Metal–Organic Frameworks Derived Interconnected Bimetallic Metaphosphate Nanoarrays for Efficient Electrocatalytic Oxygen Evolution

The development of low-cost, high-performance, and stable electrocatalysts for the sluggish oxygen evolution reaction (OER) in water splitting is essential for renewable and clean energy technologies. Herein, the interconnected nanoarrays consisting of Co–Ni bimetallic metaphosphate nanoparticles embedded in a carbon matrix (Co_2−xNi_xP₄O₁₂-C) are fabricated through a mild phosphorylating process of cobalt–nickel zeolitic imidazolate frameworks (CoNi-ZIF). Density functional theory calculations reveal moderate adsorption of oxygenated intermediates on the doping Ni site, and current density simulations imply homogeneous and higher current density due to the morphology integrity of the interconnected metaphosphate nanoarrays. As a consequence, the optimized Co_1.6Ni_0.4P₄O₁₂-C affords a superior OER activity (η = 230 mV at 10 mA cm⁻²) and long-term stability in alkaline media (1 m KOH) that are comparable to most reported catalysts. The strategy for balancing the doping effect and morphology effect provides a new perspective when designing and developing highly efficient electrocatalysts for energy conversion and storage applications.