수열합성법으로 제조된 Co3O4 분말을 사용한후막 가스센서의 CO 감지 특성

Abstract

CO sensing thick film gas sensors using Co3O4 powders prepared by hydrothermal reaction method, were fabricated, and their structural, electrical and CO gas sensing properties were investigated. The specific surface area of the Co3O4 powders obtained from BET analysis was about 79.0 m2/g. XRD and SEM results show that the thick films heat-treated at 500 oC for 30 min after screen printing had the preferred orientation of (311) direction and the crystalline size was calculated to 221 Å_. The maximum activation energy obtained from the temperature-resistance characteristics was 3.11 eV in the temperature range of 290 oC to 310 oC. The sensitivity to 1,000 ppm CO was about 150 %. The specific surface area, crystalline size, and maximum activation energy were increased significantly and the sensitivity for CO gas was improved largely.