Preparation of UiO-66-NH₂@PDA under Water System for Chemical Warfare Agents Degradation

There is an urgent need to develop catalytic degradation technologies for chemical warfare agents (CWAs) that are environmentally friendly and do not require secondary treatment. UiO-66-NH₂ and other metal-organic frameworks (MOFs) based on zirconium have been shown to promote the catalytic degradation of CWAs. At the same time, MOFs have been studied, and they have shown interesting properties in CWA removal because of their ultrahigh surface area, tunable structures, and periodically distributed abundant catalytic sites. However, MOFs synthesized by conventional methods are mostly powdery crystals that are difficult to process and have poor mechanical stability, which largely limit the development of MOFs in practical applications. An emerging trend in MOF research is hybridization with flexible materials. Polymers possess a variety of unique attributes, such as flexibility, thermal and chemical stability, and process ability, and these properties can be combined with MOFs to make a low-cost and versatile material that also provides convenience for the subsequent integration of such MOFs into independent substrates or textiles. In this article, we used a green and simple method to coat the surface of UiO-66-NH₂ with polydopamine (PDA), PDA can promote the catalytic hydrolysis of UiO-66-NH₂ to DMNP (a simulant of chemical warfare agents). Additionally, it can adsorb the toxic hydrolysis product p-nitrophenol, avoiding the trouble of secondary treatment. The half-life of UiO-66-NH₂ coated with polydopamine (UiO-66-NH₂@PDA) for catalytic hydrolysis is 8.9 min, and that of pure UiO-66-NH₂ is 20 min. We speculate that the surface coated with PDA can improve the diffusion of DMNP to the active sites of UiO-66-NH₂.