A simple method to prepare N-doped titania hollow spheres with high photocatalytic activity under visible light.

N-doped titania hollow spheres were prepared using hydrothermally prepared carbon spheres as template. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectrum (DRS). The photocatalytic activity of as-prepared hollow titania spheres was determined by degradation of Reactive Brilliant Red dye X-3B (C.I. reactive red 2) under visible light irradiation, and was compared to commercial P25 titania. It was revealed that the photocatalytic activity of the titania hollow spheres enhanced a lot. The apparent rate constant of the titania hollow spheres was almost 17 times as that of P25 titania.