Potentiometric YSZ-based sensor using NiO sensing electrode aiming at detection of volatile organic compounds (VOCs) in air environment

The potentiometric yttria-stabilized zirconia (YSZ)-based sensors using each of various oxide sensing-electrodes (SEs) were fabricated and examined for detection of toluene (C₇H₈) in several tens ppb level. As a result, the sensor using NiO-SE was found to exhibit relatively high sensitivity and selectivity to toluene at 450 °C under the wet condition (1.35 vol.% H₂O). The present sensor could respond well to toluene in the concentration range of 10–150 ppb. The response transients to 50 ppb toluene were stable and repeatable, accompanying with the response/recovery time acceptable for an actual environmental monitoring. In addition, the toluene sensitivity was hardly affected by the interference of the other co-existing gases examined.