DEVELOPMENT OF ANODIC ELECTRODES BASED ON LOW COST METAL OXIDES FOR THE GENERATION OF FREE CHLORINE

Abstract

SnO2 electrodes doped with Sb were prepared, supported on porous titanium sheets by impregnation, sintering and thermal decomposition of precursor solutions with different mass percentages of Sn and Sb (Sn: Sb = 9:1 and Sn: Sb = 7:3). The electrodes were coated with a layer of ß-PbO2 obtained by anodic electrodeposition method at 65 ° C and a current density of 30 mA cm-2, for 30 minutes. The electrodes were characterized by Raman spectroscopy, scanning electron microscopy, and cyclic voltammetry. The results obtained showed that the catalyst with the highest content of Sn provides the optimal conditions for the interlayer formation between Ti and PbO2 , such as the formation of a homogeneous film, low overpotentials for the chlorine evolution reaction and stability at neutral pH. The synthesized PbO2 film presented a pyramidal shape morphology, according to the Raman spectrum; it has the Plattnerite form [β- PbO2 ]. In addition to low overpotentials for the chlorine evolution reaction, with a life time determined by Cronopotenciometric measurements of 171.75 hours in NaCl at 6% and with a current density of 30 mA cm-2.