Effect of a porous Pt/alumina cover layer for V₂O₅/WO₃/TiO₂ resistive SO₂ sensing materials

Abstract

Planar resistive type SO 2 sensors based on V 2 O 5 /WO 3 /TiO 2 (VWT) have been reported to respond well to SO 2 but with large cross-effects of NO and NH 3 . In this study, we added a porous Pt/alumina cover layer on a VWT film in order to decrease the cross sensitivities. The sensor response to SO 2 is hardly affected by the Pt/alumina layer in the case of VWT sensor with 3.0 wt % V 2 O 5 with Au electrodes, while the Pt/alumina layer affects the response of other VWT sensors. The VWT sensor (3.0 wt % V 2 O 5 ) with Au electrodes with the porous Pt/alumina cover layer shows much smaller responses to CO, H 2 , H 2 O, NH 3 , and NO compared with the sensor without Pt/alumina cover layer. The porous Pt/alumina cover layer has a potential to improve the selectivity of the VWT sensor.

CH3SH and H2S Sensing Properties of V2O5/WO3/TiO2 Gas Sensor

“…Our group has reported a resistive-type SO 2 gas sensor based on V 2 O 5 /WO 3 /TiO 2 (VWT) [12,13]. Although this gas sensor has been confirmed to respond well to 20 to 5000 ppm SO 2 gas, its responsiveness to methyl mercaptan and hydrogen sulfide has not been investigated.…”