Electrodeposition of Iron in HNO 3 Solution Containing Iron Dissolved from Copper Slag

Abstract

Electrochemical deposition of iron in HNO3 solution containing irondissolved from copper slag was investigated with varying pH and chemicalcomponents of the solution in this study. The pH dependency of reductionpotentials of ionized iron and copper species facilitated theelimination of copper inclusion in electrodeposited iron-based layers.Hydrogen evolution in competition with iron reduction frompreferentially ferric ions was also diminished by increasing pH of thesolution with NaOH addition. Adding malonic acid was effective toconsiderably diminish the oxidation of reduced iron due to thecomplexation between ferric ion and malonate (Mal) ligand. However, ironoxidation could not be completely inhibited by adding malonic acidbecause a partial transition of Fe(Mal)(+) ions to ferrous ions, whichcan react readily with oxygen during electrodeposition, would occur atlow cathodic potentials. Controlling malonic acid concentration couldlead to the formation of alpha-Fe with very low oxygen content less than0.15 wt%. (C) The Author(s) 2014. Published by ECS. This is an openaccess article distributed under the terms of the Creative CommonsAttribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND,http://creativecommons.org/licenses/by-nc-nd/4.0/), which permitsnon-commercial reuse, distribution, and reproduction in any medium,provided the original work is not changed in any way and is properlycited. For permission for commercial reuse, please email:oa@electrochem.org. All rights reserved.