1. Progress in Biosynthesized of Silver Nanoparticles as Sustainable Approach for Photocatalytic Wastewater Treatment

Severe effects of water pollution would need to be addressed by utilizing advanced water and wastewater treatment. Due to globalization, organic dyes and emerging contaminants are significant water pollutants that can bring harm to humans and the environment. Nevertheless, conventional treatment is not suitable for removing these pollutants. Photocatalysis is an eco-friendly, cost-effective, and efficient treatment by degrading organic pollutants into harmless by-products, making it a promising technology. Among photocatalysts available, silver nanoparticles (Ag NPs) show great catalytic and chemically stable nanomaterials. The synthesis of nanoparticles is shifting toward a biological synthesis that is environmentally friendly and avoids hazardous chemicals, leading to the discovery of biosynthesized Ag NPs. Various biomaterials such as plants, fruits, biopolymers, waste, and microorganisms were successfully synthesized Ag NPs via different techniques. The result shows remarkable and significant photocatalytic properties of biosynthesized Ag NPs towards the degradation of organic pollutants from previous studies. Further improving Ag NPs as photocatalysts by lowering the band gap energy and doping with support materials for better recovery are recommended. This review critically discusses the photocatalytic mechanism and the synthesis method of Ag NPs from various biomaterials with photocatalytic properties as a potentially sustainable approach to overcoming water pollution issues with its challenges and recommendations.