Engineering metal-organic frameworks for efficient photocatalytic conversion of CO2 into solar fuels

Artificial photosynthesis is an emerging and reliable technique for CO2 mitigation, and it is also a potential method to achieve carbon dioxide resourcing and efficiently convert solar energy to storable high-density chemical energy (solar fuels), solving both the challenging universal problems of energy shortage and global warming simultaneously. Metal-organic frameworks (MOFs) are crystalline materials composed of metal ions bridged by organic ligands to form one to three-dimensional coordination networks. MOFs are emerging photocatalysts with the highest surface area compared to other photocatalytic materials known to humankind, and their flexible rational design allows the incorporation of different active sites into a particular framework, thereby generating a complex multicomponent photocatalytic system. This review surveys the updated strategies to rationally design photocatalytic MOFs for the efficient transformation of CO2 into solar fuels. The review discusses MOFs' features as semiconductor photocatalysts and various means of improving their light-harvesting, charge separation and CO2 adsorption capacity. Furthermore, different components of MOFs that are light-responsive and the light-harvesting mechanisms for the CO2 photoreduction are highlighted. The breath of work compiled in this review will stimulate further research in global CO2 abatement and will be of great importance to a broad range of researchers and industrialists.