Preparation and Electrochemical Performance of Ni-Mo-W/NF Electrodes for Alkaline Water Electrolysis

A facile and one-step direct-current electrodeposition method was employed to synthesize Ni-Mo-W coatings on nickel foam substrates with different electrochemical parameters. The corresponding microstructure and electrochemical characteristics were investigated for the optimized process conditions. A considerably rough surface and numerous spheres on the coatings were observed. X-ray diffraction analysis demonstrated that the Ni-Mo-W alloy had broadened diffraction peaks, indicating the formation of a nano amorphous structure. It also presented a meticulous cubic Mo-Ni substitutional solid solution. Electrochemical measurements revealed that a lower overpotential of only 122 mV at 0.08 mA·cm⁻² and long-term stability can be achieved. A smaller Rs of 0.2 Ω and a lower Rct of 7.236 Ω at the electrode/electrolyte interface were obtained by electrochemical impedance analysis. According to first-principles calculations, the formation energy for creating a solid solution with W atoms is negative, with a value of -6.386 eV, thereby confirming the enhanced stability of the alloy.