Hydrogen sensors with TiO2 nanotubes

Hydrogen sensors, intending to operate at low temperatures (around 25°C), based on TiO₂ nanotube arrays were fabricated and characterized in N₂/H₂ atmosphere with different nitrogen concentrations. The nanotube arrays were obtained through Ti anodic oxidation in a NH₄F in ethylene glycol (0, 5 % in weight) and 2 % H₂O bath, magnetically stirred at room temperature. The TiO₂ nanotube hydrogen sensors were characterized at room temperature with hydrogen concentration varying from 50 to 4000 ppm. A linear conductance variation between 50 and 500 ppm was observed. This result is very attractive for hydrogen sensors where low operation temperatures are needed, for example, in medical applications.