Manganese electrodeposition from urea-rich electrolyte

Abstract

<p>Pure manganese coatings were prepared on the steel (AISI 4340) electrode by non-conventional electrodeposition method, in the presence of 8 mol dm^-3 of urea as a plating additive. The influence of urea on the electrodeposition of Mn was investigated by linear sweep voltammetry. The morphology of the coatings was studied by scanning electron microscopy (SEM), and their elemental composition by energy dispersive X-ray spectrometry (EDS). The results showed that the presence of urea in the solution enhanced both the reduction of water and Mn²⁺ ions, however it also increased the current efficiency for metal reduction for around 20 %. Moreover, urea improves the characteristics of Mn deposits, <em>i.e</em>. their adhesiveness, porosity, compactness, and appearance. Except from oxygen as a part of Mn corrosion product at the coatings' surface, no carbon or nitrogen incorporation was detected in the deposits by EDS.</p>