A planar, impedancemetric NO2 sensor based on NiO nanoparticles sensing electrode

A planar, impedancemetric NO2 sensor with 8% yttria stabilized zirconia (YSZ) as electrolyte and NiO nanoparticles as sensing electrode and a Pt counter electrode was fabricated and tested. The nano-structured NiO sensing electrode was fabricated by infiltrating aqueous solutions of nickel nitrate into porous layer in a bilayer yttria-stabilized zirconia (YSZ) pellet, followed by calcination at 800 °C for 3 h. The complex impedance of the device was measured in the frequency range of 0.1–100 kHz and in the temperature range of 500–600 °C, respectively. The resistance value (Z′) of the device at low frequency varied with concentration of NO2 in sample gases. The response signal (|Z|base−|Z|gas) at 0.1 Hz of the present device was found to vary almost linearly with the logarithm of NO2 concentration from 20 to 300 ppm at fixed oxygen concentrations at 500–600 °C. The present sensor has many advantages, such as, simple structure, easy preparation, fast response and high sensitivity.

► Wet infiltration method first is used for preparation of sensing electrode materials of sensor and microstructure of sensing materials is tunable by firing temperature. ► A novel impedancemetric-type NO2 sensor based on yttria stabilized zirconia (YSZ) and nanoparticle NiO sensing electrode. The sensor showed high sensitive to NO2. ► The sensor can easily be prepared and simply operated. The preparation method is general to preparing other sensing electrode materials and sensors.