Using Donnan Steric Partitioning Model(DSPM),the data for the rejection of four salts having common co-ion(LiCl, NaCl,KCl,Na2SO4)were obtained and they show the characters of the polyethersulfone(PES)nanofiltration(NF...Using Donnan Steric Partitioning Model(DSPM),the data for the rejection of four salts having common co-ion(LiCl, NaCl,KCl,Na2SO4)were obtained and they show the characters of the polyethersulfone(PES)nanofiltration(NF)membrane in terms of three parameters:an effective pore radius(rp),the ratio of effective thickness over porosity(λ/Ak)and an effective charge density(X).Good agreement between experimental data and prediction data using the three parameters mentioned above was obtained.A theoretical model was developed to predict the transport performance of electrolyte through the hollow fiber composite NF membrane.The model prediction is in good agreement with experimental results based on the method by modern numerical solution.展开更多
Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical performance.Recently,considerable efforts have been devoted to t...Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical performance.Recently,considerable efforts have been devoted to this endeavor.This review systematically summarizes the impact of built-in electric fields on enhancing charge separation and transfer mechanisms,focusing on the modulation of built-in electric fields in terms of depth and orderliness.First,mechanisms and tuning strategies for built-in electric fields are explored.Then,the state-of-the-art works regarding built-in electric fields for modulating charge separation and transfer are summarized and categorized according to surface and interface depth.Finally,current strategies for constructing bulk built-in electric fields in photoelectrodes are explored,and insights into future developments for enhancing charge separation and transfer in high-performance photoelectrochemical applications are provided.展开更多
Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze in...Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze interaction between fluidic dynamics,electric field and ion transport.The model combines Butler-Volmer equation modified by electroactive site concentration,Nernst-Planck equation and Navier-Stokes equation.It is found that the chamber width affects solution phase resistance,thereby altering the pote ntial distribution and influencing the current distribution within the membrane.A narrow chamber increases current density in the solid phase of the membrane,enhancing Li^(+) extraction.The solution flow-field not only enhances convective transport but also increases the current density in the solid phase,promoting Li^(+) extraction.There is a synergistic effect between fluid-flow-field and electric-field for ion separation,which is only significant when the chamber width is greater than 2 mm.The synergistic mechanism differs from that in the capacitive deionization system.Therefore,the performance decline caused by a wide chamber can be compensated for by increasing the fluid-flow rate,utilizing the synergistic effect between the flu id-flow-field and electric-field to optimize the lithium extraction efficiency in the ESIX system.展开更多
The development of novel single-atom catalysts with optimal electron configuration and economical noble-metal cocatalyst for efficient photocatalytic hydrogen production is of great importance,but still challenging.He...The development of novel single-atom catalysts with optimal electron configuration and economical noble-metal cocatalyst for efficient photocatalytic hydrogen production is of great importance,but still challenging.Herein,we fabricate Pt and Co single-atom sites successively on polymeric carbon nitride(CN).In this Pt_(1)-Co_(1)/CN bimetallic single-atom catalyst,the noble-metal active sites are maximized,and the single-atomic Co_(1)N_4sites are tuned to Co_(1)N_3sites by photogenerated electrons arising from the introduced single-atomic Pt_(1)N_4sites.Mechanism studies and density functional theory(DFT)calculations reveal that the 3d orbitals of Co_(1)N_3single sites are filled with unpaired d-electrons,which lead to the improved visible-light response,carrier separation and charge migration for CN photocatalysts.Thereafter,the protons adsorption and activation are promoted.Taking this advantage of long-range electron synergy in bimetallic single atomic sites,the photocatalytic hydrogen evolution activity over Pt_(1)-Co_(1)/CN achieves 915.8 mmol g^(-1)Pt h^(-1),which is 19.8 times higher than Co_(1)/CN and 3.5 times higher to Pt_(1)/CN.While this electron-synergistic effect is not so efficient for Pt nanoclusters.These results demonstrate the synergistic effect at electron-level and provide electron-level guidance for the design of efficient photocatalysts.展开更多
Constructing a S-scheme heterojunction with tight interface contact and fast charge transfer is beneficial to improving the photocatalytic hydrogen evolution performance.Herein,a unique one-dimensional(1D)/two-dimensi...Constructing a S-scheme heterojunction with tight interface contact and fast charge transfer is beneficial to improving the photocatalytic hydrogen evolution performance.Herein,a unique one-dimensional(1D)/two-dimensional(2D)S-scheme heterojunction containing 1D Sb_(2)S_(3) nanorods and 2D ZnIn_(2)S_(4) with affluent sulfur vacancies(denoted as Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3)) was designed.The introduced sulfur vacancy can promote the effective adsorption of H+for the following interfacial hydrogen-evolution reaction.Furthermore,the larger contact area and stronger electron interaction between Sb_(2)S_(3) and ZnIn_(2)S_(4) effectively inhibits the recombination of photo-generated electron–hole pairs and abridges the migration distance of charges.As a result,the optimal Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3) sample achieves H_(2) evolution activity of 2741.3 mol·h^(−1)·g^(−1),which is 8.6 times that of pristine ZnIn_(2)S_(4) and 3.0 times that of the Sv-ZnIn_(2)S_(4) samples.Based on the experimental result,the photo-reactivity S-scheme mechanism of hydrogen evolution from water splitting with Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3) is proposed.This work provides an effective method for developing S-scheme heterojunction composites of transition metal sulfide with high hydrogen evolution performance.展开更多
Developing heterojunction photocatalyst with well-matched interfaces andmultiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal,but still remains a great c...Developing heterojunction photocatalyst with well-matched interfaces andmultiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal,but still remains a great challenge.In present work,a new strategy of chloride anion intercalation in Bi_(2)O_(3)via one-pot hydrothermal process is proposed.The as-prepared Ta-BiOCl/Bi_(24)O_(31)Cl_(10)(TBB)heterojunctions are featured with Ta-Bi_(24)O_(31)Cl_(10)and Ta-BiOCl lined shoulder-by-shouleder via semi-coherent interfaces.In this TBB heterojunctions,the well-matched semi-coherent interfaces and shoulder-by-shoulder structures provide fast electron transfer andmultiple transfer paths,respectively,leading to enhanced visible light response and improved photogenerated charge separation.Meanwhile,a type-II heterojunction for photocharge separation has been obtained,in which photogenerated electrons are drove from the CB(conduction band)of Ta-Bi_(24)O_(31)Cl_(10)to the both of bilateral empty CB of Ta-BiOCl and gathered on the CB of Ta-BiOCl,while the photogenerated holes are left on the VB(valence band)of Ta-Bi_(24)O_(31)Cl_(10),effectively hindering the recombination of photogenerated electron-hole pairs.Furthermore,the separated electrons can effectively activate dissolved oxygen for the generation of reactive oxygen species(·O_(2)^(−)).Such TBB heterojunctions exhibit remarkably superior photocatalytic degradation activity for tetracycline hydrochloride(TCH)solution to Bi_(2)O_(3),Ta-BiOCl and Ta-Bi_(24)O_(31)Cl_(10).This work not only proposes a Ta-BiOCl/Bi_(24)O_(31)Cl_(10)shoulder-by-shoulder micro-ribbon architectures with semi-coherent interfaces and successive type-Ⅱheterojunction for highly efficient photocatalytic activity,but offers a new insight into the design of highly efficient heterojunction through phasestructure synergistic transformation strategy.展开更多
Harnessing solar energy for renewable fuel production through artificial photosynthesis offers an ideal solution to the current energy and environmental crises.Among various methods,photoelectrochemical(PEC)water spli...Harnessing solar energy for renewable fuel production through artificial photosynthesis offers an ideal solution to the current energy and environmental crises.Among various methods,photoelectrochemical(PEC)water splitting stands out as a promising approach for direct solar-driven hydrogen production.Enhancing the efficiency and stability of photoelectrodes is a key focus in PEC water-splitting research.Tantalum nitride(Ta_(3)N_(5)),with its suitable band gap and band-edge positions for PEC water splitting,has emerged as a highly promising photoanode material.This review begins by introducing the history and fundamental characteristics of Ta_(3)N_(5),emphasizing both its advantages and challenges.It then explores methods to improve light absorption efficiency,charge separation and transfer efficiency,surface reaction rate,and the stability of Ta_(3)N_(5) photoanodes.Additionally,the review discusses the progress of research on tandem PEC cells incorporating Ta_(3)N_(5) photoanodes.Finally,it looks ahead to future research directions for Ta_(3)N_(5) photoanodes.The strategic approach outlined in this review can also be applied to other photoelectrode materials,providing guidance for their development.展开更多
Hydrogen,with the merits of zero emissions and high energy density,is one of the promising green energy sources.Seeking for high efficiency and low-cost catalysts is one of the key issues for hydrogen evolution and it...Hydrogen,with the merits of zero emissions and high energy density,is one of the promising green energy sources.Seeking for high efficiency and low-cost catalysts is one of the key issues for hydrogen evolution and its practical applications.Nano-structured metal cocatalysts are widely used to improve the photocatalytic performance via surface electronic structure/properties optimization of the catalyst.Herein,we report ultra-fine(*1 nm)Cu clusters decorated hydrangea-like TiO_(2)systems for photocatalytic hydrogen evolution.The pristine hydrangea-like TiO_(2)support shows a promising performance of hydrogen evolution(1.8 mmol·h^(-1)·g^(-1)),which is*10.7 times higher than that of the commercial P25(168 lmol·h^(-1)·g^(-1)).After ultra-fine Cu clusters decoration,a maximal hydrogen evolution performance(3.7 mmol·h^(-1)·g^(-1))is achieved in the optimized system 6Cu–TiO_(2)(6 wt%).Experimental and theoretical studies demonstrate that the ultra-fine Cu clusters decoration could promote the charge separation and transfer process effectively.The Cu clusters also act as reaction sites for reduction of H_(2)O to H2.These results are of great importance for the study of Cu-based co-catalyst systems and also shed light on the development of other non-noble metal co-catalysts in photocatalysis hydrogen evolution.展开更多
One of the most general methods to enhance the separation of photogenerated carriers for g‐C3N4is to construct a suitable heterojunctional composite,according to the principle of matching energy levels.The interface ...One of the most general methods to enhance the separation of photogenerated carriers for g‐C3N4is to construct a suitable heterojunctional composite,according to the principle of matching energy levels.The interface contact in the fabricated nanocomposite greatly influences the charge transfer and separation so as to determine the final photocatalytic activities.However,the role of interface contact is often neglected,and is rarely reported to date.Hence,it is possible to further enhance the photocatalytic activity of g‐C3N4‐based nanocomposite by improving the interfacial connection.Herein,phosphate-oxygen(P-O)bridged TiO2/g‐C3N4nanocomposites were successfully synthesized using a simple wet chemical method,and the effects of the P-O functional bridges on the photogenerated charge separation and photocatalytic activity for pollutant degradation and CO2reduction were investigated.The photocatalytic activity of g‐C3N4was greatly improved upon coupling with an appropriate amount of nanocrystalline TiO2,especially with P-O bridged TiO2.Atmosphere‐controlled steady‐state surface photovoltage spectroscopy and photoluminescence spectroscopy analyses revealed clearly the enhancement of photogenerated charge separation of g‐C3N4upon coupling with the P-O bridged TiO2,resulting from the built P-O bridges between TiO2and g‐C3N4so as to promote effective transfer of excited electrons from g‐C3N4to TiO2.This enhancement was responsible for the improved photoactivity of the P-O bridged TiO2/g‐C3N4nanocomposite,which exhibited three‐time photocatalytic activity enhancement for2,4‐dichlorophenol degradation and CO2reduction compared with bare g‐C3N4.Furthermore,radical‐trapping experiments revealed that the·OH species formed as hole‐modulated direct intermediates dominated the photocatalytic degradation of2,4‐dichlorophenol.This work provides a feasible strategy for the design and synthesis of high‐performance g‐C3N4‐based nanocomposite photocatalysts for pollutant degradation and CO2reduction.展开更多
Fabrication of 2D/2D heterojunction photocatalysts have attracted more attentions due to their inherent merits involving the large contact interface,short charge migration distance and plentiful active sites,which are...Fabrication of 2D/2D heterojunction photocatalysts have attracted more attentions due to their inherent merits involving the large contact interface,short charge migration distance and plentiful active sites,which are beneficial for the enhancement of photocatalytic activity.Herein,a series of 2D/2D MoS_(2)/Cd S type-I heterojunctions were prepared by incorporation the exfoliating of bulk CdS and MoS_(2) with postsintering procedure.Multiple characteristic techniques were employed to corroborate the formation of heterojunctions.By optimizing the 2D MoS_(2) amounts in the heterojunction,the 7 wt.%2D/2D MoS_(2)/CdS heterojunction displayed the maximal photocatalytic H2 evolution rate of 18.43 mmol h^(-1) g^(-1) under visible light irradiation in the presence of lactic acid as the sacrificial reagent,which was 6 times higher than that of pristine 2D CdS.Based on the photoelectrochemical and photoluminescence spectra tests,it could be deduced that the charge separation and transfer of 2D/2D MoS_(2)/CdS heterojunction was tremendously improved,and the recombination of photoinduced electron-hole pairs was effectively impeded.Moreover,the 2D MoS_(2) was used as a cocatalyst to provide the abundant active sites and lower the overpotential for H_(2) generation reaction.The current work would offer an insight to fabricate the 2D/2D heterojunction photocatalysts for splitting H_(2)O into H_(2).展开更多
Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental issues.Bismuth vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelect...Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental issues.Bismuth vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelectrochemical(PEC)water splitting.However,its PEC performance is severely hindered owing to poor surface charge transfer,surface recombination at the photoanode/electrolyte junction,and sluggish oxygen evolution reaction(OER)kinetics.In this regard,a novel solution was developed in this study to address these issues by decorating the surface of BiVO_(4)with cobalt sulfide,whose attractive features such as low cost,high conductivity,and rapid charge-transfer ability assisted in improving the PEC activity of the BiVO_(4)photoanode.The fabricated photoanode exhibited a significantly enhanced photocurrent density of 3.2 m A cm^(-2)under illumination at 1.23 V vs.a reversible hydrogen electrode,which is more than 2.5 times greater than that of pristine BiVO_(4).Moreover,the Co S/BiVO_(4)photoanode also exhibited considerable improvements in the charge injection yield(75.8%vs.36.7%for the bare BiVO_(4)film)and charge separation efficiency(79.8%vs.66.8%for the pristine BiVO_(4)film).These dramatic enhancements were primarily ascribed to rapid charge-transport kinetics and efficient reduction of the anodic overpotential for oxygen evolution enabled by the surface modification of BiVO_(4)by Co S.This study provides valuable suggestions for designing efficient photocatalysts via surface modification to improve the PEC performance.展开更多
Photocatalytic CO_(2)reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels.Numerous attempts have been made to pro...Photocatalytic CO_(2)reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels.Numerous attempts have been made to produce effective and efficient photocatalysts for CO_(2)reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO_(2)reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO_(2)reduction performance in order to achieve a long-term sustainability. Metalorganic frameworks(MOFs) are recently emerging as a new type of photocatalysts for CO_(2)reduction due to their excellent CO_(2)adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO_(2)reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO_(2)reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers,and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles(NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO_(2)reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO_(2)conversion.展开更多
The development of photocatalysts for hydrogen evolution is a promising alternative to industrial hydrogen evolution;however,generation of high active,recyclable,inexpensive heterojunctions are still challenging.Herei...The development of photocatalysts for hydrogen evolution is a promising alternative to industrial hydrogen evolution;however,generation of high active,recyclable,inexpensive heterojunctions are still challenging.Herein,a novel strategy was developed to synthesize non-noble metal co-catalyst/solid solution heterojunctions using metal-organic frameworks(MOFs)as a precursor template.By adjusting the content of MOFs,a series of Cu1.8S/ZnxCd1-xS heterojunctions were obtained,and the Cu1.8S(3.7%)/Zn0.35Cd0.65S sample exhibits a maximum hydrogen evolution rate of 14.27 mmol h^(-1) g^(-1) with an apparent quantum yield of 3.7%at 420 nm under visible-light irradiation.Subsequently,the relationship between the heterojunction and photocatalytic activity were investigated by detailed characterizations and density functional theory(DFT)calculations,which reveal that loading Cu1.8S can efficiently extend the light absorption,meanwhile,the electrons can efficiently transfer from Zn0.35Cd0.65S to Cu1.8S,thus resulting more photogenerated electrons participating in surface reactions.This result can be valuable inspirations for the exploitation of advanced materials using rationally designed nanostructures for solar energy conversion.展开更多
Phase separations have been studied for graded-indium content In_xGa_（1-x）N/GaN multiple quantum wells（MQWs） with different indium contents by means of photoluminescence（PL）,cathodeluminescence（CL） and time-re...Phase separations have been studied for graded-indium content In_xGa_（1-x）N/GaN multiple quantum wells（MQWs） with different indium contents by means of photoluminescence（PL）,cathodeluminescence（CL） and time-resolved PL（TRPL） techniques.Besides the main emission peaks,all samples show another 2 peaks at the high and low energy parts of the main peaks in PL when excited at 10 K.CL images show a clear contrast for 3 samples,which indicates an increasing phase separation with increasing indium content.TRPL spectra at 15 K of the main emissions show an increasing delay of rising time with indium content,which means a carrier transferring from low indium content structures to high indium content structures.展开更多
Oxygen evolution cocatalysts(OECs)play important roles in improving the efficiency of photocatalysts in solar water splitting.Inorganic–organic hybrid polymers(IOHPs),which have good electrolyte accessibility and eve...Oxygen evolution cocatalysts(OECs)play important roles in improving the efficiency of photocatalysts in solar water splitting.Inorganic–organic hybrid polymers(IOHPs),which have good electrolyte accessibility and evenly distributed active sites,are expected to be promising OECs.Here,a novel IOHP[Co(Bpn)_(2)(SCN)_(2)]n(1,Bpn=2,6-bis(4-pyridyl)-naphthalene,SCN=thiocyanate ion)exhibited a two-dimensional(2D)layer structure with(4,4)topology,was constructed by Bpn ligands connecting Co(II)ions,and was decorated on BiVO_(4) photoanodes for photoelectrochemical(PEC)water oxidation.The 1/BiVO_(4) hybrid electrode showed significantly negative onset potential and approximately 3.7 times higher photocurrent density at 1.23 V versus reversible hydrogen electrode(RHE)compared with the bare BiVO_(4).The mechanisms for the improved PEC efficiency were investigated and mainly ascribed to enhanced water oxidation kinetics and increased charge separation and transfer properties.This work provides a promising OEC candidate for PEC water oxidation and sheds light on the attractive application prospect of IOHPs for solar water splitting.展开更多
Single-atom catalysts(SACs)have garnered tremendous and continuous attention in photocatalytic CO_(2)reduction reactions(CO_(2)RR),due to their compelling potential in broadening the light-harvesting range,elevating t...Single-atom catalysts(SACs)have garnered tremendous and continuous attention in photocatalytic CO_(2)reduction reactions(CO_(2)RR),due to their compelling potential in broadening the light-harvesting range,elevating the charge separation/transfer efficiency,and enhancing surface reaction.Despite the surge in research and the expanding range of potential central metal candidates—including d-block,p-block,and rare metal elements,etc.—the comprehension of the structure-function relationships between the central metal and its performance remains elusive.Hence,categorized by different areas of the central metal element from periodic table,we outline the recent progress and challenges on SACs for photocatalytic CO_(2)RR.We begin by describing various synthetic strategies employed for SACs.Subsequently,a clear classification of the SACs applications in photocatalytic CO_(2)RR is provided,according to the central metal elements in different blocks of the periodic table.We also discussed how isolated metal single-atom sites from different blocks of the periodic table improve the performance of photocatalytic CO_(2)reduction from the perspective of charge separation and transfer.Finally,we end this review with some perspectives and challenges associated with SACs for photocatalytic CO_(2)reduction.Through this review,we aim to enrich the element diversity of SACs for photocatalytic CO_(2)RR,reveal trends in element evolution,and propose directions for future development in this flourishing field.展开更多
基金Project(20806094)supported by the National Natural Science Foundation of ChinaProject(2008SK1001)supported by Energy-saving and Emission-reducing Major Special Projects of Department of Science&Technology of Hunan Province,ChinaProjects(K0901082-11,K0902123-11)supported by Plan on Science and technology Bureau of Changsha,China
文摘Using Donnan Steric Partitioning Model(DSPM),the data for the rejection of four salts having common co-ion(LiCl, NaCl,KCl,Na2SO4)were obtained and they show the characters of the polyethersulfone(PES)nanofiltration(NF)membrane in terms of three parameters:an effective pore radius(rp),the ratio of effective thickness over porosity(λ/Ak)and an effective charge density(X).Good agreement between experimental data and prediction data using the three parameters mentioned above was obtained.A theoretical model was developed to predict the transport performance of electrolyte through the hollow fiber composite NF membrane.The model prediction is in good agreement with experimental results based on the method by modern numerical solution.
基金financially supported by the Industrial Technology Innovation Program of IMAST(No.2023JSYD 01003)the National Natural Science Foundation of China(Nos.52104292 and U2341209)。
文摘Constructing a built-in electric field has emerged as a key strategy for enhancing charge separation and transfer,thereby improving photoelectrochemical performance.Recently,considerable efforts have been devoted to this endeavor.This review systematically summarizes the impact of built-in electric fields on enhancing charge separation and transfer mechanisms,focusing on the modulation of built-in electric fields in terms of depth and orderliness.First,mechanisms and tuning strategies for built-in electric fields are explored.Then,the state-of-the-art works regarding built-in electric fields for modulating charge separation and transfer are summarized and categorized according to surface and interface depth.Finally,current strategies for constructing bulk built-in electric fields in photoelectrodes are explored,and insights into future developments for enhancing charge separation and transfer in high-performance photoelectrochemical applications are provided.
基金supported by the National Natural Science Foundation of China(22378285,92475117 and U21A20303)。
文摘Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze interaction between fluidic dynamics,electric field and ion transport.The model combines Butler-Volmer equation modified by electroactive site concentration,Nernst-Planck equation and Navier-Stokes equation.It is found that the chamber width affects solution phase resistance,thereby altering the pote ntial distribution and influencing the current distribution within the membrane.A narrow chamber increases current density in the solid phase of the membrane,enhancing Li^(+) extraction.The solution flow-field not only enhances convective transport but also increases the current density in the solid phase,promoting Li^(+) extraction.There is a synergistic effect between fluid-flow-field and electric-field for ion separation,which is only significant when the chamber width is greater than 2 mm.The synergistic mechanism differs from that in the capacitive deionization system.Therefore,the performance decline caused by a wide chamber can be compensated for by increasing the fluid-flow rate,utilizing the synergistic effect between the flu id-flow-field and electric-field to optimize the lithium extraction efficiency in the ESIX system.
基金the support of the National Natural Science Foundation of China (22002118,22208262,52271228,52202298,52201279,51834009,51801151)the Natural Science Foundation of Shaanxi Province (2021JQ-468,2020JZ-47)+2 种基金the Natural Science Foundation of Shaanxi Provincial Department of Education (21JP086)the Postdoctoral Research Foundation of China (2020 M683528,2020TQ0245,2018M633643XB)the Hundred Talent Program of Shaanxi Province。
文摘The development of novel single-atom catalysts with optimal electron configuration and economical noble-metal cocatalyst for efficient photocatalytic hydrogen production is of great importance,but still challenging.Herein,we fabricate Pt and Co single-atom sites successively on polymeric carbon nitride(CN).In this Pt_(1)-Co_(1)/CN bimetallic single-atom catalyst,the noble-metal active sites are maximized,and the single-atomic Co_(1)N_4sites are tuned to Co_(1)N_3sites by photogenerated electrons arising from the introduced single-atomic Pt_(1)N_4sites.Mechanism studies and density functional theory(DFT)calculations reveal that the 3d orbitals of Co_(1)N_3single sites are filled with unpaired d-electrons,which lead to the improved visible-light response,carrier separation and charge migration for CN photocatalysts.Thereafter,the protons adsorption and activation are promoted.Taking this advantage of long-range electron synergy in bimetallic single atomic sites,the photocatalytic hydrogen evolution activity over Pt_(1)-Co_(1)/CN achieves 915.8 mmol g^(-1)Pt h^(-1),which is 19.8 times higher than Co_(1)/CN and 3.5 times higher to Pt_(1)/CN.While this electron-synergistic effect is not so efficient for Pt nanoclusters.These results demonstrate the synergistic effect at electron-level and provide electron-level guidance for the design of efficient photocatalysts.
基金This study was financially supported by the National Natural Science Foundation of China(Nos.12075174 and 91963207)the National Key Research and Development Program of China(No.2022YFA1602701).
文摘Constructing a S-scheme heterojunction with tight interface contact and fast charge transfer is beneficial to improving the photocatalytic hydrogen evolution performance.Herein,a unique one-dimensional(1D)/two-dimensional(2D)S-scheme heterojunction containing 1D Sb_(2)S_(3) nanorods and 2D ZnIn_(2)S_(4) with affluent sulfur vacancies(denoted as Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3)) was designed.The introduced sulfur vacancy can promote the effective adsorption of H+for the following interfacial hydrogen-evolution reaction.Furthermore,the larger contact area and stronger electron interaction between Sb_(2)S_(3) and ZnIn_(2)S_(4) effectively inhibits the recombination of photo-generated electron–hole pairs and abridges the migration distance of charges.As a result,the optimal Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3) sample achieves H_(2) evolution activity of 2741.3 mol·h^(−1)·g^(−1),which is 8.6 times that of pristine ZnIn_(2)S_(4) and 3.0 times that of the Sv-ZnIn_(2)S_(4) samples.Based on the experimental result,the photo-reactivity S-scheme mechanism of hydrogen evolution from water splitting with Sv-ZnIn_(2)S_(4)@Sb_(2)S_(3) is proposed.This work provides an effective method for developing S-scheme heterojunction composites of transition metal sulfide with high hydrogen evolution performance.
基金supported by the National Natural Science Foundation of China(Nos.22208262,52271228,52202298,52201279,51834009,and 51801151)the Natural Science Foundation of Shaanxi Province(Nos.2021JQ-468,2020JZ-47)+3 种基金the Natural Science Foundation of Shaanxi Provincial Department of Education(No.21JP086)the Postdoctoral Research Foundation of China(Nos.2020M683528 and 2018M633643XB)the Young Talent Fund of Association for Science and Technology in Shaanxi,China(No.20230625)the Hundred Talent Program of Shaanxi Province.
文摘Developing heterojunction photocatalyst with well-matched interfaces andmultiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal,but still remains a great challenge.In present work,a new strategy of chloride anion intercalation in Bi_(2)O_(3)via one-pot hydrothermal process is proposed.The as-prepared Ta-BiOCl/Bi_(24)O_(31)Cl_(10)(TBB)heterojunctions are featured with Ta-Bi_(24)O_(31)Cl_(10)and Ta-BiOCl lined shoulder-by-shouleder via semi-coherent interfaces.In this TBB heterojunctions,the well-matched semi-coherent interfaces and shoulder-by-shoulder structures provide fast electron transfer andmultiple transfer paths,respectively,leading to enhanced visible light response and improved photogenerated charge separation.Meanwhile,a type-II heterojunction for photocharge separation has been obtained,in which photogenerated electrons are drove from the CB(conduction band)of Ta-Bi_(24)O_(31)Cl_(10)to the both of bilateral empty CB of Ta-BiOCl and gathered on the CB of Ta-BiOCl,while the photogenerated holes are left on the VB(valence band)of Ta-Bi_(24)O_(31)Cl_(10),effectively hindering the recombination of photogenerated electron-hole pairs.Furthermore,the separated electrons can effectively activate dissolved oxygen for the generation of reactive oxygen species(·O_(2)^(−)).Such TBB heterojunctions exhibit remarkably superior photocatalytic degradation activity for tetracycline hydrochloride(TCH)solution to Bi_(2)O_(3),Ta-BiOCl and Ta-Bi_(24)O_(31)Cl_(10).This work not only proposes a Ta-BiOCl/Bi_(24)O_(31)Cl_(10)shoulder-by-shoulder micro-ribbon architectures with semi-coherent interfaces and successive type-Ⅱheterojunction for highly efficient photocatalytic activity,but offers a new insight into the design of highly efficient heterojunction through phasestructure synergistic transformation strategy.
文摘Harnessing solar energy for renewable fuel production through artificial photosynthesis offers an ideal solution to the current energy and environmental crises.Among various methods,photoelectrochemical(PEC)water splitting stands out as a promising approach for direct solar-driven hydrogen production.Enhancing the efficiency and stability of photoelectrodes is a key focus in PEC water-splitting research.Tantalum nitride(Ta_(3)N_(5)),with its suitable band gap and band-edge positions for PEC water splitting,has emerged as a highly promising photoanode material.This review begins by introducing the history and fundamental characteristics of Ta_(3)N_(5),emphasizing both its advantages and challenges.It then explores methods to improve light absorption efficiency,charge separation and transfer efficiency,surface reaction rate,and the stability of Ta_(3)N_(5) photoanodes.Additionally,the review discusses the progress of research on tandem PEC cells incorporating Ta_(3)N_(5) photoanodes.Finally,it looks ahead to future research directions for Ta_(3)N_(5) photoanodes.The strategic approach outlined in this review can also be applied to other photoelectrode materials,providing guidance for their development.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.11874356,11904039,51772035 and 52071041)the Project for Fundamental and Frontier Research in Chongqing(Nos.cstc2019jcyjjqX0002 and cstc2020jcyj-msxmX0777)the Fundamental Research Funds for the Central Universities(No.106112016CDJZR308808).The work conducted at Chongqing Institute of Green and Intelligent Technology(Chinese Academy of Sciences)is also supported by Key Research Program of Frontier Sciences,CAS(No.QYZDB-SSWSLH016).
文摘Hydrogen,with the merits of zero emissions and high energy density,is one of the promising green energy sources.Seeking for high efficiency and low-cost catalysts is one of the key issues for hydrogen evolution and its practical applications.Nano-structured metal cocatalysts are widely used to improve the photocatalytic performance via surface electronic structure/properties optimization of the catalyst.Herein,we report ultra-fine(*1 nm)Cu clusters decorated hydrangea-like TiO_(2)systems for photocatalytic hydrogen evolution.The pristine hydrangea-like TiO_(2)support shows a promising performance of hydrogen evolution(1.8 mmol·h^(-1)·g^(-1)),which is*10.7 times higher than that of the commercial P25(168 lmol·h^(-1)·g^(-1)).After ultra-fine Cu clusters decoration,a maximal hydrogen evolution performance(3.7 mmol·h^(-1)·g^(-1))is achieved in the optimized system 6Cu–TiO_(2)(6 wt%).Experimental and theoretical studies demonstrate that the ultra-fine Cu clusters decoration could promote the charge separation and transfer process effectively.The Cu clusters also act as reaction sites for reduction of H_(2)O to H2.These results are of great importance for the study of Cu-based co-catalyst systems and also shed light on the development of other non-noble metal co-catalysts in photocatalysis hydrogen evolution.
基金supported by the National Natural Science Foundation of China(U1401245,91622119)the Program for Innovative Research Team in Chinese Universities(IRT1237)+1 种基金the Research Project of Chinese Ministry of Education(213011A)the Science Foundation for Excellent Youth of Harbin City of China(2014RFYXJ002)~~
文摘One of the most general methods to enhance the separation of photogenerated carriers for g‐C3N4is to construct a suitable heterojunctional composite,according to the principle of matching energy levels.The interface contact in the fabricated nanocomposite greatly influences the charge transfer and separation so as to determine the final photocatalytic activities.However,the role of interface contact is often neglected,and is rarely reported to date.Hence,it is possible to further enhance the photocatalytic activity of g‐C3N4‐based nanocomposite by improving the interfacial connection.Herein,phosphate-oxygen(P-O)bridged TiO2/g‐C3N4nanocomposites were successfully synthesized using a simple wet chemical method,and the effects of the P-O functional bridges on the photogenerated charge separation and photocatalytic activity for pollutant degradation and CO2reduction were investigated.The photocatalytic activity of g‐C3N4was greatly improved upon coupling with an appropriate amount of nanocrystalline TiO2,especially with P-O bridged TiO2.Atmosphere‐controlled steady‐state surface photovoltage spectroscopy and photoluminescence spectroscopy analyses revealed clearly the enhancement of photogenerated charge separation of g‐C3N4upon coupling with the P-O bridged TiO2,resulting from the built P-O bridges between TiO2and g‐C3N4so as to promote effective transfer of excited electrons from g‐C3N4to TiO2.This enhancement was responsible for the improved photoactivity of the P-O bridged TiO2/g‐C3N4nanocomposite,which exhibited three‐time photocatalytic activity enhancement for2,4‐dichlorophenol degradation and CO2reduction compared with bare g‐C3N4.Furthermore,radical‐trapping experiments revealed that the·OH species formed as hole‐modulated direct intermediates dominated the photocatalytic degradation of2,4‐dichlorophenol.This work provides a feasible strategy for the design and synthesis of high‐performance g‐C3N4‐based nanocomposite photocatalysts for pollutant degradation and CO2reduction.
基金financially supported by the Science and Technology Investigation Project of Hubei Provincial Department of Education,China(No.D20181805)。
文摘Fabrication of 2D/2D heterojunction photocatalysts have attracted more attentions due to their inherent merits involving the large contact interface,short charge migration distance and plentiful active sites,which are beneficial for the enhancement of photocatalytic activity.Herein,a series of 2D/2D MoS_(2)/Cd S type-I heterojunctions were prepared by incorporation the exfoliating of bulk CdS and MoS_(2) with postsintering procedure.Multiple characteristic techniques were employed to corroborate the formation of heterojunctions.By optimizing the 2D MoS_(2) amounts in the heterojunction,the 7 wt.%2D/2D MoS_(2)/CdS heterojunction displayed the maximal photocatalytic H2 evolution rate of 18.43 mmol h^(-1) g^(-1) under visible light irradiation in the presence of lactic acid as the sacrificial reagent,which was 6 times higher than that of pristine 2D CdS.Based on the photoelectrochemical and photoluminescence spectra tests,it could be deduced that the charge separation and transfer of 2D/2D MoS_(2)/CdS heterojunction was tremendously improved,and the recombination of photoinduced electron-hole pairs was effectively impeded.Moreover,the 2D MoS_(2) was used as a cocatalyst to provide the abundant active sites and lower the overpotential for H_(2) generation reaction.The current work would offer an insight to fabricate the 2D/2D heterojunction photocatalysts for splitting H_(2)O into H_(2).
文摘Solar-driven water splitting is considered as a promising method to mitigate the energy crisis and various environmental issues.Bismuth vanadate(BiVO_(4))is photoanode material with tremendous potential for photoelectrochemical(PEC)water splitting.However,its PEC performance is severely hindered owing to poor surface charge transfer,surface recombination at the photoanode/electrolyte junction,and sluggish oxygen evolution reaction(OER)kinetics.In this regard,a novel solution was developed in this study to address these issues by decorating the surface of BiVO_(4)with cobalt sulfide,whose attractive features such as low cost,high conductivity,and rapid charge-transfer ability assisted in improving the PEC activity of the BiVO_(4)photoanode.The fabricated photoanode exhibited a significantly enhanced photocurrent density of 3.2 m A cm^(-2)under illumination at 1.23 V vs.a reversible hydrogen electrode,which is more than 2.5 times greater than that of pristine BiVO_(4).Moreover,the Co S/BiVO_(4)photoanode also exhibited considerable improvements in the charge injection yield(75.8%vs.36.7%for the bare BiVO_(4)film)and charge separation efficiency(79.8%vs.66.8%for the pristine BiVO_(4)film).These dramatic enhancements were primarily ascribed to rapid charge-transport kinetics and efficient reduction of the anodic overpotential for oxygen evolution enabled by the surface modification of BiVO_(4)by Co S.This study provides valuable suggestions for designing efficient photocatalysts via surface modification to improve the PEC performance.
基金financial support from the Zhejiang Provincial Key R&D Project (No.2019C03118)the Programme of Introducing Talents of Discipline to Universities (No.D17008)。
文摘Photocatalytic CO_(2)reduction is an appealing strategy for mitigating the environmental effects of greenhouse gases while simultaneously producing valuable carbon-neutral fuels.Numerous attempts have been made to produce effective and efficient photocatalysts for CO_(2)reduction. In contrast, the selection of competitive catalysts continues to be a substantial hindrance and a considerable difficulty in the development of photocatalytic CO_(2)reduction. It is vital to emphasize different techniques for building effective photocatalysts to improve CO_(2)reduction performance in order to achieve a long-term sustainability. Metalorganic frameworks(MOFs) are recently emerging as a new type of photocatalysts for CO_(2)reduction due to their excellent CO_(2)adsorption capability and unique structural characteristics. This review examines the most recent breakthroughs in various techniques for modifying MOFs in order to improve their efficiency of photocatalytic CO_(2)reduction. The advantages of MOFs using as photocatalysts are summarized, followed by different methods for enhancing their effectiveness for photocatalytic CO_(2)reduction via partial ion exchange of metal clusters, design of bimetal clusters, the modification of organic linkers,and the embedding of metal complexes. For integrating MOFs with semiconductors, metallic nanoparticles(NPs), and other materials, a number of different approaches have been also reviewed. The final section of this review discusses the existing challenges and future prospects of MOFs as photocatalysts for CO_(2)reduction. Hopefully, this review can stimulate intensive research on the rational design and development of more effective MOF-based photocatalysts for visible-light driven CO_(2)conversion.
基金the financially support by the National Natural Science Foundation of China as general projects(Nos.21722702 and 21874099)the Tianjin Commission of Science and Technology as key technologies R&D projects(Nos.18YFZCSF00730,18YFZCSF00770 and 18ZXSZSF00230)+1 种基金National Key Basic Research Program of China(No.2017YFA0403402)Science and Technology Research Projects of Colleges and Universities in Hebei province(No.ZD2020149)。
文摘The development of photocatalysts for hydrogen evolution is a promising alternative to industrial hydrogen evolution;however,generation of high active,recyclable,inexpensive heterojunctions are still challenging.Herein,a novel strategy was developed to synthesize non-noble metal co-catalyst/solid solution heterojunctions using metal-organic frameworks(MOFs)as a precursor template.By adjusting the content of MOFs,a series of Cu1.8S/ZnxCd1-xS heterojunctions were obtained,and the Cu1.8S(3.7%)/Zn0.35Cd0.65S sample exhibits a maximum hydrogen evolution rate of 14.27 mmol h^(-1) g^(-1) with an apparent quantum yield of 3.7%at 420 nm under visible-light irradiation.Subsequently,the relationship between the heterojunction and photocatalytic activity were investigated by detailed characterizations and density functional theory(DFT)calculations,which reveal that loading Cu1.8S can efficiently extend the light absorption,meanwhile,the electrons can efficiently transfer from Zn0.35Cd0.65S to Cu1.8S,thus resulting more photogenerated electrons participating in surface reactions.This result can be valuable inspirations for the exploitation of advanced materials using rationally designed nanostructures for solar energy conversion.
基金Project supported by the National Natural Science Foundation of China(No.11174241)the Natural Science Foundation of Shandong Province,China(No.2009VRA06063)the Natural Science Foundation for Distinguished Young Scholars of Shandong Province, China(No.2008JQB01028)
文摘Phase separations have been studied for graded-indium content In_xGa_（1-x）N/GaN multiple quantum wells（MQWs） with different indium contents by means of photoluminescence（PL）,cathodeluminescence（CL） and time-resolved PL（TRPL） techniques.Besides the main emission peaks,all samples show another 2 peaks at the high and low energy parts of the main peaks in PL when excited at 10 K.CL images show a clear contrast for 3 samples,which indicates an increasing phase separation with increasing indium content.TRPL spectra at 15 K of the main emissions show an increasing delay of rising time with indium content,which means a carrier transferring from low indium content structures to high indium content structures.
基金The authors gratefully acknowledge financial support of the National Natural Science Foundation of China(grant no.21071156)the Natural Science Foundation of Chongqing(grant nos.cstc2019jcyj-msxmX0170 and cstc2020jcyj-msxmX0735).
文摘Oxygen evolution cocatalysts(OECs)play important roles in improving the efficiency of photocatalysts in solar water splitting.Inorganic–organic hybrid polymers(IOHPs),which have good electrolyte accessibility and evenly distributed active sites,are expected to be promising OECs.Here,a novel IOHP[Co(Bpn)_(2)(SCN)_(2)]n(1,Bpn=2,6-bis(4-pyridyl)-naphthalene,SCN=thiocyanate ion)exhibited a two-dimensional(2D)layer structure with(4,4)topology,was constructed by Bpn ligands connecting Co(II)ions,and was decorated on BiVO_(4) photoanodes for photoelectrochemical(PEC)water oxidation.The 1/BiVO_(4) hybrid electrode showed significantly negative onset potential and approximately 3.7 times higher photocurrent density at 1.23 V versus reversible hydrogen electrode(RHE)compared with the bare BiVO_(4).The mechanisms for the improved PEC efficiency were investigated and mainly ascribed to enhanced water oxidation kinetics and increased charge separation and transfer properties.This work provides a promising OEC candidate for PEC water oxidation and sheds light on the attractive application prospect of IOHPs for solar water splitting.
基金financially supported by Talent Start-up Fund of Fuzhou University(No.0180-511208)Fuzhou University Testing Fund of precious apparatus(No.2023T002)+1 种基金the National Natural Science Foundation of China(Nos.21703038 and 22072025)The financial support from State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences is acknowledged(No.20240018).
文摘Single-atom catalysts(SACs)have garnered tremendous and continuous attention in photocatalytic CO_(2)reduction reactions(CO_(2)RR),due to their compelling potential in broadening the light-harvesting range,elevating the charge separation/transfer efficiency,and enhancing surface reaction.Despite the surge in research and the expanding range of potential central metal candidates—including d-block,p-block,and rare metal elements,etc.—the comprehension of the structure-function relationships between the central metal and its performance remains elusive.Hence,categorized by different areas of the central metal element from periodic table,we outline the recent progress and challenges on SACs for photocatalytic CO_(2)RR.We begin by describing various synthetic strategies employed for SACs.Subsequently,a clear classification of the SACs applications in photocatalytic CO_(2)RR is provided,according to the central metal elements in different blocks of the periodic table.We also discussed how isolated metal single-atom sites from different blocks of the periodic table improve the performance of photocatalytic CO_(2)reduction from the perspective of charge separation and transfer.Finally,we end this review with some perspectives and challenges associated with SACs for photocatalytic CO_(2)reduction.Through this review,we aim to enrich the element diversity of SACs for photocatalytic CO_(2)RR,reveal trends in element evolution,and propose directions for future development in this flourishing field.
