CdS photocorrosion is one of the most important factors that greatly affect the photocatalytic H_(2)-production rate and long-time stability.However,the reported works about CdS photocorrosion are mainly focused on th...CdS photocorrosion is one of the most important factors that greatly affect the photocatalytic H_(2)-production rate and long-time stability.However,the reported works about CdS photocorrosion are mainly focused on the surface oxidation by photogenerated holes,while the possible reduction of lattice Cd^(2+) by photogenerated electrons is usually ignored.In this work,the lattice Cd^(2+) reduction by photogenerated electrons during CdS photocorrosion were carefully investigated to reveal its potential effect on the microstructure change and photocatalytic H_(2)-production performance of CdS photocatalyst based on the two typical Na_(2)S-Na_(2)SO_(3) and lactic acid H_(2)-evolution systems.It was found that many isolated metallic Cd nanoparticles(5–50 nm)were produced on the CdS surface in the Na_(2)S-Na_(2)SO_(3) system,causing its serious destroy of CdS surface and a gradually decreased photocatalytic activity,while only a metallic Cd layer(2-3 nm)is homogeneously coated on the CdS surface in the lactic acid system,leading to an increased H-evolution rate.In fact,once a certain amount of metallic Cd was produced on the CdS surface,the resulting CdS-Cd composites can present a stable photocatalytic H_(2)-production activity and excellent stability for the final CdS-Cd photocatalysts.Hence,a photoinduced self-stability mechanism of CdS photocatalyst has been proposed,namely,the spontaneously produced metallic Cd contributes to the transformation of unstable CdS into stable CdS-Cd structure,with the simultaneous realization of final stable H_(2)-evolution performance.展开更多
Interface engineering can improve the charge separation efficiency and inhibit photocorrosion is an emerging direction of developing more efficient and cost-effective photocatalytic systems.Herein,we report the sulfur...Interface engineering can improve the charge separation efficiency and inhibit photocorrosion is an emerging direction of developing more efficient and cost-effective photocatalytic systems.Herein,we report the sulfur-confined intimate Cd S intergrown Cd(Cd S/Cd)Ohmic junction(peanut-chocolate-ball like)for high-efficient H2production with superior anti-photocorrosion ability,which was fabricated from in-situ photoreduction of CdS intergrown Cd2SO4(OH)2(CdS/Cd2SO4(OH)2)prepared through a facile space-controlled-solvothermal method.The ratios of CdS/Cd can be effectively controlled by tunning that of CdS/Cd2SO4(OH)2which were prepared by adjusting the volume of reaction liquid and the remaining space of the reactor.Experiments investigations and density functional theory(DFT)calculations reveal that the Cd S intergrown Cd Ohmic junction interfaces(with appropriate content Cd intergrown on Cd S(19.54 wt%))are beneficial in facilitating the transfer of photogenerated electrons by constructing an interfacial electric field and forming sulfur-confined structures for preventing the positive holes(h+)oxidize the Cd S.This contributes to a high photocatalytic H2production activity of 95.40μmol h-1(about 32.3 times higher than bare Cd S)and possesses outstanding photocatalytic stability over 205 h,much longer than most Cd S-based photocatalysts previously reported.The interface engineering design inspired by the structure of peanut-chocolate-ball can greatly promote the future development of catalytic systems for wider application.展开更多
Semiconductor metal oxides with narrow bandgap have emerged as a promising platform for photoelectrochemical reactions,yet their photoelectron-induced photocorrosion effect has been a limitation for their wider applic...Semiconductor metal oxides with narrow bandgap have emerged as a promising platform for photoelectrochemical reactions,yet their photoelectron-induced photocorrosion effect has been a limitation for their wider applications.Understanding the conversion processes concomitant with photoelectrochemical reaction at the electrode-electrolyte interface plays a crucial role in revealing the corrosion mechanisms and advancing the development of efficient photocathodes.However,accurately and in situ tracking these dynamic chemical events remains a great challenge due to the fact that reaction processes occur at nanoscale interfaces.Here,we track the electrochemical growth and conversion of copper nanostructures at interface by the evanescent field of the surface plasmon wave by using a gold-coated optical fiber as an electrochemical electrode and light sensing probe.The results exhibit correlation between redox processes of copper species and plasmonic resonances.Furthermore,in situ fiber-optic detection reveals the photocorrosion dynamics under photoelectrochemical reaction,including photoelectron-induced self-reduction of copper oxide and self-oxidation of cuprous oxide.These demonstrations facilitate not only the diagnosis for the health condition of photocathode nanomaterial,but also the understanding of the underlying reaction mechanism,and thus are potentially crucial for advancing the development of highly efficient photocathodes in future energy applications.展开更多
The internal electric field(IEF)is key in speeding up the separation and transfer of photogenerated carriers,which boosts the production of reactive oxygen species(ROS).In this study,we present a novel silver iodide/N...The internal electric field(IEF)is key in speeding up the separation and transfer of photogenerated carriers,which boosts the production of reactive oxygen species(ROS).In this study,we present a novel silver iodide/N-rich carbon nitride(AgI/C_(3)N_(5))heterojunction catalyst with an IEF directed from AgI to C_(3)N_(5).We confirmed this IEF using density functional theory(DFT)calculations and various characterization methods.This IEF induces and reinforces the Type II transfer pathway for carrier separation and transfer,significantly increasing the production of ROS,particularly singlet oxygen(1O_(2)).As a result,the AgI/C_(3)N_(5)catalysts achieve 10.1 times the disinfection efficiency of C_(3)N_(5)and 5.6 times that of AgI,under one-min reaction time,107 CFU/mL of E.coli,visible light,and room temperature.It also outperforms most other AgI and carbon nitride-based heterojunction photocatalysts.Notably,the photogenerated holes(h+)selectively oxidize superoxide radicals(·O_(2)^(-))to 1O_(2)due to favorable energy alignment,minimizing O_(2)reduction effects and enhancing photocorrosion resistance,as demonstrated in five consecutive cycling experiments.In addition,the actual water disinfection tests confirmed its practical application potential.This work highlights the AgI/C_(3)N_(5)heterojunction catalyst’s promise as an efficient disinfection agent and sheds light on the photocatalytic disinfection mechanism.展开更多
Superior photo-mineralization of pollutants,outstanding charge separation efficiency and exceptional photostability of catalysts constitute three pivotal factors for the effective photodegradation of organic pollutant...Superior photo-mineralization of pollutants,outstanding charge separation efficiency and exceptional photostability of catalysts constitute three pivotal factors for the effective photodegradation of organic pollutants.In this study,a dual S-scheme In2 O3/Pedot/In2 S3(IO/Pedot/IS),inspired by natural photosyn-thesis,was successfully synthesized for the degradation of lignin and antibiotics.The resulting exceptional semiconductor contact creates a dual-interface electric field on Pedot,facilitating multi-channel charge transport and enhancing charge separation efficiency.The establishment of the dual S-scheme hetero-junction raised the reduction-oxidation potential of the type-II In2 O3/In2 S3.When subjected to 5 W LED irradiation for 60 min,IO/Pedot-2/IS demonstrated a remarkable mineralization rate of 85.8%for sodium lignosulfonate(SL),surpassing the 53.7%mineralization rate achieved by IO/IS.Furthermore,the degra-dation efficiency for tetracycline(TC)and ciprofloxacin(CIP)reached 91%and 88%,respectively.Crucially,the hole(h+)conductivity of Pedot efficiently alleviated the photocorrosion of sulfide,ensuring robust cyclic stability.Experimental simulations of natural photocatalysis showcased the exceptional versatility and applicability of IO/Pedot/IS.In-depth analysis led to the proposal of a potential photodegradation pathway for lignin,based on the intermediates detected through liquid chromatography-mass spectrom-etry(LC-MS).Overall,this study presents an effective strategy for the efficient photocatalytic treatment of organic pollutants.展开更多
Developing photocatalyst with high activity,superior stability and prominent selectivity for CO_(2)conversion is of great importance for the target of carbon neutralization.Herein,3 D dahlia-like NiAl-LDH/CdS heterosy...Developing photocatalyst with high activity,superior stability and prominent selectivity for CO_(2)conversion is of great importance for the target of carbon neutralization.Herein,3 D dahlia-like NiAl-LDH/CdS heterosystem is developed through in-situ decoration of exfoliated CdS nanosheets on the scaffold of NiAl-LDH and the on-spot self-assembly.The formation of a hierarchical architecture collaborating with well-defined 2 D/2 D interfacial interaction is constructed by optimizing the ratio of CdS integrated in the formation of the heterojunction.The light-harvesting capacity of NiAl-LDH/CdS is improved by this unique scaffold,and the charge transfer between NiAl-LDH and CdS is effectively facilitated by virtue of the unique 2 D/2 D interface.As a result,the 3 D hierarchical NiAl-LDH/CdS heterosystem presents 12.45μmol g^(-1)h^(-1)of CO production(3.3 and 1.6 folds of pristine NiAl-LDH and CdS) with 96% selectivity and superior stability.This 3 D hierarchical design collaborating with 2 D/2 D interfacial interaction provides a new avenue to develop ideal catalysts for artificial photosynthesis.展开更多
CdS quantum dots(QDs)have been extensively studied as photocatalysts and sensitizers for visible-light-driven water reduction.However,their efficiencies are limited by the need to accumulate sufficient redox equivalen...CdS quantum dots(QDs)have been extensively studied as photocatalysts and sensitizers for visible-light-driven water reduction.However,their efficiencies are limited by the need to accumulate sufficient redox equivalents to produce_(H2)and consequent photocorrosion associated with slow hole-transfer rates.To address these limitations,we report the formation of CdS QD assemblies(aerogels,AGs)capable of facilitating energy/charge transport between individual QDs,and evaluate their performance as photocatalysts for hydrogen evolution as a function of structure,wurtzite(w-)vs.zincblende(zb-),and different annealing temperatures.The formation of AGs from QDs resulted in increased rates of_(H2)production under visible light illumination:from 1458(QD)to 6650(AG)μmol_(H2)·h^(-1)·g^(-1)on zbCdS and from 1221(QD)to 3325(AG)μmol_(H2)·h^(-1)·g^(-1)on wCdS.This is attributed to exciton delocalization between adjacent QDs facilitating charge/energy transport.Thermal processing of CdS AGs up to 250℃ improved their activity,increasing the degree of exciton delocalization,while annealing them to 300℃ caused sintering of the primary QD particles within the AGs and a decrease in activity associated with loss in surface area.The best photocatalyst,zbCdS AG annealed at 250℃,had an average_(H2)production rate of 13,604±2017μmol_(H2)·h^(-1)·g^(-1),an apparent quantum yield of 2.8%at 425±12.5 nm,and was stable for 2 h before beginning to deactivate due to photocorrosion.This study confirms the potential of CdS AGs as matrixes for the design of more active and stable composite photocatalysts for water splitting.展开更多
Hydrogen evolution via photo-electro-chemical(PEC)co-catalysis is potential for solving energy crisis and environmental issues.The rapidly advances of fabrication and broad applications of polydopamine(PDA)and its der...Hydrogen evolution via photo-electro-chemical(PEC)co-catalysis is potential for solving energy crisis and environmental issues.The rapidly advances of fabrication and broad applications of polydopamine(PDA)and its derivatives have drawn intense attentions in recent years.Herein,an ultrathin PDA coating with nanometer accuracy was conformally grown on TiO_(2) nanotube arrays(NTAs)via electrochemical polymerization,in which the polymer provided a platform for further photoinduced assembly of CdS nanocrystals in the embedded mode.The optimized CdS@PDA/TiO_(2) NTAs hierarchical heterostructure as photoanode gave an excellent PEC performance and exhibited outstanding stability under light irradiation.The photocurrent density was heightened to 5.48 mA·cm^(–2),which was beneficial to H_(2) evolution with a rate of 20μmol·h^(–1)·cm^(–2).The improvement of PEC activity was ascribed to co-photosensitization,optimized carriers transfer,and transport route arised from CdS embedding,resulting to provide a persistent driving force for charge separation based on secure heterojunction of CdS/TiO_(2) glued by PDA.The improvement of PEC stability was due to the inhibition of CdS photocorrosion covered by PDA shelter.This advance boded well for the development of PEC field founded on multifunctional PDA.展开更多
Photoelectrochemical(PEC)water splitting can directly convert solar energy into hydrogen energy for storage,effectively ending the energy crisis and solving environmental problems.With their modification by many resea...Photoelectrochemical(PEC)water splitting can directly convert solar energy into hydrogen energy for storage,effectively ending the energy crisis and solving environmental problems.With their modification by many researchers,photoanodes have rapidly improved in PEC performance.Nevertheless,the poor stability of PEC water-splitting devices has not been effectively corrected,seriously hindering their practical application and large-scale commercialization.In this review,we provide a detailed introduction to the photocorrosion mechanism of photoanodes and characterizations of stability,summarizing the current research progress on the stability of metal oxide/sulfide photoanode materials.According to the specificity of each semiconductor,the corrosion mechanism and modification strategy of each photoanode are discussed in detail.Finally,we summarize the deficiencies in the current stability research and propose influencing factors and possible solutions that need to be considered in the photocorrosion research field of photoanodes.This review can provide a reference for the stability research of photoanodes based on metal oxides and sulfides,especially for the design of efficient and stable metal sulfide-based photoanodes.展开更多
Photoelectrochemical(PEC)hydrogen production is of great interest as an ideal avenue towards clean and renewable energy.However,the instability and low energy conversion efficiency of photoanodes hinder their practica...Photoelectrochemical(PEC)hydrogen production is of great interest as an ideal avenue towards clean and renewable energy.However,the instability and low energy conversion efficiency of photoanodes hinder their practical applications.Here we address these issues by introducing a hole extraction layer(HEL)which could rapidly transfer and consume photogenerated holes.The HEL is constructed by reduced graphene oxide(RGO)and other cocatalysts that enable rapid transfer and subsequent consumption of holes,respectively.Specifically,we showcase a high-stability photoanode composed of CdSeTe nanowires(CST NWs)and RGO/PdS nanoparticles(PdS NPs)based HEL.The photoanode achieves excellent photocorrosion resistance,which allows stable hydrogen evolution for>2 h at 0.5 VRHE.展开更多
A homogeneous layer of Bi_2O_3-Bi_(14)WO_(24) composite(BWO/Bi_2O_3) thin film was fabricated using a combination of electrodeposition and thermal treatment. The evenly distributed Bi14 WO24 component within the Bi_2O...A homogeneous layer of Bi_2O_3-Bi_(14)WO_(24) composite(BWO/Bi_2O_3) thin film was fabricated using a combination of electrodeposition and thermal treatment. The evenly distributed Bi14 WO24 component within the Bi_2O_3 layer was found to be important in stabilising the photoelectrochemical performances of Bi_2O_3 photoanode by promoting the photoelectron transport. The unmodified Bi_2O_3 suffered from severe photocorrosion as proven by X-ray diffraction(XRD) and inductively coupled plasma(ICP) analyses while the composite thin film was active without noticeable activity decay for at least 3 h of illumination. This strategy might be applicable to other photocatalysts with stability issues.展开更多
A new polymeric nanocomposite photocatalyst A15-CdS with large spherical beads (0.70-0.80 mm in diameter) was fabricated for efficient Rhodamine B (RhB) photodegradation with facile separation during cyclic runs,and p...A new polymeric nanocomposite photocatalyst A15-CdS with large spherical beads (0.70-0.80 mm in diameter) was fabricated for efficient Rhodamine B (RhB) photodegradation with facile separation during cyclic runs,and photocorrosion,a congenital drawback of CdS,was successfully inhibited for A15-CdS.The nanocomposite catalyst was obtained by impregnating CdS nanoparticles within porous polymeric cation exchanger A15 through a facile inner-surface deposition.CdS nanoparticles (<20 nm) immobilized in A15 were deliberately distributed within an outside ring-like region of 40-50 m in depth,which is dominant for photoreaction because visible light is not expected to permeate through the inner region of nontransparent A15.As expected,efficient RhB photodegradation by A15-CdS was achieved under visible light irradiation,and large-size A15-CdS beads are expected to result in their facile separation from solution for repeated use.More significantly,negligible photocorrosion for the hybrid catalyst A15-CdS was demonstrated by the constant photodegradation efficiency and negligible CdS loss during five-cycle runs.The results indicated that nano-CdS immobilization within A15 would greatly improve the applicability of CdS nanoparticles in practical environmental remediation.展开更多
基金the National Natural Science Foundation of China(Nos.22075220 and 51872221)the 111 Project(No.B18038)。
文摘CdS photocorrosion is one of the most important factors that greatly affect the photocatalytic H_(2)-production rate and long-time stability.However,the reported works about CdS photocorrosion are mainly focused on the surface oxidation by photogenerated holes,while the possible reduction of lattice Cd^(2+) by photogenerated electrons is usually ignored.In this work,the lattice Cd^(2+) reduction by photogenerated electrons during CdS photocorrosion were carefully investigated to reveal its potential effect on the microstructure change and photocatalytic H_(2)-production performance of CdS photocatalyst based on the two typical Na_(2)S-Na_(2)SO_(3) and lactic acid H_(2)-evolution systems.It was found that many isolated metallic Cd nanoparticles(5–50 nm)were produced on the CdS surface in the Na_(2)S-Na_(2)SO_(3) system,causing its serious destroy of CdS surface and a gradually decreased photocatalytic activity,while only a metallic Cd layer(2-3 nm)is homogeneously coated on the CdS surface in the lactic acid system,leading to an increased H-evolution rate.In fact,once a certain amount of metallic Cd was produced on the CdS surface,the resulting CdS-Cd composites can present a stable photocatalytic H_(2)-production activity and excellent stability for the final CdS-Cd photocatalysts.Hence,a photoinduced self-stability mechanism of CdS photocatalyst has been proposed,namely,the spontaneously produced metallic Cd contributes to the transformation of unstable CdS into stable CdS-Cd structure,with the simultaneous realization of final stable H_(2)-evolution performance.
基金supported by the National Natural Science Foundation of China(22162008,22162007)the Science and Technology Supporting Project of Guizhou Province([2022]208,[2021]480)the Basic Research Program of Science&Technology Department of Guizhou Province([2020]1Y055)。
文摘Interface engineering can improve the charge separation efficiency and inhibit photocorrosion is an emerging direction of developing more efficient and cost-effective photocatalytic systems.Herein,we report the sulfur-confined intimate Cd S intergrown Cd(Cd S/Cd)Ohmic junction(peanut-chocolate-ball like)for high-efficient H2production with superior anti-photocorrosion ability,which was fabricated from in-situ photoreduction of CdS intergrown Cd2SO4(OH)2(CdS/Cd2SO4(OH)2)prepared through a facile space-controlled-solvothermal method.The ratios of CdS/Cd can be effectively controlled by tunning that of CdS/Cd2SO4(OH)2which were prepared by adjusting the volume of reaction liquid and the remaining space of the reactor.Experiments investigations and density functional theory(DFT)calculations reveal that the Cd S intergrown Cd Ohmic junction interfaces(with appropriate content Cd intergrown on Cd S(19.54 wt%))are beneficial in facilitating the transfer of photogenerated electrons by constructing an interfacial electric field and forming sulfur-confined structures for preventing the positive holes(h+)oxidize the Cd S.This contributes to a high photocatalytic H2production activity of 95.40μmol h-1(about 32.3 times higher than bare Cd S)and possesses outstanding photocatalytic stability over 205 h,much longer than most Cd S-based photocatalysts previously reported.The interface engineering design inspired by the structure of peanut-chocolate-ball can greatly promote the future development of catalytic systems for wider application.
基金National Natural Science Foundation of China(62175090)Basic and Applied Basic Research Foundation of Guangdong Province(2024A1515011846)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2019BT02X105)。
文摘Semiconductor metal oxides with narrow bandgap have emerged as a promising platform for photoelectrochemical reactions,yet their photoelectron-induced photocorrosion effect has been a limitation for their wider applications.Understanding the conversion processes concomitant with photoelectrochemical reaction at the electrode-electrolyte interface plays a crucial role in revealing the corrosion mechanisms and advancing the development of efficient photocathodes.However,accurately and in situ tracking these dynamic chemical events remains a great challenge due to the fact that reaction processes occur at nanoscale interfaces.Here,we track the electrochemical growth and conversion of copper nanostructures at interface by the evanescent field of the surface plasmon wave by using a gold-coated optical fiber as an electrochemical electrode and light sensing probe.The results exhibit correlation between redox processes of copper species and plasmonic resonances.Furthermore,in situ fiber-optic detection reveals the photocorrosion dynamics under photoelectrochemical reaction,including photoelectron-induced self-reduction of copper oxide and self-oxidation of cuprous oxide.These demonstrations facilitate not only the diagnosis for the health condition of photocathode nanomaterial,but also the understanding of the underlying reaction mechanism,and thus are potentially crucial for advancing the development of highly efficient photocathodes in future energy applications.
基金supported by National Natural Science Foundation of China(Grant No.52300218 and 22476066)Yunnan Fundamental Research Projects(Grant No.202401CF070197).
文摘The internal electric field(IEF)is key in speeding up the separation and transfer of photogenerated carriers,which boosts the production of reactive oxygen species(ROS).In this study,we present a novel silver iodide/N-rich carbon nitride(AgI/C_(3)N_(5))heterojunction catalyst with an IEF directed from AgI to C_(3)N_(5).We confirmed this IEF using density functional theory(DFT)calculations and various characterization methods.This IEF induces and reinforces the Type II transfer pathway for carrier separation and transfer,significantly increasing the production of ROS,particularly singlet oxygen(1O_(2)).As a result,the AgI/C_(3)N_(5)catalysts achieve 10.1 times the disinfection efficiency of C_(3)N_(5)and 5.6 times that of AgI,under one-min reaction time,107 CFU/mL of E.coli,visible light,and room temperature.It also outperforms most other AgI and carbon nitride-based heterojunction photocatalysts.Notably,the photogenerated holes(h+)selectively oxidize superoxide radicals(·O_(2)^(-))to 1O_(2)due to favorable energy alignment,minimizing O_(2)reduction effects and enhancing photocorrosion resistance,as demonstrated in five consecutive cycling experiments.In addition,the actual water disinfection tests confirmed its practical application potential.This work highlights the AgI/C_(3)N_(5)heterojunction catalyst’s promise as an efficient disinfection agent and sheds light on the photocatalytic disinfection mechanism.
基金funded by the National Natural Science Foun-dation of China(Nos.U21A20309 and 21978106)the Fundamental Research Funds for the Central Universities(No.2022ZYGXZR108).
文摘Superior photo-mineralization of pollutants,outstanding charge separation efficiency and exceptional photostability of catalysts constitute three pivotal factors for the effective photodegradation of organic pollutants.In this study,a dual S-scheme In2 O3/Pedot/In2 S3(IO/Pedot/IS),inspired by natural photosyn-thesis,was successfully synthesized for the degradation of lignin and antibiotics.The resulting exceptional semiconductor contact creates a dual-interface electric field on Pedot,facilitating multi-channel charge transport and enhancing charge separation efficiency.The establishment of the dual S-scheme hetero-junction raised the reduction-oxidation potential of the type-II In2 O3/In2 S3.When subjected to 5 W LED irradiation for 60 min,IO/Pedot-2/IS demonstrated a remarkable mineralization rate of 85.8%for sodium lignosulfonate(SL),surpassing the 53.7%mineralization rate achieved by IO/IS.Furthermore,the degra-dation efficiency for tetracycline(TC)and ciprofloxacin(CIP)reached 91%and 88%,respectively.Crucially,the hole(h+)conductivity of Pedot efficiently alleviated the photocorrosion of sulfide,ensuring robust cyclic stability.Experimental simulations of natural photocatalysis showcased the exceptional versatility and applicability of IO/Pedot/IS.In-depth analysis led to the proposal of a potential photodegradation pathway for lignin,based on the intermediates detected through liquid chromatography-mass spectrom-etry(LC-MS).Overall,this study presents an effective strategy for the efficient photocatalytic treatment of organic pollutants.
基金National Natural Science Foundation of China for Excellent Young Scholars (No. 51922050)the National Natural Science Foundation of China (No. 51303083)+1 种基金the Natural Science Foundation of Jiangsu Province (No. BK20191293)the Fundamental Research Funds for the Central Universities (No.30920021123) for financial support。
文摘Developing photocatalyst with high activity,superior stability and prominent selectivity for CO_(2)conversion is of great importance for the target of carbon neutralization.Herein,3 D dahlia-like NiAl-LDH/CdS heterosystem is developed through in-situ decoration of exfoliated CdS nanosheets on the scaffold of NiAl-LDH and the on-spot self-assembly.The formation of a hierarchical architecture collaborating with well-defined 2 D/2 D interfacial interaction is constructed by optimizing the ratio of CdS integrated in the formation of the heterojunction.The light-harvesting capacity of NiAl-LDH/CdS is improved by this unique scaffold,and the charge transfer between NiAl-LDH and CdS is effectively facilitated by virtue of the unique 2 D/2 D interface.As a result,the 3 D hierarchical NiAl-LDH/CdS heterosystem presents 12.45μmol g^(-1)h^(-1)of CO production(3.3 and 1.6 folds of pristine NiAl-LDH and CdS) with 96% selectivity and superior stability.This 3 D hierarchical design collaborating with 2 D/2 D interfacial interaction provides a new avenue to develop ideal catalysts for artificial photosynthesis.
基金supported by NSF Award No.1427926,and the Talos F200X G2 S/TEM that is funded in part through NSF MRI Award No.2018587supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Award Number SC0023324.
文摘CdS quantum dots(QDs)have been extensively studied as photocatalysts and sensitizers for visible-light-driven water reduction.However,their efficiencies are limited by the need to accumulate sufficient redox equivalents to produce_(H2)and consequent photocorrosion associated with slow hole-transfer rates.To address these limitations,we report the formation of CdS QD assemblies(aerogels,AGs)capable of facilitating energy/charge transport between individual QDs,and evaluate their performance as photocatalysts for hydrogen evolution as a function of structure,wurtzite(w-)vs.zincblende(zb-),and different annealing temperatures.The formation of AGs from QDs resulted in increased rates of_(H2)production under visible light illumination:from 1458(QD)to 6650(AG)μmol_(H2)·h^(-1)·g^(-1)on zbCdS and from 1221(QD)to 3325(AG)μmol_(H2)·h^(-1)·g^(-1)on wCdS.This is attributed to exciton delocalization between adjacent QDs facilitating charge/energy transport.Thermal processing of CdS AGs up to 250℃ improved their activity,increasing the degree of exciton delocalization,while annealing them to 300℃ caused sintering of the primary QD particles within the AGs and a decrease in activity associated with loss in surface area.The best photocatalyst,zbCdS AG annealed at 250℃,had an average_(H2)production rate of 13,604±2017μmol_(H2)·h^(-1)·g^(-1),an apparent quantum yield of 2.8%at 425±12.5 nm,and was stable for 2 h before beginning to deactivate due to photocorrosion.This study confirms the potential of CdS AGs as matrixes for the design of more active and stable composite photocatalysts for water splitting.
基金supported by the National Natural Science Foundation of China(U1908227,52072041,and 51962023)the Beijing Natural Science Foundation(No.JQ21007)the University of Chinese Academy of Sciences(No.Y8540XX2D2).
文摘Hydrogen evolution via photo-electro-chemical(PEC)co-catalysis is potential for solving energy crisis and environmental issues.The rapidly advances of fabrication and broad applications of polydopamine(PDA)and its derivatives have drawn intense attentions in recent years.Herein,an ultrathin PDA coating with nanometer accuracy was conformally grown on TiO_(2) nanotube arrays(NTAs)via electrochemical polymerization,in which the polymer provided a platform for further photoinduced assembly of CdS nanocrystals in the embedded mode.The optimized CdS@PDA/TiO_(2) NTAs hierarchical heterostructure as photoanode gave an excellent PEC performance and exhibited outstanding stability under light irradiation.The photocurrent density was heightened to 5.48 mA·cm^(–2),which was beneficial to H_(2) evolution with a rate of 20μmol·h^(–1)·cm^(–2).The improvement of PEC activity was ascribed to co-photosensitization,optimized carriers transfer,and transport route arised from CdS embedding,resulting to provide a persistent driving force for charge separation based on secure heterojunction of CdS/TiO_(2) glued by PDA.The improvement of PEC stability was due to the inhibition of CdS photocorrosion covered by PDA shelter.This advance boded well for the development of PEC field founded on multifunctional PDA.
基金We acknowledge the support from the National Key Research and Development Program of China(No.2021YFA1500800)the National Natural Science Foundation of China(No.52025028),and the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Photoelectrochemical(PEC)water splitting can directly convert solar energy into hydrogen energy for storage,effectively ending the energy crisis and solving environmental problems.With their modification by many researchers,photoanodes have rapidly improved in PEC performance.Nevertheless,the poor stability of PEC water-splitting devices has not been effectively corrected,seriously hindering their practical application and large-scale commercialization.In this review,we provide a detailed introduction to the photocorrosion mechanism of photoanodes and characterizations of stability,summarizing the current research progress on the stability of metal oxide/sulfide photoanode materials.According to the specificity of each semiconductor,the corrosion mechanism and modification strategy of each photoanode are discussed in detail.Finally,we summarize the deficiencies in the current stability research and propose influencing factors and possible solutions that need to be considered in the photocorrosion research field of photoanodes.This review can provide a reference for the stability research of photoanodes based on metal oxides and sulfides,especially for the design of efficient and stable metal sulfide-based photoanodes.
基金This work was supported by the National Natural Science Foundation of China(51732011,21431006,21761132008,81788101 and 11227901)the Foundation for the Innovative Research Groups of the National Natural Science Foundation of China(21521001)+2 种基金the Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-SLH036)the National Basic Research Program of China(2014CB931800)the Users with Excellence and Scientific Research Grant of Hefei Science Center of CAS(2015HSC-UE007).This work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘Photoelectrochemical(PEC)hydrogen production is of great interest as an ideal avenue towards clean and renewable energy.However,the instability and low energy conversion efficiency of photoanodes hinder their practical applications.Here we address these issues by introducing a hole extraction layer(HEL)which could rapidly transfer and consume photogenerated holes.The HEL is constructed by reduced graphene oxide(RGO)and other cocatalysts that enable rapid transfer and subsequent consumption of holes,respectively.Specifically,we showcase a high-stability photoanode composed of CdSeTe nanowires(CST NWs)and RGO/PdS nanoparticles(PdS NPs)based HEL.The photoanode achieves excellent photocorrosion resistance,which allows stable hydrogen evolution for>2 h at 0.5 VRHE.
基金supported by the Australian Research Council under the Laureate Fellowship Scheme(FL140100081)
文摘A homogeneous layer of Bi_2O_3-Bi_(14)WO_(24) composite(BWO/Bi_2O_3) thin film was fabricated using a combination of electrodeposition and thermal treatment. The evenly distributed Bi14 WO24 component within the Bi_2O_3 layer was found to be important in stabilising the photoelectrochemical performances of Bi_2O_3 photoanode by promoting the photoelectron transport. The unmodified Bi_2O_3 suffered from severe photocorrosion as proven by X-ray diffraction(XRD) and inductively coupled plasma(ICP) analyses while the composite thin film was active without noticeable activity decay for at least 3 h of illumination. This strategy might be applicable to other photocatalysts with stability issues.
基金support from the National Natural Science Foundation of China (51008151 & 51078179)Jiangsu Natural Science Foundation (BK2009253)+1 种基金the Ministry of Education of China (200802840034)the National High Technology Research and Development Program of China (2009AA06A418)
文摘A new polymeric nanocomposite photocatalyst A15-CdS with large spherical beads (0.70-0.80 mm in diameter) was fabricated for efficient Rhodamine B (RhB) photodegradation with facile separation during cyclic runs,and photocorrosion,a congenital drawback of CdS,was successfully inhibited for A15-CdS.The nanocomposite catalyst was obtained by impregnating CdS nanoparticles within porous polymeric cation exchanger A15 through a facile inner-surface deposition.CdS nanoparticles (<20 nm) immobilized in A15 were deliberately distributed within an outside ring-like region of 40-50 m in depth,which is dominant for photoreaction because visible light is not expected to permeate through the inner region of nontransparent A15.As expected,efficient RhB photodegradation by A15-CdS was achieved under visible light irradiation,and large-size A15-CdS beads are expected to result in their facile separation from solution for repeated use.More significantly,negligible photocorrosion for the hybrid catalyst A15-CdS was demonstrated by the constant photodegradation efficiency and negligible CdS loss during five-cycle runs.The results indicated that nano-CdS immobilization within A15 would greatly improve the applicability of CdS nanoparticles in practical environmental remediation.
