Synthesis and development of rGO/ZnO composite for photocatalytic studies

Developing eco-friendly and highly efficient photocatalysts is crucial for sustainable environmental remediation. This study synthesised zinc oxide (ZnO) via a green combustion method using Withania somnifera (Ashwagandha) as a fuel. At the same time, rGO/ZnO was fabricated through a simple, environmentally benign reflux approach. The formation of well-crystallized ZnO with a sponge-like morphology distributed over rGO sheets. The composite exhibited remarkable Rose Bengal (RB) dye degradation, achieving 97% removal within 60 min at a concentration of 10 ppm, following 1st-order reaction kinetics with a half-life of 12.34 min. Photocatalytic stability and recyclability assessments, total organic carbon (TOC) analysis, pH-dependent studies, and scavenger experiments further elucidated the degradation mechanism and efficiency. The superior activity of rGO/ZnO can be attributed to enhanced charge separation and synergistic interactions between rGO and ZnO.