Novel ZnO Nanoparticles for Rapid Photocatalytic Degradation of Organic Dyes: Synthesis and Kinetics

Abstract

The removal of persistent dye pollutants from wastewater streams has drawn a lot of interest from the scientific community because photocatalysis is the most widely used practical strategy for addressing environmental contamination. Transition-metal oxides are seen to be the most prospective catalysts for efficient and environmental friendly wastewater treatment because of their significant photocatalytic activity, excellent solubility, and durability. In this study, we describe the simple, eco-sustainable and cost effective synthesis of ZnO nanoparticles and their use as photocatalysts to break down organic dyes like Congo red (CR) and Malachite Green (MG) in aqueous media. In aqueous solution at ambient temperature, ZnO nanoparticles showed outstanding photocatalytic degradation efficiency of 98.9% for the MG dye and 92.8% for the CR dye. The kinetics of photodegradation were also investigated and followed a pseudo-first-order mechanism, with rate constants of 0.0204 min− 1 MG and 0.0123 min− 1 for CR in accordance with the Langmuir-Hinshelwood model. Excellent recycling properties were displayed by ZnO nanoparticles for both dyes and the combined effects of their high adsorption capacity and photodegradation of organic dyes make them an extremely effective and affordable catalyst.