Electrodeposition of Molybdenum from Water-in-Acetate Electrolytes

Abstract

This paper reports a systematic study on the electrodeposition of metallic molybdenum from water-in-salt electrolytes containing superhigh concentrations of acetate. Cyclic voltammetry and DC deposition were carried out on rotating disk electrodes with various concentrations of CH3COOK and CH3COONH4 to determine the effects of NH4 + and K+ on Mo deposition. A comparison was performed between CH3COOLi, CH3COONa, and CH3COOK to study the effects of different alkali metal cations. A synergistic effect was observed between K+ and NH4 +, where Mo deposition rate is enhanced in the presence of both cations. However, such synergistic effect was not observed between NH4 + and other alkali cations. In addition, the impact of substrate on Mo deposition was also studied using Pt and Cu electrodes with different activity toward hydrogen evolution reaction. Electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to characterize the surface morphology, crystallographic structure, and metallic state of Mo in the electrodeposited films.