The effect of NaOH concentration on ferrate electrosynthesis

Abstract

This study investigated the electrochemical characteristics of mild steel anode in NaOH solutions with concentrations ranging from 8 to 16 m to elucidate their impact on the electrochemical synthesis of ferrate and determine the optimal electrolyte concentration for this process. The electrochemical properties of anode material were determined using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and the Tafel polarization. The ferrate concentration was determined by UV–vis method and the conductivity of electrolytes was evaluated through EIS measurement in the high‐frequent range. The results showed that a passive layer easily formed on the anode surface in NaOH solution with a concentration range of 8–12 m, preventing the formation of ferrate. Conversely, at higher electrolyte concentrations (14 and 16 m NaOH), the dissolution capability of the passive layer was enhanced, resulting in a better ability to synthesize ferrate.