A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on des...A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on desulfurization of thiophene dissolved in n-octane, which was used as a model light oil, via photocatalytic oxidation reaction under illumination by visible light. The catalyst characterization results indicated that the loading of Cu on the catalyst did not change the crystal phase of BiVO4, and the crystallinity of the Cu-BiVO4 sample was found to be better at pH=7. The Cu-BiVO4 samples presented a significant bathochromic shift of the absorption band in the visible region, and the absorption intensity increased for the composite catalyst. The desulfurization experiments showed that the Cu-BiVO4 sample prepared at a pH value of 7 had a better catalytic activity. Under proper operating conditions, the desulfurization rate of the model compound achieved by Cu-BiVO4 sample prepared at pH=7 could reach as high as 90%.展开更多
A type of visible light photocatalyst Bi2WO6 was prepared from Bi(NO3)3.5H2O and Na2WO4.2H2O by means of hydrothermal method and was characterized by UV-vis diffuse reflectance spectrometry and XRD.Oxidative desulfuri...A type of visible light photocatalyst Bi2WO6 was prepared from Bi(NO3)3.5H2O and Na2WO4.2H2O by means of hydrothermal method and was characterized by UV-vis diffuse reflectance spectrometry and XRD.Oxidative desulfurization via photocatalysis was investigated using thiophene dissolved in octane as the model compound,with hydrogen peroxide used as the oxidant.The effects of hydrogen peroxide mass fraction,irradiation time,dosage of photocatalyst Bi2WO6 on the desulfurization efficiency were also investigated.Under suitable conditions,the desulfurization rate of model compound reached over 70%.展开更多
In this study, the effects of microwave radiation intensity, radiation time and initial wood moisture content （MC） on the properties of temperature development in Eucalyptus urophylla wood samples during the microwa...In this study, the effects of microwave radiation intensity, radiation time and initial wood moisture content （MC） on the properties of temperature development in Eucalyptus urophylla wood samples during the microwave explosion pretreatment have been investigated using a new microwave pretreatment equipment. The results show that 1） with the increase of microwave radiation intensity and a decrease in initial wood MC, both the average temperature and its rate of increase in wood rise rapidly; 2） with an increase in microwave radiation time, the average temperature of wood clearly increases, while the rate of increase in temperature shows a decline. In the microwave explosion pretreatment, the temperature development curve presented two patterns of variation： i） a sharp increase in temperature - a constant temperature - a slow warm-up and ii） a sharp increase in temperature - a rapid decline in temperature - a slow warm-up.展开更多
基金supported by the National Natural Science Foundation of China (No. 21003103)the Nature Scientific Research Foundation of Shaanxi Provincial Education Office of China (No. 2010JS061)Natural Science Foundation Program of Yan’an University (YD2011-19)
文摘A photocatalyst Cu-BiVO4 was synthesized by the hydrothermal method and was characterized by XRD, UV-vis DRS, and N2 adsorption-desorption measurement. The catalytic activity of the Cu-BiVO4 samples was studied on desulfurization of thiophene dissolved in n-octane, which was used as a model light oil, via photocatalytic oxidation reaction under illumination by visible light. The catalyst characterization results indicated that the loading of Cu on the catalyst did not change the crystal phase of BiVO4, and the crystallinity of the Cu-BiVO4 sample was found to be better at pH=7. The Cu-BiVO4 samples presented a significant bathochromic shift of the absorption band in the visible region, and the absorption intensity increased for the composite catalyst. The desulfurization experiments showed that the Cu-BiVO4 sample prepared at a pH value of 7 had a better catalytic activity. Under proper operating conditions, the desulfurization rate of the model compound achieved by Cu-BiVO4 sample prepared at pH=7 could reach as high as 90%.
基金support provided by the Shaanxi Provincial Education Project (09JK816)
文摘A type of visible light photocatalyst Bi2WO6 was prepared from Bi(NO3)3.5H2O and Na2WO4.2H2O by means of hydrothermal method and was characterized by UV-vis diffuse reflectance spectrometry and XRD.Oxidative desulfurization via photocatalysis was investigated using thiophene dissolved in octane as the model compound,with hydrogen peroxide used as the oxidant.The effects of hydrogen peroxide mass fraction,irradiation time,dosage of photocatalyst Bi2WO6 on the desulfurization efficiency were also investigated.Under suitable conditions,the desulfurization rate of model compound reached over 70%.
基金supported by the State Forestry Administration of China (2006–4–99)the National Natural Science Foundation of China (Grant No. 30871983)the Hunan Provincial Natural Science Foundation of China (07JJ6166)
文摘In this study, the effects of microwave radiation intensity, radiation time and initial wood moisture content （MC） on the properties of temperature development in Eucalyptus urophylla wood samples during the microwave explosion pretreatment have been investigated using a new microwave pretreatment equipment. The results show that 1） with the increase of microwave radiation intensity and a decrease in initial wood MC, both the average temperature and its rate of increase in wood rise rapidly; 2） with an increase in microwave radiation time, the average temperature of wood clearly increases, while the rate of increase in temperature shows a decline. In the microwave explosion pretreatment, the temperature development curve presented two patterns of variation： i） a sharp increase in temperature - a constant temperature - a slow warm-up and ii） a sharp increase in temperature - a rapid decline in temperature - a slow warm-up.
