Advances in photocatalytic degradation of crystal violet using ZnO-based nanomaterials and optimization possibilities: a review

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Date

2025

Authors

Nedelkovski, Vladan
Radovanović, Milan
Antonijević, Milan

Journal Title

Journal ISSN

Volume Title

Publisher

MDPI

Source

ChemEngineering

Volume

9

Issue

6

Abstract

The photocatalytic degradation of Crystal Violet (CV) using ZnO-based nanomaterials presents a promising solution for addressing water pollution caused by synthetic dyes. This review highlights the exceptional efficiency of ZnO and its modified forms—such as doped, composite, and heterostructured variants—in degrading CV under both ultraviolet (UV) and solar irradiation. Key advancements include strategic bandgap engineering through doping (e.g., Cd, Mn, Co), innovative heterojunction designs (e.g., n-ZnO/p-Cu2O, g-C3N4/ZnO), and composite formations with graphene oxide, which collectively enhance visible-light absorption and minimize charge recombination. The degradation mechanism, primarily driven by hydroxyl and superoxide radicals, leads to the complete mineralization of CV into non-toxic byproducts. Furthermore, this review emphasizes the emerging role of Artificial Neural Networks (ANNs) as superior tools for optimizing degradation parameters, demonstrating higher predictive accuracy and scalability compared to traditional methods like Response Surface Methodology (RSM). Potential operational challenges and future directions—including machine learning-driven optimization, real-effluent testing potential, and the development of solar-active catalysts—are further discussed. This work not only consolidates recent breakthroughs in ZnO-based photocatalysis but also provides a forward-looking perspective on sustainable wastewater treatment strategies.

Description

Keywords

ZnO, crystal violet, photocatalytic degradation, advanced oxidation processes, artificial neural networks, wastewater treatment

Citation

DOI

10.3390/chemengineering9060120

Scopus

ISSN

2305-7084

ISBN

License

CC-BY

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