MOF based composites with engineering aspects and morphological developments for photocatalytic CO₂ reduction and hydrogen production: A comprehensive review

Recently, metal-organic framework (MOFs) based materials have gathered increasing interest in the field of photocatalysis for energy and environmental remediation. The discovery of the highly porous, flexible, modifiable structure with excessive active sites is effective for harnessing clean energy from the sun. Several MOFs have been successfully designed for CO₂ capture and H₂ production applications. This review highlights the engineering aspects, morphological developments, and efficiency enhancement for MOFs-based photocatalysts towards CO₂ reduction and hydrogen applications. In the first part of review characteristics, classification, band structures, morphological development, and visible light responsiveness of MOFs were critically discussed. The recent developments in MOF semiconductors ranging from single metal MOF to mixed metal is discussed. In the mainstream, enhancement approaches for photocatalytic performance of MOFs and expand their visible light absorption has been discussed. The commonly employed enhancement strategies include morphological alterations, Schottky junction, sensitization with polymers, plasmonic metals, or dye, and heterojunction formation including type I, type II, type III, and Z-scheme. The applications of MOFs based materials for photocatalytic CO₂ reduction, and hydrogen production were systematically discussed. This review will ultimately be useful for researchers looking to develop novel strategies to enhance MOF semiconductors composites for not only environmental and energy applications, but as well as other catalytic processes.