ELECTROCHEMICAL PROPERTIES AND MICROSTRUCTURE OF Ir-Ta-Ti METAL OXIDE COATED TITANIUM ANODES

Ir-Ta-Ti metal oxide coated titanium anodes prepared by thermal decomposition at aif-ferent calcination temperatures were characterized by scanning electron microscopy,cyclic voltammetry, and accelerated life test, while the consumption rate of an anodewas also measured in seawater. The SEM results indicate that all oxide layers ex-hibit a cracked-mud morphology influenced by calcination temperature. Voltammetriccharge (q*), obtained by integration of I-E curve, is proportional to the number oflayer. It is found that q* decreases linearly with the increase of calcination temper-ature, and reaches a maximum at 450℃. The anode prepared at 500℃ possesses thebest anodic stability and the longest service life in 1M H2SO4 at an anodic currentdensity of 2A/cra2. Owing to good corrosion resistance and low consumption rate inseawater, Ir-Ta-Ti metal oxide coated titanium anodes belong to insoluble materialwith excellent electracatalytic activity, which are outstanding candidates for using asanode in impressed current cathodic protection systems.