The Effect of Acetate on the Electrodeposition of Manganese on Polycrystalline Au without SeO_2 Additives

摘要

The influence of acetate additives on the mechanism of manganese electrodeposition from chloride-based acidic solution was investigated by electrochemical quartz crystal microbalance and spectroscopic ellipsometry. The EQCM data were represented as plots △m versus E. Because they are not affected by interference from the hydrogen evolution reaction, they clearly show the manganese reduction and oxidation processes. The in situ spectroscopic ellipsometry ( SE) data were analyzed with a single-layer model ( substrate Au - deposition Mn layer) and the thicknesses of Mn layer were obtained by fitting experimental data with the model．Morphology, chemical composition and structure of the manganese deposits were analyzed by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), and X-ray diffraction (XRD). The results showed that in the absence of acetate additives, Mn(OH)_2 is formed. In the presence of acetate additives, the formation of α-Mn was observed and the deposition rate of Mn electrodeposition on the Au electrode slowed down.