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 Fe 2 P-coated Ni 2 P/Co 2 P 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 Fe 2 P-Ni 2 P/Co 2 P possesses superior electrocatalytic ability and good stability. The Fe 2 P-Ni 2 P/Co 2 P achieved the lower η onset (overpotential at 1.0 mA cm−2) of 36.6, 64.2, and 65.9 mV, η 10 (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. [Display omitted] • Yolk-shelled nanospheres Fe 2 P-Ni 2 P/Co 2 P was synthesized by a template method. • The synergistic effect was used to improve the electrocatalytic performance. • Fe 2 P-Ni 2 P/Co 2 P had large surface area and high catalytic activity for HER. • Fe 2 P-Ni 2 P/Co 2 P had satisfactory HER performance over a wide pH range. [ABSTRACT FROM AUTHOR]