Tungsten Oxide Based Sensor for Oxygen Detection

Abstract

In this paper we report on the development tungsten oxide based chemiresistive sensors for the monitoring of oxygen at low temperatures (T ≤ 400 °C) in dry and humid air. The sensors were deposited onto alumina substrate by a combination of spin coating and a photolithographic process to define the sensing area. Our results show that the sensors comply with a linear relationship over a 0 to 20% concentration range, with a high response towards oxygen. The highest response was observed at 350 °C (ΔR/Ra = 7.8) in humid and in dry air (ΔR/Ra = 18). This result is a significant improvement over our previous experiments and we believe to take the concept of a metal-oxide based oxygen sensor a step closer.

Thickness Optimization of Highly Porous Flame-Aerosol Deposited WO3 Films for NO2 Sensing at ppb

“…Analytes were dosed into the dry synthetic airflow from dry calibrated gas bottles (all PanGas, Dagmersellen, Switzerland): NO 2 , H 2 S, CH 4 , NH 3 , acetone, methanol, ethanol (all 10 ppm in synthetic air); H 2 (50 ppm in synthetic air); formaldehyde (10 ppm in N 2 ); CO (500 ppm in synthetic air). Note that the O 2 concentration in the gas mixture was reduced from 20 to 18 vol% for 1 ppm formaldehyde in N 2 ; however, this should not affect the sensor performance [56]. All tubing was made out of inert Teflon and heated to 50 • C to avoid water condensation and minimize analyte adsorption.…”

WO3 and Ionic Liquids: A Synergic Pair for Pollutant Gas Sensing and Desulfurization

“…Many are the materials used in air pollutant sensors, and among them semiconducting metal oxides are very popular [111]. In particular, WO 3 , due to its peculiarities, is often used as sensor material [112][113][114][115].…”