Preparation of the Ti/TiO2-RNTs/SnO2–Sb–Ni-La Electrode and Its Electrochemical Degradation of Oily Wastewater

In this work, Ti/TiO2-RNTs/SnO2–Sb–Ni-La electrodes were developed in three deposition stages. TiO2-RNTs improved the bonding of the bottom layer, and Ni–La codoping resulted in higher film stability. Compared with other electrodes, this electrode exhibits excellent performance with a denser structure, higher OEP (2.17 V), lower Rct (5.36 Ω), longer electrode strengthening life, and larger active specific surface area. The degradation of oily wastewater revealed an oil removal rate equal to 97.88% under optimal conditions. In comparison to the Ti/TiO2-RNTs/SnO2–Sb obtained via the one-step hydrothermal technique, the service life improved by 8.60 times, and the degradation rate (RD) of the current electrode (k = 0.0254 min–1) was enhanced by 2.67 times, whereas the removal rate remained stable after 10 cycles. Under the continuous attack of free radicals such as •OH, 48 types of organic matter in wash oil were decomposed, and most of the alkanes and polycyclic aromatic hydrocarbons were mineralized. Compared with direct current, pulse current electrolysis of the oil-washing wastewater can save 47.95% electrical energy, and the energy consumption of chemical oxygen demand removal per unit mass can be reduced by 72.02%. Therefore, the Ti/TiO2-RNTs/SnO2–Sb–Ni-La pulse electrochemical oxidation method is expected to reduce energy loss and improve the electrochemical treatment of oily wastewater.