(Sb)SnO2/Ni(OH)2 CERAMIC ELECTRODE FOR ELECTROOXIDATION OF EMERGENT CONTAMINANTS

Reference Presenter Authors
(Institution)
Abstract
06-004 Sergio Mestre Mestre, S.(Universitat Jaume I); Sánchez-Rivera, M.J.(Universitat Jaume I); Pérez-Herranz, V.(Universitat Politécnica de Valencia); Gozalbo, A.(Universitat Jaume I); Electrooxidation allows the mineralization of emergent and refractory contaminants in wastewaters without addition of any chemical. The hydroxyl radicals generated in the anode can oxidize dyes, antibiotics, etc. In accordance, chemically resistant electrodes are needed. Until now, noble metals (Ti, Pt) have been used because of their excellent electrochemical behavior, but they are very expensive. An alternative are ceramic electrodes based in Sb-doped tin oxide which can balance the cost with the performance. Electrodes with low resistivity and enough mechanical resistance have been synthesized controlling doping level and sintering conditions. These electrodes have electrooxidated some dyes and antibiotics, but the mineralization have not been complete. A nickel-based catalyst has been deposited into the electrodes by four different approaches to improve the electrochemical activity. In the first approach, an aqueous solution of Ni(NO3)2 have been infiltrated into the electrode and was dried. The second approach provoked the precipitation of the hydroxide inside the porous network submerging the specimen in NH3 before the drying. The third approach infiltrated a solution of Ni(NO3)2 and urea to provoke the hydroxide precipitation during drying by the urea’s decomposition at 90 °C. These three approximations included a final calcination step at 250 °C or 400 °C to fix the catalyst and generate the hydroxide. Finally, a combustion synthesis approach has been employed using glycine as a fuel and an ignition temperature of 400 °C. Results showed that the electrodes with catalyst have a better electrooxidation behavior, but the deposition method influences the quantity of nickel hydroxide fixed in each run and its microstructure, and, consequently, the performance. Acknowledgements: Authors thanks Ministerio de Economía y Competitividad and Fondo Europeo de Desarrollo Regional for their support (Ref. CTQ2015-65202-C2-2-R MINECO/FEDER).
<< Back
Copyright © 2019 Metallum. All rights reserved.
Site produced by: SITESP.NET