草酸浸取废SCR催化剂制备光催化剂

采用草酸浸取废SCR催化剂,得到钛钨粉,制备Bi₂WO₆/钛钨粉复合光催化剂,考察了其对罗丹明B的光催化降解性能。制备光催化剂的优化工艺条件为：采用聚乙烯吡咯烷酮为表面活性剂,n（Bi₂WO₆）∶n（钛钨粉）=2∶1,前驱液pH为5,水热反应时间为18 h。在此条件下制备的光催化剂在可见光下降解罗丹明B,反应 60 min,罗丹明B降解率达94.30%。表征结果显示：钛钨粉小颗粒散落在Bi₂WO₆片表面,为光催化反应提供了更多的活性位点;Bi₂WO₆和钛钨粉两者结合可提高光生电子和空穴的分离效率,进而提高催化剂的光催化活性。Bi₂WO₆/钛钨粉光催化剂对罗丹明 B 的降解符合一级反应动力学规律。

Preparation of photocatalyst from waste SCR catalyst by leaching with oxalic acid

The waste SCR catalyst was leached with oxalic acid to obtain titanium-tungsten powders,and the Bi₂WO₆/titanium-tungsten powder composite photocatalyst was prepared. The photocatalytic degradation capability of the photocatalyst to rhodamine B was investigated. The optimized process conditions for photocatalyst preparation were as follows：Using polyvinylpyrrolidone as the surfactant,n（Bi₂WO₆）∶n（titanium-tungsten powder） = 2∶1,pH of precursor solution being 5,and hydrothermal reaction time being 18 h. The photocatalyst prepared under these conditions was used to degrade rhodamine B under visible light. After 60 min of reaction,the degradation rate of rhodamine B reaches 94.30%. The characterization results show that：Small particles of titanium-tungsten powder are scattered on the surface of Bi₂WO₆ sheet,which providemore active sites for the photocatalytic reaction;The combination of Bi₂WO₆ and titanium-tungsten powders can improve the separation efficiency of photogenerated electrons and holes,thereby improve the photocatalytic activity of the catalyst. The degradation of rhodamine B on Bi₂WO₆/titanium-tungsten powder photocatalyst conformes to the law of first-order reaction kinetics.