Effects of IrO₂ interlayer on the electrochemical performance of Ti/Sb-SnO₂ electrodes

In this work, the Ti/Sb-SnO₂ and Ti/IrO₂/Sb-SnO₂ electrodes have been successfully fabricated by coating pyrolysis method. The effects of introducing IrO₂ interlayer were analyzed systematically by X-ray diffraction (XRD), scanning electron microscopy (SEM), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and accelerated service life test. Our results showed that the presence of IrO₂ interlayer on the Ti substrate promoted the electrodes' property effectively. In contrast with the traditional Ti/Sb-SnO₂ electrode, Ti/IrO₂/Sb-SnO₂ electrode possesses smaller grains and more compact morphology structure. Then the changes of oxygen evolution potential (OEP) and charge transfer resistance (R_ct) on the electrodes were discussed. Anodic stability test results showed that the introduction of IrO₂ interlayer in the oxide coating produced a significant increase in stability. The accelerated service life of Ti/IrO₂/Sb-SnO₂ electrode was almost 30 times longer than that of Ti/Sb-SnO₂ electrode.