Fabrication of Ti/TiO2-NTs/SnO2–Sb–Mo anode and GF/Cu–C3N4 cathode and the synergistic treatment of wastewater by using the dual electrodes

Ti/TiO 2 NTs/SnO 2 –Sb–Mo anode was prepared by adding intermediate layers and elemental doping and GF/Cu–C 3 N 4 cathode was prepared by impregnation method. The electrode was characterized by SEM, XRD, LSV, CV, and EIS, which show that a more uniform and finer-grained surface structure with higher electrocatalytic activity can be prepared by doping and the addition of TiO 2 -NTs interlayer. In addition, the cathode demonstrate the successful loading of Cu–C 3 N 4 on graphite felts (GFs) by SEM and EDS. The electrochemical test shows the high electrochemical activity. The high activity of the two-electrode system was verified according to the hydroxyl radical test, and then the two electrodes were applied to the degradation of 50 mg/L methylene blue wastewater at the same time, and the results showed that the degradation rate was 98.09% in 20 min, and the COD removal was as high as 80.11%, which is 1.33 times and 2.83 times of the single-anode and single-cathode systems, respectively. In addition, the system could show excellent degradation performance in a wide pH range. At the same time, the energy consumption of the two-electrode system is only 110.9 KWh/Kg. Finally, after ten consecutive decolorization experiments, the decolorization rate of methylene blue and the removal rate of COD could still reach 90.5% and 68.7% in 20 min, which indicated that the dual-electrode system had excellent reusability. The study opens a door to the practical application of electrochemical treatment of wastewater.