Facile synthesis of m-WO3 powders via precipitation in ethanol solution and evaluation of their photocatalytic activities

Tungsten(VI) oxide (WO3) powders have been synthesized from a precursor material prepared via a simple precipitation method in ethanol medium followed by thermal treatments at 500 and 700 °C. Structural characterization by X-ray Rietveld refinement and transmission electron microscopy (TEM) revealed the presence of the monoclinic structure of WO3 (m-WO3) with cell parameters of a = 7.3222(7) Å, b = 7.5433(3) Å, c = 7.7095(1) Å and β = 90.53(2)°. TEM analysis revealed an average WO3 particle size of approximately 50 nm. The scanning electron microscopy (SEM) analysis revealed a natural tendency of the particles to form large agglomerates with oval shapes. The photocatalytic activity of the WO3 powders was evaluated in the degradation reaction of rhodamine B (rhB). The total organic carbon (TOC) analysis indicated a 38% mineralization of rhB after 96 h under irradiation with a Xe lamp.