Electrodeposition of Ni nanoparticles from deep eutectic solvent and aqueous solution as electrocatalyst for methanol oxidation in acidic media

Electrodeposited Nano-Ni films at pencil graphite electrode from aqueous acetate buffer and Ethaline solvent as an example of deep eutectic solvents (DESs) were estimated as electrocatalysts for electrooxidation of 1 M methanol in 1 M H₂SO₄. The electrodeposition process and the electrocatalytic behavior of Nano-Ni films were performed using the chronoamperometry and cyclic voltammetry techniques, respectively. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and x-ray diffraction (XRD) were used for the characterization of Ni deposits from the two different solvents. It was found that Ni/PGE deposit from Ethaline gives 6.01 mA cm^?2 current density at anodic peak potential of 0.67 V and onset potential of 0.31 V while, Ni/PGE deposit from acetate produces 5.6 mA cm^?2 current density at anodic peak potential of 0.65 V and onset potential of 0.37 V, suggesting the higher catalytic activity of Ni/PGE from DES towards methanol oxidation.