Synthesis of tungsten oxide nanostructures by laser pyrolysis

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.