Two-dimensional mesoporous ultrathin Cd0.5Zn0.5S nanosheets with a thickness of~1.5 nm were fabricated using a multistep chemical transformation strategy involving inorganic–organic hybrid ZnS-ethylenediamine(denoted...Two-dimensional mesoporous ultrathin Cd0.5Zn0.5S nanosheets with a thickness of~1.5 nm were fabricated using a multistep chemical transformation strategy involving inorganic–organic hybrid ZnS-ethylenediamine(denoted as ZnS(en)0.5)as a hard template.Inorganic–organic hybrid ZnS(en)0.5,Cd0.5Zn0.5S(en)x,and Cd0.5Zn0.5S nanosheets were sequentially fabricated,and their transformation processes were analyzed in detail.The fabricated Cd0.5Zn0.5S nanosheets exhibited high photocatalytic hydrogen evolution reaction activity in the presence of a sacrificial agent.The Cd0.5Zn0.5S nanosheets exhibited remarkably high H2 production activity of~1395μmol∙h^−1∙g^−1 in pure water with no co-catalyst,which is the highest value reported thus far for bare photocatalysts,to the best of our knowledge.The high activity of these nanosheets is attributed to their distinct nanostructure(e.g.,short transfer distance of photoinduced charge carriers,large number of unsaturated surface atoms,and large surface area).Moreover,ternary NiCo2S4 nanoparticles were employed to facilitate the charge separation and enhance the surface kinetics of H2 evolution.The H2 production rate reached~62.2 and~2436μmol∙h^−1∙g^−1 in triethanolamine and pure water,respectively,over the NiCo2S4/Cd0.5Zn0.5S heterojunctions.The result indicated that the Schottky junction was critical to the enhanced activity.The proposed method can be used for fabricating other highly efficient CdZnS-based photocatalysts for solar-energy conversion or other applications.展开更多
The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts...The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts with twin nanocrystal Zn0.5Cd0.5S(ZCS)solid solution homojunctions for an efficient visible-light-driven H2 production by a simple approach.As-synthesized Zn0.5Cd0.5S-1%Ni3C(ZCS-1)heterojunction/homojunction nanohybrid exhibited the highest photocatalytic H2-evolution rate of 783μmol h‒1 under visible light,which is 2.88 times higher than that of pristine twin nanocrystal ZCS solid solution.The apparent quantum efficiencies of ZCS and ZCS-1 are measured to be 6.13%and 19.25%at 420 nm,respectively.Specifically,the homojunctions between the zinc blende and wurtzite segments in twin nanocrystal ZCS solid solution can significantly improve the light absorption and separation of photogenerated electron-hole pairs.Furthermore,the heterojunction between ZCS and metallic Ni3C NP cocatalysts can efficiently trap excited electrons from ZCS solid solution and enhance the H2-evolution kinetics at the surface for improving catalytic activity.This study demonstrates a unique one-step strategy for constructing heterojunction/homojunction hybrid nanostructures for a more efficient photocatalytic H2 evolution compared to other noble metal photocatalytic systems.展开更多
The design and construction of low‐cost and high‐performance hybrid materials for the photocatalytic hydrogen production reaction(HER)are extremely important for the large‐scale application of hydrogen energy.Metal...The design and construction of low‐cost and high‐performance hybrid materials for the photocatalytic hydrogen production reaction(HER)are extremely important for the large‐scale application of hydrogen energy.Metal‐organic frameworks(MOFs)are considered to be potential photocatalytic materials.Herein,monodisperse,small size,non‐precious metal transition metal phosphide Ni2P is encapsulated into a typical MOF(UiO‐66‐NH2)as a hybrid core‐shell cocatalyst to modify Zn_(0.5)Cd_(0.5)S for photocatalytic hydrogen production.Ni2P is wrapped in UiO‐66‐NH_(2)via an in situ solvothermal method,and Zn_(0.5)Cd_(0.5)S sulfide is decorated with a core‐shell Ni_(2)P@UiO‐66‐NH_(2)cocatalyst to obtain ternary Ni_(2)P@UiO‐66‐NH_(2)/Zn_(0.5)Cd_(0.5)S composite materials.Photoelectric and chemical characterization confirms that the ternary composites have good kinetic hydrogen production performance.The hydrogen production rate of 10%10 mg Ni_(2)P@UiO‐66‐NH_(2)/Zn_(0.5)Cd_(0.5)S reaches 40.91 mmol·g^(–1)·h^(–1)with an apparent quantum efficiency at 420 nm of 13.57%.The addition of 10 mg Ni_(2)P@UiO‐66‐NH_(2)increases the surface area of the ternary material,providing abundant reaction sites and forming an efficient charge transfer channel,which is conducive to efficient hydrogen production by the ternary photocatalysts.It is shown that the formation of a ternary composite system is beneficial to the occurrence of an efficient catalytic reaction.This study provides a new perspective for the construction of high‐performance photocatalytic materials.展开更多
文摘Two-dimensional mesoporous ultrathin Cd0.5Zn0.5S nanosheets with a thickness of~1.5 nm were fabricated using a multistep chemical transformation strategy involving inorganic–organic hybrid ZnS-ethylenediamine(denoted as ZnS(en)0.5)as a hard template.Inorganic–organic hybrid ZnS(en)0.5,Cd0.5Zn0.5S(en)x,and Cd0.5Zn0.5S nanosheets were sequentially fabricated,and their transformation processes were analyzed in detail.The fabricated Cd0.5Zn0.5S nanosheets exhibited high photocatalytic hydrogen evolution reaction activity in the presence of a sacrificial agent.The Cd0.5Zn0.5S nanosheets exhibited remarkably high H2 production activity of~1395μmol∙h^−1∙g^−1 in pure water with no co-catalyst,which is the highest value reported thus far for bare photocatalysts,to the best of our knowledge.The high activity of these nanosheets is attributed to their distinct nanostructure(e.g.,short transfer distance of photoinduced charge carriers,large number of unsaturated surface atoms,and large surface area).Moreover,ternary NiCo2S4 nanoparticles were employed to facilitate the charge separation and enhance the surface kinetics of H2 evolution.The H2 production rate reached~62.2 and~2436μmol∙h^−1∙g^−1 in triethanolamine and pure water,respectively,over the NiCo2S4/Cd0.5Zn0.5S heterojunctions.The result indicated that the Schottky junction was critical to the enhanced activity.The proposed method can be used for fabricating other highly efficient CdZnS-based photocatalysts for solar-energy conversion or other applications.
文摘The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts with twin nanocrystal Zn0.5Cd0.5S(ZCS)solid solution homojunctions for an efficient visible-light-driven H2 production by a simple approach.As-synthesized Zn0.5Cd0.5S-1%Ni3C(ZCS-1)heterojunction/homojunction nanohybrid exhibited the highest photocatalytic H2-evolution rate of 783μmol h‒1 under visible light,which is 2.88 times higher than that of pristine twin nanocrystal ZCS solid solution.The apparent quantum efficiencies of ZCS and ZCS-1 are measured to be 6.13%and 19.25%at 420 nm,respectively.Specifically,the homojunctions between the zinc blende and wurtzite segments in twin nanocrystal ZCS solid solution can significantly improve the light absorption and separation of photogenerated electron-hole pairs.Furthermore,the heterojunction between ZCS and metallic Ni3C NP cocatalysts can efficiently trap excited electrons from ZCS solid solution and enhance the H2-evolution kinetics at the surface for improving catalytic activity.This study demonstrates a unique one-step strategy for constructing heterojunction/homojunction hybrid nanostructures for a more efficient photocatalytic H2 evolution compared to other noble metal photocatalytic systems.
文摘The design and construction of low‐cost and high‐performance hybrid materials for the photocatalytic hydrogen production reaction(HER)are extremely important for the large‐scale application of hydrogen energy.Metal‐organic frameworks(MOFs)are considered to be potential photocatalytic materials.Herein,monodisperse,small size,non‐precious metal transition metal phosphide Ni2P is encapsulated into a typical MOF(UiO‐66‐NH2)as a hybrid core‐shell cocatalyst to modify Zn_(0.5)Cd_(0.5)S for photocatalytic hydrogen production.Ni2P is wrapped in UiO‐66‐NH_(2)via an in situ solvothermal method,and Zn_(0.5)Cd_(0.5)S sulfide is decorated with a core‐shell Ni_(2)P@UiO‐66‐NH_(2)cocatalyst to obtain ternary Ni_(2)P@UiO‐66‐NH_(2)/Zn_(0.5)Cd_(0.5)S composite materials.Photoelectric and chemical characterization confirms that the ternary composites have good kinetic hydrogen production performance.The hydrogen production rate of 10%10 mg Ni_(2)P@UiO‐66‐NH_(2)/Zn_(0.5)Cd_(0.5)S reaches 40.91 mmol·g^(–1)·h^(–1)with an apparent quantum efficiency at 420 nm of 13.57%.The addition of 10 mg Ni_(2)P@UiO‐66‐NH_(2)increases the surface area of the ternary material,providing abundant reaction sites and forming an efficient charge transfer channel,which is conducive to efficient hydrogen production by the ternary photocatalysts.It is shown that the formation of a ternary composite system is beneficial to the occurrence of an efficient catalytic reaction.This study provides a new perspective for the construction of high‐performance photocatalytic materials.
