Ce enhanced humidity-independent acetone-sensing properties of Co3O4 at a low operating temperature

Abstract

As a p-type MOS, Co3O4 can detect acetone at low working temperatures. However, humidity significantly impacts the gas-sensing properties of MOS, particularly when the sensors are operated at a low temperature. Due to the incorporation of Ce, the operating temperatures of the Co3O4-based sensors were reduced from 160℃ to 100℃, while the humidity independences were enhanced. In a high relative humidity environment of 80 %, the gas response of the pure Co3O4 sample deteriorated significantly at 160℃. In contrast, the response of the 10 at% Ce-Co3O4 sample were remained, even at the lower operating temperature. In addition, the 10 at% Ce-Co3O4 sample showed a high and a selective response to 50 ppm acetone in the relative humidity environment of 80 %, and the detection limit for acetone reached 0.1 ppm. The influence of the interaction between the sensing material with water molecules on the humidity-independent gas-sensing property of Ce-Co3O4 was also explored.