The nanosized binary mixed oxides of Zn/Sn had been prepared by the fractional homogeneous precipitation route using urea as the latent precipitant under boiling reflux condition The samples prepared with the differen...The nanosized binary mixed oxides of Zn/Sn had been prepared by the fractional homogeneous precipitation route using urea as the latent precipitant under boiling reflux condition The samples prepared with the different initial concentrations of urea or calcined at different temperatures had been investigated by X-ray diffration (XRD) or transmission electron microscopy (TEM). The calcination temperature had obvious effect on the phase composition and the crystal size of the samples attained, and the precipitant concentration also had obvious effect on the oxide particles size and the production rate of ZnO.展开更多
TiO2-SnO2-SiO2 nanocomposite photocatalysts were prepared with Na2SiO3·9H2O, SnCl4·5H2O and TiCl4 as precursors by chemistry coating processes and supercritical fluid drying (SCFD) method. Characterizations ...TiO2-SnO2-SiO2 nanocomposite photocatalysts were prepared with Na2SiO3·9H2O, SnCl4·5H2O and TiCl4 as precursors by chemistry coating processes and supercritical fluid drying (SCFD) method. Characterizations with XRD, TEM, NMR and FTIR showed that in addition to anatase type TiO2, a new active phase(Ti,Sn)O2 was also formed in the range of the studied doping concentration, The catalytic activity was evaluated by photocatalytic degradation of phenol as model reaction. SiO2 remained amphorous at all samples. It could prevent from growth of the size of nanopaticle and transformation from anatase to rutile. Compared with pure TiO2, or TiO2-SnO2 catalyst prepared by Sol-gel method, Nano-composite photo-catalyst showed significant improvement in catalytic activity, the photo-catalytic degradation rate of phenol in 7 h reached 88.7%. Application of the composite catalysts for the photocatalytic decomposition of phenol not only gave the same activity relative to pure ultrafine TiO2, but also reduced cost. The experimental results also proved that the thermal stability of TiO2 was greatly enhanced after mixing with small amount of SiO2. The optimized doping of SiO2 was 20.3%. The photo-catalyst prepared by SCFD combination technology was characterized with smaller particle size, larger surface area and higher activity.展开更多
TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transm...TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.展开更多
基金Acknowledgments: This work was supported by the National Natural Science Foundation of China (No. 20673042), the Natural Science Foundation of Anhui Provincial Education Committee (No. K12007B014), the Natural Science Foundation of Anhui Province (No. 070415211), China Postdoctoral Science Foundation (No. 2004036511), the Laboratory Open Foundation of Green Materials Chemistry (No. KLSF(I)09), and the Laboratory Open Foundation of Guangdong Public Laboratory of Environmental Science and Technology. The authors thank Mr. LUO S. M., Mr. CHEN D. Z., and Mr. TAO Q. for their assistance.
摘要The nanosized binary mixed oxides of Zn/Sn had been prepared by the fractional homogeneous precipitation route using urea as the latent precipitant under boiling reflux condition The samples prepared with the different initial concentrations of urea or calcined at different temperatures had been investigated by X-ray diffration (XRD) or transmission electron microscopy (TEM). The calcination temperature had obvious effect on the phase composition and the crystal size of the samples attained, and the precipitant concentration also had obvious effect on the oxide particles size and the production rate of ZnO.
摘要TiO2-SnO2-SiO2 nanocomposite photocatalysts were prepared with Na2SiO3·9H2O, SnCl4·5H2O and TiCl4 as precursors by chemistry coating processes and supercritical fluid drying (SCFD) method. Characterizations with XRD, TEM, NMR and FTIR showed that in addition to anatase type TiO2, a new active phase(Ti,Sn)O2 was also formed in the range of the studied doping concentration, The catalytic activity was evaluated by photocatalytic degradation of phenol as model reaction. SiO2 remained amphorous at all samples. It could prevent from growth of the size of nanopaticle and transformation from anatase to rutile. Compared with pure TiO2, or TiO2-SnO2 catalyst prepared by Sol-gel method, Nano-composite photo-catalyst showed significant improvement in catalytic activity, the photo-catalytic degradation rate of phenol in 7 h reached 88.7%. Application of the composite catalysts for the photocatalytic decomposition of phenol not only gave the same activity relative to pure ultrafine TiO2, but also reduced cost. The experimental results also proved that the thermal stability of TiO2 was greatly enhanced after mixing with small amount of SiO2. The optimized doping of SiO2 was 20.3%. The photo-catalyst prepared by SCFD combination technology was characterized with smaller particle size, larger surface area and higher activity.
基金financially supported by the National Natural Science Foundation of China (No.20873046)the Specialized Research Fund for the Doctoral Program of HigherEducation (No.200805740004)Natural Science Foundation of Guangdong Province (No.10351063101000001)
摘要TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.