Metal organic frameworks (MOFs) has been widely investigated as co-catalysts for photocatalysis owing to their unique property for controlling the reaction kinetics. They are generally presented in a solid state. Recent studies have presented MOF in the liquid phase, meanwhile preserving the framework structure. Acting as a co-catalyst, significantly improved efficiency has been realized for photocatalytic CO2 reduction. This concept article focuses on the chemical principle of liquid MOF (LMOF). Their applications in CO2 adsorption and the photocatalytic CO2 reduction have been discussed with showing key examples. In addition, the other relevant applications of LMOF have been presented. </p
