Tungsten oxide nanowires chemical sensors

Tungsten oxide nanowires have been synthetized by a simple thermal oxidation route in an oxygen atmosphere, at low vacuum pressure. The morphology of the nanostructures was investigated by scanning electron microscope (SEM). Chemical sensors were fabricated using tungsten oxide nanowires as active layer, directly deposited on the transducer. Gas sensing performances were evaluated towards some target chemical species (CO, NO2, NH3, Acetone, Ethanol). Firstly, a temperature screening was performed in presence of a fixed gas concentration, to determine the optimal working temperature of the sensors. Then, calibration curves for some chemical species were estimated. The influence of relative humidity was taken into account. Fabricated devices seem very promising for the detection of ammonia and carbon monoxide.