J. Kristof et al., THERMOANALYTICAL INVESTIGATION ON THE FORMATION OF IRO2-BASED MIXED-OXIDE COATINGS, Journal of Applied Electrochemistry, 23(6), 1993, pp. 615-624
The formation reactions of IrO2/TiO2 mixed oxide films supported on ti
tanium metal plate were followed by thermoanalytical (simultaneous TGA
, DTG, DTA) and combined thermoanalytical-mass spectrometric (TGA-MS)
techniques. The electrochemical characterization of the fired coatings
was made by cyclic voltammetry. The thermal decomposition of the tita
nium precursor salt, titanium diisopropoxide bis-2,4-pentanedionate, s
hows a major change in the presence of hydrated iridium (III) chloride
. Due to the catalytic effect of the added noble metal, an almost comp
lete conversion of the organic components of the precursor mixture to
CO2 and H2O is observed in the combustion stage. Chlorine, from therma
l decomposition of the iridium salt, is produced in a separate stage a
t higher temperatures, indicating that a sequence of steps occurs prio
r to the oxide formation. For iridium chloride alone a complexation be
tween the metal ion and the solvent (isopropanol) is observed, leading
eventually to H2O and CO2 production (combustion step) between 300 an
d 500-degrees-C. The cyclic voltammetry results indicate that the feat
ures of the precursor reaction affect the charge storage capacity of t
he oxide films.