Engineering Nanostructured Bi2WO6–TiO2 Toward Effective Utilization of Natural Light in Photocatalysis

Abstract

Being expected as one of the most promising solutions in water and air purification as photocatalyst, TiO2 is attracting intensive and extensive research interests globally despite its wide band gap (~3.2 eV for anatase structure) which limits it only to be activated under UV irradiation. In pursuit of extending the active region of TiO2 toward visible light, considerable attention was devoted to develop TiO2‐based photocatalyst. We report herein, for the first time, novel “bud‐on‐branch” Bi2WO6–TiO2 nanofibers fabricated via a facile and large‐scale electrospinning technique from a biphased precursor. Formed by surface‐decorating continuous TiO2 nanofibers (mixed anatase–rutile system with an average diameter of about 100 nm) with ~13 nm well‐crystallized Bi2WO6 nanoparticles, the as‐synthesized Bi2WO6–TiO2 nanofibers achieved an evidently increased specific surface area. Furthermore, corresponding photocatalytic experiments revealed that the optimal photodegradation rate from our designed heterostructure was as high as three times to that of pure TiO2 nanofibers; this increase in optimal photodegradation rate is attributed to the relatively well‐matched energy band between TiO2 and Bi2WO6 and hence an excellent separation efficiency of photogenerated electron–hole pairs in both ultraviolet and visible light regions, suggesting that the designed heterostructures can give better rise to practise photocatalysis under natural light.