Ir-YSZ nano-composite electrodes for oxygen sensors

Iridium (Ir)-yttrium-stabilized zirconia (YSZ) nano-composite electrodes were prepared by MOCVD, and their electrode properties were examined. Ir-YSZ nano-composite electrodes consisted of amorphous YSZ and Ir particles of 5-10 nm in diameter. The interfacial conductivity for the Ir-YSZ electrodes was almost 1000 times higher than that of sputtered-Pt electrodes due to large contact area between YSZ and Ir in nano-composite electrodes and high catalytic activity of Ir nano-particles. The electro-motive-force values of the oxygen concentration cell constructed from the Ir-YSZ electrodes and YSZ electrolyte showed the Nernstian theoretical response within 10-20 s at 650 °C.