Properties of SnO_2/TiO_2 composite materials derived by sol-gel

SnO2/TiO2 composite photocatalysts were prepared by sol-gel processes.With HAC as complexation and Ti(C4H9O)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.