Fabrication of C and N co-doped CdS semiconductor photocatalysts derived from a novel Cd-MOF for enhancing photocatalytic performance

Abstract

The narrow bandgap value and long lifetime of photo generated charges make CdS exhibit higher photocatalytic activity compared to other semiconductor catalysts. Given the excellent optoelectronic properties of CdS, a novel 2D cadmium-organic framework (Cd-MOF) was obtained by solvothermal method, which was served as a precursor template in this paper. C and N co-doped CdS-T (T = 600/800/1000) semiconductor materials were successfully prepared by chemical deposition method under different high temperatures. The as-prepared materials had been characterized in detail. Furthermore, the Cd-MOF and CdS-T were used to conduct the photocatalytic activity of organic dyes. Among them, CdS-800 showed excellent photocatalytic degradation effects on five organic dyes, especially on RB with the photocatalytic degradation efficiency of 98.87 %, which was significantly improved 6.5 times compared to Cd-MOF (58.23 %). Free radical capture experiments have shown that •O₂⁻ play a dominant role in the photocatalytic process. In addition, UV–vis diffuse reflection, photoluminescence (PL), photoelectrochemical (PEC) testing and density functional theory (DFT) calculations had shown that CdS-800 could effectively delay the recombination of photo generated charges, improve the rapid migration and separation of photo generated carriers, and enhance photocatalytic activity. This work provides new ideas for the preparation of efficient and recyclable CdS semiconductor photocatalytic materials.