Synthesis of three-dimensional WO3 octahedra: characterization, optical and efficient photocatalytic properties

Three dimensional (3D) novel tungsten trioxide (WO3) octahedra have been prepared by a simple surfactant/ catalyst-free hydrothermal method. The phase and morphological structure of the as-synthesized material were analysed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS). FESEM results showed that the as-prepared WO3 octahedron structure was in the range of 1-5 mu m. Furthermore, the optical properties like the UV-VIS absorption spectrum, photoluminescence (PL) spectrum and Fourier transform infrared (FTIR) spectra of the product were also studied. The {120} side facet of the exposed surface of the resulting product with a large surface area (15.26 m(2) g (1)), effective crystallinity and increased number of surface active sites exhibited excellent photocatalytic efficiency with a higher rate constant (0.03254 min(-1)) for the degradation of methylene blue (MB) under visible light irradiation. The photocatalytic performance of as-synthesized WO3 octahedra was about 5.33 times greater than that of the bulk sample. The apparent excellent photocatalytic efficiency of the prepared sample can be attributed to large surface area and a highly reactive {120} facet of the exposed surface of the WO3 octahedra.