Lingling Feng, Chenfeng Xia, Xinyao Zhang, Yan She, Huiyue Wang, Xueying Wen, Guixing Hu, Ran Niu, Jiang Gong*, Bao Yu Xia*

Mechanochemical upcycling of waste polyethylene terephthalate into hydroxyl-functionalized metal-organic framework for efficient oxygen evolution reaction

Advanced Functional Materials (2026) Accept. (IF2026 = 19.9)

Metal-organic framework (MOF) has been regarded as a promising electrocatalyst for oxygen evolution reaction (OER). However, synthesizing stable, cost-effective MOF electrocatalysts remains challenging, and the role of functionalized ligands, particularly their interplay with metal hydroxylation, remains unclear. Herein, a mechanochemistry-driven synthesis & functionalization collaborative (MSFC) strategy is developed to directly upcycle waste poly(ethylene terephthalate) (PET) into hydroxyl-functionalized MIL-88B(Fe)-OH. Firstly, in situ generated hydroxyl radicals (·OH) from homolytic cleavage of crystal water enable kilogram-scale production from recycled PET. Such MSFC strategy owns merits of organic solvent-free, atmospheric temperature and pressure, and low-cost, of which the material cost is ca. 1/34 of traditional solvothermal/hydrothermal methods. Secondly, MIL-88B(Fe)-OH exhibits low overpotential of 176 mV at 10 mA cm^–2 and operates stably for 500 h at 100 mA cm^–2, ranking as one of the most efficient MOF electrocatalysts. The coordination and electronic microenvironment of Fe sites are regulated via p–π interactions between –OH and the aromatic ring. Specifically, β-FeOOH forms selectively while the framework is preserved via Fe–O···H–O hydrogen bonding. Such electronic modulation optimizes oxygen intermediate adsorption and lowers the OER kinetic barrier. This work offers a scalable platform for producing low-cost, high-performance functionalized MOF electrocatalysts.