State of the art and prospectives of heterogeneous photocatalysts based on metal–organic frameworks (MOFs): design, modification strategies, and their applications and mechanisms in photodegradation, water splitting, and CO2 reduction

Metal organic frameworks (MOFs) have sparked a wave of research in the field of photocatalysis due to their ultrahigh specific surface area, porous sparse structure, and tunable topology and composition brought about by numerous metal centers/organic ligands. In this study, we first summarize and refine the basic design strategies of MOFs as photocatalysts and their modification strategies in enhancing photocatalytic performance from the perspective of heterogeneous photocatalysts. Subsequently, we review the recent research progress on the specific applications of MOFs in heterogeneous photocatalysis, i.e., photocatalytic degradation of water pollutants, photocatalytic water separation, and photocatalytic reduction of CO2, including the selection of design strategies and modification strategies for MOF-based photocatalysts, photocatalytic mechanisms, and parameters affecting the photocatalytic performance. In addition, this study highlights the mechanistic studies of MOF-based heterogeneous photocatalysts from different perspectives according to their specific applications and compares and refines the photocatalytic mechanistic studies in different fields through different techniques such as in situ characterization and DFT as well as the commonalities and connections between different mechanistic studies. Finally, the disadvantages and advantages of heterogeneous photocatalysts based on MOFs, possible ending directions for existing problems, and possible key research directions for the future, are discussed.