Fabrication of Ti/TiO2/SnO2-Sb-Ir/SnO2-Sb-Ni Using Three Kinds of TiO2 Interlayer and an Optimized TiO2-Nanotube Interlayer-Based Anode for Electrochemical Treatment of Wastewater

Ti/TiO2/SnO2-Sb-Ir/SnO2-Sb-Ni electrodes modified with three kinds of TiO2 interlayer materials were fabricated. TiO2 macroporous membrane (MAc) substrate was prepared by direct calcination, and TiO2 nanotubes (NTs) and TiO2 mesoporous membrane (MEs) substrate were fabricated by anodic oxidation under different conditions. The study shows that the TiO2-nanotube-based anode reduces crack morphology and provides a larger surface area for loading the electrochemically active materials. TiO2-NTs as the optimized interlayer improve the oxygen evolution potential (OEP) from 1.49 to 1.85 V and increase the current density of the oxidation peak from 0.28 to 0.55 mA cm(-2), which enhances the oxidative degradation ability of the electrode. In addition, the service life of the Ti/TiO2-NTs/SnO2-Sb-Ir/SnO2-Sb-Ni electrodes is 3.18 times longer than that of the Ti/SnO2-Sb-Ir/SnO2-Sb-Ni electrodes according to accelerated life tests. The degradation rate of methylene blue (MB) wastewater with an initial concentration of 20 mg L-1 reaches 99.14% under 5.0 V within 5 min by using Ti/TiO2-NTs/SnO2-Sb-Ir/SnO2-Sb-Ni electrodes, which is 1.67 times more than that of the Ti/SnO2-Sb-Ir/SnO2-Sb-Ni electrodes. [GRAPHICS] .