Application of UiO-66 and its composites for remediation and resource recovery of typical environmental contaminants: a review

UiO-66 series metal–organic framework materials (MOFs) are typical porous materials assembled by Zr4+ with a large mass-to-nucleus ratio and terephthalic acid ligands, which form tetrahedral and octahedral cages arranged in a periodic triangular window pattern. Due to the strong interaction between Zr and O, UiO-66 series MOFs exhibit high thermal stability, structural stability, and chemical stability. This article mainly reviews the applications of UiO-66 and its composites in adsorption, photocatalysis, and resource utilization, while exploring the harm of pollutants to human health and the environment. In the first part, the differences in adsorption and removal mechanisms of liquid organic pollutants, heavy metals, and volatile organic compounds (VOCs) are investigated. The results show that organic pollutants are mainly removed by physical adsorption, electrostatic interactions, hydrogen bonding, and π-π interactions, while heavy metals are mainly removed by chemical adsorption, electrostatic interactions, reduction, and chelation. VOCs are mainly removed by the pore volume and pore size structure of the material. Heterojunction catalysis can achieve non-toxic treatment of pollutants, and this study mainly focuses on UiO-based composite materials constructed by strategies such as semiconductor composites, ion doping, and metal/dye encapsulation. In the second part, the synergistic effect between the components of UiO-based composite materials promotes the oriented and rapid separation and transfer of carriers at the material interface, thereby promoting the generation of active species such as h+, ·O2− and ·OH, and achieving rapid degradation of pollutants and detoxification of heavy metals. In the third part, heterojunctions can realize the resource utilization of pollutants in water and air, producing energy-type substances such as hydrogen and methanol while solving environmental problems. In addition, this article also summarizes the harm of common typical pollutants to the environment and human health. Finally, the development prospects and unresolved problems of UiO-66-based materials in water remediation, gas purification, and environmental resource utilization are reviewed.