A facile one step route to synthesize WO nanoplatelets for CO oxidation and photodegradation of RhB: microstructural, optical and electrical studies

• Published in: RSC advances 2016-07, Vol.6 (73), p.69615-69626
• Main Authors: Dirany, N, Arab, M, Madigou, V, Leroux, Ch, Gavarri, J. R
• Format: Article
• ISSN: 2046-2069
• DOI: 10.1039/c6ra13500e

Two-dimensional nanoplatelets of tungsten trioxide (NP-WO 3 ) were synthesized at room temperature, using a wet chemical method, without any surfactants or templates; aqueous mineralization was obtained by simply adjusting the pH. The resulting nanostructures were characterized using X-ray diffraction combined with Rietveld refinements, Raman and UV-Vis spectroscopies. Their morphologies and sizes were analyzed by scanning and electron microscopies. The electrical, optical, catalytic and photocatalytic properties of the NP-WO 3 nanoplatelets were then determined and compared to the ones of pseudospherical (PS-WO 3 ) standard samples. Nanoplatelets as well as pseudospherical particles crystallized in the single orthorhombic WO 3 phase. The Rietveld refinement calculations and HRTEM analyses revealed a strong distortion of the WO 6 octahedra, according to the W-O splitting. The electrical conductivity of WO 3 compact pellets showed that both samples were semi-conducting with a weak difference in activation energies. Using a homemade photocatalytic device, the NP-WO 3 particles used as photocatalyst in an aqueous medium, exhibited a significant efficiency to decompose rhodamine B over their large exposed surface (010), compared to PS-WO 3 particles. These NP-WO 3 particles were also used as the catalytic material for oxidation in an air-CO gas flow. They exhibited catalytic activity higher than the one in the PS form. Two-dimensional nanoplatelets of WO 3 were synthesized at room temperature. The large exposed (020) facets of the nanoplatelets show a high catalytic activities, for CO conversion and for photodegradation of organic pollutant.