The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS...The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.展开更多
Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ ...Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.展开更多
Developing efficient photocatalysts for CO_(2)conversion under full-spectrum irradiation remains a key challenge for solar-to-chemical energy conversion.In this study,a novel S-scheme heterojunction composed of reduct...Developing efficient photocatalysts for CO_(2)conversion under full-spectrum irradiation remains a key challenge for solar-to-chemical energy conversion.In this study,a novel S-scheme heterojunction composed of reduction Cs_(0.32)WO_(3)(CWO)nanosheets with hexagonal structure and oxidation WO_(3)·2H_(2)O(WO)nanorods with monoclinic structure photocatalyst was successfully constructed via an ultrasound strategy.Under full-spectrum irradiation for 4 h,the optimized 2D/1D of heterostructure CWO/WO-0.8 exhibited superior photocatalytic performance,achieving CO and CH_(3)OH yields of 29.74 and 63.71μmol·g^(-1),respectively.The enhanced activity is primarily ascribed to the formation of an S-scheme charge transfer pathway,which facilitates efficient separation and directional migration of photogenerated charge carriers through the internal electric field at the CWO/WO interface.This process facilitates the electron enrichment on the CWO surface and significantly enhances its CO_(2)reduction ability.Besides,the results of various characterizations show that CWO/WO-0.8 possesses enhanced optical response capability.The results of density functional theory calculations and CO_(2)-temperature programmed desorption analysis confirmed that the CWO/WO heterojunction exhibits stronger CO_(2)adsorption and activation abilities compared to the pristine CWO and WO.The reaction pathway for CH_(3)OH production was elucidated by in-situ diffused reflectance Fourier transformed infrared tests.This work provides new insights into the rational design of S-scheme photocatalysts for efficient and selective CO_(2)conversion.展开更多
文摘The rapid recombination of photogenerated carriers poses a significant limitation on the use of CdS quantum dots(QDs)in photocatalysis.Herein,the construction of a novel S-scheme heterojunction between cubic-phase CdS QDs and hollow nanotube In_(2)O_(3)is successfully achieved using an electrostatic self-assembly method.Under visible light irradiation,all CdS-In_(2)O_(3)composites exhibit higher hydrogen evolution efficiency compared to pure CdS QDs.Notably,the photocatalytic H_(2)evolution rate of the optimal CdS-7%In_(2)O_(3)composite is determined to be 2258.59μmol g^(−1)h^(−1),approximately 12.3 times higher than that of pure CdS.The cyclic test indicates that the CdS-In_(2)O_(3)composite maintains considerable activity even after 5 cycles,indicating its excellent stability.In situ X-ray photoelectron spectroscopy and density functional theory calculations confirm that carrier migration in CdS-In_(2)O_(3)composites adheres to a typical S-scheme heterojunction mechanism.Additionally,a series of characterizations demonstrate that the formation of S-scheme heterojunctions between In_(2)O_(3)and CdS inhibits charge recombination and accelerates the separation and migration of photogenerated carriers in the CdS QDs,thus achieving enhanced photocatalytic performance.This work elucidates the pivotal role of S-scheme heterojunctions in photocatalytic H_(2)production and offers novel insights into the construction of effective composite photocatalysts.
文摘Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.
文摘Developing efficient photocatalysts for CO_(2)conversion under full-spectrum irradiation remains a key challenge for solar-to-chemical energy conversion.In this study,a novel S-scheme heterojunction composed of reduction Cs_(0.32)WO_(3)(CWO)nanosheets with hexagonal structure and oxidation WO_(3)·2H_(2)O(WO)nanorods with monoclinic structure photocatalyst was successfully constructed via an ultrasound strategy.Under full-spectrum irradiation for 4 h,the optimized 2D/1D of heterostructure CWO/WO-0.8 exhibited superior photocatalytic performance,achieving CO and CH_(3)OH yields of 29.74 and 63.71μmol·g^(-1),respectively.The enhanced activity is primarily ascribed to the formation of an S-scheme charge transfer pathway,which facilitates efficient separation and directional migration of photogenerated charge carriers through the internal electric field at the CWO/WO interface.This process facilitates the electron enrichment on the CWO surface and significantly enhances its CO_(2)reduction ability.Besides,the results of various characterizations show that CWO/WO-0.8 possesses enhanced optical response capability.The results of density functional theory calculations and CO_(2)-temperature programmed desorption analysis confirmed that the CWO/WO heterojunction exhibits stronger CO_(2)adsorption and activation abilities compared to the pristine CWO and WO.The reaction pathway for CH_(3)OH production was elucidated by in-situ diffused reflectance Fourier transformed infrared tests.This work provides new insights into the rational design of S-scheme photocatalysts for efficient and selective CO_(2)conversion.
