银掺杂TiO_2光催化剂的制备及光催化性能研究

Preparation and photocatalytic activity of Ag-doping TiO_2

采用溶胶-凝胶法,以钛酸四丁酯、硝酸银为原料制备了不同银含量掺杂TiO2光催化剂,并以TG-DTA、XRD、TEM对样品进行了表征,XRD结果显示,掺杂银TiO2光催化剂为锐钛矿型,银掺杂量较低时,银均匀分布在TiO2的表面,在掺杂量为4%时,出现银的团聚。光催化亚甲基蓝结果表明,银掺杂TiO2光催化剂比未掺杂TiO2降解率明显提高,在2%银掺杂TiO2光催化剂用量为25mg,pH值为6～8,降解时间为120min,降解率可达93%。

TiO2 nanoparticles with various amounts of silver were prepared by sol-gel process using tetrabutyl titan- ate and silve nitrate as raw materials. The photoeatalysis of Ag-doping TiO2 were characterized by TG-DTA, XRD and TEM. The results showed that the crystalline phase of Ag-doping TiO2 was only anatase. In addition, the silver was well- distributed on the surfaces of the photocatalyzer when small amount silver was added and the composite grains were ag- glomerated obviously as the silve amount up to 4%. The activities of photocatalyzer were evaluated by degradation of meth ylene blue（MB）aqueous solution. Results indicated that degradation rate of Ag-doping TiO2 was improved observably and the optimal photocatalysis conditions were as following： Ag-doping content was 2 %, quality was 25mg, pH value was 6-8, time was 120min and the degradation rate of MB was 93%.