Preparation and Photocatalytic Performances of WO<sub>3</sub>/TiO<sub>2</sub> Composite Nanofibers
Xiuping Han, Binghua Yao, Keying Li, Wenjing Zhu, Xuyuan Zhang
Abstract
The use of sunlight for photocatalytic oxidation is an ideal strategy, but it is limited by factors such as insufficient light absorption intensity of the photocatalyst and easy recombination of photogenerated electron holes. TiO 2 is favored by researchers as an environment-friendly catalyst. In this paper, TiO 2 is combined with WO 3 to obtain a nanofiber with excellent catalytic performance under sunlight. The WO 3 /TiO 2 composite nanofibers were synthesized by using the electrospinning method. The X-ray diffraction (XRD) analysis indicated that WO 3 was successfully integrated onto the surface of TiO 2 . The photodegradation performance and photocurrent analysis of the prepared nanofibers showed that the addition of WO 3 really improved the photocatalytic performance of TiO 2 nanofibers, methylene blue (MB) degradation rate increased from 72% to 96%, and 5% was the optimal composite mole percentage of W to Ti. The scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectra (UV-Vis DRS), and Brunauer-Emmett-Teller (BET) analysis further characterized the properties of 5% WO 3 /TiO 2 nanofibers. The H 2 generation rate of 5% WO 3 /TiO 2 nanofibers was 107.15 μ mol·g −1 ·h −1 , in comparison with that of TiO 2 nanofibers (73.21 μ mol·g −1 ·h −1 ) under the same condition. The 5% WO 3 /TiO 2 produced ·OH under illumination, which played an important role in the MB degradation. Also, the enhanced photocatalytic mechanism was also proposed based on the detailed analysis of the band gap and the active species trapping experiment. The results indicated that the effective separation of Z-scheme photogenerated electron-hole pairs and transfer system constructed between TiO 2 and WO 3 endowed the excellent photocatalytic activity of 5% WO 3 /TiO 2 nanofibers.