Chiang Mai Journal of Science

Photocatalysis is one of the most promising and attractive types of technology for solving water pollution problems. In this work, Z scheme C-doped ZnO/CdS heterostructure is successfully prepared. In situ carbon-doped ZnO was prepared using ZIF-8 as the precursor. The optimum temperature for the preparation of C-doped ZnO has been discussed through XRD, TG, DTG analysis. From the XRD analysis, it is clear that the as-prepared composites compose of hexagonal phase ZnO and CdS. According to the TEM, XPS, Uv-vis analyses, a heterostructure is built between ZnO and CdS. The composites appear as spherical crystals and have enhanced light absorption properties. Nevertheless, the C-doped ZnO/CdS composites show improved photocatalytic performance. Under visible light, C-doped ZnO/CdS can degrade methylene blue by more than 98% within 80 min, which is 5 times of commercial nano ZnO. Besides, the C-doped ZnO/CdS composites still maintain a high photocatalytic performance after the cycling experiment. Moreover, C-ZnO/CdS possesses stronger photocatalytic properties than ZnO/CdS composites. Through ICP analysis, ESR analysis, and scavengers trapped experiment, it is proposed that C-ZnO/CdS heterostructure is a Z-type heterojunction.