材料期刊网

助剂修饰是促进光生电子和空穴分离的有效途径.采用新型无定型Ti(IV)空穴助剂与高电子传输率的还原石墨烯(rGO)电子助剂相结合,以水热–浸渍沉积法合成Ti(IV)和rGO共修饰的高效片状钨酸铋(Ti(IV)-rGO/Bi2WO6)可见光光催化剂.结果表明,与单独Bi2WO6相比,助剂Ti(IV)或rGO修饰的Bi2WO6可见光光催化降解甲基橙(MO)性能增强.双助剂共修饰的Bi2WO6光催化剂光催化活性更高,当Ti(IV)含量为5wt%时,双助剂共修饰的Bi2WO6光催化剂性能最佳,光催化速率常数达2.2×10-2 min-1,是纯Bi2WO6的88倍.光催化性能增强主要归因于新型Ti(IV)空穴助剂与rGO电子助剂的协同作用,即Ti(IV)快速转移光生空穴,同时rGO快速传递并转移电子.本文有望为新型助剂修饰光催化材料研究提供新思路.

Cocatalyst modification is an effective way to promote the separation of photogenerated electron-hole pairs. The reduced graphene oxide (rGO) with high electron transfer rate and the amorphous Ti(IV) compounds as hole co-catalyst were loaded on the surface of highly-efficient and flake-like Bi2WO6 nanoparticles by a hydrother-mal-impregnation method to prepare Ti(IV)-rGO/Bi2WO6 visible-light-driven photocatalyst. It was found that the Ti(IV) and rGO single-cocatalyst modified Bi2WO6 exhibited an enhanced photocatalytic activity and dual-cocatalyst modified Bi2WO6 photocatalyst showed higher photocatalytic performance than single-cocatalyst modified Bi2WO6. When the amount of Ti(IV) was 5wt%, the photocatalytic rate constant of Ti(IV)-rGO/Bi2WO6photocatalyst reached 2.2×10-2 min-1, which was 88-fold higher than that of bare Bi2WO6. The enhancement of photocatalytic performance mainly depends on the synergistic effect of novel Ti(IV)-hole cocatalyst and rGO-electron cocatalyst, namely, Ti(IV) compounds rapidly transfer the photogenerated holes, while rGO rapidly capture the photogenerated electrons. The present amorphous Ti(IV) and rGO cocatalysts can be widely applied in the design and development of highly efficient cocatalyst-modified photocatalytic materials.