Synthesis of hierarchical Fe₂O₃/SnO₂ hollow heterostructures and their improved photocatalytic properties

In the present study, hierarchical α-Fe₂O ₃/SnO₂ hollow heterostructures were successfully synthesized by a template growth method. The crystal structure, morphology, composition and surface area of obtained heterostructures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and BET surface area analysis. The results reveal that [001]-directed SnO₂ nanorods grow on the side surface of the [001]-directed α-Fe₂O₃ hollow nanotubes/nanorings, forming (110)α-Fe₂O₃//(101) SnO₂ and (100)α-Fe₂O₃//(001)SnO ₂ interfaces. These heterostructures can be further converted into magnetic γ-Fe₂O₃/SnO₂ heterostructure without any significant change in morphology. These α-Fe₂O ₃/SnO₂ hollow heterostructures exhibit much higher photocatalytic activities for degradation of methylene blue in comparison with that of pure α-Fe₂O₃ nanotubes/nanorings in the wide spectral region from UV to visible due to both larger surface area and improved electron-hole separation efficiency in the interface of heterostructure.