Spontaneous Electronic Redistribution Strategy for Efficient Electrocatalytic Upcycling PET (Polyethylene Terephthalate) and Nitrate Wastes

Abstract

The electrocatalytic valorization of poly(ethylene terephthalate) (PET) waste into valuable chemicals offers a promising strategy for mitigating environmental pollution. Herein, we develop a spontaneous electronic regulation strategy for the rational synthesis of Co-doped hierarchical Ni-based electrocatalysts, which are employed for the valorization of PET plastic waste. Comprehensive characterization and DFT theoretical calculations reveal that the introduction of Co species in the Ni0.3Co0.7/IF electrode pushes its partial electrons to neighboring Ni sites. This adjustment accelerates the formation of NiIII, enhancing the catalytic activity for the oxidation of ethylene glycol (EG) derived from the PET hydrolyzate. Specifically, the Ni0.3Co0.7/IF electrode exhibited a significantly low potential of 1.28 V (vs RHE) to achieve a current density of 100 mA cm–2 during EG oxidation, which is 150 mV lower than that of the Ni/IF electrode without Co doping. Finally, a membrane electrolysis assembly system was constructed by coupling PET hydrolyzate oxidation and nitrate reduction, demonstrating high performance, with a high Faradaic efficiency of approximately 90%. This work provides a promising strategy for the concurrent recycling of PET waste and treatment of nitrate-contaminated wastewater.