Redox study of magnesium in non-aqueous electrolyte for purification and recovery

Room-temperature electrolysis in a non-aqueous electrolyte was investigated for refining, winning or thin-film preparation of magnesium. The electrochemical redox behaviors of magnesium and its alloy in a solution of tetrahydrofuran dissolved with EtMgBr demonstrated the use of this technique for obtaining metallic film or refining for pure magnesium at room temperature. From the potentiodynamic results, optimal electrochemical conditions were found for the selective dissolution of magnesium from a magnesium alloy and for its direct reduction of magnesium on a copper cathode surface. The composition, crystal structure, and morphology of the magnesium films were confirmed by X-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy. The pure magnesium metal was uniformly distributed on the copper electrode surface without dendrites or impurities and exhibited (002) crystal orientation.