Use of Nanostructured Photocatalysts for Dye Degradation: A Review

Among the technologies proposed for wastewater treatment, the Advanced Oxidation Processes are viable and technological strategies for dyes degradation. Different photocatalytic systems classified in metal oxides alone or combined through hybrid composites or immobilized onto supports have been designed in various nanostructured shapes for their application in the photodegradation of polluting dyes. This review aims to describe the dyes as an environmental threat, photocatalysis as an effective process to remove dyes from water and provide an overview of the recent studies using photocatalytic systems grouped according to their development. Furthermore, this review describes the main parameters of a photocatalytic system with an important role in dye photodegradation. Finally, we discuss the limitations of photocatalysis for real industrial applications and the challenges for this environmental nanotechnology.