Jyothish Thangala1, Chandrashekhar Pendyala1, Zhiqiang Chen2, Alan Chin3, Cun-Zheng Ning3, and Mahendra K. Sunkara4. (1) Chemical engineering, University of Louisville, 106, Ernst Hall, Louisville, KY 40292, (2) Institute of Advanced Materials and Renewable Energy, Louisville, KY 40292, (3) ELORET Corporation, NASA Ames Research Center, Building N230, Room 232, M/S N229-1,, Moffett Field, CA 94035-1000, (4) Department of Chemical Engineering, University of Louisville, 106 Ernst Hall, Department of Chemical Engineering,, University of Louisville, Louisville, KY 40292
Transition metal oxide nanomaterials find enormous applications in electrochromic, gas sensing, and catalysis. In this regard, a novel synthesis technique for transition metal oxide nanowires was developed using a scaled up Hot Filament CVD process. The synthesis concept involves the chemical vapor transport of metal oxide vapor phase species using air or oxygen flow over hot-filaments onto substrates kept at a distance. By varying the substrate temperature, the nanowire densities could be varied from 106-1010/cm2 by varying the substrate temperature. The diameter of the nanowires ranged from 100 nm to 20 nm. In the experiments, variations in oxygen flow and substrate temperature were successfully employed for affecting the nanowire morphologies from straight to bundled to branched nanowires. The synthesis of III-antimonide nanowires were carried out by both spontaneous nucleation and reactive vapor transport techniques.