2011 journal article

Solid support flame synthesis of 1-D and 3-D tungsten-oxide nanostructures

PROCEEDINGS OF THE COMBUSTION INSTITUTE, 33, 1899–1908.

By: W. Merchan-Merchan *, A. Saveliev n & W. Jimenez*

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
author keywords: Nanorods; Tungsten-oxide nanostructures; Counter-flow flame; Combustion; Synthesis
Source: Web Of Science
Added: August 6, 2018

In this paper we report the growth of 1-D and 3-D tungsten-oxide nanostructures on tungsten wire probes inserted in an opposed-flow oxy-fuel flame. The probe diameter and oxygen content in the oxidizer were varied to study their influence on the growth of tungsten-oxide nanostructures. The introduction of a 1-mm diameter W probe into the flame environment with an oxidizer composition of 50%O2 + 50%N2, resulted in the formation of 1-D nanorods on the upper surface of the probe. The formation of triangular, rectangular, square, and cylindrical 3-D channels with completely hollow or semi-hollow morphology was achieved by reducing the probe diameter to 0.5 mm. Whereas, the increase of the O2 content to 100% and the employment of a 1-mm probe resulted in the growth of ribbon-like micron-sized structures. The lattice spacing of ∼0.38 nm measured for the 1-D W-oxides closely matches a monoclinic WO3 structure. X-ray photoelectron spectroscopy analysis revealed that the larger 3-D structures also consist of WO3 confirming that the chemical composition of the structures remains the same while varying the probe and flame parameters. The proposed growth mechanism states that the 3-D WO3 structures are formed through the lateral coalescence of 1-D W-oxide nanorods.