Modulating Electronic Structure and Morphology in Nb‐NiCoS for PET Plastic Upcycling

ABSTRACT Electrocatalytic polyethylene terephthalate (PET) upcycling coupled with green hydrogen production offers an energy‐efficient route for plastic waste valorization. Herein, Nb‐incorporated NiCoS electrocatalysts are synthesized on nickel foam via a one‐step chemical bath deposition route for PET electro‐upcycling. Nb incorporation modulates the electronic structure and morphology of NiCoS, producing defect‐rich vertically interconnected nanosheets with abundant electrochemically dynamic Ni 3+ /Co 3+ active sites. The optimized electronic structure promotes reconstruction into active NiOOH/CoOOH species, resulting in enhanced performance toward the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), ethylene glycol oxidation reaction (EGOR), and PET hydrolysate oxidation reaction (POR). Nb‐NiCoS requires 1.32 and 1.34 V vs RHE to achieve 100 mA cm −2 for EGOR and POR, respectively, significantly lower than OER (1.52 V vs RHE). Mechanistic analysis reveals an indirect oxy‐hydroxide‐mediated oxidation pathway, enabling selective conversion of PET‐derived EG into formic acid with a Faradaic efficiency of 93.3% (with ~100% selectivity) and a production rate of 1.16 mmol h −1 cm −2 at 100 mA cm −2 . Coupling PET electro‐upcycling with hydrogen production reduces the energy consumption to 3.52 kWh Nm −3 from 4.49 kWh Nm −3 for conventional water electrolysis, enabling energy saving of 21.3%, highlighting a scalable strategy for simultaneous plastic waste valorization and hydrogen production.