Synthesis Of WO3 Nanostructures Research Articles

Ionic liquids and nanotechnology: Synthesis of WO3 nanostructures by anodization as photoelectrocatalysts

Two ionic liquids, [BMIM][BF4] and [EMIM][BF4], have been used for the first time to synthesize ordered and well-defined WO3 nanoplates by electrochemical anodization. Different amounts of these ionic liquids have been added to the electrolytes and their influence on the morphological, structural and photoelectrocatalytic properties of the WO3 nanoplates has been extensively studied. The resulted nanostructures, especially those synthesized in the presence of 5%–10% ionic liquids, showed excellent photoelectrocatalytic performances under irradiation, due to their better morphology, size and arrangement. These results confirm the potentiality of ionic liquids, such as [BMIM][BF4] and [EMIM][BF4], in the synthesis by anodization of high-efficiency photoelectrocatalysts, which could be used in the energy and environmental fields.

Synthesis of WO3 nanostructures and their ultraviolet photoresponse properties

Tungsten oxide (WO3) nanostructures such as nanowires, nanorod bundles and nanotube bundles are synthesized by a facile hydrothermal method. The ultraviolet (UV) photoresponse characteristics of devices containing these WO3 nanostructures are investigated for the first time and new photosensitive mechanisms involving both photo-generated electron–hole pairs and reversible electrochemical reactions are proposed. We find that h-WO3 nanowires with large specific surface areas and fewer defects exhibit excellent UV photoresponse properties with switch ratios (defined as Iphoto/Idark) as high as 60, which is due to the existing large tunnels serving as channels and intercalation sites for mobile ions and active electrochemical reactions, and our findings provide a new family and more selectivity for UV photosensitive nanomaterials in the future.

Synthesis of tungsten oxide nanostructures by laser pyrolysis

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.