Modified UiO-66 as photocatalysts for boosting the carbon-neutral energy cycle and solving environmental remediation issues

UiO-66, a water-resistant zirconium-based metal–organic framework (MOF) with ultra-high porosity, larger surface area and plentiful active sites, has an advantage over conventional photocatalysts. Notably, its excellent environmental resistances (chemical, hydrothermal and mechanical stability) make it more competent for practical applications than other types of MOFs. Furthermore, the photoresponse range and charge separation efficiency of UiO-66 can be significantly improved by rational design and adjustment. In this review, we aim to provide an overview of the latest advances in the modification and design of UiO-66 for photocatalytic applications, including the selection of metal node, the functionalization of organic linker, defect engineering, foreign metal loading, dye sensitization, and combination with semiconductors. Then, the applications of modified UiO-66 photocatalysts in CO2 reduction, hydrogen generation, organic pollutants removal, Cr(VI) reduction and so on, are elaborated. In particular, the reaction mechanisms are principally highlighted. Finally, referencing these studies, future insights and perspectives are proposed. Our intention is to comprehensively review various modified UiO-66 photocatalysts, which can stimulate for the design of efficient photocatalysts to make better utilization of solar energy.