Green synthesized ZnO nanocatalysts for rapid and effective visible-light degradation of industrial dyes
Toton Sarkar, Ashis Bhattacharjee
Abstract
, respectively. The degradation followed pseudo-first-order kinetics according to the Langmuir-Hinshelwood model. Optimal RB degradation occurred at pH 6, whereas MB degradation peaked at pH 10, reflecting the influence of electrostatic interactions between dye molecules and the ZnO surface. Scavenger experiments indicated that hydroxyl radicals were the dominant reactive species for RB degradation, while photogenerated holes played the key role in MB degradation. ZnO15 maintained significant activity over five successive cycles, suggesting good reusability. This work demonstrates that green-synthesized ZnO is an efficient photocatalyst for dye degradation under visible light and systematically assesses the influence of crystallite size, pH, catalyst loading, and temperature. While promising for wastewater treatment applications, further studies are needed to validate performance in complex effluents and under long-term operational conditions.