Ni deposition on nickel foam via the use of high-frequency currents for enhanced hydrogen evolution reaction in alkaline media

Abstract

Herein, a novel laboratory apparatus of physical vapor deposition (PVD) for Ni thin film fabrication is applied to improve the Hydrogen Evolution Reaction (HER) kinetics of nickel foam (NF) electrodes. The proposed setup utilizes high-frequency currents (Eddy currents), applying a Zero Voltage Switching (ZVS) heater to sublimate the sacrificial material, offering lower energy consumption, faster deposition time, and uniform thin film deposition. Morphological and structural characterizations revealed the formation of a well-anchored thin film consisting of Ni nanoparticles of dendrite-like morphology, which offers an increased electrochemically active surface area and improved charge transport. Electrochemical tests demonstrated the superiority of the proposed electrode prepared by the proposed PVD setup (Ni@NF-PVD), offering a low Tafel slope of 88 mV dec⁻¹ and a high double-layer capacitance (C_DL) of 12.6 mF cm⁻². This performance surpasses the corresponding one of similar Ni@NF electrodes prepared by other techniques, such as electrodeposition and pulsed laser deposition.