Critical Aspects and Recent Advances in Structural Engineering of Photocatalysts for Sunlight-Driven Photocatalytic Reduction of CO2 into Fuels

The catalytic conversion of CO2 into valuable fuels is a compelling solution for tackling the global warming and fuel crisis. Light absorption and charge separation, as well as adsorption/activation of CO2 on the photocatalyst surface, are essential steps for this process. This article reviews the CO2 photoreduction mechanisms and critical aspects that greatly affect the photoreduction efficiency. Additionally, different materials for CO2 photoreduction are provided, including d(0) and d(10) metal oxides/mixed oxides, sulfides, polymeric materials, and metal phosphides with visible response, metal-organic frameworks, and layer double hydroxides. Furthermore, various structural engineering strategies and corresponding state-of-the-art photocatalytic systems are reviewed and discussed, such as bandgap engineering, geometrical nanostructure engineering, and heterostructure engineering. Each strategy has advantages and disadvantages, requiring further adjustment to further improve the photocatalytic performance of the photocatalyst. Based on this review, it is greatly expected that efficiently artificial systems and the breakthrough technologies for CO2 reduction will be successfully developed in the future to solve the energy shortage as well as the environmental problem.