Mechanochemistry Milling of Waste Poly(Ethylene Terephthalate) into Metal-Organic Frameworks

Converting poly(ethylene terephthalate) (PET) into metal-organic frameworks (MOFs) has emerged as a promising innovation for upcycling of waste plastics. However, previous solvothermal methods suffer from toxic solvent consumption, long reaction time, high pressure, and high temperature. Herein, a mechanochemical milling strategy was reported to transform waste PET into a series of MOFs with high yields. This strategy had the merits of solvent-free conditions, ambient reaction temperature, short running time, and easy scale-up for large-scale production of MOFs. The as-prepared MOFs exhibited definite crystal structure and porous morphology composed of agglomerated nanoparticles. It was proven that, under mechanochemical milling, PET was firstly decomposed into 1,4-benzenedicarboxylate, which acted as linkers to coordinate with metal ions for forming fragments, followed by the gradual arrangement of fragments into MOFs. This work not only promotes high value-added conversion of waste polyesters but also offers a new opportunity to produce MOFs in a green and scalable manner.