(2020) Progress in Energy and Combustion Science_Metal-organic framework as a photocatalyst: Progress in modulation strategies and environmental/energy applications

Younis S.A., Kwon E.E., Qasim M., Kim K.-H., Kim T., Kukkar D., Dou X., Ali I.

(Elsevier Ltd) Progress in Energy and Combustion Science ISSN: 3601285 Vol.81 Issue. Article No.100870 DOI: 10.1016/j.pecs.2020.100870

Progress in the design, synthesis, and modification of metal-organic frameworks (MOFs) has immensely helped expand their applications in a wide variety of research fields. Such developments offered great opportunities for upgrading their efficiencies in diverse photocatalytic applications (e.g., N2/CO2 reduction, H2 generation, organic synthesis, and environmental remediation) through enhanced conversion/storage of solar energy. The MOF-based photocatalytic platforms are, nonetheless, subject to many practical problems (e.g., inapplicability for industrial upscaling and thermodynamic instability under environmental conditions). In this review, the effects of synthesis/modification strategies on MOF photocatalysis have been discussed with respect to the type of inorganic nodes, the modulation of organic ligands, and the pre-/post-synthesis modification in MOF networks (i.e., MOF-based composite). Particular emphasis was placed on the technical advances achieved in the photoelectronic/catalytic performances of MOFs in multiple energy/environmental (redox) reactions based on both experimental and theoritical analyses. Further, the technical merits/disadvantages of MOF photocatalysts (in terms of structural defects, light absorption, active sites, and kinetic/thermodynamic stability) have been evaluated in relation to quantum efficiency and charge transfer mechanisms in various photo-redox reactions. The pursuit of strategies for enhanced kinetic stability of MOFs have also been highlighted based on the nature/strength of coordination modes, the inertness of metal centers, and the functionality of ligand types. Lastly, the current limitations of MOF-based photocatalysts are addressed with respect to their practical applications at industrial scales along with a discussion on their future use. © 2020

We acknowledge support provided by the R&D Center for Green Patrol Technologies through the R&D for Global Top Environmental Technologies funded by the Ministry of the Environment (Grant #: 2018001850001 ) as well as by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (Grant #: 2016R1E1A1A01940995 ). DK acknowledges the financial support of SERB received under the early career research program (No. YSS/2015/00212 ).