TiO2/SnO2 double-shelled hollow spheres-highly efficient photocatalyst for the degradation of rhodamine B

• TiO2/SnO2 hollow spheres were fabricated by a two-step LPD using C sphere templates.
• TiO2/SnO2 hollow spheres have surface area of 46.1 m2/g and mesopore size of 3.5 nm.
• TiO2/SnO2 hollow spheres show a distinctly stronger SPV response.
• TiO2/SnO2 hollow spheres show a superior photocatalytic activity for decomposition of RhB.

TiO2/SnO2 double-shelled hollow spheres are successfully synthesized by two-step liquid-phase deposition method using carbon sphere templates. The formation process of TiO2/SnO2 hollow spheres is discussed. The samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and UV–vis absorption spectroscopy. The behavior of photogenerated charges in the TiO2/SnO2 heterojunction structures has been investigated through surface photovoltage spectroscopy. The TiO2/SnO2 hollow spheres which are realized show significantly enhanced photocatalytic activities, with respect to the cases of SnO2 and TiO2 hollow spheres. Furthermore, TiO2/SnO2 hollow spheres show good recyclable photocatalytic activities.