Electronic structure tailoring via P-ligation in CoP nanoflowers drives bifunctional electrocatalysis for plastic waste valorization and hydrogen evolution

The valorization of plastic waste via electrocatalytic conversion into value-added chemicals and hydrogen represents a promising sustainable technology, yet is hindered by the lack of efficient and cost-effective bifunctional catalysts. Herein, we develop a hierarchically structured cobalt phosphide nanoflower catalyst anchored on nickel foam (CoP-F@NF) through fluoride-mediated morphology control. Comprehensive characterization confirms the successful synthesis of crystalline CoP nanoflowers with homogeneous elemental distribution. When applied to polyethylene terephthalate (PET) hydrolysate electro-oxidation, CoP-F@NF exhibits exceptional activity, high formic acid selectivity (>95 %) and Faradaic efficiency (>86 %), attributed to synergistic effects of the CoP phase and nanoflower architecture that optimize mass/charge transport (Tafel slope: 110.12 mV dec −1 ). Mechanistic studies reveal the dominant reaction pathway: ethylene glycol → glycolaldehyde → glyoxal → formic acid. Simultaneously, CoP-F@NF demonstrates efficient hydrogen evolution reaction (HER) activity (Tafel slope: 117.7 mV dec −1 ), leveraging PET oxidation to replace energy-intensive oxygen evolution. In an integrated two-electrode system, CoP-F@NF achieves concurrent formic acid production (FE: >92 %, selectivity: >92 % at 2.0 V) and H₂ generation with superior stability over five cycles. Control experiments with CoO-F@NF and density functional theory calculations reveal that P-modulation elevates the Co d-band center (εd = −1.295 eV vs. -1.601 eV for CoO), optimizing intermediate adsorption strength for both anodic oxidation (weakened *CHO-CHO binding) and cathodic HER. This work establishes a noble metal-free route for plastic waste upcycling and green hydrogen production via electronic and morphological catalyst design.