Photocatalytic Degradation of Dyes Present in Industrial Effluents: A Review

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, reducing 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. Photocatalysis can treat dye‐containing effluent in an eco‐friendly and cost‐effective manner. Three photocatalyst categories are outlined. Mass‐transfer, the photo‐Fenton effect, charge carriers, secondary pollution, and photocatalyst poisoning are key issues discussed. FOM evaluates photocatalyst efficacy more realistically.