Morphology-dependent activities of TiO2-NTs@Sb-SnO2 electrodes for efficient electrocatalytic methyl orange decolorization

Novel two-stage pulse electrodeposition was used to fabricate TiO2-NTs@Sb-SnO2 electrodes. At the first pulse stage, a compact Sb-SnO2-coating TiO2-NTs interlayer was realized; at the second, various morphologies of apparent layers including flower-like, hierarchical, and dendritic morphologies were realized through regulating pulse parameters. Morphology-dependent electrode activities were investigated. Electrochemical experiment results show that dendritic-morphology electrode has the lowest charge transfer impedance (27.5 Omega vs. 43.2, 38.1, and 37.5 Omega) in comparison with other electrodes, and chronopotentiometry tests show a higher accelerated service lifetime of dendritic electrode (23 h vs. 17.8, 17.4, and 13.9 h), indicating the optimal electrochemical activity. The electrocatalytic methyl orange decolorization processes show that dendritic electrode possesses a higher first-order kinetics rate constant than other two electrodes (51.7 x 10(-3) min(-1) vs. 32.5 x 10(-3), 39.7 x 10(-3), and 35.5 x 10(-3) min(-1)). These results demonstrate that the dendritic electrode possesses the most efficient catalytic performance.