Characteristics of Thick Film Gas Sensors Using Nano ZnO:CNT

Abstract

Abstract The effects of an addition of CNT on the sensing properties of nano ZnO:CNT-based gas sensors were studied forH 2 S gas. The nano ZnO sensing materials were grown by a hydrothermal reaction method. The nano ZnO:CNT was preparedby ball-milling method. The weight range of the CNT addition on the ZnO surface was from 0 to 10 %. The nano ZnO:CNTgas sensors were fabricated by a screen-printing method on alumina substrates. The structural and morphological properties ofthe ZnO:CNT sensing materials were investigated by XRD, EDS, and SEM. The XRD patterns revealed that nano ZnO:CNTpowders with a wurtzite structure were grown with (1 0 0), (0 0 2), and (1 0 1) dominant peaks. The size of the ZnO wasabout 210 nm, as confirmed by SEM images. The sensitivity of the nano ZnO:CNT-based sensors was measured for 5 ppmof H 2 S gas at room temperature by comparing the resistance in air with that in target gases.Key wordsZnO, CNT, H 2 S, ball-mill. 1. 서 론 산업 발전과 더불어 대기오염 문제로 인해 여러 가지가연성 가스와 유독성 가스 등을 감지하기 위한 가스센서의 필요성이 증가하고 있다. 현재, 가스 센서는 사용 목적과 감지 대상에 따라 다양한 종류가 개발되고 있다.