Advanced N-doping nickel-cobalt phosphides for boosting hydrogen evolution in acid and alkali media

In this article, the hydrogen evolution performance in 0.5 M H 2 SO 4 and 1.0 M KOH is improved by introducing N atoms into Ni 2 P/Co 2 P through high-temperature doping (N–Ni 2 P/Co 2 P). N–Ni 2 P/Co 2 P has a lower overpotential than Ni 2 P/Co 2 P, which can achieve cathodic current densities of 10 mA cm −2 , 100 mA cm −2 at overpotentials of 48 mV, 228 mV in 1.0 M KOH and 63 mV, 211 mV in 0.5 M H 2 SO 4 . Density functional theory (DFT) results found that the introduction of N atoms changed the electronic structure of the catalyst. Due to the forward shift of d-band center, the binding force between the catalyst and H∗ is enhanced, providing favorable conditions for hydrogen evolution. Furthermore, the results of scaled-up tests show that 5 cm × 5 cm N–Ni 2 P/Co 2 P electrodes still exhibit superior performance, revealing a prospect of industrialization.