Effect of the preparation methodology on some physical and electrochemical properties of Ti/Ir x Sn(1−x)O2 materials
The aim of this work was to prepare electrodes based on the Ti/Ir x Sn(1−x)O2 composition, as well as test their stability toward the chlorine evolution reaction (ClER). To this end, two different preparation routes were investigated: thermal decomposition of polymeric precursors (DPP) and standard decomposition using isopropanol as solvent (SD/ISO). A systematic investigation of the structural, morphological, and electrochemical properties of the anodes with a nominal composition of Ti/Ir x Sn(1−x)O2, prepared through the two different methodologies, was carried out. The oxide layer surface morphology, microstructure, and composition were investigated by Energy Dispersive X-ray Spectroscopy (EDS) and Scanning Electron Microscopy (SEM) techniques prior to and after accelerated life tests. EDS analyses following total deactivation of the electrode gave evidence of a relatively large content of Ir in the coating. XRD results showed there was formation of solid solution between IrO2 and SnO2, and the degree of miscibility of these solutions is controlled by the preparation method. Thus, the DPP method led to phase separation and large interval of immiscibility between the oxides analyzed. On the other hand, the SD/ISO method led to formation of solid solution for all the investigated compositions. The SD/ISO method produced materials rich in Ir, so the electrode lifetime was much longer if compared with the DPP counterparts.
KeywordsSnO2 Iridium IrO2 Accelerate Life Test Scanning Electron Microcopy
A.R. de Andrade acknowledges the financial support to this work by FAPESP foundation. The scholarships granted by CAPES (P.D.P. Alves) and FAPESP (J. Ribeiro #02/06465–0) are greatly acknowledged.
- 1.Beer HB (1966) U. S. Patent. New York 3:199Google Scholar
- 4.Trasatti S, Lodi G (1981) In: Trasatti S (ed) Electrode of conductive metallic oxides, part A. Elsevier, Amsterdam, p 521Google Scholar
- 10.Ortiz PI, De Pauli CP, Trasatti S (2004) J New Mater Electrochem Syst 7:153Google Scholar
- 13.Handbook of chemistry and physics, 55th edn. C.P. INC. 1974–75, Clevend, OhioGoogle Scholar
- 15.Pechini MP, Adams N (1967) US Patent, 3,330,697:1Google Scholar
- 21.Cullity BD (1978) Elements of X-ray diffraction. Addison-Wesley, California, p 102Google Scholar
- 22.Powder Diffraction File in: Joint Committee on Powder Diffraction Standards, International Center for Diffraction Data. 1996: Pennsylvania. PDF-file: 43-1019 for IrO2 and 41-1445 for SnO2 Google Scholar
- 24.Callister WD (1999) Materials science and engineering, 5a edn. John Wiley & Sons, USAGoogle Scholar
- 25.Huheey JE, Keiter EA, Keiter RL (1933) Inorganic chemistry—principles of structure and reactivity, 4th edn. HarperCollins, New York, USAGoogle Scholar
- 26.Alves PDP, Magali S, Tremiliosi-Filho G., De Andrade AR (2004) J Braz Chem Soc 15:626Google Scholar