S-doped g-C3N4 (S-CN) nanosheets effects on the photocatalytic performance of ZnSe/S-CN heterostructures

Abstract

The effects of S-doped g-C3N4 (S-CN) nanosheets on the photocatalytic performance of ZnSe nanostructures have been investigated. ZnSe/S-CN nanocomposites with different S-doping concentrations (2 %, 4 %, and 6 % (w%)) have been synthesized using a cost-effective co-precipitation method in an ambient condition. In addition, the pristine ZnSe nanostructures and ZnSe/g-C3N4 (g-CN) nanocomposites have also been synthesized with the same process and requirements. The X-ray diffraction (XRD) pattern indicated an optimum concentration of S-doping for the introduction in the g-CN structure, which was 4 %. Furthermore, the XRD results indicated an additional phase of selenium for the ZnSe/S-CN and ZnSe/g-CN nanocomposites. The obtained samples were used to degrade the Methylene blue (MB) dye under the radiation of a visible light source, and it was observed that the ZnSe/S-CN nanocomposites degraded almost all the dye molecules at a faster rate in about 60 min. In comparison, this time was 90 min for the ZnSe/g-CN nanocomposites. Different studies, such as textural study by Brunauer–Emmett–Teller (BET) method, electrical study by Electrochemical Impedance Spectroscopy (EIS), and optical study by Photoluminescence (PL) spectroscopy have been carried out to understand why the ZnSe/S-CN nanocomposites exhibited better photocatalytic performance in compared to the ZnSe/g-CN nanocomposites.