The hierarchical BiOCl_(x)Br_(1–x)was synthesized by a simple solvothermal method.The samples were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),UV-visible diffuse reflect...The hierarchical BiOCl_(x)Br_(1–x)was synthesized by a simple solvothermal method.The samples were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),UV-visible diffuse reflectance spectroscopy(UV-vis DRS)and Brunauer-Emmett-Teller adsorption method.Compared to pure BiOCl or BiOBr,the BiOCl_(x)Br_(1–x)solid solution has enhanced photocatalytic degradation activity for rhodamine B.This phenomenon can be explained to the hierarchical structure,lager specific surface area and appropriate energy gap of the obtained BiOCl_(x)Br_(1–x)solid solution.The renewability and stability of photocatalyst were determinated and a possible mechanism of photocatalytic degradation was also proposed.展开更多
ZnO/ZnGa_2O_4 composite microspheres with heterojunction were successfully synthesized by one-pot hydrothermal method.These samples were characterized by TG/DTA,XRD,TEM,HRTEM,UV-vis DRS,FL and BET techniques.The resul...ZnO/ZnGa_2O_4 composite microspheres with heterojunction were successfully synthesized by one-pot hydrothermal method.These samples were characterized by TG/DTA,XRD,TEM,HRTEM,UV-vis DRS,FL and BET techniques.The results indicated the as-prepared samples showed better degree of crystalline and large specific surface area.The photocatalytic activity was evaluated by degradation of methyl orange with the concentration of 50 mg/L under the irradiation of simulated sunlight.The effects of molar ratio of Zn to Ga and calcination temperature on the photocatalytic activity were investigated in detail.The results showed that the highest photocatalytic degradation efficiency was observed at the molar ratio of Zn to Ga of 1:0.5 in the starting materials and the calcination temperature of 400 °C.The maximum photocatalytic degradation rate of MO was 97.1% within 60 min under the simulated sunlight irradiation,which is greatly higher than that of ZnO and ZnGa_2O_4.展开更多
A sustainable process was explored for the preparation of 5-hydroxymethylfurfural(HMF) by catalytic degradation of the waste cotton stalk. Solid super-acid(SO_4^(2-)/ZrO_2) was used as an efficient catalyst for the de...A sustainable process was explored for the preparation of 5-hydroxymethylfurfural(HMF) by catalytic degradation of the waste cotton stalk. Solid super-acid(SO_4^(2-)/ZrO_2) was used as an efficient catalyst for the degradation of cotton stalk. Both decomposition experiments and kinetic study were conducted for the exploration of degradation condition and kinetics mechanism. The optimized experimental conditions are reaction temperature 503 K, reaction time 75 min and dosage of catalyst 30%(mass fraction) based on the decomposition experiments, under which a maximum yield of 27.2% for HMF could be achieved. Kinetic study was then carried out in the presence of SO_4^(2-)/ZrO_2. The theoretical results indicate that the activation energies for reducing sugar and HMF with catalyst are 96.71 k J/mol, 84.21 kJ/mol in the presence of SO_4^(2-)/ZrO_2, and they are 105.96 k J/mol and 119.37 k J/mol in the absence of SO_4^(2-)/ZrO_2.展开更多
基金Project(2016TP1007)supported by the Hunan Provincial Science and Technology Plan Project,China
文摘The hierarchical BiOCl_(x)Br_(1–x)was synthesized by a simple solvothermal method.The samples were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),UV-visible diffuse reflectance spectroscopy(UV-vis DRS)and Brunauer-Emmett-Teller adsorption method.Compared to pure BiOCl or BiOBr,the BiOCl_(x)Br_(1–x)solid solution has enhanced photocatalytic degradation activity for rhodamine B.This phenomenon can be explained to the hierarchical structure,lager specific surface area and appropriate energy gap of the obtained BiOCl_(x)Br_(1–x)solid solution.The renewability and stability of photocatalyst were determinated and a possible mechanism of photocatalytic degradation was also proposed.
基金Projects(21306041,21271071)supported by the National Natural Science Foundation of ChinaProject(15A076)supported by the Scientific Research Foundation of Hunan Provincial Education Department of China
文摘ZnO/ZnGa_2O_4 composite microspheres with heterojunction were successfully synthesized by one-pot hydrothermal method.These samples were characterized by TG/DTA,XRD,TEM,HRTEM,UV-vis DRS,FL and BET techniques.The results indicated the as-prepared samples showed better degree of crystalline and large specific surface area.The photocatalytic activity was evaluated by degradation of methyl orange with the concentration of 50 mg/L under the irradiation of simulated sunlight.The effects of molar ratio of Zn to Ga and calcination temperature on the photocatalytic activity were investigated in detail.The results showed that the highest photocatalytic degradation efficiency was observed at the molar ratio of Zn to Ga of 1:0.5 in the starting materials and the calcination temperature of 400 °C.The maximum photocatalytic degradation rate of MO was 97.1% within 60 min under the simulated sunlight irradiation,which is greatly higher than that of ZnO and ZnGa_2O_4.
基金Project(2010DFA41440)supported by China-Japan International CooperationProject(2016TP1007)supported by the Hunan Provincial Science and Technology Plan,ChinaProject(21376269)supported by the National Natural Science Foundation of China
文摘A sustainable process was explored for the preparation of 5-hydroxymethylfurfural(HMF) by catalytic degradation of the waste cotton stalk. Solid super-acid(SO_4^(2-)/ZrO_2) was used as an efficient catalyst for the degradation of cotton stalk. Both decomposition experiments and kinetic study were conducted for the exploration of degradation condition and kinetics mechanism. The optimized experimental conditions are reaction temperature 503 K, reaction time 75 min and dosage of catalyst 30%(mass fraction) based on the decomposition experiments, under which a maximum yield of 27.2% for HMF could be achieved. Kinetic study was then carried out in the presence of SO_4^(2-)/ZrO_2. The theoretical results indicate that the activation energies for reducing sugar and HMF with catalyst are 96.71 k J/mol, 84.21 kJ/mol in the presence of SO_4^(2-)/ZrO_2, and they are 105.96 k J/mol and 119.37 k J/mol in the absence of SO_4^(2-)/ZrO_2.
