CdS-based photocatalysts offer an efficient route for simultaneous photocatalytic hydrogen evolution and benzyl alcohol oxidation to value-added chemicals.However,the rapid charge recombination,poor oxidation capabili...CdS-based photocatalysts offer an efficient route for simultaneous photocatalytic hydrogen evolution and benzyl alcohol oxidation to value-added chemicals.However,the rapid charge recombination,poor oxidation capabilities,and strong photocorrosion of CdS,when used alone,can lead to low productivity of H2 and benzaldehyde.Herein,we present a novel S-scheme heterojunction through coupling CdS with Fluorenone-COF as the promising oxidation end.The suitable band level and active center of the fluorenone moiety impart strong oxidative capabilities to the fluorenone-based COFs,enabling them to efficiently catalyze the oxidation of benzyl alcohol with a low reaction energy barrier.Furthermore,the intrinsic electric field of the S-scheme heterojunction significantly improves the separation and mobility of photoinduced charge carriers,while effectively suppressing charge recombination,which in turn reduces the corrosive effect of photogenerated holes on CdS.Consequently,the heterojunction significantly improved the yield of both benzaldehyde and hydrogen.In the presence of Pt as a cocatalyst,the production rates of H2 and benzaldehyde reached 23.38 and 17.36 mmol g^(-1) h^(-1),respectively.This work not only addresses the challenges associated with the utilization of electron holes but also provides an effective green and low-carbon pathway to overcome the challenges of low efficiency and high cost in photocatalytic hydrogen production.展开更多
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National Natural Science Foundation of China(22378148,52472110,22308113)Natural Science Foundation of Guangdong Province(2024A1515012433)for their support.
文摘CdS-based photocatalysts offer an efficient route for simultaneous photocatalytic hydrogen evolution and benzyl alcohol oxidation to value-added chemicals.However,the rapid charge recombination,poor oxidation capabilities,and strong photocorrosion of CdS,when used alone,can lead to low productivity of H2 and benzaldehyde.Herein,we present a novel S-scheme heterojunction through coupling CdS with Fluorenone-COF as the promising oxidation end.The suitable band level and active center of the fluorenone moiety impart strong oxidative capabilities to the fluorenone-based COFs,enabling them to efficiently catalyze the oxidation of benzyl alcohol with a low reaction energy barrier.Furthermore,the intrinsic electric field of the S-scheme heterojunction significantly improves the separation and mobility of photoinduced charge carriers,while effectively suppressing charge recombination,which in turn reduces the corrosive effect of photogenerated holes on CdS.Consequently,the heterojunction significantly improved the yield of both benzaldehyde and hydrogen.In the presence of Pt as a cocatalyst,the production rates of H2 and benzaldehyde reached 23.38 and 17.36 mmol g^(-1) h^(-1),respectively.This work not only addresses the challenges associated with the utilization of electron holes but also provides an effective green and low-carbon pathway to overcome the challenges of low efficiency and high cost in photocatalytic hydrogen production.
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.
