a1 Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210
A template-based, electroless wet-chemical method for synthesis of nanotubes and nanowires of nanocrystalline anatase titanium oxide (titania) at 45 °C is reported. Single-nanowire electrical property measurements reveal low dc resistivities (7–21 × 10−4 Ω cm) in these titania nanowires. In the presence of 1000 parts per million of CO gas at 100 °C, the resistivity is found to increase reversibly, indicating low-temperature gas-sensing capability in these titania nanowires. Thin films of nanocrystalline anatase titania, deposited using a similar wet-chemical method, also have low room-temperature dc resistivities (6–8 × 10−3 Ω cm), and they are transparent to visible light. Nanostructure-properties relations, together with possible electrical conduction, optical absorption, and gas-sensing mechanisms, are discussed. The ability to fashion transparent-conducting and gas-sensing nanocrystalline anatase titania into nanotubes/nanowires and thin films at near-ambient conditions could open a wider field of applications for titania, including nanoelectronics, chemical sensing, solar cells, large-area windows and displays, invisible security circuits, and incorporation of biomolecules and temperature-sensitive moieties.
(Received April 29 2006)
(Accepted July 12 2006)
(Online publication March 03 2011)
c1 Address all correspondence to this author. e-mail: [email protected] This author was an editor of this journal during the review and decision stage. For the JMR policy on review and publication of manuscripts authored by editors, please refer to http://www.mrs. org/jmr_policy
p1 Present address: Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan.