Two-Dimensional NiMo-Fc/NF Nanosheets as a Bifunctional Electrocatalyst for Integrating Hydrogen Evolution and Formate Production from Poly(ethylene terephthalate) Hydrolysate

Plastic waste represents a largely untapped resource for the production of chemicals and fuels, particularly in view of its growing environmental and ecological threats. Herein, we report an electrocatalytic strategy for upcycling poly(ethylene terephthalate) (PET) into valuable chemicals and hydrogen fuel using a two-dimensional (2D) metal–organic framework nanosheet catalyst, denoted as NiMo-Fc/NF, synthesized on nickel foam through coordination of ferrocene carboxylic acid with nickel and molybdenum salts. The integrated electrolyzer simultaneously facilitates the hydrogen evolution reaction (HER) and ethylene glycol oxidation reaction (EGOR), achieving a Faradaic efficiency larger than 95% and formate productivity about 99% at a low potential of 1.29 V. The NiMo-Fc/NF catalyst demonstrates outstanding activity for both the oxygen evolution reaction (OER) and HER, requiring overpotentials of only 208 mV and 135 mV to deliver 10 mA cm–2 in an alkaline medium, respectively. The superior performance is attributed to the unique 2D layered architecture, which provides abundant exposed active sites and promotes efficient electron transfer. The incorporation of ferrocene enhances the redox activity and stabilizes the Ni/Mo catalytic centers, while the synergistic interaction between the Fc ligand and bimetallic nodes optimizes the electronic structure and enhances charge transport kinetics. This work demonstrates a sustainable route for upcycling waste PET into high-value products, advancing circular resource utilization, and sustainable waste management.