Ultrasonic-assisted synthesis of two dimensional BiOCl/MoS2 with tunable band gap and fast charge separation for enhanced photocatalytic performance under visible light.

Janus shaped BiOCl/MoS2 composites with two dimensional configuration are successfully prepared via a facile pulse ultrasonic assisted method, which spontaneously introduces oxygen vacancies on the BiOCl surface and builds well-defined heterojuction at the BiOCl/MoS2 interfaces. The as-prepared BiOCl/MoS2 composites possess reduced band gap and defect energy levels due to the incorporation of MoS2 and the oxygen vacancies, which permits the enhanced light harvesting efficiency in the visible range. In addition, because of the formed BiS bonds at the BiOCl/MoS2 interface, the composites demonstrate improved charge separation of the photo-generated carriers. Therefore, when used as photocatalyst for Rhodamine B photodegradation, the optimized composite demonstrates a degradation rate of 0.078 min-1, which is much enhanced compared with that of pure BiOCl (0.052 min-1). Mechanism investigation indicates the degradation is a hole mediated process. In addition, the composite shows good stability and outstanding organic carbon removal efficiency, which could serve as a promising photocatalyst for water remediation under visible light.