Thirty minutes laser calcination method for the preparation of DSA ® type oxide electrodes

Abstract

In this paper, a new approach for the preparation of dimensionally stable anodes DSA ® type oxide electrodes, using a CO 2 laser as a heat source, is proposed. Commercial composition of (TiO 2) 0.7(RuO 2) 0.3 was used for this feasibility study in which thermal decomposition of precursor chlorides, for the growth of a coating 2–3 μm thick, is carried out in 30 min. The resulting oxide layer presented the usual cracked-mud morphology that lasted 8 h in an accelerated service life test at 400 mA cm −2 , in a H 2SO 4 1 M solution. The results involving the effects of laser beam power and scan rate are examined. Voltammetric anodic charge was maximized by the combination of 15 W beampower, focal distance of 210 mm and beam scan rate of 35 mm s −1 . By cycling potential between 0.2 and 1.1 V vs SCE the oxide coating behaved as a capacitor capable of being charged and discharged reversibly and the cathodic/anodic charge ratio remained close to one. Currents related to oxygen evolution reaction were observed after 1.37 V vs SCE.