Sumiya Akter Dristy+, Md Ahasan Habib+, Mehedi Hasan Joni, Md Najibullah, Rutuja Mandavkar, Shusen Lin, Jihoon Lee*

Cite this article: Chin. J. Struct. Chem., 2025, 44(12), 100747. DOI: 10.1016/j.cjsc.2025.100747

Publication date: December 1, 2025

Keywords: Electrocatalysis; Multi-functional; HER; OER; Overall water splitting; Industrial stability

ABSTRACT

The development of robust, cost-effective and high-performance electrocatalysts is essential for industrial-scale green hydrogen production under high-current operating conditions (>500 mA/cm2) to ensure both high output and economic efficiency. Herein, a binder-free bimetallic vanadium-nickel-boride-phosphide (VNiBP) spherical electrocatalyst (SE) is synthesized via a simple hydrothermal method, followed by post-annealing. The VNiBP catalyst exhibits low overpotentials of 91 mV for the hydrogen evolution reaction (HER) and 270 mV for the oxygen evolution reaction (OER) at 100 mA/cm2 in 1 M KOH with stable operation over 150 h, surpassing most of the state-of-the-art electrocatalysts. The bifunctional VNiBP (-, +) exhibits a low turnover voltage of 1.57 V at 100 mA/cm2 and outperforms the Pt/C || RuO2 benchmark system up to 2,000 mA/cm2 high-current density. The Pt/C || VNiBP hybrid configuration shows a low 2-E cell voltage of 2.55 V at 2,000 mA/cm2 under industrially relevant conditions (6 M KOH, 60°C). Notably, the VNiBP demonstrates exceptional long-term stability, maintaining continuous operation for over 6 days in both 1 M and 6 M KOH at 1,000 mA/cm2. The outstanding overall water splitting (OWS) performance can be attributed to the synergistic combination of rapid intermediate formation, optimized adsorption/desorption kinetics, high electrochemical surface area and low charge transfer resistance offered by favorable composition and spherical morphology.