Preparation and characterization of WO3/TiO2 hollow microsphere composites with catalytic activity in dark

The WO3/TiO2 hollow microsphere composites with the diameter of 3–5 μm were prepared by an alcohothermal method. The obtained composites were characterized by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen sorption isotherms and ultraviolet–vision spectroscopy (UV–vis). After light irradiation, the catalytic activity of the pure TiO2 hollow microspheres and the WO3/TiO2 composites in dark was evaluated by the degradation of methyl orange (MO) in aqueous solution. The results indicated that the presence of WO3 may be responsible for more preferable properties and the catalytic activity in dark of the composites. Compared with the pure TiO2, the WO3/TiO2 hollow microsphere composites provided the higher specific surface area and the wider absorption wavelength range. In particular, the maximum degradation efficiency in dark reached 22% as the WO3 content of the hollow microsphere composites was 15 mol%.