Nano-sized NiO Sensing Electrodes with Different Additives Using in Msxed-potentiai-type YSZ-based Planar Sensors

摘要

The nano-structured pure NiO powder was synthesized by a simultaneous-precipitation method, followed by a low-temperature sintering-process. The obtained NiO sample was loaded with each of BaO, La2O3, CuO and Au (10 wt.% each) in order to modify its morphology as well as its electrochemical properties. It was found that the CuO addition gave more porous microstructure, whereas the BaO (or La2O3) loading leaded to decrease the average grain-size of the NiO powder. The NOx sensing characteristics of mixed-potential-type YSZ-based planar sensor attached with each of the obtained NiO-based samples as a sensing electrode (SE) were examined at elevated temperatures. As a result, the CuO- and the Au-added NiO-SEs were found to give a large enhancement in the NO2 sensitivity as well as the NO2 selectivity at 800°C even under wet condition, in comparison with the pure NiO-SE.