采用溶胶-凝胶工艺制备了SnO2/TiO2复合光催化剂。以钛酸丁脂(Ti(C4H9O)4)为前驱体,冰醋酸为螯合剂,通过水解缩聚反应制备纳米TiO2,掺杂不同比例(n(SnO2)/n(TiO2)分别为1%、2.5%、5%)的SnO2对纳米TiO2进行改性,并对1%掺杂的粉体样品进行了不同温度(350~550℃)的焙烧处理。采用浸渍提拉法制备了1%(n(SnO2)/n(TiO2))掺杂的纳米SnO2/TiO2膜。运用X射线衍射(XRD)、透射电镜(TEM)、X射线光电子能谱(XPS)、原子力显微镜(AFM)及光吸收等手段,研究了不同掺杂量、热处理温度及光照时间对TiO2相变和光催化活性的影响。研究结果表明,350℃焙烧时,1%(n(SnO2)/n(TiO2))掺杂的粉体样品出现了合适比例的锐钛矿型和金红石型的混晶结构,具有较高的光催化效率,可达96.55%。而1%(n(SnO2)/n(TiO2))掺杂的纳米SnO2/TiO2光催化膜晶粒尺寸在20~30nm左右,光催化效率为79.6%,低于相同掺杂含量的纳米SnO2/TiO2掺杂光催化剂粉体。
SnO2/TiO2 composite photocatalysts were prepared by sol-gel processes. With HAC as complexation and Ti(C4 H9O)4 as precursor in the start materials, TiO2 gelation was obtained through hydrolyse and condensation process. Different doping amount(n(SnO2)/n(TiO2) is 1%, 2.5 %, 5 % respectively) was introduced into the nanocrystalline TiO2 to improve the photocatalystic capacity and the nanoparticles with 1% (n(SnO2)/n (TiO2))doping were calcinated at different temperatures (350-550℃). The SnO2/TiO2 film with 1% atom ratio (n(SnO2) : n(TiO2))was prepared with dip-coating method. The effect of the technical process parameters, such as doping amount and heat treatment temperatures on photocatalysis performance were studied using XRD, TEM, XPS, AFM and optical adsorption etc. Results showed that the nanometer TiO2 photocatalysts doped with SnO2 at%=1% have the highest photocatalystic performance of 96.55% with mixed phase (suitable proportion of anatase to rutile), which were treated at 350℃. The SnO2/TiO2 film with 1% atom ratio(n(SnO2)/ n(TiO2)) showed the porous nature with crystalline size at the range of 20-30nm and the photocatalystic performance of 79.6%, which was lower than that of the nanoparticles with same doping amount.