Distinctive Tin Dioxide Anode Fabricated by Pulse Electrodeposition: High Oxygen Evolution Potential and Efficient Electrochemical Degradation of Fluorobenzene

A distinctive Sb-doped SnO2 anode with a high oxygen evolution potential, 2.4 V vs the saturated calomel electrode, and a strong electrochemical oxidation ability was prepared on TiO2 nanotubes through the pulse electrodeposition method. Compared with the traditional Sb-doped SnO2 electrode prepared by the sol−gel method, the proposed SnO2 electrode has a higher crystallinity, a higher order degree of the atomic lattice, and a lower concentration of oxygen vacancies. The scanning electron microscopy image confirms that the surface of the electrode presents a three-dimensional structure consisting of Sb-doped SnO2 nanoparticles with a certain microspherical structure, which increases the specific area greatly and provides more active sites. The reaction activation energy also decreases from 11.67 kJ mol−1 for the traditional SnO2 electrode to 5.73 kJ mol−1. This SnO2 electrode is demonstrated to have a superior electrochemical oxidation ability for refractory fluorobenzene, which is extremely stable and cannot even be degraded effectively on a boron-doped diamond electrode with a strong oxidation capacity. The results also indicate that the distinctive SnO2 electrode has a higher apparent rate constant, total organic carbon removal, and mineralization current efficiency, which are 12, 2.6, and 3.3 times those of the traditional SnO2 electrode, respectively. The evolution of intermediates and the degradation mechanism of fluorobenzene were further discussed. This study provides a distinctive SnO2 anode for the effective electrochemical oxidation of refractory toxic organic pollutants.