Aerosol-assisted chemical vapour deposited vanadium oxide thin films on nickel foam with auspicious electrochemical water oxidation properties

Sustainable green hydrogen production via electrocatalytic water splitting could become viable if the oxygen evolution reaction (OER) is accomplished at extremely high rates on robust surfaces of low-cost transition metal catalysts. Herein, nanoscale vanadium oxide (VO_x) thin films were deposited on porous nickel foam (NiF) by an aerosol-assisted chemical vapor deposition process with different deposition times and were further used as electrocatalysts for OER. The sample with 30 min of deposition time showed an enhanced OER response with a high current density of 1000 mAcm⁻² at 1.7 V (η = 470 mV) vs. RHE. This sample demonstrated a small Tafel slope of 68 mV/dec, and high conductivity. Notably, VO_x-30 (specified for samples deposited for 30 min) exhibited long-term durability by maintaining its initial current density even after 48 h of continuous exposure, thus outperforming several conventional OER catalysts under similar conditions. This distinct behaviour from other catalysts may be attributed to the nanoscale morphologies and the synergistic effect of vanadium-based catalysts with the underlying conductive nickel support.