Engineering NiCoP/MoxC heterojunction for highly efficient hydrogen evolution reaction in alkaline and acid solution

A hybrid electrocatalyst composed of NiCoP and MoxC has been prepared via the two-step calcination method. Microscopic analysis demonstrates that the heterojunctions formed by the NiCoP and MoxC are disordered and stacked irregularly. The NiCoP/MoxC heterojunctions are produced during the second calcination treatment. The synergistic effects promote water adsorption and dissociation, and H-2 desorption. More active sites are provided by the irregular structure, the NiCoP/MoxC-X catalyst are imparted excellent electrocatalytic activity toward hydrogen evolution reaction (HER) activity. To sustain a current density of 10.0 mA/cm(2), the overpotentials of NiCoP/MoxC-15 are 79.0 and 116.0 mV while the Tafel slopes are 52.3 and 57.4 mV/dec for the electrocatalyst operated in 1.0 M KOH and 0.50 M H2SO4, respectively. When operating in alkaline medium for 10.0 h at an overpotential of 123.0 mV, the retaining catalytic activity of this material reaches 93.0%. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.