Conductivity-Type Sensor Based on CNT-WO3 Composite for NO2Detection
The CNTs with 20–50 nm in diameter were directly grown on Au microgap electrode by means of thermal CVD at 700∘C for 60 minutes under EtOH-Ar-H2 atmosphere (6 kPa). The CNTs with entangled shape formed the network structure with contacting each other. In the CNTs-WO3 composite, WO3 grains with disk...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Hindawi Limited
2008-01-01
|
| Series: | Journal of Nanomaterials |
| Online Access: | http://dx.doi.org/10.1155/2008/352854 |
| Summary: | The CNTs with 20–50 nm in diameter were directly grown on Au microgap electrode by means of thermal CVD at 700∘C for 60 minutes under EtOH-Ar-H2 atmosphere (6 kPa). The CNTs with entangled shape formed the network structure with contacting each other. In the CNTs-WO3 composite, WO3 grains with disk shape (50–200 nm) were independently trapped. The CNTs-WO3 composite sensor showed the fairly good sensor response (Ra/Rg = 3.8 at 200∘C). The sensor response was greatly improved with CNTs-WO3 composite, comparing with that of CNT sensor (Ra/Rg = 1.05). This phenomenon can be explained by formation of p-n junction, between CNT(p) and WO3(n), and thus improvement of NO2 adsorption. The sensor response was decreased with increasing the WO3 amount in CNTs-WO3 composite, suggesting the electronic conduction due to WO3 connection. |
|---|---|
| ISSN: | 1687-4110 1687-4129 |