Metal Oxide-Based Nanocomposites for Photocatalytic Reduction of CO2

Climate change and environmental health degradation are gaining attention worldwide to survive life sustainability. Regular increase of carbon dioxide (CO2) in the environment is a matter of concern, and various attempts have been made to cope with this. Photocatalytic reduction of CO2 into valuable chemicals and solar fuels is one of the best attempts, which not only mitigate the CO2 but also fulfill the demands of energy. Numerous efforts have been put forward to develop advanced visible light-driven semiconductor materials that efficiently utilize CO2 photo-reduction under solar irradiation. Titanium dioxide (TiO2) was the first material used for the photocatalytic conversion of CO2 into valuable chemicals. Since then, researchers have paid much attention on the metal oxides and metal oxide-based nanocomposites for photocatalytic reduction of CO2 into solar fuels or chemicals. This chapter aims to develop an organized and updated panorama about the application of metal oxide nanocomposites in the photocatalytic reduction of CO2, highlighting their role as semiconductor materials and the properties and structural designing that make an impact on their photocatalytic response. It clearly describes the fundamentals behind the advancements in the development of visible light-active metal oxide nanocomposites by doping with metal and nonmetal, and coupling with other semiconductor materials, which will be helpful in improved CO2 photo-reduction for future applications. In addition, the mechanism of CO2 reduction under solar light using metal oxides as photocatalyst has also been described.