Distinguished from commonly used Fe2O3 and Fe3O4,a three-dimensional multilevel macromicro-mesoporous structure of FeC2O4/graphene composite has been prepared as binderfree electrode for supercapacitors.The as-prepare...Distinguished from commonly used Fe2O3 and Fe3O4,a three-dimensional multilevel macromicro-mesoporous structure of FeC2O4/graphene composite has been prepared as binderfree electrode for supercapacitors.The as-prepared materials are composed of macroporous graphene and microporous/mesoporous ferrous oxalate.Generally,the decomposition voltage of water is 1.23 V and the practical voltage window limit is about 2 V for asymmetric supercapacitors in aqueous electrolytes.When FeC2O4/rGO hydrogel was used as the negative electrode and a pure rGO hydrogel was used as the positive electrode,the asymmetrical supercapacitor voltage window raised to 1.7 V in KOH(1.0 mol/L)electrolyte and reached up to 2.5 V in a neutral aqueous Na2SO4(1.0 mol/L)electrolyte.Correspondingly it also exhibits a high performance with an energy density of 59.7 Wh/kg.By means of combining a metal oxide that owns micro-mesoporous structure with graphene,this work provides a new opportunity for preparing high-voltage aqueous asymmetric supercapacitors without addition of conductive agent and binder.展开更多
Titanium dioxide （TiO2） is widely employed as a solid photocatalyst for solar energy conversion and envi- ronmental remediation. The ability to construct porous TiO2 with controlled particle size and narrowed bandga...Titanium dioxide （TiO2） is widely employed as a solid photocatalyst for solar energy conversion and envi- ronmental remediation. The ability to construct porous TiO2 with controlled particle size and narrowed bandgap is an essential requirement for the design of highly efficient and recyclable photocatalysts. Here, we report a template- free acetic acid induced method for the synthesis of visible- light responsive carbon-doped TiO2 microplates with high crystallinity and mesoporous structure. It is shown that the electron-withdrawing bidentate carboxylate ligands derived from acetic acid can narrow the bandgap of TiO2 （1.84 eV） substantially. Moreover, the resultant microplate photo- catalysts exhibit excellent photocatalytic efficiency and solid-liquid separation performance, which will be bene- ficial for future industrial applications.展开更多
A series of CuxO self-assembled mesoporous microspheres （SMMs）, with different and controlled mor- phology （virus-like, urchin-like, spherical）, were synthesized by facile liquid phase approach. The morphology of ...A series of CuxO self-assembled mesoporous microspheres （SMMs）, with different and controlled mor- phology （virus-like, urchin-like, spherical）, were synthesized by facile liquid phase approach. The morphology of the as- prepared CuxO SMMs was evolved from spherical to virus-like shape by controlling the ratio of DI water in solution. It can also realize the transformation from loose assembly to dense assembly by extending the reaction time. These CuxO SMMs exhibited good response to NO2 gas at room temperature, benefiting from their 3D self-assembly structure. Among these the resulting virus-like CuxO SNMMs-based sensor exhibits largely enhanced response to 1 ppm NO2 gas at room temperature. The enhanced response of the virus-like Cn2O SMMs-based sensor can be ascribed to the high surface area, hier- archical 3D nanostructures, micropores for effective gas diffusion, the heterojunctions formed between CuO and Cu2O, and the existence of abundant surface oxygen vacancies.展开更多
基金supported by the National Natural Science Foundation of China (No.51673180 and No. 51673180)
文摘Distinguished from commonly used Fe2O3 and Fe3O4,a three-dimensional multilevel macromicro-mesoporous structure of FeC2O4/graphene composite has been prepared as binderfree electrode for supercapacitors.The as-prepared materials are composed of macroporous graphene and microporous/mesoporous ferrous oxalate.Generally,the decomposition voltage of water is 1.23 V and the practical voltage window limit is about 2 V for asymmetric supercapacitors in aqueous electrolytes.When FeC2O4/rGO hydrogel was used as the negative electrode and a pure rGO hydrogel was used as the positive electrode,the asymmetrical supercapacitor voltage window raised to 1.7 V in KOH(1.0 mol/L)electrolyte and reached up to 2.5 V in a neutral aqueous Na2SO4(1.0 mol/L)electrolyte.Correspondingly it also exhibits a high performance with an energy density of 59.7 Wh/kg.By means of combining a metal oxide that owns micro-mesoporous structure with graphene,this work provides a new opportunity for preparing high-voltage aqueous asymmetric supercapacitors without addition of conductive agent and binder.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （20966006）, the Natural Science Foun- dation of the Inner Mongolia Autonomous Region （2014MS0218）, and the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region （NMGIRT-A1603）.
文摘Titanium dioxide （TiO2） is widely employed as a solid photocatalyst for solar energy conversion and envi- ronmental remediation. The ability to construct porous TiO2 with controlled particle size and narrowed bandgap is an essential requirement for the design of highly efficient and recyclable photocatalysts. Here, we report a template- free acetic acid induced method for the synthesis of visible- light responsive carbon-doped TiO2 microplates with high crystallinity and mesoporous structure. It is shown that the electron-withdrawing bidentate carboxylate ligands derived from acetic acid can narrow the bandgap of TiO2 （1.84 eV） substantially. Moreover, the resultant microplate photo- catalysts exhibit excellent photocatalytic efficiency and solid-liquid separation performance, which will be bene- ficial for future industrial applications.
基金supported by the National Natural Science Foundation(51501010,91323301,51631001,51372025 and21643003)
文摘A series of CuxO self-assembled mesoporous microspheres （SMMs）, with different and controlled mor- phology （virus-like, urchin-like, spherical）, were synthesized by facile liquid phase approach. The morphology of the as- prepared CuxO SMMs was evolved from spherical to virus-like shape by controlling the ratio of DI water in solution. It can also realize the transformation from loose assembly to dense assembly by extending the reaction time. These CuxO SMMs exhibited good response to NO2 gas at room temperature, benefiting from their 3D self-assembly structure. Among these the resulting virus-like CuxO SNMMs-based sensor exhibits largely enhanced response to 1 ppm NO2 gas at room temperature. The enhanced response of the virus-like Cn2O SMMs-based sensor can be ascribed to the high surface area, hier- archical 3D nanostructures, micropores for effective gas diffusion, the heterojunctions formed between CuO and Cu2O, and the existence of abundant surface oxygen vacancies.
