Enhanced electrocatalytic activity of nano-TiN composited Ti/Sb–SnO2 electrode fabricated by pulse electrodeposition for methylene blue decolorization

Abstract

A Ti/Sb–SnO₂ electrode modified with titanium nitride (TiN) nanoparticles was prepared by the pulse electro-codeposition method. X-ray diffraction and scanning electron microscopy show that compared with Ti/Sb–SnO₂, the Ti/Sb–SnO₂–TiN electrode has a small unit cell volume of tetragonal SnO₂ and a refined, compact particle film. X-ray photoelectron spectroscopy analysis shows that introducing titanium nitride nanoparticles facilitates the formation of Sb⁵⁺. And the adsorbed hydroxyl oxygen species content of Ti/Sb–SnO₂–TiN (43.07%) is higher than that of Ti/Sb–SnO₂ (21.85%), indicating that the Ti/Sb–SnO₂–TiN electrode has more active sites for electrochemical oxidation of organic pollutants. In 0.25 M Na₂SO₄ solution, the charge transfer resistance of Ti/Sb–SnO₂–TiN (150 ohm) is much smaller than that of Ti/Sb–SnO₂ (1334 ohm). With a constant current density of 100 mA cm⁻², the accelerated service lifetime of Ti/Sb–SnO₂–TiN is improved significantly, which is 15.7 times as long as that of Ti/Sb–SnO₂. The Ti/Sb–SnO₂–TiN electrode is demonstrated to have a prominent ability for oxidative decolorization of methylene blue. The results also confirm that the Ti/Sb–SnO₂–TiN electrode has a higher decolorization efficiency and kinetic rate constant, which are 1.54 and 3.24 times as efficient as those of Ti/Sb–SnO₂, respectively.