A solid‐state pH sensor was fabricated using a transparent conductive titanium oxide film on a glass substrate. The coating of the glass substrate was achieved by a novel simple chemical vapor deposition (CVD) procedure. The sensor slope was found to increase as the temperature of the solution was increased. The performance of the sensor was investigated in the pH range from 2.2 to 11.19. The E‐pH curve is linear with slope of 0.054 V at 298.15 K. This value is closed to the theoretical value 2.303RT/F (0.059 V at 298.15). The standard potential of this electrode, E°, is computed as 177.58 mV with respect to the SCE as reference electrode. Results obtained by the suggested sensor compares very well with conventional pH electrodes where the square of the correlation coefficient was 0.998. This electrode can be used as an indicator electrode in potentiometric acid‐base titration. This electrode behaves reversibly and responds to the oxide ion concentration in molten NaNO3. K2Cr2O7 was potentiometrically titrated with Na2O2 and K2CO3 as titrants in molten NaNO3 at 350°C, using the above mentioned indicator electrodes. An acidity/basicity scale of the oxyanions was established in molten NaNO3 at 350°C.
This work was accomplished through a grant from the Deanery of Scientific Research in the Al‐Azhar University of Gaza.