A Review on Photocatalysis Used For Wastewater Treatment: Dye Degradation

Water pollution is a global issue as a consequence of rapid industrialization and urbanization. Organic compounds which are generated from various industries produce problematic pollutants in water. Recently, metal oxide (TiO2, SnO2, CeO2, ZrO2, WO3, and ZnO)-based semiconductors have been explored as excellent photocatalysts in order to degrade organic pollutants in wastewater. However, their photocatalytic performance is limited due to their high band gap (UV range) and recombination time of photogenerated electron-hole pairs. Strategies for improving the performance of these metal oxides in the fields of photocatalysis are discussed. To improve their photocatalytic activity, researchers have investigated the concept of doping, formation of nanocomposites and core-shell nanostructures of metal oxides. Rare-earth doped metal oxides have the advantage of interacting with functional groups quickly because of the 4f empty orbitals. More precisely, in this review, in-depth procedures for synthesizing rare earth doped metal oxides and nonocomposites, their efficiency towards organic pollutants degradation and sources have been discussed. The major goal of this review article is to propose high-performing, cost-effective combined tactics with prospective benefits for future industrial applications solutions.

Automated summary

Water pollution is a global issue caused by rapid industrialization and urbanization. Metal oxide-based semiconductors have been explored as photocatalysts to degrade organic pollutants in wastewater, but their performance is limited. Strategies such as doping, nanocomposite formation, and core-shell nanostructures have been discussed to improve their photocatalytic activity. Rare-earth doped metal oxides show advantages in interacting with functional groups quickly. This review article focuses on synthesizing rare earth doped metal oxides and nanocomposites, their efficiency in degrading organic pollutants, and potential industrial applications.