Novel KOH electrolyte for one-step electrochemical synthesis of high purity solid K2FeO4: Comparison with NaOH

An electrosynthesis from an iron wire gauze in KOH electrolyte is first presented for the in situ direct synthesis of the solid K2FeO4, with a highest efficiency of 73.2%, purities of 95.3-98.1% and a highest yield of 49 g l−1 K2FeO4 at 65 °C, which is far better than that in NaOH electrolyte as a whole. A variety of electrolysis conditions including cell configuration, applied current density, temperature and electrolyte concentration have been explored. The in situ and ex situ electrochemically directly synthesized K2FeO4 powders exhibit similar IR absorption spectra and XRD patterns to the chemical synthesized K2FeO4 but different crystal morphologies.