Green Synthesis and Direct Z-Scheme CdSe/BiOCl Heterojunctions for Enhanced Photocatalytic Performance

The introduction of heterojunctions is an effective way to improve catalytic activity in photocatalytic composites. Herein, a series of CdSe quantum dot-modified BiOCl heterojunction composites were successfully prepared by a green in-situ deposition protocol. Photocatalytic ability of CdSe/BiOCl composite can be simply tailored by adjusting CdSe amount. The obtained CdSe/BiOCl composites showed superior photodegradation capability and excellent stability. The optimum BiOCl composite with 1.0% CdSe modification exhibited a 1.5 times higher degradation rate than pure BiOCl nanosheets, and photodegradation efficiency maintains still high after four cycles. Physical characterization confirms the formation of heterostructure, while electrochemical impedance spectroscopy and photoluminescence spectrum demonstrate composite with higher separation efficiency of photo-generated electron-hole pairs. At last, the heterojunction of Z-Scheme satisfies the photocatalytic mechanism of CdSe/BiOCl, and the holes (h(+)) with superoxide radicals (.O-2(-)) are the main active factors in photodegradation process based on the experiment of scavengers.