Photocatalysis: TiO2, ZnO, and species of iron oxides

Dyes and other organic pollutants are normally not completely degraded through numerous environmental treatment processes. The undegraded components of dyes and other organic pollutants persist in the environment and causes adverse impacts on wildlife and human beings. Photocatalysis has received great importance for environmental remediation due to its ease of operation, simplicity of equipment, viability, high performance, and low cost. In this work, the concept of photocatalysis and the factors affecting the efficiency of photocatalytic process are discussed. The present work further highlights the advantages and disadvantages of heterogeneous photocatalyst. A comprehensive report of the important work on photocatalysis involving TiO2, ZnO, and of iron oxides species has also been presented. The work also presents the mechanistic pathways of photocatalysis and its challenges and future prospects.