Effect of Sintering Temperature on Microstructure and Electrocatalytic Properties of Ti/IrO2-Ta2O5 Anodes by Pechini Method

The anodes of Ti/IrO2-Ta2O5 were prepared using Pechini method. The microstructure and electrochemical properties of the anodes were studied with SEM, EDX, XRD, potentiodynamic polarization, cyclic voltammetry, electrochemical impedance spectroscopy and accelerated life test. It has been shown that the prepared oxide anodes have uniform surface composition, and there is no evident aggregation of IrO2 particles. Tantalum forms solid solution in the rutile IrO2 phase. With the increase of the sintering temperature, the mutual solubility between iridium and tantalum increases, and the crystallite grains of the oxide coating become finer. Moreover, with rising of the sintering temperature, the electrocatalytic activity of the oxide electrode for oxygen evolution and the electrochemically active surface area are reduced. The Ti/IrO2-Ta2O5 anode prepared at 500 °C presents the longest service life.