Photocatalytic Degradation of Dyes Present in Industrial Effluents: A Review

Abstract

Photocatalytic degradation has recently emerged as an environmentally friendly and cost-effective strategy for treating dye-contaminated water existing in the environment that has detrimental effects on the natural ecosystem and also affects human health. In this review article, the authors aim to provide an overview of the latest developments in photocatalysis processes for the purpose of dye degradation in industrial effluents. For this purpose, the photocatalyst materials are mainly classified into three generations: the first generation (1G), the second generation (2G), and the third generation (3G). The phenomena such as mass transfer, efficiency of the photo-Fenton process, minimizing electron-hole recombination, re-ducing pollution that is supplementary to byproducts, preventing inactivation due to poisoning, etc. are analyzed in depth to get efficient photocatalytic degradation of dye-contaminated wastewater. A brief discussion on photocatalytic fuel cell technology and the simultaneous production of sustainable and renewable energy is emphasized. A more realistic approach for assessing the efficacy of various generations of photocatalysts in the process of dye degradation has been highlighted. This review article aims to examine the challenges and uncertainties associated with dye degradation in the photocatalytic process as well as provide a conceptual framework for the widespread implementation of this technology.

Hydrothermal Synthesis and Photocatalytic Activity of NiTiO3 for the Degradation of Malachite Green under Visible Light Irradiation

“…From these results, it is clear that the surface‐bound (OH*) radicals and holes have the principal role in the oxidation of MG in the presence of a titanium‐based photocatalyst ($${{{\rm N}{\rm i}{\rm T}{\rm i}{\rm O}}_{3})}$$ . Moreover, the degradation process occurred mainly on the external surface rather than the catalyst used [74,75] …”

Green Synthesis of novel <em>Rhododendron arboreum</em> Based Zinc Nanocomposites for Enhanced Antimicrobial and Photocatalytic Degradation Activities

“…It has been well understood that nanoparticles with antibacterial potentials can reduce the development of resistance by specific microbes [12]. Likewise, due to their unique characteristics including larger excitation binding energy and wide band gap metal nanoparticles are considered as an attractive photocatalyst for the degradation of dyes [13].…”

Green Synthesis of Novel Rhododendron arboreum-Based Zinc Oxide Nanoparticles for Enhanced Antimicrobial and Photocatalytic Degradation Activities

“…It has been well understood that nanoparticles with antibacterial potentials can reduce the development of resistance in specific microbes [12]. Likewise, due to their unique characteristics including larger excitation binding energy and wide band gap, metal-based nanoparticles are considered an attractive photocatalyst for the degradation of various types of dyes [13].…”