Plasma‐Constructed Co2P–Ni2P Heterointerface for Electro‑Upcycling of Polyethylene Terephthalate Plastic to Co‐Produce Hydrogen and Formate

Abstract

AbstractIntegrating electrochemical upcycling of polyethylene‐terephthalate (PET) and the hydrogen evolution reaction (HER) is an energy‐saving approach for electrolytic hydrogen (H2) production, along with the coproduction of formate. Herein, a novel and rapid strategy of cold plasma phosphating is employed to synthesize Co2P–Ni2P heterointerface decorated on carbon cloth (Co2P‐Ni2P/CC) to catalyze H2 generation and reform PET. Notably, the obtained Co2P–Ni2P/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−2 for the EGOR and HER, respectively, also attaining an ultralow cell bias of 1.300 V at 10 mA cm−2 for EG oxidation assisted‐water splitting. DFT and characterization results validate that the as‐formed built‐in electric fields in the Co2P–Ni2P 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 Co2P‐Ni2P/CC pair achieves an intriguing formate Faradaic efficiency of 90.6% and an extraordinary stable operation of over 70 h at 100 mA cm−2. The work exemplifies a facile and effective strategy for synthesizing metal phosphides electrocatalysts with extraordinary performance toward H2 generation of water splitting and recycling of PET.