TiO2-CeO2 assisted heterostructures for photocatalytic mitigation of environmental pollutants: A comprehensive study on band gap engineering and mechanistic aspects

Industrial pollution is a substantial problem in the growing world of continuous innovative products and intensive developments. Pollution due to organic contaminants is the major detrimental components to envi-ronmental cleanness and sustainability. The textile industries alone produce about 1.3 million various dyes and pigments that absorb and reflect sunlight in water. This process highly affects the photosynthetic cycle of algae and other living organisms, thus balancing natural ecosystem. The breakdown of organic pollutants into harmful products, which are mutagenic, carcinogenic, and toxic to living organisms, creates a serious environmental concern globally. Nevertheless, recently application of heterogeneous photocatalysis in facilitating the removal of these organic effluents is very attractive and efficient, using various semiconductor-based composite materials which act as catalysts under light irradiation. This review focuses on recent developments of TiO2-CeO2 based nanostructure semiconductor materials, which include structural and interfacial ameliorations such as doping with other metals, non-metals, metal oxides and carbonaceous materials. Both TiO2 and CeO2 are highly redox and exchangeable (Ti+4/Ti+3 and Ce+4/Ce+3), and their performance is boasted by their associated defects and oxygen vacancy structure properties, making them amenable to high photoactivity performances. Herein, the effect of various synthesis factors on structural, electronic, optical, and morphological properties, and thus on modification of band gap edges, as well as on their photocatalytic activity and applications, is also reviewed.

Automated summary

Industrial pollution is a significant issue in the world of continuous innovation and intensive development. Organic contaminants from textile industries cause environmental damage and sustainability issues. Heterogeneous photocatalysis using TiO2-CeO2 based nanostructure semiconductor materials has shown great potential for efficient removal of these pollutants under light irradiation.