WO3−x /S-Doped g-C3N4 Step-Scheme Heterojunction for High-Efficiency and Stable Vis–NIR Photocatalytic Removal of Pharmaceuticals and Personal Care Products

Pharmaceuticals and personal care products (PPCPs) have attracted widespread attention due to their durability to the environment. Therefore, it is highly desirable to develop new technologies that are environmentally friendly, energy saving, and compatible to degrade these pollutants. In this study, a vis–NIR-driven and highly efficient S-scheme photocatalyst, WO 3− x /S doped g-C 3 N 4 , is used for PPCPs degradation. The results show that the photocatalytic activity of WO 3− x /S doped g-C 3 N 4 composite system for PPCPs is much higher than that of WO 3− x and g-C 3 N 4 . The introduced WO 3− x has a great positive effect on the photocatalytic performance of WO 3− x /S doped g-C 3 N 4 S-scheme composite photocatalyst for both naproxen and diclofenac. Due to the fast photogenerated carrier separation brought by the S-scheme, the WO 3− x /S-doped g-C 3 N 4 nanocomposite exhibits enhanced performance in photocatalytic PPCPs degradation. The degradation rate of naproxen is 99.2%, and the degradation rate of diclofenac can also be as high as 99.5%. This research has important reference value for the synthesis of WO 3 -based S-scheme photocatalysts for energy and environmental applications.