Metal-Organic Frameworks: Versatile Materials for Heterogeneous Photocatalysis

Photocatalysis is one of the most important chemical methods to mitigate the energy and environmental crisis via converting inexhaustible solar energy into clean chemical potential. The general history of the development of photocatalysis based on porous metal-organic frameworks (MOFs) is simply divided into three branches with a focus placed on the distinct structural role of the photocatalytic center: the inorganic cluster nodes, the organic linkers, and the guests in the pores of MOFs. In each branch, these photocatalytic centers are considered to be monodispersed within the crystal lattices with the other two structure roles regularly distributed to isolate the active centers and sometimes to provide more functions other than photoactivity. This distinctive nature has rendered MOFs as promising candidates for photocatalysis not only because they combine the benefits of heterogeneous catalysis and homogeneous catalysis but also because they facilitate the possibility of merging multifunctional catalytic sites for concerted or cascade photocatalysis. The design strategy and improvement approaches for MOF-based photocatalysts are also introduced with an emphasis on structure. Our intention is for this comprehensive view of MOFs-involved photocatalysts to inspire new ideas for designing heterogeneous photocatalysts toward the better utilization of solar energy.