Three-dimensionally hierarchical NiCoP@PANI architecture for high-performance hydrogen evolution reaction

Ternary phosphides are attracting great attention in the field of electrocatalytic hydrogen evolution and they have been verified to be highly active for water splitting. Herein, we developed polyaniline (PANI) coated nickel-cobalt metal phosphides nanowire arrays grown on nickel foam (NiCoP@PANI) as hydrogen evolution reaction electrocatalysts. The appearance of PANI with excellent electric conductivity can accelerate H+ in electrolyte transfer into H2 and offer a masking layer to restrain the damage of electrode structural. Besides, the 3D porous structural of nickel foam can act as a skeleton to avoid electrode structure collapse and a channel for electron transfer. The optimized NiCoP@PANI can drive a current density of 10 mA cm-2 at low overpotential of 80.6 mV in 1 M KOH solution, and satisfactory electrochemical stability with unbroken structure and unchanged composition after electrochemical test.