Cu₃p/N-Doped Carbon Catalyst with One-Step Synthesis Method for Hydrogen Evolution Reaction of Alkaline Water Electrolysis

Hydrogen energy is in the spotlight to resolve the imbalance in the supply and demand for renewable energy. Water electrolysis is an eco-friendly method of producing hydrogen, and it is necessary to develop a high-efficiency, low-cost hydrogen evolution reaction (HER) catalyst. This study presents a copper phosphide/N-doped carbon (Cu3P/N-C) catalyst with relatively abundant reserves and low cost. This catalyst is synthesized in a one-step process involving phosphorization of copper and cyclization of polyacrylonitrile (PAN). By adding PAN to the phosphorus precursor, the Cu3P particles are electrically and physically connected, providing improved electrical conductivity and structural integrity of the Cu3P electrode. The disordered N-doped carbon structure formed under the influence of the phosphorus source induces a synergistic effect with the extended electrochemically active surface area (ECSA), increasing HER activity. The P to PAN ratio is optimized to achieve the best HER activity, and Cu3P/N-C prepared in copper foam exhibits HER overpotentials of 211.1 and 301.8 mV at 10 and 50 mA cm-2 current densities in 1 M KOH solution. At a current density of 10 mA cm-2, the HER overvoltage remained stable between 211.1 and 222.1 mV for 24 hours.