Nanocarving of titania (TiO2): a novel approach for fabricating chemical sensing platform

A simple, inexpensive method for producing titania (TiO2) surfaces comprised of nanofibers has been discovered. These nanofibers are formed via the reaction of dense polycrystalline TiO2 in a H2/N2 environment at 700 °C for 8 h. The nanofibers formed by this process have diameters of 15–50 nm and lengths of 1–5 μm. The preferred crystallographic orientation for this “nanocarving” process is the [0 0 1] direction and the nanofibers are single crystal TiO2. Several processing variables are found to affect the nanofiber formation. The sintered state before the nanocarving treatment plays a critical role in the formation of nanofibers. The flow rate of H2/N2 gas during the treatment also influences the rate of nanofiber formation. Preliminary results show enhanced gas sensitivity, though the response is sluggish.