Bi-functional Ni-Co-P/rGO/NF flower-like structure as an electrocatalyst for hydrogen production assisted by urea oxidation reaction

Abstract

Replacing the inert oxygen evolution reaction (OER) with alternative electrochemical reactions is critical for large-scale hydrogen generation. Here the Ni-Co-P flower-like nanostructure coated on reduced graphene oxide which was synthesized via two-step electrodeposition method (as Ni-Co-P/rGO/NF) is described. First, rGO was deposited on the nickel foam precursor by the pulse-reverse electrodeposition, then Ni-Co-P nano-layer by the Chronoamperometry was electrodeposited. The η10 for HER and UOR was 53 mV and 1.23 V, respectively, demonstrate enhanced electrocatalytic activity. XRD, XPS, and TEM analysis revealed that the Ni-Co-P/rGO catalyst has a flower-like structure depending on its composition. In the two-electrode cell at a voltage of 1.35 V, the generated current density of urea electrolysis (37.84 mA cm−2 in 0.33 M urea + 1.0 M KOH electrolyte) was 3.31 times greater than that of the conventional water splitting (11.41 mA cm−2). According to the findings, Ni-Co-P/rGO could be employed as a dual-functional catalyst toward UOR and HER for energy-saving and H2 generation.