Use of TiO2 in Photocatalysis for Air Purification and Wastewater Treatment: A Review


This study reviews recent research on the synthesis and application of titaniumdioxide (TiO2)-based photocatalysts for environmental applications. Theprinciples of non-homogenous photo-catalysis include utilizing a solidsemiconductor, such as titanium dioxide Nano or macro, to form a stablesuspension (heterogeneous phase) at the impact of irradiation to elevate a reactionat the surface interface of the different phases in the system. Recently, titaniumdioxide has been considered the better semiconductor in non-homogenousphotoinduced treatment. TiO2-based photocatalysts have broad applications forindustrial processes because of their exceptional physicochemical properties.Nevertheless, having a narrow band near the ultraviolet region limits itsapplications within visible radiation. As a result of this, there have beenconsiderable research efforts to improve the visible light tendency of TiO2 throughmodifications of its optical and electronic properties. Several strategies, such ascoupling TiO2 tightly and incorporating other metallic components duringsynthesis, have increased the bandgap of TiO2 for visible light applications.Moreover, an overview of nanotechnology that could enhance the properties ofTiO2-based catalysts in an environmentally friendly way to decompose pollutantsis also presented. The various TiO2-based photocatalysts have wide applicationsin degrading recalcitrant pollutants in the air, water, and wastewater treatmentunder visible light