Chemical Physics Letters, Vol.449, No.1-3, 175-181, 2007
Flame synthesis of zinc oxide nanowires
Single-crystalline ZnO nanowires are grown directly on zinc-plated-steel substrates at high rates (microns/minute) using a flame-synthesis method, with no catalysts. The growth of the nanostructures is very sensitive to local gas-phase chemical species concentrations (O-2, H-2, CO2, H2O) and temperature (800-1500 K) as measured by laser-based spontaneous Raman spectroscopy. Larger-diameter (> 100 nm) hexagonal-cross-section nanowires, with [0001] growth direction, are produced at higher temperatures; while smaller-diameter (25-40 nm) nanowires, with [11 (2) over bar0] growth direction, are produced at lower temperatures, and only on the fuel side of the reaction zone (with no oxygen present). Nanoribbons and other nanowire-based morphologies are also found and discussed. (c) 2007 Elsevier BN. All rights reserved.