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 H2SO4 and 1.0 M KOH is improved by introducing N atoms into Ni2P/Co2P through high-temperature doping (N-Ni2P/Co2P). N-Ni2P/Co2P has a lower overpotential than Ni2P/Co2P, 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 H2SO4. 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 dband 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 x 5 cm N-Ni2P/Co2P electrodes still exhibit superior performance, revealing a prospect of industrialization.