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/TiO 2 / SnO 2 -Sb-Ir/SnO 2 -Sb-Ni electrodes modified with three kinds of TiO 2 interlayer materials were fabricated. TiO 2 macroporous membrane (MAc) substrate was prepared by direct calcination, and TiO 2 nanotubes (NTs) and TiO 2 mesoporous membrane (MEs) substrate were fabricated by anodic oxidation under different conditions. The study shows that the TiO 2 -nanotube-based anode reduces crack morphology and provides a larger surface area for loading the electrochemically active materials. TiO 2 -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/TiO 2 -NTs/SnO 2 -Sb-Ir/SnO 2 -Sb-Ni electrodes is 3.18 times longer than that of the Ti/SnO 2 -Sb-Ir/SnO 2 -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/TiO 2 -NTs/SnO 2 -Sb-Ir/SnO 2 -Sb-Ni electrodes, which is 1.67 times more than that of the Ti/SnO 2 -Sb-Ir/SnO 2 -Sb-Ni electrodes. Graphical Abstract Ti/SnO 2 -Sb-Ir/SnO 2 -Sb-Ni electrodes modified with three kinds of TiO 2 interlayer have been fabricated. The service life of the optimized Ti/TiO 2 -NTs/SnO 2 -Sb-IrO 2 /SnO 2 -Sb-Ni electrode is 3.18 times longer than that of the Ti/SnO 2 -Sb-Ir/SnO 2 -Sb-Ni electrodes. The degradation rate of the optimized electrode reaches 99.1 % within 5 min, which is 1.67 times more than that of the Ti/SnO 2 -Sb-Ir/SnO 2 -Sb-Ni electrodes.