Conductivity-Type Sensor Based onCNT-WO3Composite forNO2Detection

[摘要] The CNTs with 20–50 nm in diameter were directly grown on Au microgap electrode by means of thermal CVD at700∘C for 60 minutes under EtOH-Ar-H2atmosphere (6 kPa). The CNTs with entangled shape formed the network structure with contacting each other. In the CNTs-WO3composite,WO3grains with disk shape (50–200 nm) were independently trapped. The CNTs-WO3composite sensor showed the fairly good sensor response (Ra/Rg = 3.8 at200∘C). The sensor response was greatly improved with CNTs-WO3composite, comparing with that of CNT sensor (Ra/Rg = 1.05). This phenomenon can be explained by formation of p-n junction, between CNT(p) andWO3(n), and thus improvement ofNO2adsorption. The sensor response was decreased with increasing theWO3amount in CNTs-WO3composite, suggesting the electronic conduction due toWO3connection.

[学科分类] 材料工程