One-step facile synthesis of polyethylene terephthalate–derived metal–organic framework for liquid-phase adsorption of benzophenone-4

UiO-66 (Universitet i Oslo 66) is a type of metal–organic framework (MOF) comprising zirconium oxoclusters and terephthalic acid that is expected to be applicable as a liquid-phase adsorbent owing to its high thermal and chemical stability and regular pore structure. Recently, MOFs synthesized from polyethylene terephthalate (PET) as a starting material have attracted much attention. However, developing a one-step process for synthesizing PET-derived UiO-66 with high crystallinity and high purity is difficult because the reaction conditions for PET depolymerization and UiO-66 crystallization are different. In this study, we used acetone with hydrochloric acid as a reaction solvent to carry out PET depolymerization and UiO-66 crystallization simultaneously and successfully developed a one-step process for synthesizing PET-derived UiO-66. In experiments, the PET-derived UiO-66 performed comparably to conventional UiO-66 at adsorbing benzophenone-4 from an aqueous solution, which suggests that it is an effective adsorbent. This is the first report of the one-step facile synthesis without the use of special equipment of PET-derived UiO-66 with high crystallinity and high purity.