The metal-organic frameworks as unique platform for photocatalytic CO2 conversion to liquid fuels

Carbon dioxide (CO2) is the largest greenhouse gas from fossil fuels combustion, which has caused great impact on global climate change and remarkable environmental issues. On the other hand, CO2 is also a kind of abundant, cheap and special renewable C1 resource. Therefore, the rational resource utilization of CO2 and the realization of "turning waste into treasure", not only solve the ecological and environmental problems, but also bring great opportunities for industrial development. Photocatalytic CO2 conversion to liquid fuels is a very effective method to mitigate environmental problems and improve CO2 resource utilization. A platform is required for photocatalytic CO2 conversion. Metal-Organic Frameworks (MOFs) with high porosity, large surface area and flexible synthetic strategies have become an emerging class of promising platform for photocatalytic CO2 conversion. This review focuses on the state-of-the-art development process of MOFs for photocatalytic CO2 conversion to liquid fuels under visible light irradiation. The representative research works of photocatalytic CO2 conversion to various liquid fuels, such as formic acid, methyl alcohol, ethyl alcohol and cyclocarbonate by MOFs-based photocatalysts were highlighted. The strategies for structure and property optimization of MOFs-based photocatalysts have been presented. The strategies for structure and property optimization of MOFs-based photocatalysts at molecular-level have been presented for improving the photocatalytic performance. The reaction mechanism has also been discussed, which is conducive to gain valuable insights into specific solar to chemical energy conversion. Furthermore, the summarization and generalization of structure-activity relationship provide guidance for the design and synthesis of MOFs-based photocatalytic system.