<p>Widespread adoption of electrolytic water splitting for hydrogen production is limited by the high overpotential and slow kinetics of the oxygen evolution reaction. This work presents a bifunctional electrocatalyst of cobalt phosphide-doped porous carbon electrocatalyst (CoP/Co₂P/C). The catalyst was synthesized via direct pyrolysis of a composite precursor (denoted as Co/Zn-PO@Co-MOF), which consisted of spherical cobalt/zinc phosphate (Co/Zn-PO) coated with Co-based metal-organic framework. The spherical Co/Zn-PO served as a novel and safer phosphorus source, eliminating the need for conventional NaH₂PO₂ carbonization which releases toxic gases. Although minimally incorporated into the composite precursor, Ni²⁺ played two key roles: it primarily functioned to assist the coordination of Co²⁺ with 2-methylimidazole on the surface of Co/Zn-PO, and additionally modulated the resulting CoP/Co₂P ratio. Moreover, the carbonization temperature was a critical variable in converting Co/Zn-PO@Co-MOF into CoP/Co₂P and affected the final ratio between them. Based on the interfacial synergistic effect between CoP and Co₂P, along with three catalytic active sites of Co, P and Pyridinic N, the optimized CoP/Co₂P/C achieved a current density of 10&#xa0;mA cm^− 2 at low overpotentials (η₁₀) of 204 mV for HER and 339 mV for OER. The performance of CoP/Co₂P/C remains comparable to that of most recently reported cobalt phosphide-based catalysts.</p> Graphical Abstract <p></p>