Enhancement of visible photocatalytic performances of a Bi2MoO6-BiOCl nanocomposite with plate-on-plate heterojunction structure.

A visible-light-sensitive Bi2MoO6-BiOCl heterojunction photocatalyst was synthesized via a hydrothermal process. The as-prepared Bi2MoO6-BiOCl composite shows an irregular multi-plate structure with length ranging from 100 nm to 1 μm, indicating a possibility of the plate-on-plate structure by placing Bi2MoO6 and BiOCl nanoplates over each other. The Bi2MoO6-BiOCl photocatalyst not only had a good visible-light photocatalytic performance, but also exhibited higher photocatalytic activity than pure BiOCl and Bi2MoO6. The optimal Bi2MoO6 content for the photocatalytic activity of the Bi2MoO6-BiOCl composites is 30%. Compared to pure Bi2MoO6 the photoactivity of the Bi2MoO6-BiOCl composites is almost 2.0 times higher for the RhB photodegradation, and 1.5 times higher for the phenol photodegradation under visible light irradiation. The photocatalytic mechanism was elucidated via active species trapping experiments and ESR. The ˙OH and ˙O2(-) played the key roles in the degradation of RhB via the Bi2MoO6-BiOCl composite. Finally, the possible charge transfer mechanism of the enhanced visible light photocatalytic activity was proposed.