Enhanced HER and OER Electrocatalytic Activity of Hexagonal Cu3P/NF Electrode for Hydrogen Production

In summary, hexagonal Cu3P was successfully synthesized on the surface of a nickel foam substrate using a two-step method. Electrochemical tests revealed that the Cu3P/NF electrode exhibited excellent catalytic activity for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in a Na2CO3 solution. Importantly, the catalytic performance was further enhanced by the addition of 0.2 M CuSO4 to the Na2CO3 solution. This addition enabled the SO42- group in the electrolyte to form a localized electron cloud, thereby promoting the reaction. The Cu3P/NF electrode achieved a HER current density of 10 mA•cm-2 at an overpotential of 131 mV, and an OER current density of 50 mA•cm-2 at an overpotential of 230 mV. The presence of CuSO4 not only improved the electrocatalytic performance but also enhanced the stability of the Cu3P/NF electrode, resulting in a remarkable increase in HER stability by 90.22% and OER stability by 74.54% in the NC-0.2 electrolyte.

The exceptional catalytic performance of the Cu3P/NF electrode can be attributed to several factors. Firstly, the selection of a three-dimensional porous nickel foam substrate provided a larger surface area and more catalytic active sites, facilitating effective contact with electrolyte ions and enhancing the catalytic efficiency for HER and OER. Secondly, the electronic hybridization between copper and phosphorus elements lowered the energy barrier of the redox reaction, leading to reduced overpotentials and accelerated electrocatalysis. Lastly, the presence of nonmetallic elements in the Cu3P lattice resulted in a distinct electronic structure, with both the copper center and the proximal hanging base P contributing to hydrogen generation.

This study highlights the promising prospects of Cu3P as a catalyst for hydrogen production and provides valuable insights for its practical application.