Development of low-cost metal oxide pH electrodes based on the polymeric precursor method.
In this work, the polymeric precursor method was used to prepare low-cost solid-state sensors for pH determination based on iridium oxide as the main pH sensitive material. The iridium content was reduced with addition of TiO(2), forming the binary system IrO(x)-TiO(2), whose electroanalytical properties were evaluated in comparison with a commercial glass pH electrode. The minimum iridium content which gave suitable results was 30mol%, and the electrode presented Nernstian and fast response in the pH range from 1 to 13, with no hysteresis effect observed. Besides, the electrode showed high selectivity in the presence of alkali ions as Li(+), Na(+) or K(+). The amount of iridium in the prepared electrodes was very small (<0.1mg), supporting the efficiency of this method on the simple preparation of functional low-cost pH electrodes.
da Silva
G M
GM
Laboratório Interdisciplinar de Eletroquímica e Cerâmica, Departamento de Química, Universidade Federal de São Carlos, C.P.: 676, 13560-970, São Carlos, SP, Brazil.
Lemos
S G
SG
Pocrifka
L A
LA
Marreto
P D
PD
Rosario
A V
AV
Pereira
E C
EC
D004563:Electrochemistry; D004566:Electrodes; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry* / Q000191:economics*; D010084:Oxidation-Reduction; D010316:Particle Size; D011108:Polymers / Q000737:chemistry* / Q000191:economics*; D017680:Potassium Compounds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012972:Sodium Hydroxide / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry
D006878:Hydroxides; D011108:Polymers; D017680:Potassium Compounds; C044458:iridium oxide; C009495:titanium dioxide; D007495:Iridium; D012972:Sodium Hydroxide; D014025:Titanium; C029943:potassium hydroxide