以 Sn Cl4· Ti( OBu) 4、氨水、乙醇为原料 ,采用活性层包覆法 ,制备出 Ti O2 / Sn O2 复合光催化剂 ,并用IR、XRD、TEM和 BET等手段对样品进行了表征 .研究其对有机磷农药敌敌畏的光催化降解效果 ,与单一半导体催化剂 Sn O2 、Ti ...以 Sn Cl4· Ti( OBu) 4、氨水、乙醇为原料 ,采用活性层包覆法 ,制备出 Ti O2 / Sn O2 复合光催化剂 ,并用IR、XRD、TEM和 BET等手段对样品进行了表征 .研究其对有机磷农药敌敌畏的光催化降解效果 ,与单一半导体催化剂 Sn O2 、Ti O2 做了简单对比 .结果表明 :所制 Ti O2 / Sn O2 样品为包覆型结构 ,由锐钛矿型 Ti O2 金红石型 Sn O2 组成 ,与 Sn O2 及 Ti O2 晶体粉末相比所制 Ti O2 / Sn O2 包覆粒子光催化活性得到明显提高 .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
TiO 2 nanoparticles were obtained from industrial TiOSO 4 by hydrolysis method. SnO 2/TiO 2 and SnO 2-TiO 2 composite powders were prepared by stepwise precipitation method and coating method, respectively. The phase ...TiO 2 nanoparticles were obtained from industrial TiOSO 4 by hydrolysis method. SnO 2/TiO 2 and SnO 2-TiO 2 composite powders were prepared by stepwise precipitation method and coating method, respectively. The phase transformation of TiO 2 and the effect of composite mode of SnO 2 on phase transformation of TiO 2 have been investigated by TG-DTA and XRD. The phase transform of pure TiO 2 from anatase to rutile begins at 750 ℃ and the presence of SnO 2 markedly reduces the transform temperature: for coated SnO 2-TiO 2 composite with ω(SnO 2)=20% it was 400 ℃. The SnO 2/TiO 2 composite prepared by precipitation method and followed by calcination at 400 ℃ for 30 min possesses 55% rutile TiO 2. The formation of SnO 2-TiO 2 solid- solution occurrs mainly due to the substitution of Ti 4+ crystal lattice sites by Sn 4+ ions of SnO 2.展开更多
文摘以 Sn Cl4· Ti( OBu) 4、氨水、乙醇为原料 ,采用活性层包覆法 ,制备出 Ti O2 / Sn O2 复合光催化剂 ,并用IR、XRD、TEM和 BET等手段对样品进行了表征 .研究其对有机磷农药敌敌畏的光催化降解效果 ,与单一半导体催化剂 Sn O2 、Ti O2 做了简单对比 .结果表明 :所制 Ti O2 / Sn O2 样品为包覆型结构 ,由锐钛矿型 Ti O2 金红石型 Sn O2 组成 ,与 Sn O2 及 Ti O2 晶体粉末相比所制 Ti O2 / Sn O2 包覆粒子光催化活性得到明显提高 .
文摘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.
文摘TiO 2 nanoparticles were obtained from industrial TiOSO 4 by hydrolysis method. SnO 2/TiO 2 and SnO 2-TiO 2 composite powders were prepared by stepwise precipitation method and coating method, respectively. The phase transformation of TiO 2 and the effect of composite mode of SnO 2 on phase transformation of TiO 2 have been investigated by TG-DTA and XRD. The phase transform of pure TiO 2 from anatase to rutile begins at 750 ℃ and the presence of SnO 2 markedly reduces the transform temperature: for coated SnO 2-TiO 2 composite with ω(SnO 2)=20% it was 400 ℃. The SnO 2/TiO 2 composite prepared by precipitation method and followed by calcination at 400 ℃ for 30 min possesses 55% rutile TiO 2. The formation of SnO 2-TiO 2 solid- solution occurrs mainly due to the substitution of Ti 4+ crystal lattice sites by Sn 4+ ions of SnO 2.
