CdS photocatalysts have broad application prospects in environmental purification,energy conversion,and organic synthesis.However,their practical use is often hindered by the rapid recombination of photo-generated ele...CdS photocatalysts have broad application prospects in environmental purification,energy conversion,and organic synthesis.However,their practical use is often hindered by the rapid recombination of photo-generated electron-hole pairs,which limits their efficiency on various reactions.Controlling morphological structures and crystal facets engineering are effective methods to enhance the photocatalytic performance of CdS.In this work,two different forms of CdS photocatalysts were synthesized by a hydrothermal method,namely nanoflower-shaped (CdS-NF) and nanorod-shaped (CdS-NR) for hydrogen peroxide (H_(2)O_(2)) production.The exposed crystal planes of CdS-NF are mainly (0 0 2) planes,while the accesible crystal planes of CdS-NR are notablly (1 0 1) planes.Notably,the photocatalytic hydrogen peroxide production yield of CdS-NR was high at 1225.13 μmol·h^(−1)·g^(−1),which is 1.78 times higher than the H_(2)O_(2) generation rate of CdS-NF.Moreover,through free radical capture experiments and DFT calculations,the reaction pathway was further explored.Both different configurations of cadmium sulfide based photocatalysts conform to the reaction mechanism of oxygen reduction as the main and water oxidation as the auxiliary.展开更多
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
基金support from Natural Science Foundation of Shandong Province(ZR2022MB049,ZR2021MB104)the National Natural Science Foundation of China(22078174).
文摘CdS photocatalysts have broad application prospects in environmental purification,energy conversion,and organic synthesis.However,their practical use is often hindered by the rapid recombination of photo-generated electron-hole pairs,which limits their efficiency on various reactions.Controlling morphological structures and crystal facets engineering are effective methods to enhance the photocatalytic performance of CdS.In this work,two different forms of CdS photocatalysts were synthesized by a hydrothermal method,namely nanoflower-shaped (CdS-NF) and nanorod-shaped (CdS-NR) for hydrogen peroxide (H_(2)O_(2)) production.The exposed crystal planes of CdS-NF are mainly (0 0 2) planes,while the accesible crystal planes of CdS-NR are notablly (1 0 1) planes.Notably,the photocatalytic hydrogen peroxide production yield of CdS-NR was high at 1225.13 μmol·h^(−1)·g^(−1),which is 1.78 times higher than the H_(2)O_(2) generation rate of CdS-NF.Moreover,through free radical capture experiments and DFT calculations,the reaction pathway was further explored.Both different configurations of cadmium sulfide based photocatalysts conform to the reaction mechanism of oxygen reduction as the main and water oxidation as the auxiliary.
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.
