Interfacial synergism of cobalt phthalocyanine modulated Ni3V2O8-NrGO self-assemblies as effective and durable electrocatalyst for overall water splitting

The development of efficient, durable, and noble-metal-free electrocatalysts remains a central challenge in advancing alkaline overall water splitting for green hydrogen production. Herein, we report a rationally designed hybrid electrocatalyst comprising Ni₃V₂O₈ nanosheets integrated with nitrogen-doped reduced graphene oxide (NrGO) and molecularly anchored cobalt phthalocyanine (CoPc). The synergistic coupling between CoPc and the Ni₃V₂O₈ framework induces electronic modulation that stabilizes Ni in high-valence states (Ni³⁺/Ni⁴⁺), significantly enhancing oxygen evolution reaction (OER) activity. Concurrently, high-valence V species and CoPc–NrGO interfaces serve as highly active sites for the hydrogen evolution reaction (HER). The resulting electrode delivers low overpotentials of 231 mV for OER and 201 mV for HER at 10 mA cm⁻² in KOH and H 2 SO 4 respectively, outperforming benchmark RuO₂ and Pt/C catalysts. Strong π–π stacking between CoPc and NrGO, coupled with a conductive and robust carbonaceous architecture, ensures exceptional operational stability. A two-electrode alkaline electrolyzer using this electrode achieves a cell voltage of only 1.46 V at 10 mA cm⁻² and 1.59 V at 50 mA cm⁻², with negligible degradation over extended operation surpassing the performance of conventional Pt/C||RuO₂ systems. This work demonstrates that molecular–inorganic integration offers a powerful strategy to engineer high-performance, scalable electrocatalysts for sustainable energy conversion.