P25光催化剂可见光催化的改性研究

硫脲为改性剂,P25为改性对象,采用研磨-共煅烧的方法制备了具有可见光催化活性的硫改性P25(S-P25)。利用XPS能谱、拉曼光谱、紫外-可见吸收光谱和元素分析等测试手段对其结构、光谱性质进行了表征。结果表明,S以S4+和S2-的形式分别替换了P25中的少量晶格Ti4+和O2-,光响应波长范围扩大,紫外、可见光区均产生较强吸收。以亚甲基蓝水溶液的光催化降解为模型反应,评价了该催化剂在可见光照射下的光催化活性,500℃煅烧2 h得到的试样的可见光活性最佳。

Modifying research on P25 photo catalyst under visible light

This paper presents the preparation of P25 with visible light irradiation by grinding and calcining using thiourea as modifier.The structure and morphology of the obtained samples were characterized by XPS energy spectrum,Raman spectrum,UV-vis adsorption spectrum and atomic absorption spectrophotometry.S4+ and S2+ incorporated into the lattice of P25 crystalline,replacing Ti4+ and O2-respectively,and producing intensive absorption both in ultraviolet and visible light region.The photocatalytic activity was evaluated by the degradation of methylene blue solution under visible light irradiation as model reaction.The photo-degradation test of methylene blue(MB) under visible light further proved the good visible light excited activity and the P25-modified calcined at 500 ℃ for 2 h possessed a better decoloration to MB.