Fe2P-coated Ni2P/Co2P yolk-shelled porous nanospheres as advanced Pt-free electrocatalysts for efficient pH-universal hydrogen evolution

At present, the exploration of renewable energy is a huge challenge, and water electrolysis is regarded as a promising method for producing hydrogen. However, the hydrogen evolution reaction (HER) has been hampered due to expensive Pt-based catalysts. Herein, the Fe2P-coated Ni2P/Co2P nanospheres with yolk-shelled structure were successfully synthesized according to a facile approach of doping transition metal elements and phosphating on the template Ni-Co nanospheres, successively. All samples were tested as HER catalysts at various pH environments. The results showed that the Fe2P-Ni2P/Co2P possesses superior electrocatalytic ability and good stability. The Fe2P-Ni2P/Co2P achieved the lower ηonset (overpotential at 1.0 mA cm−2) of 36.6, 64.2, and 65.9 mV, η10 (overpotential at 10 mA cm−2) of 89.7, 125, and 212 mV, and Tafel slopes of 48.0, 60.3, and 135 mV dec−1 in acidic, alkaline, and neutral solutions, respectively, exhibiting an excellent electrocatalytic activity of the multicomponent phosphides for HER.