Preparation of a SnO2-Sb electrode on a novel TiO2 network structure with long service lifetime for degradation of dye wastewater.

Abstract

Developing effective electrodes with long service lifetime for electrochemical degradation of dyes is of paramount importance for their practical industrial applications. We constructed a novel SnO2–Sb electrode (Ti/TiO2-NW/SnO2–Sb electrode) based on a uniform TiO2 network structure decorated Ti plate (Ti/TiO2-NW) for a long-term electrocatalytic performance. The SnO2–Sb coating layer on this electrode was grown on the Ti/TiO2-NW by pulse electrodeposition. The introduction of the three-dimensional TiO2-NW enhances the bonding strength between the Ti substrate and the SnO2–Sb surface coating. An accelerated life test shows that the service life of Ti/TiO2-NW/SnO2–Sb electrode is 11.15 times longer than that of the traditional Ti/SnO2–Sb electrode. The physicochemical properties of the electrodes were characterized through SEM, EDS, XRD and HRTEM. In addition, through LSV, EIS, CV and voltammetric charge analysis, it is found that compared with the traditional electrode, the Ti/TiO2-NW/SnO2–Sb electrode possesses a higher oxygen evolution potential, a lower charge transfer resistance and a larger electrochemical active surface area. Besides, this novel electrode also exhibits an outstanding electrocatalytic oxidation ability for degradation of acid red 73 in simulated sewage. After a 5 hours' test, the removal efficiency of acid red 73 and the COD reached 98.6% and 71.8%, respectively, which were superior to those of Ti/SnO2–Sb electrode (89.1% and 58.8%). This study highlights the excellent stability of the Ti/TiO2-NW/SnO2–Sb electrode and provides an energy-efficient strategy for dye degradation.