials for H_(2)O_(2)production.展开更多
Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocat...Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocatalysts,while concurrently preventing side reactions and photocorrosion on the semiconductor surface.Herein,Ni-Co bimetallic hydroxides with varying Ni/Co molar ratios(Ni_(x)Co_(1-x)(OH)_(2),x=1,0.75,0.5,0.25,and 0)were grown in situ on a model 2D/2D S-scheme heterojunction composed of Cu_(2)O nanosheets and Fe_(2)O_(3)nanoplates to form a series of Cu_(2)O/Fe_(2)O_(3)@Ni_(x)Co_(1-x)(OH)_(2)(CF@NiCo)photocatalysts.The combined experimental and theoretical investigation demonstrates that incorporating an appropriate amount of Co into Ni(OH)_(2)not only modulates the energy band structure of Ni_(x)Co_(1-x)(OH)_(2),balances the electron-and hole-trapping abilities of the bifunctional cocatalyst and maximizes the charge separation efficiency of the heterojunction,but also regulates the d-band center of Ni_(x)Co_(1-x)(OH)_(2),reinforcing the adsorption and activation of CO_(2)and H_(2)O on the cocatalyst surface and lowering the rate-limiting barriers in the CO_(2)-to-CO and H_(2)O-to-O_(2)conversion.Benefiting from the Ni-Co synergy,the redox reactions proceed stoichiometrically.The optimized CF@Ni_(0.75)Co_(0.25)achieves CO and O_(2)yields of 552.7 and 313.0μmol gcat^(-1)h^(-1),respectively,11.3/9.9,1.6/1.7,and 4.5/5.9-fold higher than those of CF,CF@Ni,and CF@Co.This study offers valuable insights into the design of bifunctional noble-metal-free cocatalysts for high-performance artificial photosynthesis.展开更多
By harnessing the power of MoS_(2) as a cocatalyst to enhance electron transfer and charge carrier separation,a groundbreaking two-in-one redox photocatalytic system was developed.This innovative system integrated 2D ...By harnessing the power of MoS_(2) as a cocatalyst to enhance electron transfer and charge carrier separation,a groundbreaking two-in-one redox photocatalytic system was developed.This innovative system integrated 2D MoS_(2) nanosheets onto hydrangea-like Zn_(3)In_(2)S_(6) nanosheets,forming a 2D/3D heterostructure that established a stable and intimate interface.This unique architecture significantly improved cooperative photocatalytic performance,enabling the simultaneous production of hydrogen and benzaldehyde under light irradiation≥420 nm.Notably,the system achieved remarkable yields of hydrogen(41.9 mmol g^(-1) h^(-1))and benzaldehyde(38.9 mmol g^(-1) h^(-1)),surpassing the pristine Zn_(3)In_(2)S_(6) by 22.4 times.An impressive electron-hole pair utilization rate of approximately 93%was attained,underscoring the high efficiency of this two-in-one redox system.Additionally,the targeted 10 wt%-MoS_(2) loaded Zn_(3)In_(2)S_(6)(10MZ)nanohybrids at 400 nm obtained an apparent quantum yield(AQY)value of 17.66%without sacrificial agents or noble metals.The exceptional performance was attributed to improved charge carrier separation and reduced recombination,facilitated by cocatalyst integration and evidenced via photoluminescence,photoelectrochemical and Kelvin probe force microscopy measurements.This work highlighted the critical role of two-in-one redox-functioning heterojunctions in optimizing electron-hole pair utilization,offering a promising approach for sustainable energy production and organic synthesis.By demonstrating the potential for efficient,simultaneous generation of valuable chemicals and fuels,this research paves the way for the development of next-generation photocatalytic systems.展开更多
Efficient photocatalytic reduction of CO_(2) to high-calorific-value CH4,an ideal target product,is a blueprint for C_(1)industry relevance and carbon neutrality,but it also faces great challenges.Herein,we demonstrat...Efficient photocatalytic reduction of CO_(2) to high-calorific-value CH4,an ideal target product,is a blueprint for C_(1)industry relevance and carbon neutrality,but it also faces great challenges.Herein,we demonstrate unprecedented hybrid SiC photocatalysts modified by Fe-based cocatalyst,which are prepared via a facile impregnation-reduction method,featuring an optimized local electronic structure.It exhibits a superior photocatalytic carbon-based products yield of 30.0μmol g^(−1) h^(−1) and achieves a record CH_(4) selectivity of up to 94.3%,which highlights the effectiveness of electron-rich Fe cocatalyst for boosting photocatalytic performance and selectivity.Specifically,the synergistic effects of directional migration of photogenerated electrons and strongπ-back bonding on low-valence Fe effectively strengthen the adsorption and activation of reactants and intermediates in the CO_(2)→CH_(4) pathway.This study inspires an effective strategy for enhancing the multielectron reduction capacity of semiconductor photocatalysts with low-cost Fe instead of noble metals as cocatalysts.展开更多
In addition to the electron transfer,the appropriate H-adsorption affinity of active centers on the metal cocatalyst surface is quite important for high hydrogen-production activity of cocatalyst-modified photo-cataly...In addition to the electron transfer,the appropriate H-adsorption affinity of active centers on the metal cocatalyst surface is quite important for high hydrogen-production activity of cocatalyst-modified photo-catalysts.The typical Cu and Ru metal cocatalysts clearly exhibit a weak Cu-H bond and a strong Ru-H bond,respectively,resulting in limited activity for photocatalytic H_(2)evolution.In this work,an ingenious strategy of self-optimized H-adsorption affinity in CuRu alloy cocatalyst is developed to simultaneously reinforce the Cu-H bond and weaken the Ru-H bond by the intrinsic electron transfer from Cu to Ru atom.The CuRu alloy nanoparticles(2-3 nm)were deposited on the TiO_(2)surface to prepare CuRu/TiO_(2)through a one-step photoreduction method.Photocatalytic tests exhibited that the highest H_(2)-production rate of CuRu/TiO_(2)photocatalyst reached up to 5.316 mmol h^(-1)g^(-1),which was 24.80,1.86,and 2.60 times higher than that of the TiO_(2),Cu/TiO_(2),and Ru/TiO_(2),respectively.Based on the characterization results and theoretical calculations,the CuRu alloy cocatalyst exhibits excellent self-optimized H-adsorption affinity via the spontaneous electron transfer from Cu to Ru atom,which can greatly accelerate the photocatalytic H_(2)-production rate of TiO_(2).This work provides a feasible idea for the self-optimized H-adsorption affinity of metal active sites in the photocatalytic H_(2)-generation field.展开更多
Recently,Yu and co-workers deeply explore the potential impact of free electron transfer between co-catalysts and photocatalyst carriers on H_(2)evolution efficiency of active sites over MoS_(2+x).They pro-pose an ele...Recently,Yu and co-workers deeply explore the potential impact of free electron transfer between co-catalysts and photocatalyst carriers on H_(2)evolution efficiency of active sites over MoS_(2+x).They pro-pose an electron-reversal tactics to evade the unexpected electron transfer and synchronously regulate the above transfer in a beneficial orientation for weakening hydrogen adsorption on S sites.Herein,this highlight not only discusses and summarizes the essences of electron reversal and the optimized H ad-sorption/desorption mechanism,but also emphasizes the significance of femtosecond transient absorp-tion spectroscopy(fs-TAS)and in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS)for revealing charge transfer dynamics and processes.We anticipate that this highlight can disseminate a new per-spective on the roles of photocatalyst carriers in improving cocatalytic H_(2)-production kinetics.展开更多
The visible-light-driven hydrogen evolution is extremely important,but the poor charge transfer capa-bility,a sluggish evolution rate of hydrogen,and severe photo-corrosion make photocatalytic hydrogen evolution impra...The visible-light-driven hydrogen evolution is extremely important,but the poor charge transfer capa-bility,a sluggish evolution rate of hydrogen,and severe photo-corrosion make photocatalytic hydrogen evolution impractical.In this study,we present 1D/2D ReS_(2)-CdS hybrid nanorods for photocatalytic hy-drogen evolution,comprised of a ReS_(2)nanosheet layer grown on CdS nanorods.We found that precise control of the contents of the ReS_(2)nanosheet layer allows for manipulating the electronic structure of Re in the ReS_(2)-CdS hybrid nanorods.The ReS_(2)-CdS hybrid nanorods with optimal ReS_(2)nanosheet layer content dramatically improve photocatalytic hydrogen evolution activity.Notably,photocatalytic hydro-gen evolution activity(64.93 mmol g^(−1)h^(−1))of ReS_(2)-CdS hybrid nanorods with ReS_(2)nanosheet layers(Re/Cd atomic ratio of 0.051)is approximately 136 times higher than that of pure CdS nanorods under visible light irradiation.Furthermore,intimated coupling of the ReS_(2)nanosheet layer with CdS nanorods reduced the surface trap-site of the CdS nanorods,resulting in enhanced photocatalytic stability.The de-tailed optical and electrical investigations demonstrate that the optimal ReS_(2)nanosheet layer contents in the ReS_(2)-CdS hybrid nanorods can provide improved charge transfer capability,catalytic activity,and light absorption efficiency.This study sheds light on the development of photocatalysts for highly efficient photocatalytic hydrogen evolution.展开更多
Photoelectrochemical(PEC)energy conversion has emerged as a promising and efficient approach to sustainable energy harvesting and storage.By utilizing semiconductor photoelectrodes,PEC devices can harness solar energy...Photoelectrochemical(PEC)energy conversion has emerged as a promising and efficient approach to sustainable energy harvesting and storage.By utilizing semiconductor photoelectrodes,PEC devices can harness solar energy and drive electrochemical reactions such as water splitting or carbon dioxide(CO_(2))reduction to generate clean fuels and value-added chemicals.However,PEC energy conversion faces several challenges such as high overpotential,sluggish reaction kinetics,charge carrier recombination,and stability issues,which limit its practical implementation.Recently,significant research has been conducted to improve the overall conversion efficiency of PEC devices.One particularly promising approach is the use of cocatalysts,which involves introducing specific cocatalysts onto the photoelectrode surface to promote charge separation,improve reaction kinetics,and reduce the overpotential,thereby enhancing the overall performance of PEC energy conversion.This review provides a comprehensive overview of the recent developments in the earth-abundant cocatalysts for PEC water splitting and CO_(2) reduction.The main earth-abundant catalysts for the PEC water splitting include transition-metal dichalcogenide(TMD)-based materials,metal phosphides/carbides,and metal oxides/hydroxides.Meanwhile,PEC-CO_(2)RR was divided into C_(1) and C_(2+)based on the final product since various products could be produced,focusing on diverse earth-abundant materials-based cocatalysts.In addition,we provide and highlight key advancements achieved in the very recent reports on novel PEC system design engineering with cocatalysts.Finally,the current problems associated with PEC systems are discussed along with a suggested direction to overcome these obstacles.展开更多
Metal halide perovskite(MHP)has become one of the most promising materials for photocatalytic CO_(2) reduction owing to the wide light absorption range,negative conduction band position and high reduction ability.Howe...Metal halide perovskite(MHP)has become one of the most promising materials for photocatalytic CO_(2) reduction owing to the wide light absorption range,negative conduction band position and high reduction ability.However,photoreduction of CO_(2) by MHP remains a challenge because of the slow charge separation and transfer.Herein,a cobalt single-atom modified nitrogen-doped graphene(Co-NG)cocatalyst is prepared for enhanced photocatalytic CO_(2) reduction of bismuth-based MHP Cs_(3)Bi_(2)Br_(9).The optimal Cs_(3)Bi_(2)Br_(9)/Co-NG composite exhibits the CO production rate of 123.16μmol g^(-1)h^(-1),which is 17.3 times higher than that of Cs_(3)Bi_(2)Br_(9).Moreover,the Cs_(3)Bi_(2)Br_(9)/Co-NG composite photocatalyst exhibits nearly 100% CO selectivity as well as impressive long-term stability.Charge carrier dynamic characterizations such as Kelvin probe force microscopy(KPFM),single-particle PL microscope and transient absorption(TA)spectroscopy demonstrate the vital role of Co-NG cocatalyst in accelerating the transfer and separation of photogenerated charges and improving photocatalytic performance.The reaction mechanism has been demonstrated by in situ diffuse reflectance infrared Fourier-transform spectroscopy measurement.In addition,in situ X-ray photoelectron spectroscopy test and theoretical calculation reveal the reaction reactive sites and reaction energy barriers,demonstrating that the introduction of Co-NG promotes the formation of ^(*)COOH intermediate,providing sufficient evidence for the highly selective generation of CO.This work provides an effective single-atom-based cocatalyst modification strategy for photocatalytic CO_(2) reduction and is expected to shed light on other photocatalytic applications.展开更多
This study ingeniously synthesized a novel CdS/NiS hollow nanoflower sphere(HNS)using a one-step method to enhance photocatalytic hydrogen production activity.Compared to conventional preparation methods,this approach...This study ingeniously synthesized a novel CdS/NiS hollow nanoflower sphere(HNS)using a one-step method to enhance photocatalytic hydrogen production activity.Compared to conventional preparation methods,this approach features seamlessly interfaced contact that facilitates efficient electron transfer across the interface.The internal hollow structure allows for multiple light reflections,maximizing light absorption,while the exterior shell and inner surfaces simultaneously offer active sites for reactions.The modification with non-noble metal NiS enables the extraction of electrons from CdS to the NiS surface,achieving rapid charge separation.Furthermore,adsorption-free energy calculations reveal that the NiS surface is more conducive to photocatalytic hydrogen generation,providing additional reaction active sites.The results demonstrate a hydrogen production rate of 2.18 mmol g^(-1)h^(-1)for CdS/NiS HNS,which is 9.48 times greater than that of pristine CdS.This work presents a novel approach for synthesizing seamlessly interfaced contacts between photocatalysts and cocatalysts,offering new insight into efficient one-step synthesis for enhanced photocatalytic performance.展开更多
Novel WO3/g-C3N4/Ni（OH）x hybrids have been successfully synthesized by a two-step strategy of high temperature calcination and in situ photodeposition.Their photocatalytic performance was investigated using TEOA as ...Novel WO3/g-C3N4/Ni（OH）x hybrids have been successfully synthesized by a two-step strategy of high temperature calcination and in situ photodeposition.Their photocatalytic performance was investigated using TEOA as a hole scavenger under visible light irradiation.The loading of WO3 and Ni（OH）x cocatalysts boosted the photocatalytic H2 evolution efficiency of g-C3N4.WO3/g-C3N4/Ni（OH）x with 20 wt%defective WO3 and 4.8 wt%Ni（OH）x showed the highest hydrogen production rate of 576 μmol/（g·h）,which was 5.7,10.8 and 230 times higher than those of g-C3N4/4.8 wt%Ni（OH）x,20 wt%WO3/C3N4 and g-C3N4 photocatalysts,respectively.The remarkably enhanced H2 evolution performance was ascribed to the combination effects of the Z-scheme heterojunction（WO3/g-C3N4） and loaded cocatalysts（Ni（OH）x）,which effectively inhibited the recombination of the photoexcited electron-hole pairs of g-C3N4 and improved both H2 evolution and TEOA oxidation kinetics.The electron spin resonance spectra of ·O2^- and ·OH radicals provided evidence for the Z-scheme charge separation mechanism.The loading of easily available Ni（OH）x cocatalysts on the Z-scheme WO3/g-C3N4 nanocomposites provided insights into constructing a robust multiple-heterojunction material for photocatalytic applications.展开更多
Owing to their unique physicochemical,optical and electrical properties,two-dimensional(2D)MoS_(2) cocatalysts have been widely applied in designing and developing highly efficient composite photocatalysts for hydroge...Owing to their unique physicochemical,optical and electrical properties,two-dimensional(2D)MoS_(2) cocatalysts have been widely applied in designing and developing highly efficient composite photocatalysts for hydrogen generation under suitable light irradiation.In this review,we first elaborated on the fundamental aspects of 2D MoS_(2) cocatalysts to include the structural design principles,synthesis strategies,strengths and challenges.Subsequently,we thoroughly highlighted and discussed the modification strategies of 2D MoS_(2) H2-evolution cocatalysts,including doping heteroatoms(e.g.metals,non-metals,and co-doping),designing interfacial coupling morphologies,controlling the physical properties(e.g.thickness,size,structural defects or pores),exposing the reactive facets or edge sites,constructing cocatalyst heterojunctions,engineering the interfacial bonds and confinement effects.In the future,the forefront challenges in understanding and in precise controlling of the active sites at molecular level or atomic level should be carefully studied,while various potential mechanisms of photogenerated-electrons interactions should be proposed.The applications of MoS_(2) cocatalyst in the overall water splitting are also expected.This review may offer new inspiration for designing and constructing novel and efficient MoS_(2)-based composite photocatalysts for highly efficient photocatalytic hydrogen evolution.展开更多
g-C3N4 is a metal-free semiconductor and a potential candidate for photocatalytic H2 production,however,the drawbacks,rapid recombination rate and limited migration efficiency of photogenerated carriers,restrict its p...g-C3N4 is a metal-free semiconductor and a potential candidate for photocatalytic H2 production,however,the drawbacks,rapid recombination rate and limited migration efficiency of photogenerated carriers,restrict its photocatalytic activity.Herein,Co(II)as a hole cocatalyst modified P-doped g-C3N4 were successfully prepared to ameliorate the separation efficiency of photoinduced carriers and enhance the photocatalytic hydrogen production.The photocatalytic results demonstrated that the P-doped g-C3N4(PCN)exhibited higher photocatalytic activity compared with pure g-C3N4,while Co(II)/PCN photocatalyst exhibited further enhancement of photocatalytic performance.The proposed possible mechanism based on various characterizations is that P-doping can modulate the electronic structure of g-C3N4 to boost the separation of photogenerated-e-and h+;while the synergistic effect of both Co(II)(as hole cocatalyst)and Pt(as electron cocatalyst)can not only lead to the directional shunting of photogenerated e+-h?pairs,but further accelerate the photogenerated electrons transfer to Pt in order to join the photocatalytic reduction process for hydrogen evolution.As a result,the transportation and separation of photoinduced carriers were accelerated to greatest extent in the Pt/Co(II)/PCN photocatalyst.展开更多
2D-layered graphitic carbon nitride(g-C_(3)N_(4))is regarded as a great prospect as a photocatalyst for H_(2)generation.However,g-C_(3)N_(4)’s photocatalytic hydrogen evolution(HER)activity is significantly restricte...2D-layered graphitic carbon nitride(g-C_(3)N_(4))is regarded as a great prospect as a photocatalyst for H_(2)generation.However,g-C_(3)N_(4)’s photocatalytic hydrogen evolution(HER)activity is significantly restricted by the recombination of photocarriers.We find that cobalt sulfide(CoS_(2))as a cocatalyst can promote g-C_(3)N_(4)nanosheets(NSs)to realize very efficient photocatalytic H_(2)generation.The prepared CoS_(2)/g-C_(3)N_(4)hybrids display highly boosted photocatalytic H_(2)generation performance and outstanding cycle stability.The optimized 7%-CoS_(2)/g-C_(3)N_(4)hybrids show a much improved photocatalytic H_(2)generation rate of 36.2μmol-1h-1,which is about 180 times as much as bare g-C_(3)N_(4)(0.2μmol-1h-1).In addition,the apparent quantum efficiency(AQE)of all the samples was computed under light atλ=370 nm,in which the AQE of 7%-CoS_(2)/g-C_(3)N_(4)hybrids is up to 5.72%.The experimental data and the DFT calculation suggest that the CoS_(2)/g-C_(3)N_(4)hybrid’s excellent HER activity is attributable to the lower overpotential and the smaller Co-H bond activation energy for HER.Accordingly,the CoS_(2)cocatalyst loading effectively boosts the photocatalytic performance of g-C_(3)N_(4)for H_(2)evolution.The project promotes fast development of high-efficiency photocatalysts and low-cost for photocatalytic H_(2)generation.展开更多
Photocatalytic hydrogen(H2)evolution via water spilling over semiconductors has been considered to be one of the most promising strategies for sustainable energy supply in the future to provide non-pollution and renew...Photocatalytic hydrogen(H2)evolution via water spilling over semiconductors has been considered to be one of the most promising strategies for sustainable energy supply in the future to provide non-pollution and renewable energy.The key to efficient conversion of solar-chemical energy is the design of an efficient structure for high charge separation and transportation.Therefore,cocatalysts are necessary in boosting photocatalytic H2 evolution.To date,semiconductor photocatalysts have been modified by various cocatalysts due to the extended light harvest,enhanced charge carrier separation efficiency and improved stability.This review focuses on recent developments of cocatalysts in photocatalytic H2 evolution,the roles and mechanism of the cocatalysts are discussed in detail.The cocatalysts can be divided into the following categories:metal/alloy cocatalysts,metal phosphides cocatalysts,metal oxide/hydroxide cocatalysts,carbon-based cocatalysts,dual cocatalysts,Z-scheme cocatalysts and MOFs cocatalysts.The future research and forecast for photocatalytic hydrogen generation are also suggested.展开更多
文摘Although bimetallic phosphide cocatalysts have attracted considerable interest in photocatalysis research owing to their advantageous thermodynamic characteristics,superstable and efficient cocatalysts have rarely been produced through the modulation of their structure and composition.In this study,a series of bimetallic nickel-iron phosphide(Ni_(x)Fe_(2-x)P,where 0<x<2)cocatalysts with controllable structures and overpotentials were designed by adjusting the atomic ratio of Ni/Fe onto nonmetallic elemental red phosphorus(RP)for the photocatalytic selective oxidation of benzyl alcohol(BA)coupled with hydrogen production.The catalysts exhibited an outstanding photocatalytic activity for benzaldehyde and a high H_(2)yield.The RP regulated by bimetallic phosphide cocatalysts(Ni_(x)Fe_(2-x)P)demonstrated higher photocatalytic oxidation-reduction activity than that regulated by monometallic phosphide cocatalysts(Ni_(2)P and Fe2P).In particular,the RP regulated by Ni_(1.25)Fe_(0.75)P exhibited the best photocatalytic performance.In addition,experimental and theoretical calculations further illustrated that Ni_(1.25)Fe_(0.75)P,with the optimized electronic structure,possessed good electrical conductivity and provided strong adsorption and abundant active sites,thereby accelerating electron migration and lowering the reaction energy barrier of RP.This finding offers valuable insights into the rational design of highly effective cocatalysts aimed at optimizing the photocatalytic activity of composite photocatalysts.
基金supported by the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.52488201)the National Natural Science Foundation of China(No.52376209)+1 种基金the China Postdoctoral Science Foundation(Nos.2020T130503 and 2020M673386)China Fundamental Research Funds for the Central Universities.
文摘The development of stable and efficient non-noble metal cocatalysts has arisen as a promising yet challenging endeavor in the context of photocatalytic overall water splitting.In this study,NiCo alloy cocatalysts were synthesized with nickel/cobalt metal organic framework(NiCo-MOF)as source of nickel and cobalt.Systematic characterization results demonstrate the successful deposition of alloy cocatalysts onto the surface of SrTiO_(3).The prepared SrTiO_(3)loaded NiCo-alloy can generate hydrogen and oxygen in a stoichiometric ratio for photocatalytic overall water splitting,achieving an apparent quantum yield of 11.9%at 350±10 nm.Theoretical calculations indicate that the introduction of cobalt has a beneficial regulatory effect on the hydrogen evolution sites of Ni,reducing the free energy of H adsorption.The synergistic catalytic effect of bimetallic catalysts contributes to enhancing photocatalytic activity and stability.This study offers constructive insights for the development of high-efficiency and cost-effective cocatalyst systems.
基金financial supports provided by the Natural Science Foundation of Fujian Province(No.2024J01195)the National Nature Science Foundation of China(No.21905279)+1 种基金Sanming University(Nos.22YG11 and PYT2201)the Education Scientific Research Project of Youth Teachers in the Education Department of Fujian Province(No.JAT220351).
文摘Negatively charged open-framework metal sulfides(NOSs),taking advantages of the characteristics of excellent visible light absorption,easily exchanged cations,and abundant active sites,hold significant promise as highly efficient photocatalysts for hydrogen evolution.However,their applications in photocatalytic hydrogen evolution(PHE)are infrequently documented and the corresponding photocatalytic mechanism has not yet been explored.Herein,we excavated a novel NOS photocatalyst of(Me_(2)NH_(2))_(6)In_(10)S_(18)(MIS)with a three-dimensional(3D)structure,and successfully incorporated divalent Co(Ⅱ)and metal Co(0)into its cavities via the convenient cation exchange-assisted approach to regulate the critical steps of photocatalytic reactions.As the introduced Co(0)allows for more efficient light utilization and adroitly surficial hydrogen desorption,and meanwhile acts as the‘electron pump’for rapid charge transfer,Co(0)-modified MIS delivers a surprising PHE activity in the initial stage of photocatalysis.With the prolonging of illumination,metal Co(0)gradually escapes from MIS framework,resulting in the decline of PHE performance.By stark contrast,the incorporated Co(Ⅱ)can establish a strong interaction with MIS framework,and simultaneously capture photogenerated electrons from MIS to produce Co(0),which constructs a stable photocatalytic system as well as provides additional channels for spatially separating photogenerated carriers.Thus,Co(Ⅱ)-modified MIS exhibits a robust and highly stable PHE activity of~4944μmol/g/h during the long-term photocatalytic reactions,surpassing most of the previously reported In–S framework photocatalysts.This work represents a breakthrough in the study of PHE performance and mechanism of NOS-based photocatalysts,and sheds light on the design of vip confined NOS-based photocatalysts towards high-efficiency solar-to-chemical energy conversion.
文摘Photocatalysts are essential for the preparation of wanted fine chemical and biomedical intermediates via visible photocatalysis,but existing photocatalysts with low catalytic efficiency limit their wide applications.Herein,CdS/Ti_(3)C2T_(x)/MBI nanocomposites have been successfully fabricated through anchoring reduction cocatalyst Ti_(3)C_(2)T_(x) with electron-drawing ability and oxidation cocatalyst 2-mercaptobenzimidazole(MBI)with hole-capturing capacity on CdS nanoparticles.The Ti_(3)C_(2)T_(x) and MBI of CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites can extract electrons and holes from CdS nanoparticles to come true electron-hole separation,respectively.Moreover,the electron-drawing and hole-capturing abilities of the CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites depend on Ti_(3)C_(2)T_(x) and MBI contents,and the quantifiable electron and hole transfers finally determine photocatalytic efficiency of the CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites.The transient photocurrent density of the CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites is 6-fold higher than that of the CdS nanoparticles.The CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites with strong electron-hole separation capability exhibit outstanding visible photocatalytic organic transformation properties.The CdS/Ti_(3)C_(2)T_(x)/MBI nanocomposites produce(E)-N-benzyl-1-phenylmethylimine in~96%yield(~8000μmol·g^(-1)·h^(-1)),which is 3-fold higher than the CdS nanoparticles(~2500μmol·g^(-1)·h^(-1),30%).This work provides a new strategy for constructing efficient and stable photocatalysts that can be used for efficient visible light-driven organic transformations.
文摘Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) production,cocatalyst modification is commonly employed to provide active sites for the hydrogen evolution reaction(HER)[4,5].In this context,the kinetics of hydrogen adsorption and desorption at these active sites play a crucial role in enhancing overall photocatalytic H_(2) production efficiency.However,the H adsorption/desorption kinetics often exhibit a trade-off,presenting a significant challenge in achieving an optimal equilibrium between Hads and Hdes in many cocatalyst systems.Therefore,fine-tuning the active sites to optimize the H_(2) evolution kinetics is essential for improving photocatalytic activity[6].
基金Funded by the National Natural Science Foundation of China(Nos.22178276,22178275,U22A20147,and 22075220)the Natural Science Foundation of Hubei Province of China(No.2022CFA001)。
文摘BiVO_(4)is an ideal photocatalysts for H_(2)O_(2)generation due to its suitable band edge.In practice,however,the photocatalytic performance of BiVO_(4)is substantially low owing to the slow kinetics of 2e^(-)O_(2)reduction(2e^(-)ORR)and water oxidation(WOR)processes.To solve the problems,in this work,the AuPd alloy cocatalyst and the NiOOH cocatalys were modified on the electron(010)facets and the(110)hole facet of BiVO_(4)by photodeposition method.The designed AuPd/BiVO_(4)/NiOOH(0.5%)photocatalyst showed prominent photocatalytic H_(2)O_(2)production activity of 289.3μmmol_·L^(-1)with an AQE value of 0.89%at 420 nm,which was increased by 40 times compared with the BiVO_(4)sample(7.1μmmol_?L^(-1)).The outstanding photocatalytic activity of the AuPd/BiVO_(4)/NiOOH photocatalyst can be attributed to the synergistic effect of AuPd and NiOOH cocatalysts,which promoted the kinetics of oxygen reduction and water oxidation,and concurrently facilitated the charge separation.The present strategy of dual-cocatalyst rational assembly on different facets of BiVO_(4)provides an insight into explore efficient BiVO_(4)-based materials for H_(2)O_(2)production.
文摘Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocatalysts,while concurrently preventing side reactions and photocorrosion on the semiconductor surface.Herein,Ni-Co bimetallic hydroxides with varying Ni/Co molar ratios(Ni_(x)Co_(1-x)(OH)_(2),x=1,0.75,0.5,0.25,and 0)were grown in situ on a model 2D/2D S-scheme heterojunction composed of Cu_(2)O nanosheets and Fe_(2)O_(3)nanoplates to form a series of Cu_(2)O/Fe_(2)O_(3)@Ni_(x)Co_(1-x)(OH)_(2)(CF@NiCo)photocatalysts.The combined experimental and theoretical investigation demonstrates that incorporating an appropriate amount of Co into Ni(OH)_(2)not only modulates the energy band structure of Ni_(x)Co_(1-x)(OH)_(2),balances the electron-and hole-trapping abilities of the bifunctional cocatalyst and maximizes the charge separation efficiency of the heterojunction,but also regulates the d-band center of Ni_(x)Co_(1-x)(OH)_(2),reinforcing the adsorption and activation of CO_(2)and H_(2)O on the cocatalyst surface and lowering the rate-limiting barriers in the CO_(2)-to-CO and H_(2)O-to-O_(2)conversion.Benefiting from the Ni-Co synergy,the redox reactions proceed stoichiometrically.The optimized CF@Ni_(0.75)Co_(0.25)achieves CO and O_(2)yields of 552.7 and 313.0μmol gcat^(-1)h^(-1),respectively,11.3/9.9,1.6/1.7,and 4.5/5.9-fold higher than those of CF,CF@Ni,and CF@Co.This study offers valuable insights into the design of bifunctional noble-metal-free cocatalysts for high-performance artificial photosynthesis.
基金support provided by the Ministry of Higher Education Malaysia under the Xiamen University Malaysia.-Fundamental Research Grant Scheme(FRGS)(Ref no.FRGS/1/2024/TK08/XMU/02/1)supported by the PETRONAS-Academia Collaboration Dialogue(PACD 2023)grant,provided by PETRONAS Research Sdn.Bhd.(PRSB)+6 种基金the Ministry of Science,Technology and Innovation(MOSTI)Malaysia under the Strategic Research Fund(SRF)(S.22015)supported by the National Natural Science Foundation of China(Ref no:22202168)Guangdong Basic and Applied Basic Research Foundation(Ref no:2021A1515111019)the financial support from the State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University(Ref no:2023X11)supported by the Xiamen University,Embassy of the People's Republic of China in Malaysia(EENG/0045)funded by Xiamen University Malaysia Investigatorship Grant(Grant no:IENG/0038)Xiamen University Malaysia Research Fund(ICOE/0001,XMUMRF/2021-C8/IENG/0041 and XMUMRF/2025-C15/IENG/0080).
文摘By harnessing the power of MoS_(2) as a cocatalyst to enhance electron transfer and charge carrier separation,a groundbreaking two-in-one redox photocatalytic system was developed.This innovative system integrated 2D MoS_(2) nanosheets onto hydrangea-like Zn_(3)In_(2)S_(6) nanosheets,forming a 2D/3D heterostructure that established a stable and intimate interface.This unique architecture significantly improved cooperative photocatalytic performance,enabling the simultaneous production of hydrogen and benzaldehyde under light irradiation≥420 nm.Notably,the system achieved remarkable yields of hydrogen(41.9 mmol g^(-1) h^(-1))and benzaldehyde(38.9 mmol g^(-1) h^(-1)),surpassing the pristine Zn_(3)In_(2)S_(6) by 22.4 times.An impressive electron-hole pair utilization rate of approximately 93%was attained,underscoring the high efficiency of this two-in-one redox system.Additionally,the targeted 10 wt%-MoS_(2) loaded Zn_(3)In_(2)S_(6)(10MZ)nanohybrids at 400 nm obtained an apparent quantum yield(AQY)value of 17.66%without sacrificial agents or noble metals.The exceptional performance was attributed to improved charge carrier separation and reduced recombination,facilitated by cocatalyst integration and evidenced via photoluminescence,photoelectrochemical and Kelvin probe force microscopy measurements.This work highlighted the critical role of two-in-one redox-functioning heterojunctions in optimizing electron-hole pair utilization,offering a promising approach for sustainable energy production and organic synthesis.By demonstrating the potential for efficient,simultaneous generation of valuable chemicals and fuels,this research paves the way for the development of next-generation photocatalytic systems.
基金supported by the National Natural Science Foundation of China(Grant No.22072022)the Natural Science Foundation of Fujian Province(2021L3003)the Science Foundation of Shandong Province(ZR2019BB065).
文摘Efficient photocatalytic reduction of CO_(2) to high-calorific-value CH4,an ideal target product,is a blueprint for C_(1)industry relevance and carbon neutrality,but it also faces great challenges.Herein,we demonstrate unprecedented hybrid SiC photocatalysts modified by Fe-based cocatalyst,which are prepared via a facile impregnation-reduction method,featuring an optimized local electronic structure.It exhibits a superior photocatalytic carbon-based products yield of 30.0μmol g^(−1) h^(−1) and achieves a record CH_(4) selectivity of up to 94.3%,which highlights the effectiveness of electron-rich Fe cocatalyst for boosting photocatalytic performance and selectivity.Specifically,the synergistic effects of directional migration of photogenerated electrons and strongπ-back bonding on low-valence Fe effectively strengthen the adsorption and activation of reactants and intermediates in the CO_(2)→CH_(4) pathway.This study inspires an effective strategy for enhancing the multielectron reduction capacity of semiconductor photocatalysts with low-cost Fe instead of noble metals as cocatalysts.
基金supported by the National Natural Science Foun-dation of China(Nos.22178275 and U22A20147)the Natural Science Foundation of Hubei Province of China(No.2022CFA001).
文摘In addition to the electron transfer,the appropriate H-adsorption affinity of active centers on the metal cocatalyst surface is quite important for high hydrogen-production activity of cocatalyst-modified photo-catalysts.The typical Cu and Ru metal cocatalysts clearly exhibit a weak Cu-H bond and a strong Ru-H bond,respectively,resulting in limited activity for photocatalytic H_(2)evolution.In this work,an ingenious strategy of self-optimized H-adsorption affinity in CuRu alloy cocatalyst is developed to simultaneously reinforce the Cu-H bond and weaken the Ru-H bond by the intrinsic electron transfer from Cu to Ru atom.The CuRu alloy nanoparticles(2-3 nm)were deposited on the TiO_(2)surface to prepare CuRu/TiO_(2)through a one-step photoreduction method.Photocatalytic tests exhibited that the highest H_(2)-production rate of CuRu/TiO_(2)photocatalyst reached up to 5.316 mmol h^(-1)g^(-1),which was 24.80,1.86,and 2.60 times higher than that of the TiO_(2),Cu/TiO_(2),and Ru/TiO_(2),respectively.Based on the characterization results and theoretical calculations,the CuRu alloy cocatalyst exhibits excellent self-optimized H-adsorption affinity via the spontaneous electron transfer from Cu to Ru atom,which can greatly accelerate the photocatalytic H_(2)-production rate of TiO_(2).This work provides a feasible idea for the self-optimized H-adsorption affinity of metal active sites in the photocatalytic H_(2)-generation field.
基金supported by the Natural Science Foundation of Hebei of China(Nos.B2020205013,B2022205008)the Science and Technology Project of Hebei Normal University of China(No.L2021K01).
文摘Recently,Yu and co-workers deeply explore the potential impact of free electron transfer between co-catalysts and photocatalyst carriers on H_(2)evolution efficiency of active sites over MoS_(2+x).They pro-pose an electron-reversal tactics to evade the unexpected electron transfer and synchronously regulate the above transfer in a beneficial orientation for weakening hydrogen adsorption on S sites.Herein,this highlight not only discusses and summarizes the essences of electron reversal and the optimized H ad-sorption/desorption mechanism,but also emphasizes the significance of femtosecond transient absorp-tion spectroscopy(fs-TAS)and in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS)for revealing charge transfer dynamics and processes.We anticipate that this highlight can disseminate a new per-spective on the roles of photocatalyst carriers in improving cocatalytic H_(2)-production kinetics.
基金supported by the National Re-search Foundation of Korea(Nos.NRF-2020R1C1C1008514,2019R1A6A1A11053838,and NRF-2023R1A2C1004015)the“Regional Innovation Strategy(RIS)”through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(No.2021RIS-003).
文摘The visible-light-driven hydrogen evolution is extremely important,but the poor charge transfer capa-bility,a sluggish evolution rate of hydrogen,and severe photo-corrosion make photocatalytic hydrogen evolution impractical.In this study,we present 1D/2D ReS_(2)-CdS hybrid nanorods for photocatalytic hy-drogen evolution,comprised of a ReS_(2)nanosheet layer grown on CdS nanorods.We found that precise control of the contents of the ReS_(2)nanosheet layer allows for manipulating the electronic structure of Re in the ReS_(2)-CdS hybrid nanorods.The ReS_(2)-CdS hybrid nanorods with optimal ReS_(2)nanosheet layer content dramatically improve photocatalytic hydrogen evolution activity.Notably,photocatalytic hydro-gen evolution activity(64.93 mmol g^(−1)h^(−1))of ReS_(2)-CdS hybrid nanorods with ReS_(2)nanosheet layers(Re/Cd atomic ratio of 0.051)is approximately 136 times higher than that of pure CdS nanorods under visible light irradiation.Furthermore,intimated coupling of the ReS_(2)nanosheet layer with CdS nanorods reduced the surface trap-site of the CdS nanorods,resulting in enhanced photocatalytic stability.The de-tailed optical and electrical investigations demonstrate that the optimal ReS_(2)nanosheet layer contents in the ReS_(2)-CdS hybrid nanorods can provide improved charge transfer capability,catalytic activity,and light absorption efficiency.This study sheds light on the development of photocatalysts for highly efficient photocatalytic hydrogen evolution.
基金supported by the National Research Foundation of Korea (NRF)funded by the Korean government (2021R1A4A3027878,2022M3H4A1A01012712)。
文摘Photoelectrochemical(PEC)energy conversion has emerged as a promising and efficient approach to sustainable energy harvesting and storage.By utilizing semiconductor photoelectrodes,PEC devices can harness solar energy and drive electrochemical reactions such as water splitting or carbon dioxide(CO_(2))reduction to generate clean fuels and value-added chemicals.However,PEC energy conversion faces several challenges such as high overpotential,sluggish reaction kinetics,charge carrier recombination,and stability issues,which limit its practical implementation.Recently,significant research has been conducted to improve the overall conversion efficiency of PEC devices.One particularly promising approach is the use of cocatalysts,which involves introducing specific cocatalysts onto the photoelectrode surface to promote charge separation,improve reaction kinetics,and reduce the overpotential,thereby enhancing the overall performance of PEC energy conversion.This review provides a comprehensive overview of the recent developments in the earth-abundant cocatalysts for PEC water splitting and CO_(2) reduction.The main earth-abundant catalysts for the PEC water splitting include transition-metal dichalcogenide(TMD)-based materials,metal phosphides/carbides,and metal oxides/hydroxides.Meanwhile,PEC-CO_(2)RR was divided into C_(1) and C_(2+)based on the final product since various products could be produced,focusing on diverse earth-abundant materials-based cocatalysts.In addition,we provide and highlight key advancements achieved in the very recent reports on novel PEC system design engineering with cocatalysts.Finally,the current problems associated with PEC systems are discussed along with a suggested direction to overcome these obstacles.
文摘Metal halide perovskite(MHP)has become one of the most promising materials for photocatalytic CO_(2) reduction owing to the wide light absorption range,negative conduction band position and high reduction ability.However,photoreduction of CO_(2) by MHP remains a challenge because of the slow charge separation and transfer.Herein,a cobalt single-atom modified nitrogen-doped graphene(Co-NG)cocatalyst is prepared for enhanced photocatalytic CO_(2) reduction of bismuth-based MHP Cs_(3)Bi_(2)Br_(9).The optimal Cs_(3)Bi_(2)Br_(9)/Co-NG composite exhibits the CO production rate of 123.16μmol g^(-1)h^(-1),which is 17.3 times higher than that of Cs_(3)Bi_(2)Br_(9).Moreover,the Cs_(3)Bi_(2)Br_(9)/Co-NG composite photocatalyst exhibits nearly 100% CO selectivity as well as impressive long-term stability.Charge carrier dynamic characterizations such as Kelvin probe force microscopy(KPFM),single-particle PL microscope and transient absorption(TA)spectroscopy demonstrate the vital role of Co-NG cocatalyst in accelerating the transfer and separation of photogenerated charges and improving photocatalytic performance.The reaction mechanism has been demonstrated by in situ diffuse reflectance infrared Fourier-transform spectroscopy measurement.In addition,in situ X-ray photoelectron spectroscopy test and theoretical calculation reveal the reaction reactive sites and reaction energy barriers,demonstrating that the introduction of Co-NG promotes the formation of ^(*)COOH intermediate,providing sufficient evidence for the highly selective generation of CO.This work provides an effective single-atom-based cocatalyst modification strategy for photocatalytic CO_(2) reduction and is expected to shed light on other photocatalytic applications.
基金supported by the National Natural Science Foundation of China(Nos.22278169 and 51973078)the Excellent Scientific Research and Innovation team of the Education Department of Anhui Province(No.2022AH010028)+2 种基金the Major projects of the Education Department of Anhui Province(No.2022AH040068)the Key Foundation of Educational Commission of Anhui Province(Nos.2022AH050396 and 2022AH050376)Anhui Provincial Quality Engineering Project(No.2022sx134).
文摘This study ingeniously synthesized a novel CdS/NiS hollow nanoflower sphere(HNS)using a one-step method to enhance photocatalytic hydrogen production activity.Compared to conventional preparation methods,this approach features seamlessly interfaced contact that facilitates efficient electron transfer across the interface.The internal hollow structure allows for multiple light reflections,maximizing light absorption,while the exterior shell and inner surfaces simultaneously offer active sites for reactions.The modification with non-noble metal NiS enables the extraction of electrons from CdS to the NiS surface,achieving rapid charge separation.Furthermore,adsorption-free energy calculations reveal that the NiS surface is more conducive to photocatalytic hydrogen generation,providing additional reaction active sites.The results demonstrate a hydrogen production rate of 2.18 mmol g^(-1)h^(-1)for CdS/NiS HNS,which is 9.48 times greater than that of pristine CdS.This work presents a novel approach for synthesizing seamlessly interfaced contacts between photocatalysts and cocatalysts,offering new insight into efficient one-step synthesis for enhanced photocatalytic performance.
基金supported by the National Natural Science Foundation of China (51672089)the Industry and Research Collaborative Innovation Major Projects of Guangzhou (201508020098)+1 种基金the State Key Laboratory of Advanced Technology for Material Synthesis and Processing (Wuhan University of Technology) (2015-KF-7)the Hunan Key Laboratory of Applied Environmental Photocatalysis (Changsha University) (CCSU-XT-04)~~
文摘Novel WO3/g-C3N4/Ni（OH）x hybrids have been successfully synthesized by a two-step strategy of high temperature calcination and in situ photodeposition.Their photocatalytic performance was investigated using TEOA as a hole scavenger under visible light irradiation.The loading of WO3 and Ni（OH）x cocatalysts boosted the photocatalytic H2 evolution efficiency of g-C3N4.WO3/g-C3N4/Ni（OH）x with 20 wt%defective WO3 and 4.8 wt%Ni（OH）x showed the highest hydrogen production rate of 576 μmol/（g·h）,which was 5.7,10.8 and 230 times higher than those of g-C3N4/4.8 wt%Ni（OH）x,20 wt%WO3/C3N4 and g-C3N4 photocatalysts,respectively.The remarkably enhanced H2 evolution performance was ascribed to the combination effects of the Z-scheme heterojunction（WO3/g-C3N4） and loaded cocatalysts（Ni（OH）x）,which effectively inhibited the recombination of the photoexcited electron-hole pairs of g-C3N4 and improved both H2 evolution and TEOA oxidation kinetics.The electron spin resonance spectra of ·O2^- and ·OH radicals provided evidence for the Z-scheme charge separation mechanism.The loading of easily available Ni（OH）x cocatalysts on the Z-scheme WO3/g-C3N4 nanocomposites provided insights into constructing a robust multiple-heterojunction material for photocatalytic applications.
基金the National Natural Science Foundation of China(Nos.21975084 and 51672089)the Guangdong Provincial Applied Science and Technology Research and Development Program(No.2017B020238005)+2 种基金the Ding Ying Talent Project of South China Agricultural University for their supportthe Hong Kong Research Grant Council(RGC)General Research Fund(No.GRF1305419)for financial supportthe National Natural Science Foundation of China(Nos.51972287 and 51502269)。
文摘Owing to their unique physicochemical,optical and electrical properties,two-dimensional(2D)MoS_(2) cocatalysts have been widely applied in designing and developing highly efficient composite photocatalysts for hydrogen generation under suitable light irradiation.In this review,we first elaborated on the fundamental aspects of 2D MoS_(2) cocatalysts to include the structural design principles,synthesis strategies,strengths and challenges.Subsequently,we thoroughly highlighted and discussed the modification strategies of 2D MoS_(2) H2-evolution cocatalysts,including doping heteroatoms(e.g.metals,non-metals,and co-doping),designing interfacial coupling morphologies,controlling the physical properties(e.g.thickness,size,structural defects or pores),exposing the reactive facets or edge sites,constructing cocatalyst heterojunctions,engineering the interfacial bonds and confinement effects.In the future,the forefront challenges in understanding and in precise controlling of the active sites at molecular level or atomic level should be carefully studied,while various potential mechanisms of photogenerated-electrons interactions should be proposed.The applications of MoS_(2) cocatalyst in the overall water splitting are also expected.This review may offer new inspiration for designing and constructing novel and efficient MoS_(2)-based composite photocatalysts for highly efficient photocatalytic hydrogen evolution.
基金supported by the National Natural Science Foundation of China(51672113)QingLan Project Foundation of Jiangsu Province(201611)~~
文摘g-C3N4 is a metal-free semiconductor and a potential candidate for photocatalytic H2 production,however,the drawbacks,rapid recombination rate and limited migration efficiency of photogenerated carriers,restrict its photocatalytic activity.Herein,Co(II)as a hole cocatalyst modified P-doped g-C3N4 were successfully prepared to ameliorate the separation efficiency of photoinduced carriers and enhance the photocatalytic hydrogen production.The photocatalytic results demonstrated that the P-doped g-C3N4(PCN)exhibited higher photocatalytic activity compared with pure g-C3N4,while Co(II)/PCN photocatalyst exhibited further enhancement of photocatalytic performance.The proposed possible mechanism based on various characterizations is that P-doping can modulate the electronic structure of g-C3N4 to boost the separation of photogenerated-e-and h+;while the synergistic effect of both Co(II)(as hole cocatalyst)and Pt(as electron cocatalyst)can not only lead to the directional shunting of photogenerated e+-h?pairs,but further accelerate the photogenerated electrons transfer to Pt in order to join the photocatalytic reduction process for hydrogen evolution.As a result,the transportation and separation of photoinduced carriers were accelerated to greatest extent in the Pt/Co(II)/PCN photocatalyst.
基金funding from the National Natural Science Foundation of China(No.51872173 and 51772176)Taishan Scholar Foundation of Shandong Province(No.tsqn201812068 and tspd20161006)+2 种基金Youth Innovation Technology Project of Higher School in Shandong Province(No.2019KJA013)Science and Technology Special Project of Qingdao City(No.20-3-4-3-nsh)the Opening Fund of State Key Laboratory of Heavy Oil Processing(No.SKLOP202002006)。
文摘2D-layered graphitic carbon nitride(g-C_(3)N_(4))is regarded as a great prospect as a photocatalyst for H_(2)generation.However,g-C_(3)N_(4)’s photocatalytic hydrogen evolution(HER)activity is significantly restricted by the recombination of photocarriers.We find that cobalt sulfide(CoS_(2))as a cocatalyst can promote g-C_(3)N_(4)nanosheets(NSs)to realize very efficient photocatalytic H_(2)generation.The prepared CoS_(2)/g-C_(3)N_(4)hybrids display highly boosted photocatalytic H_(2)generation performance and outstanding cycle stability.The optimized 7%-CoS_(2)/g-C_(3)N_(4)hybrids show a much improved photocatalytic H_(2)generation rate of 36.2μmol-1h-1,which is about 180 times as much as bare g-C_(3)N_(4)(0.2μmol-1h-1).In addition,the apparent quantum efficiency(AQE)of all the samples was computed under light atλ=370 nm,in which the AQE of 7%-CoS_(2)/g-C_(3)N_(4)hybrids is up to 5.72%.The experimental data and the DFT calculation suggest that the CoS_(2)/g-C_(3)N_(4)hybrid’s excellent HER activity is attributable to the lower overpotential and the smaller Co-H bond activation energy for HER.Accordingly,the CoS_(2)cocatalyst loading effectively boosts the photocatalytic performance of g-C_(3)N_(4)for H_(2)evolution.The project promotes fast development of high-efficiency photocatalysts and low-cost for photocatalytic H_(2)generation.
基金financially supported by the National Natural Science Foundation of China(51572295,21273285 and 21003157)Beijing Nova Program(2008B76)Science Foundation of China University of Petroleum,Beijing(KYJJ2012-06-20 and 2462016YXBS05)~~
文摘Photocatalytic hydrogen(H2)evolution via water spilling over semiconductors has been considered to be one of the most promising strategies for sustainable energy supply in the future to provide non-pollution and renewable energy.The key to efficient conversion of solar-chemical energy is the design of an efficient structure for high charge separation and transportation.Therefore,cocatalysts are necessary in boosting photocatalytic H2 evolution.To date,semiconductor photocatalysts have been modified by various cocatalysts due to the extended light harvest,enhanced charge carrier separation efficiency and improved stability.This review focuses on recent developments of cocatalysts in photocatalytic H2 evolution,the roles and mechanism of the cocatalysts are discussed in detail.The cocatalysts can be divided into the following categories:metal/alloy cocatalysts,metal phosphides cocatalysts,metal oxide/hydroxide cocatalysts,carbon-based cocatalysts,dual cocatalysts,Z-scheme cocatalysts and MOFs cocatalysts.The future research and forecast for photocatalytic hydrogen generation are also suggested.
