The investigation of Ag decorated double‐wall hollow TiO2 spheres as photocatalyst

In this paper, a novel TiO 2 nanosheets assembled double‐wall hollow sphere (DHS)has been prepared successfully via hydrothermal treatment of SiO 2 @TiO 2 with the assistant of CTAB.The prepared samples are characterized with transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron spin resonance (ESR), X‐ray diffraction (XRD) and X‐ray photoelectron spectra (XPS), etc.Results show that redeposited silica species play a key role in the formation of the double‐wall structure. The as‐synthesized DHS nanostructure exhibits a large surface area (417.6 m 2 g ‐1 ) and excellent mechanical strength. Furthermore, after decoration of Ag and calcination treatment, the double‐shelled TiO 2 /Ag heterostructures show an enhanced photocatalytic performance in the degradation of RhB under UV or visible light irradiations for the following reasons: the surface plasmon resonance effect of Ag, strong interaction between Ag and TiO 2 nanosheets, large surface area, excellent adsorption capacityand unique double‐wall structure. On the basis of the experimental results, a possible mechanism for pollutantdegradation under visual light irradiation has been proposed.