NiPd nano-alloy film as a promising low overpotential electrocatalyst for high activity water oxidation reaction

Electrolytic water splitting is promising strategy for the production of Green Hydrogen (H2) but the sluggish kinetics during the oxygen evolution reaction (OER) is still a challenge. Herein, nickel palladium (NiPd) electrocatalyst has been presented for energy-efficient water oxidation. The catalyst films have been deposited on nickel foam (NF) substrate using a single-step aerosol-assisted chemical vapor deposition technique. The thickness of the deposited film is controlled by varying the deposition time from 60 to 180 min. The morphology and structure of the NiPd catalysts were characterized and directly employed for OER investigation in 1.0 M KOH. The catalyst made for 120 min initiates OER at an extremely low onset potential of 1.4 V vs. RHE (η = 170 mV), requires an overpotential of just 180 mV to approach the benchmark current density of 10 mA cm-2 and peak current density of > 1300 mA cm-2 is achieved at an overpotential of mere 370 mV. Moreover, the catalyst demonstrates excellent durability during prolonged water electrolysis experiments and imposing kinetics for OER. The catalytic performance of NiPd electrode is many folds better than the star catalyst (IrO2) investigated under similar circumstances. The superior OER activity of NiPd alloy at such low overpotentials is accredited to the mutual relevance of high electroactive sites at intermetallic catalyst surface, the favorable synergy created between intrinsically active 3d-transition metal Ni and noble metal, Pd grown over porous and conductive NF surface that cumulatively favors electronic communications and adsorption/desorption process at nano surfaces of the catalytic film.