Morphology Effects of TiO₂ Mediated Layer on Electrolytic Chlorine Evolution Performance of Ru-Ir Oxide Electrodes

TiO₂ mediated layers with various morphologies such as nanosheets and nanowires have been realized through the alkaline hydrothermal method to improve the electrochemical performance of Ru-Ir oxide electrodes. After introducing the TiO₂ mediated layers, the electrode cracking morphology turns to the hierarchical structures with nanosheets and nanowires, and the cracks on the electrode surface disappear. Linear sweeping voltammetry analysis indicates that the chlorine evolution potential of electrode reduces from 1.171 V (vs. SCE) to 1.162 V (vs. SCE), and that the chlorine evolution polarizability decreases from 0.516 V to 0.454 V when the electric current densities are 2 mA·cm^-2 and 20 mA·cm^-2. The voltammetry charge calculation shows the amount of voltammetric charge for TiO₂-mediated Ru-Ir oxide electrode increases to 18.3 mC·cm^-2, which is 4.78 times as much as that of Ti/Ru-Ir electrode (3.83 mC·cm^-2). Meanwhile, the charge transfer impedance decreases. Introducing the TiO₂ mediated layers with various morphologies can improve the electrochemical activity of electrode and enhance the electrocatalytic chlorine evolution ability.