Title: Synthesis of tungsten oxide nanostructures by laser pyrolysis

Authors: Bonex Wakufwa Mwakikunga, Andrew Forbes, Elias Sideras-Haddad, Rudolph Marthinus Erasmus, Gift Katumba, Bathusile Masina

Addresses: School of Physics, University of the Witwatersrand, Private Bag 3, PO Wits 2050, Johannesburg, South Africa; CSIR National Centre for Nano-Structured Materials, P.O. Box 395, Pretoria 0001, South Africa; Department of Physics and Biochemical Sciences, University of Malawi, Private Bag 303, Chichiri, Blantyre 3, Malawi. ' Council for Scientific and Industrial Research, National Laser Centre, P.O. Box 395, Pretoria 0001, South Africa; School of Physics, University of Kwazulu-Natal, Private Bag X54001, Durban 4000, South Africa. ' School of Physics, University of the Witwatersrand, Private Bag 3, PO Wits 2050, Johannesburg, South Africa. ' School of Physics, University of the Witwatersrand, Private Bag 3, PO Wits 2050, Johannesburg, South Africa. ' Department of Physics, University of Zimbabwe, P.O. Box MP 167, Mt Pleasant, Harare, Zimbabwe; CSIR National Laser Centre, P.O. Box 395, Pretoria, South Africa. ' Council for Scientific and Industrial Research, National Laser Centre, P.O. Box 395, Pretoria 0001, South Africa; Department of Physics, University of Zululand, Private Bag X1001, Kwadlangezwa 3886, South Africa

Abstract: Since the proposal to synthesise materials by laser assisted pyrolysis in the 1970s, and its practical realisation in 1982, a number of researchers have used this method in obtaining nano-powders from liquid droplets. This study revisits this technique by introducing a new aspect in that it considers obtaining thin films rather than powders. A full experimental arrangement, including laser optimisation, optical layout and materials processing procedures is described. Synthesis of WO3 nanostructures by this method is reported for the first time, with the mean diameter and length determined to be 51 nm and 6.8 µm, respectively. A possible mechanism for production of such nanostructures is proposed owing to the selective dissociation of the O-C bonds in the tungsten ethoxide precursor liquid which resonate with the 10.6 µm emission wavelength of the CO2 laser employed.

Keywords: WO3 nanostructures; nanorods; laser pyrolysis; multiphoton dissociation; laser beam propagation; tungsten oxide nanostructures; thin films; nanoparticles.

DOI: 10.1504/IJNP.2008.020895

International Journal of Nanoparticles, 2008 Vol.1 No.3, pp.185 - 202

Published online: 23 Oct 2008 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article