Y-N-TiO_2/凹凸棒土光催化剂制备及性能研究

Preparation and Property of Y-N-TiO_2/Attapulgite Photocatalysts

以钛酸丁酯为钛源、硝酸钇和二乙醇胺为改性剂原料,凹凸棒土为载体,采用溶胶-凝胶法制备了凹凸棒土负载的Y-N-TiO_2/凹凸棒土光催化剂,通过IR和XRD对其结构进行表征。考察了焙烧温度、催化剂用量、溶液pH值、光照条件等因素对光催化剂降解诺氟沙星性能的影响。结果表明,Y、N掺入了TiO_2晶格,其中部分TiO_2进入了催化剂载体凹凸棒土的层间并通过化学键与其成功复合。500℃焙烧的催化剂中锐钛矿型TiO_2比例相对较高,表现出最优的光催化活性,当催化剂用量为2g/L,溶液pH值为6,在可见光或太阳光下反应2h后,该催化剂对25mg/L的诺氟沙星降解率分别达89.6%和91.3%。此外,该催化剂易于回收,再生性良好。

Attapulgite loaded Y-N co-doped TiO2 composite photocatalysts were prepared by sol-gel method with attapulgite as the carrier, tetrabutyl titanate as the titanium source and the trihydrated yttrium nitrate and diethanolamine as the raw materials of the modifier. The structure of the samples was characterized by IR and XRD technique. And the calcination temperature, catalyst dosage, pH value of the solution, illumination conditions and other factors were tested to photocatalytic degradation of norfloxacin wastewater performance. The results show that Y and N might incorporate into the lattice structure of TiO2 and part of TiO2 permeating into the interlayer of attapulgite. And then the immobilization of TiO2 particles with attapulgite via the bond of Ti-O-Si was testified. In addition, a high proportion of anatase TiO2 make the photocatalyst calcined at 500℃ of optimal performance. When the initial concentration of n orfloxacin is 25 mg/L, the catalyst dosage is 2 g/L, pH value of the solution is 6, illumination lasted 2 h in visible light or sunlight, the degradation rate of the norfloxacin can reach up to 89.6% or 91.3%, respectively. Besides, the photocatalyst is easy to recycle and have a good regenerability.