Effects of high-humidity aging on platinum, palladium, and gold loaded tin oxide--volatile organic compound sensors.

This study is an investigation of high-humidity aging effects on the total volatile organic compound (T-VOC) gas-sensing properties of platinum, palladium, and gold-loaded tin oxide (Pt,Pd,Au/SnO(2)) thick films. The sensor responses of the high-humidity aged Pt,Pd,Au/SnO(2), a non-aged Pt,Pd,Au/SnO(2), and a high-humidity aged Pt/SnO(2) to T-VOC test gas have been measured. The high-humidity aging is an effective treatment for resistance to humidity change for the Pt,Pd,Au/SnO(2) but not effective for the Pt/SnO(2). The mechanism of the high-humidity aging effects is discussed based on the change of surface state of the SnO(2) particles.