Plasma-Constructed CoP-NiP Heterointerface for Electro‑Upcycling of Polyethylene Terephthalate Plastic to Co-Produce Hydrogen and Formate.

Integrating electrochemical upcycling of polyethylene-terephthalate (PET) and the hydrogen evolution reaction (HER) is an energy-saving approach for electrolytic hydrogen (H) production, along with the coproduction of formate. Herein, a novel and rapid strategy of cold plasma phosphating is employed to synthesize CoP-NiP heterointerface decorated on carbon cloth (CoP-NiP/CC) to catalyze H generation and reform PET. Notably, the obtained CoP-NiP/CC exhibits eminent ethylene glycol oxidation reaction (EGOR) and HER activities, effectuating low potentials of merely 1.300 and -0.112 V versus RHE at 100 mA cm for the EGOR and HER, respectively, also attaining an ultralow cell bias of 1.300 V at 10 mA cm for EG oxidation assisted-water splitting. DFT and characterization results validate that the as-formed built-in electric fields in the CoP-NiP heterointerface can accelerate electrons transfer and deepen structural self-reconstruction, thereby boosting effectively water dissociation and ethylene glycol (EG) dehydrogenation. Impressively, coupling HER with PET-derived EG-to-formate in a flow-cell electrolyzer assembled with CoP-NiP/CC pair achieves an intriguing formate Faradaic efficiency of 90.6% and an extraordinary stable operation of over 70 h at 100 mA cm. The work exemplifies a facile and effective strategy for synthesizing metal phosphides electrocatalysts with extraordinary performance toward H generation of water splitting and recycling of PET.