Binary CdS-WO3 nanostructures supported on biochar substrate for visible-light-driven photocatalytic degradation of malachite green
Mahdi Salimi, Amin Abolghasemi Mahani
Abstract
The advancements made in the field of nanoscience have resulted in the production of semiconductor materials that are both cleaner and safer. These materials have proven to be highly effective in breaking down toxic and resistant pollutants in water. Additionally, semiconductor photocatalysts must possess ecological and environmental friendliness, which can be achieved by implementing green synthetic methods. Consequently, this research paper focuses on synthesizing biochar with a specific biomorphic structure, utilizing spent coffee grounds as a natural carbon source and bio-template. Subsequently, a nanocomposite consisting of biochar-WO 3 /CdS (BC-WO 3 /CdS) was successfully synthesized, and the resulting products were thoroughly characterized. Furthermore, the efficiency of synthesized nanocomposite in Malachite Green (MG) dye degradation under visible light irradiation was extensively investigated. Remarkably, a photocatalytic efficiency of approximately 98 % was achieved for MG dye with a concentration of 2 ppm, utilizing a catalyst dosage of 200 mg and maintaining a pH level of 8. In addition, the apparent reaction rate constant was obtained at 0.0548. Moreover, the materials exhibited the capability of being recycled up to 8 times without any noticeable decrease in stability. • The kinetics of the photocatalytic degradation process followed a pseudo-first-order model for MG. • The BC/WO 3 -CdS nanocomposite is a promising photocatalyst for the degradation of toxic pollutants aquatic environments. • Photocatalytic efficiency of 98 % was achieved for MG dye with a concentration of 2 ppm.