The fabrication of S-scheme heterojunctions has received considerable attention as an effective approach to promote the separation and migration of photoexcited electron/hole pairs and retain strong redox abilities.He...The fabrication of S-scheme heterojunctions has received considerable attention as an effective approach to promote the separation and migration of photoexcited electron/hole pairs and retain strong redox abilities.Herein,an imine-based porous covalent organic framework(COF-LZU1)is integrated with controllably fabricated Cd S hollow cubes,resulting in the formation of an S-scheme heterojunction.When the COF content reaches 1.5 wt%,the COF/Cd S heterostructure(1.5%COF/Cd S)achieves the highest hydrogen generation rate of 8670μmol·h^(-1)·g^(-1),which is approximately 2.1 times higher than that of pure Cd S.The apparent quantum efficiency(AQE)of 1.5%COF/Cd S is approximately 8.9%at 420 nm.Further systematic analysis shows that the intimate contact interface and suitable energy band structures between Cd S and COF can induce the formation of an internal electric field at the heterojunction interface,which can effectively drive the spatial separation of photoexcited charge carriers and simultaneously maintain a strong redox ability,thus enhancing the photocatalytic H_(2) evolution performance.展开更多
Hierarchically structured nanomaterials have attracted much attention owing to their unique properties.In this study,TiO2 nanofibers assembled from nanosheets(TiO2-NFs-NSs)were fabricated through electrospinning techn...Hierarchically structured nanomaterials have attracted much attention owing to their unique properties.In this study,TiO2 nanofibers assembled from nanosheets(TiO2-NFs-NSs)were fabricated through electrospinning technique,which was followed by hydrothermal treatment in NaOH solution.The effect of hydrothermal reaction time(0-3 h)on the structure and properties of TiO2 nanofibers(TiO2-NFs)was systematically studied,and TiO2-NFs was evaluated in terms of the photocatalytic activity toward photocatalytic oxidation of acetone and the photoelectric conversion efficiency of dye-sensitized solar cells.It was found that(1)hydrothermal treatment of TiO2-NFs in NaOH solution followed by acid washing and calcination results in the formation of TiO2-NFs-NSs;(2)upon extending the hydrothermal reaction time from 0 h to 3 h,the BET surface area of TiO2-NFs-NSs(T3.0 sample)increases 3.8 times(from 28 to 106 m2 g^-1),while the pore volume increases 6.0 times(from 0.09 to 0.54 cm3 g^-1);(3)when compared with those of pristine TiO2-NFs(T0 sample),the photoreactivity of the optimized TiO2-NFs-NSs toward acetone oxidation increases 3.1 times and the photoelectric conversion efficiency increases 2.3 times.The enhanced photoreactivity of TiO2-NFs-NSs is attributed to the enlarged BET surface area and increased pore volume,which facilitate the adsorption of substrate and penetration of gas,and the unique hollow structure of TiO2-NFs-NSs,which facilitates light harvesting through multiple optical reflections between the TiO2 nanosheets.展开更多
This paper describes the sodium storage mechanism of hard carbon,including the insertion-adsorption model,adsorption-insertion model,adsorption-filling model,and adsorption-insertion-filling model.The research progres...This paper describes the sodium storage mechanism of hard carbon,including the insertion-adsorption model,adsorption-insertion model,adsorption-filling model,and adsorption-insertion-filling model.The research progress of hard carbon prepared by synthetic polymers in recent years is reviewed.The modification strategies of morphology and structure regulation,surface engineering,defect engineering,heteroatom doping,and pretreatment are proposed to improve the electrochemical performance of hard carbon materials and promote the research and development of hard carbon as anode materials for sodium-ion batteries.展开更多
文摘The fabrication of S-scheme heterojunctions has received considerable attention as an effective approach to promote the separation and migration of photoexcited electron/hole pairs and retain strong redox abilities.Herein,an imine-based porous covalent organic framework(COF-LZU1)is integrated with controllably fabricated Cd S hollow cubes,resulting in the formation of an S-scheme heterojunction.When the COF content reaches 1.5 wt%,the COF/Cd S heterostructure(1.5%COF/Cd S)achieves the highest hydrogen generation rate of 8670μmol·h^(-1)·g^(-1),which is approximately 2.1 times higher than that of pure Cd S.The apparent quantum efficiency(AQE)of 1.5%COF/Cd S is approximately 8.9%at 420 nm.Further systematic analysis shows that the intimate contact interface and suitable energy band structures between Cd S and COF can induce the formation of an internal electric field at the heterojunction interface,which can effectively drive the spatial separation of photoexcited charge carriers and simultaneously maintain a strong redox ability,thus enhancing the photocatalytic H_(2) evolution performance.
基金supported by the National Natural Science Foundation of China(51672312,21373275)the Fundamental Research Funds for the Central Universities,South-Central University for Nationalities(CZT19006)~~
文摘Hierarchically structured nanomaterials have attracted much attention owing to their unique properties.In this study,TiO2 nanofibers assembled from nanosheets(TiO2-NFs-NSs)were fabricated through electrospinning technique,which was followed by hydrothermal treatment in NaOH solution.The effect of hydrothermal reaction time(0-3 h)on the structure and properties of TiO2 nanofibers(TiO2-NFs)was systematically studied,and TiO2-NFs was evaluated in terms of the photocatalytic activity toward photocatalytic oxidation of acetone and the photoelectric conversion efficiency of dye-sensitized solar cells.It was found that(1)hydrothermal treatment of TiO2-NFs in NaOH solution followed by acid washing and calcination results in the formation of TiO2-NFs-NSs;(2)upon extending the hydrothermal reaction time from 0 h to 3 h,the BET surface area of TiO2-NFs-NSs(T3.0 sample)increases 3.8 times(from 28 to 106 m2 g^-1),while the pore volume increases 6.0 times(from 0.09 to 0.54 cm3 g^-1);(3)when compared with those of pristine TiO2-NFs(T0 sample),the photoreactivity of the optimized TiO2-NFs-NSs toward acetone oxidation increases 3.1 times and the photoelectric conversion efficiency increases 2.3 times.The enhanced photoreactivity of TiO2-NFs-NSs is attributed to the enlarged BET surface area and increased pore volume,which facilitate the adsorption of substrate and penetration of gas,and the unique hollow structure of TiO2-NFs-NSs,which facilitates light harvesting through multiple optical reflections between the TiO2 nanosheets.
基金supported by the Guangdong University of Technology Hundred Talents Program(220418136).
文摘This paper describes the sodium storage mechanism of hard carbon,including the insertion-adsorption model,adsorption-insertion model,adsorption-filling model,and adsorption-insertion-filling model.The research progress of hard carbon prepared by synthetic polymers in recent years is reviewed.The modification strategies of morphology and structure regulation,surface engineering,defect engineering,heteroatom doping,and pretreatment are proposed to improve the electrochemical performance of hard carbon materials and promote the research and development of hard carbon as anode materials for sodium-ion batteries.
