Synergistic Effect of Nickel and Cobalt Nanoparticles Anchored on Boron-Doped Reduced Graphene Oxide for Enhanced Alkaline Hydrogen Evolution Reaction

In this study, novel electrocatalysts based on boron-doped reduced graphene oxide (B-rGO-H) decorated with nickel (Ni) and cobalt (Co) nanoparticles were synthesized via a modified polyol method and evaluated for their hydrogen evolution reaction (HER) performance in alkaline media. The structural, morphological, and compositional properties of the synthesized materials swere thoroughly characterized using FTIR, Raman spectroscopy, XRD, XPS, SEM-EDS, and HR-TEM analyses. Electrochemical evaluations were carried out through linear sweep voltammetry (LSV), Tafel slope analysis, electrochemical impedance spectroscopy (EIS), and chronopotentiometry. Among the prepared catalysts, the NiCo@B-rGO-H hybrid demonstrated superior HER performance with a low overpotential of 242 mV at 10 mA cm^-2, a favorable Tafel slope of 165 mV dec^-1, and exhibits long-term electrochemical stability comparable to that of a 20% Pt@C commercial electrocatalyst over 24 h. The enhanced activity is attributed to the synergistic interaction between Ni and Co nanoparticles and the conductive, defect-rich B-doped graphene matrix, which collectively improve the electron transfer kinetics and increase the electrochemically active sites. These findings highlight the potential of NiCo@B-rGO-H as a promising, cost-effective, and durable noble-metal-free electrocatalyst for efficient hydrogen production via water splitting in alkaline conditions.