Fe3O4/Sb–SnO2 Granules Loaded on Ti/Sb–SnO2 Electrode Shell by Magnetic Force: Good Recyclability and High Electro-oxidation Performance

Abstract

Guided by the ideas of green chemistry and green engineering, a new developed electrode with interchangeable coatings was fabricated for electrochemical oxidation (EO). This electrode consists of a permanent magnet NdFeB, a Ti/Sb–SnO2 electrode shell and a number of magnetic Fe3O4/Sb–SnO2 granules. The granules are fixed on the electrode shell by magnetic attraction force. Necessary characterizations were used to reveal the morphology, composition and magnetic property of the magnetic granules. The electrochemical properties of the new electrode were investigated by the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The performance of the new electrode and its stability in the EO process were carried out. Finally, the recyclability of the granules was also tested. Results show that the new electrode has a larger real surface area than the conventional electrode (two-dimensional electrode). The real current density on the new electrode is decreased, which results in a higher EO ability and higher electrode stability. The energy is also saved because the cell voltage is decreased. In addition, the magnetic granules could still be attracted and recycled after a long time use. This new electrode could be considered as a renewable electrode, and the lifetime of the EO system could be increased by a factor of 5 when granules are renewed timely.