Photocatalytic hydrogen evolution through water splitting holds tremendous promise for converting solar energy into a clean and renewable fuel source.However,the efficiency of photocatalysis is often hindered by poor ...Photocatalytic hydrogen evolution through water splitting holds tremendous promise for converting solar energy into a clean and renewable fuel source.However,the efficiency of photocatalysis is often hindered by poor light absorption,insufficient charge separation,and slow reaction kinetics of the photocatalysts.In this study,we designed and synthesized a novel S-scheme heterojunction comprising Ti_(3)C_(2)MXene,CdS nanorods,and nitrogen-doped carbon coated Cu_(2)O(Cu_(2)O@NC)core-shell nanoparticles.Ti_(3)C_(2)MXene as a cocatalyst enhances the light absorption and charge transfer of CdS nanorods.Simultaneously,the core-shell Cu_(2)O@NC nanoparticles establish a pathway for transferring photogenerated electrons and create a favorable band alignment for efficient hydrogen evolution.The synergistic effects of Ti_(3)C_(2)MXene and Cu_(2)O@NC on CdS nanorods result in multiple charge transfer channels and improved photocatalytic performance.The optimal hydrogen evolution rate of the Ti_(3)C_(2)-CdS-Cu_(2)O@NC S-scheme heterojunction photocatalyst is 7.4 times higher than that of pure CdS.Experimental techniques and DFT calculations were employed to explore the structure,morphology,optical properties,charge dynamics,and band structure of the heterojunction.The results revealed that the S-scheme mechanism effectively suppresses the recombination of photogenerated carriers and facilitates the separation and migration of photo-generated electrons and holes to the reaction sites.Furthermore,Ti_(3)C_(2)MXene provides abundant active sites essential for accelerating the surface H_(2)-evolution reaction kinetics.The Cu_(2)O@NC core-shell nanoparticles with a large surface area and high stability are closely adhered to CdS nanorods and establish an S-scheme internal electric field with CdS nanorods to drive charge separation.This investigation provides valuable insights into the rational design of CdS-based photocatalysts,enabling efficient hydrogen production by harnessing the robust kinetic driving force provided by the S-scheme heterojunctions.展开更多
基金the National Natural Science Foundation of China(22378148,21975084,51672089)the Natural Science Foundation of Guangdong Province(2021A1515010075)for their supports。
基金National Natural Science Foundation of China(21975084,51672089)Natural Science Foundation of Guangdong Province(2021A1515010075)for their support
文摘Photocatalytic hydrogen evolution through water splitting holds tremendous promise for converting solar energy into a clean and renewable fuel source.However,the efficiency of photocatalysis is often hindered by poor light absorption,insufficient charge separation,and slow reaction kinetics of the photocatalysts.In this study,we designed and synthesized a novel S-scheme heterojunction comprising Ti_(3)C_(2)MXene,CdS nanorods,and nitrogen-doped carbon coated Cu_(2)O(Cu_(2)O@NC)core-shell nanoparticles.Ti_(3)C_(2)MXene as a cocatalyst enhances the light absorption and charge transfer of CdS nanorods.Simultaneously,the core-shell Cu_(2)O@NC nanoparticles establish a pathway for transferring photogenerated electrons and create a favorable band alignment for efficient hydrogen evolution.The synergistic effects of Ti_(3)C_(2)MXene and Cu_(2)O@NC on CdS nanorods result in multiple charge transfer channels and improved photocatalytic performance.The optimal hydrogen evolution rate of the Ti_(3)C_(2)-CdS-Cu_(2)O@NC S-scheme heterojunction photocatalyst is 7.4 times higher than that of pure CdS.Experimental techniques and DFT calculations were employed to explore the structure,morphology,optical properties,charge dynamics,and band structure of the heterojunction.The results revealed that the S-scheme mechanism effectively suppresses the recombination of photogenerated carriers and facilitates the separation and migration of photo-generated electrons and holes to the reaction sites.Furthermore,Ti_(3)C_(2)MXene provides abundant active sites essential for accelerating the surface H_(2)-evolution reaction kinetics.The Cu_(2)O@NC core-shell nanoparticles with a large surface area and high stability are closely adhered to CdS nanorods and establish an S-scheme internal electric field with CdS nanorods to drive charge separation.This investigation provides valuable insights into the rational design of CdS-based photocatalysts,enabling efficient hydrogen production by harnessing the robust kinetic driving force provided by the S-scheme heterojunctions.
