Engineering Amorphous Cobalt–Nickel Phosphate Nanostructures on Exfoliated Graphite: A Molecular Precursor‐Driven Route to High‐Performance Alkaline Water Splitting Catalysts

ABSTRACT The development of earth‐abundant, bifunctional electrocatalysts is essential for advancing alkaline water electrolysis as a sustainable hydrogen production technology. Herein, a low‐temperature molecular precursor strategy is employed to synthesize an amorphous cobalt–nickel phosphate (Co─Ni─Pi) catalyst anchored on exfoliated graphite (EG). The use of thermolytically labile [(M(tmeda)(H ₂ O) ₄ )(dtbp) ₂ ] (M = Co, Ni) complexes enables in situ formation of a redox‐active, amorphous bimetallic phosphate phase under solvothermal conditions. Structural and spectroscopic analyses confirm the homogeneous dispersion of phosphate nanoparticles and the presence of mixed‐valent Co ²⁺ /Co ³⁺ and Ni ²⁺ /Ni ³⁺ species. Electrochemical investigations reveal enhanced bifunctional performance of Co ─ Ni ─ Pi/EG toward both the oxygen evolution reaction and the hydrogen evolution reaction in alkaline media outperforming the monometallic analogues. The catalyst also achieves overall water splitting at 1.70 V cell voltage with excellent stability for 72 h in a two‐electrode configuration. This study underscores the effectiveness of molecular precursor engineering, heterometallic synergy and carbon scaffold integration in designing robust, low‐cost electrocatalysts for renewable hydrogen production.