机构地区: 河南大学
出 处: 《化学研究》 2003年第2期13-17,共5页
摘 要: 利用溶胶-凝胶提拉成膜法制备了TiO2,SnO2,Ag/SnO2,Ag/SnO2/TiO2纳米薄膜半导体催化剂.采用粉末电导法初步研究了纳米半导体薄膜催化剂的表面结构,测定了表面态能级相对于半导体导带边的位置.实验表明:四种催化剂在不同的表面能级位置都存在表面态:TiO2具有两类表面态,其能量分别为0.75eV和0.58eV.Ag/SnO2/TiO2由于Ag的担载,出现更负的表面态能级(0.33eV).这将会显著提高导带电子密度,加速光催化反应速率. Nanometer TiO2,SnO2,Ag/SnO2,Ag/SnO2/TiO2 films were prepared by the method of solgel. The surface structures, energy levels and their distribution of the surface states were measured by the powder conductivity. The experimental results show that the different energy levels exist at the surface of the four samples. Two types of surface states exist at the surface of TiO2 , the energy levels are 0.75 eV and 0.58 eV respectively. Because of the Ag loaded, the energy level of Ag/SnO2/TiO2 changes towards more negative (0.33 eV ), which increases the electron concentration in the conduction band and accelerates the reaction speed of photocatalysis.