Preparation of CdS/g-C3N4 heterojunction photocatalyst with high activity sites by acid treatment

The key to achieve efficient degradation of organic pollutants lies in improving the separation efficiency of photogenerated electron-hole pairs in photocatalysts. Here, the hydrogen bonds between g-C3N4 layers were broken by concentrated acid etching and exfoliation to obtain a more dispersed and lighter g-C3N4 nanosheet structure, and then the CdS spherical nanoparticles were dispersed on g-C3N4 nanosheets by hydrothermal method. The optimal loading of CdS on g-C3N4 nanosheets was determined by testing the degradation performance of the composite photocatalysts with different loading amounts. The degradation performance was tested by simulating sunlight using a 700-800 W xenon lamp equipped with a 420 nm cut-off filter, which showed that the degradation of MB by 7% CdS/g-C3N4 photocatalyst was 90.7% for MB. It indicates that concentrated acid treatment and loading of CdS nanoparticles can significantly improve the photocatalytic activity of g-C3N4 nanosheets, which is attributed to the enhancedup conversion function of g-C3N4 by loading CdS to enhance the response range and ability of g-C3N4 in visible light and the photogenerated electron-hole pair separation rate by loading CdS, thus improving the photocatalytic performance of the composite.