CalcinationTemperature Effect on Electrochemical Properties and Microstructure of Ir-Ta-Ti Metal Oxide Coated Titanium Anodes

摘要

Ir-Ta-Ti metal oxide coated titanium anodes prepared by thermal decomposition at different caldination temperatures were characterized by scanning electron microscopy, cyclic voltammetry, and accelerated life test, while the consumption rate of an anode was also measured in seawater. The SEM results indicate that all oxide layers exhibit a cracked-mud morphology influenced by calcination temperature. Voltammetric charge (q~*), obtained by integration of I-E curve, is proportional to the number of surface active sites, and can be taken as a measure of the active surface area of oxide layer. It is found that q~* decreases linearly with the increase of calcination temperature, and reaches a maximum at 450 °C. The anode prepared at 500 °C possesses the best anodic stability and the longest service life in 1M H_2SO_4 at 2A/cm~2. Owing to good corrosion resistance and low consumption rate in seawater, Ir-Ta-Ti metal oxide coated titanium anodes belong to insoluble material, which are outstanding candidates for using as anode. in impressed current cathodic protection systems.