碳量子点修饰Bi_(2)MoO_(6)复合电极的制备及光电催化性能研究

Preparation and Photoelectrocatalytic Performance of CQDs Modified Bi_(2)MoO_(6) Hybrid Electrode

为改善Bi_(2)MoO_(6)电极的光吸收与表面光生载流子的迁移能力,提升其在可见光下对水体中有机物的催化降解性能,通过溶剂热、煅烧与吸附过程对Bi_(2)MoO_(6)电极进行了表面碳量子点修饰,并将其应用于光电催化系统中,通过多种物理表征与实验测试探究了CQDs修饰与光电催化偏压对改善Bi_(2)MoO_(6)催化性能的影响。结果显示,CQDs均匀分散在Bi_(2)MoO_(6)表面,2者复合作用良好,CQDs/Bi_(2)MoO_(6)复合电极具有更强的可见光利用能力与表面载流子迁移能力,其中实验制得的15-CQDs/Bi_(2)MoO_(6)电极具有最高的催化降解活性,在可见光下2 h内对亚甲基蓝的降解率最高可达82.7%,相比于Bi_(2)MoO_(6)单体电极16.0%的降解率有了明显的提升,且具有较好的循环稳定性。

In order to improve the visible light absorption and the photogenerated charges migration ability of Bi_(2)MoO_(6) electrode,and to further enhance its catalytic degradation of organics in waste water,the carbon quantum dots were modified on the surface of Bi_(2)MoO_(6) electrode through solvothermal,calcination and adsorption processes and the hybrid electrode was applied to the photoelectrocatalytic system. The effects of CQDs modification and photoelectrocatalytic bias on improving the catalytic performance of Bi_(2)MoO_(6) were explored through various characterizations and tests. The results show that CQDs are evenly dispersed on the surface of Bi_(2)MoO_(6),and the connection between two materials are successfully formed.The CQDs/Bi_(2)MoO_(6) hybrid electrode has stronger capacity of visible light utilization and surface charges migration than the Bi_(2)MoO_(6) monomer electrode. Therefore,the 15-CQDs/Bi_(2)MoO_(6) hybrid electrode shows the highest photoelectrocatalytic degradation rate of 82. 7% toward methylene blue within 2 h under visible light,which is greatly enhanced compared to 16. 0% for Bi_(2)MoO_(6) electrode. Besides,the hybrid also possesses a better cycle stability.