The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metall...The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metallic co-catalysts Ti3C2 MXene and metallic octahedral(1T)phase tungsten disulfide(WS2)act pathways transferring photoexcited electrons in assisting the photocatalytic H2 evolution.TiO2 nanosheets were in situ grown on highly conductive Ti3C2 MXenes and 1T-WS2 nanoparticles were then uniformly distributed on TiO2@Ti3C2 composite.Thus,a distinctive 1T-WS2@TiO2@Ti3C2 composite with double metallic co-catalysts was achieved,and the content of 1T phase reaches 73%.The photocatalytic H2 evolution performance of 1T-WS2@TiO2@Ti3C2 composite with an optimized 15 wt%WS2 ratio is nearly 50 times higher than that of TiO2 nanosheets because of conductive Ti3C2 MXene and 1T-WS2 resulting in the increase of electron transfer efficiency.Besides,the 1T-WS2 on the surface of TiO2@Ti3C2 composite enhances the Brunauer–Emmett–Teller surface area and boosts the density of active site.展开更多
Photocatalysis is an efective means to solve the greenhouse efect caused by the large amount of carbon dioxide(CO_(2))emissions from fossil fuel consumption.Graphitic carbon nitride(g-C_(3)N_(4))has the advantages of ...Photocatalysis is an efective means to solve the greenhouse efect caused by the large amount of carbon dioxide(CO_(2))emissions from fossil fuel consumption.Graphitic carbon nitride(g-C_(3)N_(4))has the advantages of suitable band gap,easy preparation,low price,and good stability,making it a promising semiconductor photocatalyst.However,bulk g-C3N4 also has disadvantages such as low gas adsorption,low photocatalytic efciency,narrow spectral response,and easy recombination of electron–hole pairs.The modifcation method based on g-C_(3)N_(4) photocatalyst helps to improve the above-mentioned problems.This review summarizes the research progress in recent years from four aspects:morphology adjustment,co-catalysts,heterostructures and doping.Each aspect includes the pros and cons of diferent improvement methods,the comparison of theoretical calculations and experimental results,the application of diferent characterization methods,and the detailed listing of product yield and selectivity.Prior to this,there was an explanation of the basic theory of semiconductor photocatalytic CO_(2) reduction.Finally,the future challenges and development prospects are also briefy prospected.展开更多
In this study, a potentially universal new strategy is reported for the large-scale, low-cost fabrication of visible-light-active highly ordered heteronanostructures based on the spontaneous photoelectric-field-enhanc...In this study, a potentially universal new strategy is reported for the large-scale, low-cost fabrication of visible-light-active highly ordered heteronanostructures based on the spontaneous photoelectric-field-enhancement effect inherent in pyramidal morphology. The hierarchical vertically oriented arrayed structures comprise an active molecular co-catalyst at the apex of a visible-light-active large band gap semiconductor for low-cost solar water splitting in a neutral aqueous medium without the use of a sacrificial agent.展开更多
In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and exper...In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and experimental data have shown that the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure has a stronger light absorption capacity and larger specific surface area than pure g-C_(3)N_(4) NCs and g-C_(3)N_(4) nanosheets(NSs),and the presence of the co-catalysts 1T'-MoS_(2) can effectively inhibit the photoinduced carrier recombination.As a result,the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure with an optimum 1T'-MoS_(2) loading of 9 wt%displays a hydrogen evolution rate of 1949 mmol h^(-1) g^(-1),162.4,1.2,1.5,1.6 and 1.2 times than pure g-C_(3)N_(4) NCs(12 mmol h^(-1) g^(-1)),Pt/g-C_(3)N_(4) NCs(1615 mmol h^(-1) g^(-1))and Pt/g-C_(3)N_(4) nanosheets(NSs,1297 mmol h^(-1) g^(-1)),1T'-MoS_(2)/g-C_(3)N_(4) nanosheets(1216 mmol h^(-1) g^(-1))and 2H-MoS_(2)/g-C_(3)N_(4) nanocages(1573 mmol h^(-1) g^(-1)),respectively,and exhibits excellent cycle stability.Therefore,1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure is a suitable photocatalyst for green H_(2) production.展开更多
Photosynthesis with the chloroplast works efficiently because of the envelope structure that serves to carry enzymes and to simultaneously maintain the spatial separation of photosynthesis and cellular respiration.Ins...Photosynthesis with the chloroplast works efficiently because of the envelope structure that serves to carry enzymes and to simultaneously maintain the spatial separation of photosynthesis and cellular respiration.Inspired by the spatially separated architecture,a chloroplast-like structured photocatalyst(PdS@CdS@MoS_(2)),in which the PdS and MoS_(2) function as enzymes in the chloroplast and CdS shell functions as the chloroplast envelope,was developed to improve the photocatalytic H_(2) evolution.In this unique nanoscale bionic structure,the poriferous CdS shell enhances light absorption,generates photoinduced carriers,and separates oxidation and reduction reactions.Meanwhile,PdS and MoS_(2) dual cocatalysts enhance the charge separation efficiency through forming a built-in electric field with CdS.We demonstrate that the separation efficiency of carriers,carrier lifetime,and the yield of H_(2) are both higher than that of CdS nanoparticles,evidencing the feasibility of the chloroplast-like structure in enhancing the photocatalyst activity.This work emphasizes the synergism of the three key processes of the photocatalytic reaction by simulating the chloroplast structure and provides a general synthesis strategy,the synthesis of novel structured for photocatalysts for diverse applications in the energy field.展开更多
Photocatalytic water splitting is a promising strategy to produce hydrogen as a sustainable and clean energy carrier,based on abundant solar energy and semiconductor photocatalysts,and it has received extensive resear...Photocatalytic water splitting is a promising strategy to produce hydrogen as a sustainable and clean energy carrier,based on abundant solar energy and semiconductor photocatalysts,and it has received extensive research and discussion over the past several decades.It is challenging,however,to achieve an efficient solar-to-hydrogen evolution process with a single particulate photocatalyst due to the weak solar spectrum harvest and the rapid recombination of photogenerated electron-hole pairs during the photocatalysis reaction.Combining semiconductors to create different co-catalysts presents a viable solution to the above issues.Recently,semiconductor photocatalysts modified by different transition metal sulfidebased co-catalysts with designed functions,especially in light absorption enhancement and chargecarrier-separation efficiency promotion,have attracted much attention.As continued breakthroughs have been made in the preparation,modification,and solar-to-hydrogen evolution application of the 1T phase MS_(2)(M=W,Mo)co-catalyst-based photocatalysis system in recent years,we believe that a comprehensive review of this kind of co-catalyst would further promote its research and development to address the energy and environmental challenges that we are currently facing.Herein,recent studies and progress are summarized on the fabrication of 1T phase MS_(2)(M=W,Mo)-based co-catalyst materials,as well as their roles and functional mechanisms for photocatalytic H;evolution.Finally,concluding perspectives on the opportunities in and challenges for the further exploration of the 1T-MS_(2)(M=W,Mo)-based solar-tohydrogen evolution system are presented.展开更多
Solar-driven photoelectrochemical(PEC)water splitting systems are highly promising for converting solar energy into clean and sustainable chemical energy.In such PEC systems,an integrated photoelectrode incorporates a...Solar-driven photoelectrochemical(PEC)water splitting systems are highly promising for converting solar energy into clean and sustainable chemical energy.In such PEC systems,an integrated photoelectrode incorporates a light harvester for absorbing solar energy,an interlayer for transporting photogenerated charge carriers,and a co-catalyst for triggering redox reactions.Thus,understanding the correlations between the intrinsic structural properties and functions of the photoelectrodes is crucial.Here we critically examine various 2D layered photoanodes/photocathodes,including graphitic carbon nitrides,transition metal dichalcogenides,layered double hydroxides,layered bismuth oxyhalide nanosheets,and MXenes,combined with advanced nanocarbons(carbon dots,carbon nanotubes,graphene,and graphdiyne)as co-catalysts to assemble integrated photoelectrodes for oxygen evolution/hydrogen evolution reactions.The fundamental principles of PEC water splitting and physicochemical properties of photoelectrodes and the associated catalytic reactions are analyzed.Elaborate strategies for the assembly of 2D photoelectrodes with nanocarbons to enhance the PEC performances are introduced.The mechanisms of interplay of 2D photoelectrodes and nanocarbon co-catalysts are further discussed.The challenges and opportunities in the field are identified to guide future research for maximizing the conversion efficiency of PEC water splitting.展开更多
The catalytic activity for methanol electro-oxidation on CoPc-Pt/C co-catalysts, prepared by impregna-tion method, was studied in details through electrochemical methods. Cyclic voltammetry (CV) result demonstrates th...The catalytic activity for methanol electro-oxidation on CoPc-Pt/C co-catalysts, prepared by impregna-tion method, was studied in details through electrochemical methods. Cyclic voltammetry (CV) result demonstrates that CoPc has higher forward anodic peak current density and jf / jb value (forward anodic peak current density/backward anodic peak current density) than Pt/C. Chronoamperometry (CA) analysis indicates that CoPc-Pt/C exhibits both excellent transient current density and stable current density for methanol electro-oxidation compared with Pt/C. Two main mechanisms related to the pro-motion of catalytic activity are as follows: CoPc-Pt/C has the activity of tolerance to carbonaceous in-termediates, thus inhibiting the self-poisoning of catalysts; CoPc-Pt/C owns prominent intrinsic cata-lytic activity indicated by the apparent activation energy for methanol oxidation on CoPc-Pt/C, which is 18 kJ/mol, less than that on Pt and PtRu catalysts as reported.展开更多
基金fundings from the National Natural Science Foundation of China (Nos. 51872173 and 51772167)Taishan Scholarship of Young Scholars (No. tsqn201812068)+2 种基金Natural Science Foundation of Shandong Province (No. ZR2017JL020)Taishan Scholarship of Climbing Plan (No. tspd20161006)Key Research and Development Program of Shandong Province (No. 2018GGX102028)
文摘The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst’s surface.In this paper,we report that double metallic co-catalysts Ti3C2 MXene and metallic octahedral(1T)phase tungsten disulfide(WS2)act pathways transferring photoexcited electrons in assisting the photocatalytic H2 evolution.TiO2 nanosheets were in situ grown on highly conductive Ti3C2 MXenes and 1T-WS2 nanoparticles were then uniformly distributed on TiO2@Ti3C2 composite.Thus,a distinctive 1T-WS2@TiO2@Ti3C2 composite with double metallic co-catalysts was achieved,and the content of 1T phase reaches 73%.The photocatalytic H2 evolution performance of 1T-WS2@TiO2@Ti3C2 composite with an optimized 15 wt%WS2 ratio is nearly 50 times higher than that of TiO2 nanosheets because of conductive Ti3C2 MXene and 1T-WS2 resulting in the increase of electron transfer efficiency.Besides,the 1T-WS2 on the surface of TiO2@Ti3C2 composite enhances the Brunauer–Emmett–Teller surface area and boosts the density of active site.
基金This research was supported by Key Program for International S&T Cooperation Program of China(2017YFE0113000)the National Natural Science Foundation of China(51971133,51801121,51902200,and 52072241)+2 种基金the Shanghai Science and Technology Committee(18JC1410500,19JC1410400,19ZR1425100,and 18ZR1420900)the National Key Research and Development Program(YS2017YFGH000385)State Key Laboratory for Modifcation of Chemical Fibers and Polymer Materials,Donghua University.
文摘Photocatalysis is an efective means to solve the greenhouse efect caused by the large amount of carbon dioxide(CO_(2))emissions from fossil fuel consumption.Graphitic carbon nitride(g-C_(3)N_(4))has the advantages of suitable band gap,easy preparation,low price,and good stability,making it a promising semiconductor photocatalyst.However,bulk g-C3N4 also has disadvantages such as low gas adsorption,low photocatalytic efciency,narrow spectral response,and easy recombination of electron–hole pairs.The modifcation method based on g-C_(3)N_(4) photocatalyst helps to improve the above-mentioned problems.This review summarizes the research progress in recent years from four aspects:morphology adjustment,co-catalysts,heterostructures and doping.Each aspect includes the pros and cons of diferent improvement methods,the comparison of theoretical calculations and experimental results,the application of diferent characterization methods,and the detailed listing of product yield and selectivity.Prior to this,there was an explanation of the basic theory of semiconductor photocatalytic CO_(2) reduction.Finally,the future challenges and development prospects are also briefy prospected.
文摘In this study, a potentially universal new strategy is reported for the large-scale, low-cost fabrication of visible-light-active highly ordered heteronanostructures based on the spontaneous photoelectric-field-enhancement effect inherent in pyramidal morphology. The hierarchical vertically oriented arrayed structures comprise an active molecular co-catalyst at the apex of a visible-light-active large band gap semiconductor for low-cost solar water splitting in a neutral aqueous medium without the use of a sacrificial agent.
基金funding from the National Natural Science Foundation of China (No.51872173)Taishan Scholar Foundation of Shandong Province (No.tsqn201812068)+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In this work,we report the preparation of 1T'-MoS_(2)/g-C_(3)N_(4) nanocage(NC)heterostructure by loading 2D semi-metal noble-metal-free 1T'-MoS_(2) on the g-C_(3)N_(4) nanocages(NCs).DFT calculation and experimental data have shown that the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure has a stronger light absorption capacity and larger specific surface area than pure g-C_(3)N_(4) NCs and g-C_(3)N_(4) nanosheets(NSs),and the presence of the co-catalysts 1T'-MoS_(2) can effectively inhibit the photoinduced carrier recombination.As a result,the 1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure with an optimum 1T'-MoS_(2) loading of 9 wt%displays a hydrogen evolution rate of 1949 mmol h^(-1) g^(-1),162.4,1.2,1.5,1.6 and 1.2 times than pure g-C_(3)N_(4) NCs(12 mmol h^(-1) g^(-1)),Pt/g-C_(3)N_(4) NCs(1615 mmol h^(-1) g^(-1))and Pt/g-C_(3)N_(4) nanosheets(NSs,1297 mmol h^(-1) g^(-1)),1T'-MoS_(2)/g-C_(3)N_(4) nanosheets(1216 mmol h^(-1) g^(-1))and 2H-MoS_(2)/g-C_(3)N_(4) nanocages(1573 mmol h^(-1) g^(-1)),respectively,and exhibits excellent cycle stability.Therefore,1T'-MoS_(2)/g-C_(3)N_(4) NC heterostructure is a suitable photocatalyst for green H_(2) production.
基金supported by the Gansu Provincial Development and Reform Commission(NDRC,No.2013-1336).
文摘Photosynthesis with the chloroplast works efficiently because of the envelope structure that serves to carry enzymes and to simultaneously maintain the spatial separation of photosynthesis and cellular respiration.Inspired by the spatially separated architecture,a chloroplast-like structured photocatalyst(PdS@CdS@MoS_(2)),in which the PdS and MoS_(2) function as enzymes in the chloroplast and CdS shell functions as the chloroplast envelope,was developed to improve the photocatalytic H_(2) evolution.In this unique nanoscale bionic structure,the poriferous CdS shell enhances light absorption,generates photoinduced carriers,and separates oxidation and reduction reactions.Meanwhile,PdS and MoS_(2) dual cocatalysts enhance the charge separation efficiency through forming a built-in electric field with CdS.We demonstrate that the separation efficiency of carriers,carrier lifetime,and the yield of H_(2) are both higher than that of CdS nanoparticles,evidencing the feasibility of the chloroplast-like structure in enhancing the photocatalyst activity.This work emphasizes the synergism of the three key processes of the photocatalytic reaction by simulating the chloroplast structure and provides a general synthesis strategy,the synthesis of novel structured for photocatalysts for diverse applications in the energy field.
基金supported by the National Natural Science Foundation of China(21501137)Graduate Education Innovation Fund of Wuhan Institute of Technology(CX2020257)the Australian Research Council for funding through Discovery Early Career Researcher Award(DECRA,No.DE180101478)。
文摘Photocatalytic water splitting is a promising strategy to produce hydrogen as a sustainable and clean energy carrier,based on abundant solar energy and semiconductor photocatalysts,and it has received extensive research and discussion over the past several decades.It is challenging,however,to achieve an efficient solar-to-hydrogen evolution process with a single particulate photocatalyst due to the weak solar spectrum harvest and the rapid recombination of photogenerated electron-hole pairs during the photocatalysis reaction.Combining semiconductors to create different co-catalysts presents a viable solution to the above issues.Recently,semiconductor photocatalysts modified by different transition metal sulfidebased co-catalysts with designed functions,especially in light absorption enhancement and chargecarrier-separation efficiency promotion,have attracted much attention.As continued breakthroughs have been made in the preparation,modification,and solar-to-hydrogen evolution application of the 1T phase MS_(2)(M=W,Mo)co-catalyst-based photocatalysis system in recent years,we believe that a comprehensive review of this kind of co-catalyst would further promote its research and development to address the energy and environmental challenges that we are currently facing.Herein,recent studies and progress are summarized on the fabrication of 1T phase MS_(2)(M=W,Mo)-based co-catalyst materials,as well as their roles and functional mechanisms for photocatalytic H;evolution.Finally,concluding perspectives on the opportunities in and challenges for the further exploration of the 1T-MS_(2)(M=W,Mo)-based solar-tohydrogen evolution system are presented.
基金the support from the National Natural Science Foundation of China(21878271,51702284,21878270,and 21961160742)the Zhejiang Provincial Natural Science Foundation of China(LR19B060002)+8 种基金the Fundamental Research Funds for the Central Universitiesthe Startup Foundation for Hundred-Talent Program of Zhejiang Universitythe Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2019R01006)Key Laboratory of Marine Materials and Related Technologies,CASZhejiang Key Laboratory of Marine Materials and Protective Technologies(2020K10)the support of the NSFC 21501138the Natural Science Foundation of Hubei Province(2019CFB556)Science Research Foundation of Wuhan Institute of Technology(K2019039)the Australian Research Council(ARC)and QUT Centre for Materials Science for partial support.
文摘Solar-driven photoelectrochemical(PEC)water splitting systems are highly promising for converting solar energy into clean and sustainable chemical energy.In such PEC systems,an integrated photoelectrode incorporates a light harvester for absorbing solar energy,an interlayer for transporting photogenerated charge carriers,and a co-catalyst for triggering redox reactions.Thus,understanding the correlations between the intrinsic structural properties and functions of the photoelectrodes is crucial.Here we critically examine various 2D layered photoanodes/photocathodes,including graphitic carbon nitrides,transition metal dichalcogenides,layered double hydroxides,layered bismuth oxyhalide nanosheets,and MXenes,combined with advanced nanocarbons(carbon dots,carbon nanotubes,graphene,and graphdiyne)as co-catalysts to assemble integrated photoelectrodes for oxygen evolution/hydrogen evolution reactions.The fundamental principles of PEC water splitting and physicochemical properties of photoelectrodes and the associated catalytic reactions are analyzed.Elaborate strategies for the assembly of 2D photoelectrodes with nanocarbons to enhance the PEC performances are introduced.The mechanisms of interplay of 2D photoelectrodes and nanocarbon co-catalysts are further discussed.The challenges and opportunities in the field are identified to guide future research for maximizing the conversion efficiency of PEC water splitting.
基金Supported by the National Natural Science Foundation of China (Grant No. 20576106)
文摘The catalytic activity for methanol electro-oxidation on CoPc-Pt/C co-catalysts, prepared by impregna-tion method, was studied in details through electrochemical methods. Cyclic voltammetry (CV) result demonstrates that CoPc has higher forward anodic peak current density and jf / jb value (forward anodic peak current density/backward anodic peak current density) than Pt/C. Chronoamperometry (CA) analysis indicates that CoPc-Pt/C exhibits both excellent transient current density and stable current density for methanol electro-oxidation compared with Pt/C. Two main mechanisms related to the pro-motion of catalytic activity are as follows: CoPc-Pt/C has the activity of tolerance to carbonaceous in-termediates, thus inhibiting the self-poisoning of catalysts; CoPc-Pt/C owns prominent intrinsic cata-lytic activity indicated by the apparent activation energy for methanol oxidation on CoPc-Pt/C, which is 18 kJ/mol, less than that on Pt and PtRu catalysts as reported.
