Hydrogen sensing using titania nanotubes

Titanium dioxide nanotubes, made by anodization, are highly sensitive to hydrogen; for example, cycling between nitrogen atmosphere and 1000 ppm hydrogen a variation in measured resistance of 103 is seen for 46 nm diameter nanotubes at 290 °C. The hydrogen sensors are completely reversible and have response times of approximately 150 s. Field emission scanning electron microscopy and Glancing angle X-ray diffraction (GAXRD) are used to study the surface morphology and crystal structure of the nanotubes.