Review on inorganic and polymeric materials-coordinated metal–organic-framework photocatalysts for green hydrogen evolution

Metal-organic frameworks (MOFs) possess a distinct advantage over conventional heterogeneous photocatalysts because of their carefully defined architecture and particular pores, which facilitate the targeted incorporation of other efficient cocatalysts or semiconductor materials. The integration of MOFs with other materials has resulted in significant breakthroughs, as the coupled materials improve the performance due to the combined effect. The unique MOF structures allow them to host foreign materials, which results in harvesting the visible region of the solar spectrum and effectively mitigating charge recombination by promoting charge separation. The review presents an evaluation of the latest developments in the utilization of surface and/or pore chemistry of MOF-supported heterojunctions for photocatalytic green-hydrogen generation with a basic understanding of the mechanism involved. The review begins with the basic principles of photocatalysis, the significance of MOFs, their optical properties, the methods used for synthesizing MOFs, and their coordination with other inorganic and polymeric materials. Furthermore, methods to increase photocatalytic H₂ evolution using MOF-supported heterojunction have been proposed as standard practice. Lastly, to address environmental challenges, we highlight the future potential of MOF-supported heterojunctions for use in green-energy production. We hope that this review provides guidance to researchers in the development of effective heterojunctions based on MOFs to address challenges in energy applications and catalytic processes.