Preparation of IrO2-Ta2O5|Ti electrodes by immersion, painting and electrophoretic deposition for the electrochemical removal of hydrocarbons from water

Abstract

After intense years of great development, the electrochemical technologies have become very suitable alternatives in niche markets like industrial wastewater reclamation and soil remediation. A key role to achieve a high efficiency in such treatments is played by the characteristics of the coating of the electrodes employed. This paper compares three techniques, namely immersion, painting and electrophoresis, for the preparation of IrO2-Ta2O5|Ti, so-called dimensionally stable anodes (DSA®). The quality of the coatings has been investigated by means of surface and electrochemical analysis. Their ability to generate hydroxyl radicals and degrade aqueous solutions of hydrocarbons like phenanthrene, naphthalene and fluoranthene has been thoroughly assessed. Among the synthesis techniques, electrophoretic deposition yielded the best results, with DSA® electrodes exhibiting a homogeneous surface coverage that led to a good distribution of active sites, thus producing hydroxyl radicals that were able to accelerate the degradation of hydrocarbons.