溶胶-凝胶法合成分级结构BiVO_4:W及光催化活性

Preparation and Photocatalytic Activity of Hierarchical BiVO_4:W Photocatalysts Fabricated by Sol-gel Method

采用乙二醇(EG)溶胶-凝胶法制备了BiVO_4∶W,并以亚甲基蓝(MB)为降解目标,考察了不同W掺杂量、煅烧温度以及H_2O_2对样品催化性能的影响.结果表明,不同的W掺杂量、煅烧温度影响BiVO_4的形貌和光催化性能.中性条件下,W掺入量为2.2wt%、煅烧温度为350℃时制得的BiVO_4∶W对MB的降解率最大,光催化反应90min,对MB的降解率为96.7%.H_2O_2作为电子捕获剂,与光生电子反应生成羟基自由基(·OH),抑制电子和空穴复合的同时,协同催化显著提高了光催化效率.

BiVO4 : W was prepared by ethylene glycol (EG) sol-gel method,and methylene blue (MB) was used as the degradation target. The effects of different W doping amount,calcination temperature and H2O2 on the catalytic performance of the samples were investigated. The results show that different W doping and calcination temperatures affect the morphology and photocatalytic propeties of BiVO4. Under neutral conditions,BiVO4 : W prepared with W incorporation amount of 2. 2wt% and calcination temperature of 350℃ had the highest degradation rate of MB. The photocatalytic reac tion was 90 min, and the degradation rate of MB was 96. 7%. As an electron trapping agent,H2O2 reacts with photogenerated electrons to form hydroxyl radicals (·OH),which inhibits the recombination of electrons and holes,and synergistically catalyzes the photocatalytic efficiency.