Photocatalysis is a sunrise technology with great potential for hydrogen production 1,2,carbon dioxide reduction 3,and so on.However,a single-component photocatalyst often exhibits severely limited activity due to rap...Photocatalysis is a sunrise technology with great potential for hydrogen production 1,2,carbon dioxide reduction 3,and so on.However,a single-component photocatalyst often exhibits severely limited activity due to rapid photogenerated carrier recombination and weak redox abilities.展开更多
The persistent increase of CO_(2) levels in the atmosphere,already exceeding 400 ppm,urges the exploration of CO_(2) emission reduction and recycling technologies.Ideally,photocatalytic conversion of CO_(2) into valua...The persistent increase of CO_(2) levels in the atmosphere,already exceeding 400 ppm,urges the exploration of CO_(2) emission reduction and recycling technologies.Ideally,photocatalytic conversion of CO_(2) into valuable hydrocarbons realizes solar-to-chemical energy conversion,which is a desirable“kill two birds with one stone”strategy;namely,CO_(2) photoreduction can simultaneously tackle energy shortage and keep global carbon balance.Graphitic carbon nitride(g-C_(3)N_(4))working on CO_(2) reduction reaction deserves a highlight not only for the metal-free feature that endows it with low cost,tunable electronic structure,and easy fabrication properties but also because of its strong reduction ability.The present review concisely summarizes the latest advances of g-C_(3)N_(4)-based photocatalysts toward CO_(2) reduction.It starts with the discussion of thermodynamics and dynamics aspects of the CO_(2) reduction process.Then the modification strategies to promote g-C_(3)N_(4)-based photocatalysts in CO_(2) photoreduction have been discussed in detail,including surface functionalization,molecule structure engineering,crystallization,morphology engineering,loading cocatalyst,and constructing heterojunction.Meanwhile,the intrinsic factors affecting CO_(2) reduction activity and selectivity are analyzed and summarized.In the end,the challenges and prospects for the future development of highly g-C_(3)N_(4)-based photocatalysts in CO_(2) reduction are also presented.展开更多
The fabrication of S-scheme heterojunctions has received considerable attention as an effective approach to promote the separation and migration of photoexcited electron/hole pairs and retain strong redox abilities.He...The fabrication of S-scheme heterojunctions has received considerable attention as an effective approach to promote the separation and migration of photoexcited electron/hole pairs and retain strong redox abilities.Herein,an imine-based porous covalent organic framework(COF-LZU1)is integrated with controllably fabricated Cd S hollow cubes,resulting in the formation of an S-scheme heterojunction.When the COF content reaches 1.5 wt%,the COF/Cd S heterostructure(1.5%COF/Cd S)achieves the highest hydrogen generation rate of 8670μmol·h^(-1)·g^(-1),which is approximately 2.1 times higher than that of pure Cd S.The apparent quantum efficiency(AQE)of 1.5%COF/Cd S is approximately 8.9%at 420 nm.Further systematic analysis shows that the intimate contact interface and suitable energy band structures between Cd S and COF can induce the formation of an internal electric field at the heterojunction interface,which can effectively drive the spatial separation of photoexcited charge carriers and simultaneously maintain a strong redox ability,thus enhancing the photocatalytic H_(2) evolution performance.展开更多
Synergistic catalysis opens up a new venue to improve the comprehensive application of the catalyst.Herein,a composite catalyst(Mo-Pd@N-C)consisting of the N-doped carbon derived from pyrolysis of spherical polypyrrol...Synergistic catalysis opens up a new venue to improve the comprehensive application of the catalyst.Herein,a composite catalyst(Mo-Pd@N-C)consisting of the N-doped carbon derived from pyrolysis of spherical polypyrrole and MoPd nanoparticles(NPs)was constructed to emphasize the strong metal-support interaction for robust oxygen reduction reaction(ORR).The enhanced anchoring between the MoPd NPs and the substrate,and the N-species formed on the carbon matrix make the Mo-Pd@N-C deliver excellent performance with a half-wave potential of 0.945 V(vs.reversible hydrogen electrode(RHE))for ORR,superior than that of commercial Pt/C(0.86 V).More importantly,it shows a negligible half-wave potential decline(<5 mV)and only~20%of mass activity(MA)attenuation after 30,000 cycles stability test,obviously better than those of Pt/C(~70%of MA attenuation and~30 mV of half-wave potential decline after only 15,000 cycles).This work highlights a novel synergistic method to prolong the life and improve the commercial prospects of the catalysts.展开更多
Recently,a new opinion was put forward on general design standards for S-scheme heterojunction photocatalyst.Four types of S-scheme heterojunctions were analyzed.Specifically,the critical understanding on the curved F...Recently,a new opinion was put forward on general design standards for S-scheme heterojunction photocatalyst.Four types of S-scheme heterojunctions were analyzed.Specifically,the critical understanding on the curved Fermi level at the interface of S-scheme heterojunction is helpful to strengthen and promote the basic theory of photocatalysis.展开更多
The rapid charge recombination and low surface reaction kinetics are the two major constraints to the photocatalytic performance of covalent organic frameworks(COFs).To accelerate the charge separation behavior,TpPa-1...The rapid charge recombination and low surface reaction kinetics are the two major constraints to the photocatalytic performance of covalent organic frameworks(COFs).To accelerate the charge separation behavior,TpPa-1-COF is decorated with WO_(3)Bvia an in-situ growth approach,and the resultant WO_(3)/TpPa-1-COF composites show significantly improved photocatalytic performance.Especially,when the WO_(3)loading arrives at 3 wt%,3%WO_(3)/TpPa-1-COF exhibits the maximum photocatalytic H_(2)evolution rate of 19.89 mmol g^(-1)h^(-1),which is approximately 4.8 times higher than that of pure TpPa-1-COF.The apparent quantum efficiency(AQE)of 3%WO_(3)/TpPa-1-COF at 420 nm is detected to be 12.4%.X-ray photoelectron spectroscopy(XPS)characterization confirms the formation of internal electric field between WO_(3)and TpPa-1-CF,which can drive the photogenerated charge carrier diffusion in S-scheme mode.As a result,WO_(3)/TpPa-1-COF composite possesses high charge separation efficiency and strong redox ability,which is further supported by the photoelectrochemical results,thus benefiting the photocatalysis process.This work provides a rational strategy to modify COFs in photocatalytic water splitting.展开更多
Direct conversion of solar energy into chemical fuels via semiconducting materials through photocatalytic technology is a sustainable way to tackle the global warming, environmental issue and energy crisis. Transition...Direct conversion of solar energy into chemical fuels via semiconducting materials through photocatalytic technology is a sustainable way to tackle the global warming, environmental issue and energy crisis. Transition metal carbides and nitrides(MXenes), a newly emerging class of 2D layered materials, has gained tremendous attention as a noble metal-free co-catalyst for boosting photoreactivity due to its extraordinary characteristics like elemental abundance, excellent electrical conductivity, abundant surface functional groups, unique hydrophilic behavior and flexible modulation of chemical composition. The rational integration of low-dimensional MXenes in the form of 2D layered structures or 0D quantum dots with diverse semiconducting materials offer more versatile and robust heterostructured-photocatalysts that are applicable in solar fuel generation. Herein, we summarize the recent advances and achievements in the synthesis of low-dimensional MXenes and their application in hydrogen production from water splitting and CO_(2) photoreduction. A comprehensive discussion of the fundamentals for solar fuel production, synthesis strategies and theoretical calculations for MXenes-based photocatalysts are also given. Finally, the existing challenges and further perspectives of MXenes-based nanostructures for efficient solar fuel production are addressed.展开更多
Photoelectrochemical oxygen reduction reaction(ORR)toward H_(2)O_(2)is highly desirable because only sunlight,O_(2)and water are required in the process.However,the corresponding studies are still at its infancy becau...Photoelectrochemical oxygen reduction reaction(ORR)toward H_(2)O_(2)is highly desirable because only sunlight,O_(2)and water are required in the process.However,the corresponding studies are still at its infancy because of the lack of suitable photocathodes,especially inorganic semiconductor photocathodes.In this work,we report CuBi_(2)O_(4)/CuO(CBO/CuO)heterojunction submicrocrystalline film photocathodes with efficient ORR activity for H_(2)O_(2)production.The heterojunction film photocathodes were prepared through thermal evaporation of Cu and Bi metals under vacuum and subsequent annealing treatment.Furthermore,the doping of Gd^(3+)ions into CBO/CuO could significantly enhance the yield of H_(2)O_(2).As a result,the concentration of H_(2)O_(2)could reach 1.3 mM within 30 min,which is 6 times higher than that obtained on the pristine CBO/CuO photocathode.The theoretical calculations suggested that the introduction of Gd could adjust the electronic structure of CBO surface and promote 2e ORR pathway for selective production of H_(2)O_(2).Our work not only provides a new strategy for designing highly efficient photocathode for H_(2)O_(2)production but also will evoke more interest in photoelectrocatalytic ORR through inorganic semiconductor photocathode.展开更多
文摘Photocatalysis is a sunrise technology with great potential for hydrogen production 1,2,carbon dioxide reduction 3,and so on.However,a single-component photocatalyst often exhibits severely limited activity due to rapid photogenerated carrier recombination and weak redox abilities.
基金Natural Science Foundation of Xinjiang Province,Grant/Award Numbers:2019D01C064,2020D01A49,2020D01B25,2021D01B40National Natural Science Foundation of China,Grant/Award Numbers:21905209,52072273Tianshan innovation team project of Xinjiang Uygur Autonomous Region,Grant/Award Number:2021D14013。
文摘The persistent increase of CO_(2) levels in the atmosphere,already exceeding 400 ppm,urges the exploration of CO_(2) emission reduction and recycling technologies.Ideally,photocatalytic conversion of CO_(2) into valuable hydrocarbons realizes solar-to-chemical energy conversion,which is a desirable“kill two birds with one stone”strategy;namely,CO_(2) photoreduction can simultaneously tackle energy shortage and keep global carbon balance.Graphitic carbon nitride(g-C_(3)N_(4))working on CO_(2) reduction reaction deserves a highlight not only for the metal-free feature that endows it with low cost,tunable electronic structure,and easy fabrication properties but also because of its strong reduction ability.The present review concisely summarizes the latest advances of g-C_(3)N_(4)-based photocatalysts toward CO_(2) reduction.It starts with the discussion of thermodynamics and dynamics aspects of the CO_(2) reduction process.Then the modification strategies to promote g-C_(3)N_(4)-based photocatalysts in CO_(2) photoreduction have been discussed in detail,including surface functionalization,molecule structure engineering,crystallization,morphology engineering,loading cocatalyst,and constructing heterojunction.Meanwhile,the intrinsic factors affecting CO_(2) reduction activity and selectivity are analyzed and summarized.In the end,the challenges and prospects for the future development of highly g-C_(3)N_(4)-based photocatalysts in CO_(2) reduction are also presented.
文摘The fabrication of S-scheme heterojunctions has received considerable attention as an effective approach to promote the separation and migration of photoexcited electron/hole pairs and retain strong redox abilities.Herein,an imine-based porous covalent organic framework(COF-LZU1)is integrated with controllably fabricated Cd S hollow cubes,resulting in the formation of an S-scheme heterojunction.When the COF content reaches 1.5 wt%,the COF/Cd S heterostructure(1.5%COF/Cd S)achieves the highest hydrogen generation rate of 8670μmol·h^(-1)·g^(-1),which is approximately 2.1 times higher than that of pure Cd S.The apparent quantum efficiency(AQE)of 1.5%COF/Cd S is approximately 8.9%at 420 nm.Further systematic analysis shows that the intimate contact interface and suitable energy band structures between Cd S and COF can induce the formation of an internal electric field at the heterojunction interface,which can effectively drive the spatial separation of photoexcited charge carriers and simultaneously maintain a strong redox ability,thus enhancing the photocatalytic H_(2) evolution performance.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21671152 and 52171145)the Natural Science Foundation of Zhejiang Province(No.LY20B010004)the China Postdoctoral Science Foundation(No.2021M703071).
文摘Synergistic catalysis opens up a new venue to improve the comprehensive application of the catalyst.Herein,a composite catalyst(Mo-Pd@N-C)consisting of the N-doped carbon derived from pyrolysis of spherical polypyrrole and MoPd nanoparticles(NPs)was constructed to emphasize the strong metal-support interaction for robust oxygen reduction reaction(ORR).The enhanced anchoring between the MoPd NPs and the substrate,and the N-species formed on the carbon matrix make the Mo-Pd@N-C deliver excellent performance with a half-wave potential of 0.945 V(vs.reversible hydrogen electrode(RHE))for ORR,superior than that of commercial Pt/C(0.86 V).More importantly,it shows a negligible half-wave potential decline(<5 mV)and only~20%of mass activity(MA)attenuation after 30,000 cycles stability test,obviously better than those of Pt/C(~70%of MA attenuation and~30 mV of half-wave potential decline after only 15,000 cycles).This work highlights a novel synergistic method to prolong the life and improve the commercial prospects of the catalysts.
基金the Deanship of Scientific Research(DSR)at King Abdulaziz University,Jeddah(No.RG-72–130–42)DSR for technical and financial support。
文摘Recently,a new opinion was put forward on general design standards for S-scheme heterojunction photocatalyst.Four types of S-scheme heterojunctions were analyzed.Specifically,the critical understanding on the curved Fermi level at the interface of S-scheme heterojunction is helpful to strengthen and promote the basic theory of photocatalysis.
基金supported by the National Natural Science Foundation of China(Nos.52073263,21905209,21673160)the Natural Science Foundation of Henan Province(No.212300410080)。
文摘The rapid charge recombination and low surface reaction kinetics are the two major constraints to the photocatalytic performance of covalent organic frameworks(COFs).To accelerate the charge separation behavior,TpPa-1-COF is decorated with WO_(3)Bvia an in-situ growth approach,and the resultant WO_(3)/TpPa-1-COF composites show significantly improved photocatalytic performance.Especially,when the WO_(3)loading arrives at 3 wt%,3%WO_(3)/TpPa-1-COF exhibits the maximum photocatalytic H_(2)evolution rate of 19.89 mmol g^(-1)h^(-1),which is approximately 4.8 times higher than that of pure TpPa-1-COF.The apparent quantum efficiency(AQE)of 3%WO_(3)/TpPa-1-COF at 420 nm is detected to be 12.4%.X-ray photoelectron spectroscopy(XPS)characterization confirms the formation of internal electric field between WO_(3)and TpPa-1-CF,which can drive the photogenerated charge carrier diffusion in S-scheme mode.As a result,WO_(3)/TpPa-1-COF composite possesses high charge separation efficiency and strong redox ability,which is further supported by the photoelectrochemical results,thus benefiting the photocatalysis process.This work provides a rational strategy to modify COFs in photocatalytic water splitting.
基金supported by National Natural Science Founda-tion of China(Nos.51902243,21905209).
文摘Direct conversion of solar energy into chemical fuels via semiconducting materials through photocatalytic technology is a sustainable way to tackle the global warming, environmental issue and energy crisis. Transition metal carbides and nitrides(MXenes), a newly emerging class of 2D layered materials, has gained tremendous attention as a noble metal-free co-catalyst for boosting photoreactivity due to its extraordinary characteristics like elemental abundance, excellent electrical conductivity, abundant surface functional groups, unique hydrophilic behavior and flexible modulation of chemical composition. The rational integration of low-dimensional MXenes in the form of 2D layered structures or 0D quantum dots with diverse semiconducting materials offer more versatile and robust heterostructured-photocatalysts that are applicable in solar fuel generation. Herein, we summarize the recent advances and achievements in the synthesis of low-dimensional MXenes and their application in hydrogen production from water splitting and CO_(2) photoreduction. A comprehensive discussion of the fundamentals for solar fuel production, synthesis strategies and theoretical calculations for MXenes-based photocatalysts are also given. Finally, the existing challenges and further perspectives of MXenes-based nanostructures for efficient solar fuel production are addressed.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21673160 and 12075154)Natural Science Foundation of Zhejiang for Distinguished Young Scholars(No.LR16B010002)startup funds of Shaoxing University.
文摘Photoelectrochemical oxygen reduction reaction(ORR)toward H_(2)O_(2)is highly desirable because only sunlight,O_(2)and water are required in the process.However,the corresponding studies are still at its infancy because of the lack of suitable photocathodes,especially inorganic semiconductor photocathodes.In this work,we report CuBi_(2)O_(4)/CuO(CBO/CuO)heterojunction submicrocrystalline film photocathodes with efficient ORR activity for H_(2)O_(2)production.The heterojunction film photocathodes were prepared through thermal evaporation of Cu and Bi metals under vacuum and subsequent annealing treatment.Furthermore,the doping of Gd^(3+)ions into CBO/CuO could significantly enhance the yield of H_(2)O_(2).As a result,the concentration of H_(2)O_(2)could reach 1.3 mM within 30 min,which is 6 times higher than that obtained on the pristine CBO/CuO photocathode.The theoretical calculations suggested that the introduction of Gd could adjust the electronic structure of CBO surface and promote 2e ORR pathway for selective production of H_(2)O_(2).Our work not only provides a new strategy for designing highly efficient photocathode for H_(2)O_(2)production but also will evoke more interest in photoelectrocatalytic ORR through inorganic semiconductor photocathode.
