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 H-2/N-2 environment at 700degreesC for 8 h. The nanofibers formed by this process have diameters of 15-50 nm and lengths of 1-5 mum. The preferred crystallographic orientation for this "nanocarving" process is the [001] 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 H-2/N-2 gas during the treatment also influences the rate of nanofiber formation. Preliminary results show enhanced gas sensitivity, though the response is sluggish. (C) 2004 Elsevier Ltd and Techna Group S.r.1. All rights reserved.