A Study on Selectivity and Temperature Coefficients of the Chloride Ion Sensors With RuOx Thin Film

This paper investigated the response time, chloride selectivity, and temperature coefficients of the arrayed flexible ruthenium oxide chloride ion sensor in sodium chloride (NaCl) solutions with concentrations from 10
^-5
M to 1 M. The response time was 7 s in 1 M NaCl solution at room temperature, showing that the sensor had the characteristics of the fast response. The selectivity coefficients of the SO
₄
^2-
ion, NO
₃
^-
ion, CO
₃
^2-
ion, ClO
^-
ion, and ClO
₄
^-
ion were 0.001, 0.056, 0.004, 0.015, and 0.006, respectively. The chloride ion sensing device had the good chloride selectivity. Finally, the sensitivity was investigated with different solution temperatures from 5 °C to 50 °C. The sensitivity was increased with higher solution temperature. The temperature coefficient of the sensitivity of the chloride ion sensing device was approximately 0.681 mV/pCl °C between 5 °C and 35 °C.