New Bi2WO6 Nanocages with High Visible-Light-Driven Photocatalytic Activities Prepared in Refluxing EG

New Bi2WO6 nanocages were successfully synthesized with colloidal carbon as the template via a facile refluxing process in ethylene glycol (EG). The as-prepared nanocages consisted of small nanoparticles with a size of ca. 50-80 nm. By adjusting the concentration of the precursor, Bi2WO6 with different morphologies and microstructures could be obtained. The growth mechanism of such special nanocages was investigated, and EG played a key role in the formation of Bi2WO6 nanocages. The Bi2WO6 nanocages exhibited excellent visible-light-driven photocatalytic efficiency, which was increased to nearly 10 times that of products prepared by traditional solid-state reactions and commercially available TiO2. Close investigation revealed that the surface area and the porous hollow structure of the as-prepared Bi2WO6 nanocages could improve the photocatalytic activities. Moreover, the nanocages could settle naturally in 15 min, which is beneficial for separation and recycling, considering their future applications in wastewater treatment.