MOF-based composites for visible-light-driven heterogeneous photocatalysis: Synthesis, characterization and environmental application studies

The heterogeneous photocatalysis (HP), an advanced oxidation process that generates reactive oxygen species by activating a catalyst under irradiation, is considered one of the most viable treatment alternatives with various environmental applications. Thus, new visible-light active composite photocatalysts with a reduced e−−h+ ​recombination rate have been synthesized incorporationg metal-organic frameworks (MOFs) in semiconductors such as TiO2, ZnO, Fe2O3, Fe3O4, WO3, g-C3N4, RGO, and BiOBr for efficient and sustainable processes. MOFs have attracted much interest in the last years in the photocatalysis field due to their ordered crystalline structure, high porosity, and good optical response. Among the most described MOFs, MIL-n, UiO, and ZIF are notable interest families due to their excellent thermal stability and resistance to organic solvents and water. This review describes the characteristics, synthesis methods, and environmental applications of MOF-based composite materials as visible-light active catalysts. The photocatalytic results and potential applications of MOF-based composites for the degradation of organic compounds, Cr(VI) reduction, microorganisms inactivation, NOx oxidation, CO2 reduction, and H2 production are discussed, concluding with future perspectives.