Photocatalytic degradation of methylene blue, rhodamine B, methyl orange and Eriochrome black T dyes by modified ZnO nanocatalysts: A concise review

One of the issues receiving global attention is the prevalence of dyes in wastewater and water resources. These chemicals' persistence, toxicity, and carcinogenic potential have a significant influence on aquatics and humans, making their removal prior to discharge into the environment necessary. Semiconducting metal oxide and modified metal oxide-mediated photocatalysis has emerged as a superior wastewater treatment process to tackle the major challenges faced by traditional technologies. The multifunctional ZnO nanomaterial due to its inexpensive nature, eco-friendly, structure-dependent properties, and complete mineralization of pollutants make them more efficient semiconducting photocatalysts than other materials. It has been seen that ZnO nanomaterials can show high performance in photo-induced degradation of cationic and anionic dyes and for the treatment of industrial effluent due to its high efficiency under ultraviolet light, with a 3.37 eV the bandgap. Taking account of all these crucial aspects, this paper presents a review of recent achievements in the degradation of methylene blue, and rhodamine B as a cationic dye, and methyl orange andEriochrome black T as an anionic dye, by studying the operating parameters like reaction time, pH, initial dye concentration, and catalyst concentration, etc.

Automated summary

The prevalence of dyes in wastewater and water resources is a global concern due to their persistence, toxicity, and carcinogenic potential. Semiconducting metal oxide and modified metal oxide-mediated photocatalysis has emerged as an efficient wastewater treatment process. ZnO nanomaterials, with their inexpensive nature and high efficiency under ultraviolet light, are superior semiconducting photocatalysts for the degradation of dyes and treatment of industrial effluent.