Recent trends in metal-organic framework-based photocatalysts for Cr(VI) reduction: confronts and prospects

Water purification is a critical problem for the development and survival of human society, and now it has become a great challenge for the research community. Therefore, MOFs attracted the great intention owing to the large number of active sites, and tailorable porous composition as a fast-growing branch of coordination chemistry. Moreover, MOF-based photocatalysts have proven to be excellent adsorbents in photocatalysis for wastewater treatment. In current review, we have discussed the various synthesis routes, and historical developments of the MOFs. Additionally, recent developments have been explored in the removal, and degrading hexavalent chromium through MOFs under visible light irradiations. In addition, this review demonstrated the development of sustained and efficient metal-organic materials (MOMs), and their modularity, fine-tuneable, and diverse composition with structural features. In this context, numerous investigations have been explored with their classifications of MOF-based heterostructures including 0D, 1D, 2D, and 3D materials, according to their structural, morphological and nature of the catalyst. Furthermore, we have explored the different parameters to enhance photocatalytic reducing ability of hexavalent chromium (Cr6+). In summary, various challenges and future prospects are explained for further advancements in Cr(VI) reduction through MOFs-based nanocomposites under visible light in aqueous media.