High-efficient photocatalytic degradation of commercial drugs for pharmaceutical wastewater treatment prospects: A case study of Ag/g-CN/ZnO nanocomposite materials.

Pharmaceutical drugs' removal from wastewater by photocatalytic oxidation process is considered as an attractive approach and environmentally friendly solution. This report aims to appraise the practical application potential of Ag/g-CN/ZnO nanorods toward the wastewater treatment of the pharmaceutical industry. The catalysts are synthesized by straightforward and environmentally-friendly strategies. Specifically, g-CN/ZnO nanorods heterostructure is constructed by a simple self-assembly method, and then Ag nanoparticles are decorated on g-CN/ZnO nanorods by a photoreduction route. The results show that three commercial drugs (paracetamol, amoxicillin, and cefalexin) with high concentration (40 mg L) are significantly degraded in the existence of a small dosage of Ag/g-CN/ZnO nanorods (0.08 g L). The Ag/g-CN/ZnO nanorods photocatalyst exhibits degradation performance of paracetamol higher 3.8, 1.8, 1.3 times than pristine g-CN, ZnO nanorods, and g-CN/ZnO nanorods. Furthermore, Ag/g-CN/ZnO nanorods have an excellent reusability and a chemical stability that achieved paracetamol degradation efficiency of 78% and remained chemical structure of the photocatalyst after five cycles. In addition, the photocatalytic mechanism explanation and comparison of photocatalytic drugs' degradation ability have also been discussed in this study.