Enhanced performance of an Al-doped SnO2 anode for the electrocatalytic oxidation of organic pollutants in water

Abstract To prepare an anode with high catalytic activity, long service life and suitability for electrochemical oxidation of industrial wastewater, a noble Al-doped SnO2-Sb electrode on a porous titanium substrate was prepared via an improved sol-gel process. The Al concentration in the sol for the doped metallic oxide on the electrode was investigated. The surface morphologies of the electrodes were characterized via SEM, EDS, XRD and XPS. The electrochemical properties and stabilities of the anodes were investigated by CV, LSV, EIS and accelerated life tests. The surface of the SnO2-Sb-Al anode was uniform and compact when the amount of doped Al was 2.0 at.%, and it possessed the smallest particle size with a long service life. Moreover, the SnO2-Sb-Al-2 anode had the highest oxygen evolution potential (1.57 V). The mineralization degree of phenol reached 69.2% after 2 h when the effective area of the SnO2-Sb-Al-2 anode was 8 cm2 and the applied current density was 10 mA/cm2. Thus, the electrode is suitable for printing, dyeing, and electroplating, while also having potential applications in the pharmaceutical industry and in wastewater cleanup of other refractory biodegradables.