Extreme Changes in the Electrical Resistance of Titania Nanotubes with Hydrogen Exposure


  • This work was partially supported by a Seed Grant provided by Penn State Materials Research Institute and the Penn State MRSEC under NSF grants DMR 0080019 and DMR 0213623.


Extremely sensitive, drift-free, and robust hydrogen sensors based on titania nanotube arrays (see Figure) are reported. Very large changes in the electrical conductivity of the nanotubes upon exposure to hydrogen gas have been measured, over one order of magnitude greater than the previous record. Dependence of the electrical conductivity on both temperature and nanotube pore size is found.