Nickel-manganese double hydroxide mixed with reduced graphene oxide electrocatalyst for efficient ethylene glycol electrooxidation and hydrogen evolution reaction

Abstract

Nickel-Manganese (Ni-Mn) double hydroxide catalysts were synthesized on reduced graphene oxide (RGO) and examined for both ethylene glycol (EG) electrooxidation and hydrogen evolution reaction (HER). Different modified electrodes were fabricated and compared with pristine β-Ni(OH)2. The surfaces of the prepared modified electrodes were characterized using scanning electron microscopy (SEM), elemental mapping, X-ray diffraction (XRD), Raman spectroscopy, and differential scanning calorimetry (DSC). Cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS) were used to examine the electrochemical behavior of the prepared electrodes. Furthermore, the Ni-Mn double hydroxide loaded RGO showed a remarked performance as a dual catalyst towards cathodic and anodic reactions, i.e., ethylene glycol electrooxidation and Hydrogen evolution reaction (HER). Additionally, the activity of RGO-NiMn double hydroxide towards ethylene glycol electrooxidation was achieved to 38 mA cm−2 in 1.0 M KOH at a potential of 500 mV (vs. Ag/AgCl). At the same time, the recorded potential of the electrode for hydrogen evolution was − 600 mV (vs. Ag/AgCl) at the current density of 10 mA cm−2.