Potentiometric YSZ-based Sensors Using Zn-Ta-O-based Sensing Electrode for Selective H_2 Detection

摘要

An yttria-stabilized-zirconia (YSZ)-based gas sensor utilizing a sensing electrode (SE) comprised of a mixture of co-sintered ZnO and Ta_2O_5 powders was developed and reported here. The addition of 30 wt.% Ta_2O_5 into ZnO after sintering at 1000°C, was found to increase the H_2 sensitivity when compared with other SEs with different mixture compositions. Unfortunately, the response toward H_2 was accompanied by high responses toward CO and hydrocarbons (HCs). The sensitivity as well as the selectivity improvement investigation was extended by elevating the sintering temperature from 1000" to 1300°C. The sensor utilizing ZnO(+ 30 wt.% Ta_2O_5)-SE that was sintered at 1300°C was found to be capable of generating high response toward 100 ppm H_2, with only minor responses toward other gases examined in this study at an operating temperature of 600°C under humid conditions.