Improving charge separation Bi19S27Cl3/BiOCl Z-scheme heterojunction for efficient visible-light photocatalytic degradation of 2-mercaptobenzothiazole

The construction of semiconductor photocatalyst with Z-scheme heterojunction can improve the photogenerated electron-hole pairs separation efficiency during photocatalytic degradation. Herein, visible light driven Bi19S27Cl3/BiOCl Z-scheme heterojunction was prepared with a one-step in situ precise control of synthesis solvothermal method. It is possible to achieve the transformation process from Bi2S3 to Bi19S27Cl3 and subsequently to generate the Bi19S27Cl3/BiOCl composite by precisely controlling the Bi:S ratio of initial materials. The degradation efficiency of Bi19S27Cl3/BiOCl Z-scheme heterojunction was 94.48 % for MBT, which was 2.3 times of the Bi19S27Cl3 and 9.7 times of the BiOCl. During the photocatalytic reaction process, the Z-scheme heterojunction can improve light utilization by increasing specific surface area and exposing many active sites. It can also inhibit the rapid recombination of photogenerated electron-hole pairs by giving carriers a short and wide transport path. This work provides novel strategies and ideas to develop effective photocatalysts.