2.3.1 Xylene Sensor Using Double-layered Thin Film and Ni-Deposited Porous Alumina
- Event
- 14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany - Chapter
- 2.3 Metal Oxide-based Gas Sensors II
- Author(s)
- T. Akiyama, Y. Ishikawa, K. Hara - Tokyo Denki University (Japan)
- Pages
- 185 - 188
- DOI
- 10.5162/IMCS2012/2.3.1
- ISBN
- 978-3-9813484-2-2
- Price
- free
Abstract
A xylene sensor using a double-layered metal-oxide thin film and a Ni-catalyst deposited on a porous alumina is presented. The sensing film has double-layered structure; the first layer is Fe2O3 + TiO2(5mol%) + MgO(4mol%), and the second layer is WO3 + TiO2(10mol%). The thickness of the first layer and the second layer is 200nm and 70nm, respectively. Both the sensitivity and the stability are improved by adopting double-layered structure. The Nideposited porous alumina is placed over the sensing film. The pores in the porous alumina are cylindrical. The inner diameter and the height of the pores are about 200nm and 60µm. Xylene gas goes through the Ni-deposited pores in the porous alumina to reach the sensing film. The catalytic action of the deposited Ni enhances the chemical activity of xylene gas. Thus the sensor is highly sensitive to xylene gas. Moreover, the selectivity to xylene gas is satisfactory. The sensor response time and recovery time are approximately 20s and 300s, respectively, at an operating temperature of 340°C. All films and Ni are deposited by r.f. sputtering while the porous alumina is formed by anodic oxidation of aluminum.