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 <i>R</i>_ct (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 (<i>R</i>_D) of the current electrode (<i>k</i> = 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.