In situ fabricated nickel vanadate/N-doped reduced graphene oxide hybrid as an advanced electrocatalyst in alkaline hydrogen evolution reaction

Abstract

Inthe current work, we reported the in situ fabrication of a nickel vanadate (Ni₃V₂O₈)-anchored N-doped reduced graphene oxide (NRGO) hybrid by a simple one-step reflux method. Subsequently, the electrocatalytic performance of the Ni₃V₂O₈/NRGO hybrid was investigated in an alkaline medium (1.0 M KOH) for the hydrogen evolution reaction (HER). It was noted that the optimization of the NRGO content (∼5.6 wt%) highly influenced the homogeneous distribution of quasi-spherical Ni₃V₂O₈ nanoparticles over NRGO sheets and enhanced the water reduction ability. This hybrid material exhibited a sufficiently high electrochemical active surface area (517.5 cm²) and remarkably low charge transfer resistance (∼1.6 Ω). Furthermore, the very low overpotential (∼43 mV) and the high exchange current density (∼1.24 mA cm⁻²) of Ni₃V₂O₈/NRGO (5.6 wt%) demonstrated its promising HER performance. Additionally, superior long-term and accelerated stability compared to that of the benchmark Pt/C in a strong basic medium clearly signified that Ni₃V₂O₈/NRGO (5.6 wt%) can act as an efficient, cost-effective, and durable electrocatalyst for water electrolyzers.