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

摘要

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.