3D Bi12TiO20/TiO2 hierarchical heterostructure: synthesis and enhanced visible-light photocatalytic activities

A three-dimensional (3D) multicomponent oxide, Bi(12)TiO(20)/TiO(2) hierarchical heterostructure was successfully synthesized via a one-step and template-free hydrothermal route. X-ray diffraction and X-ray photoelectron spectroscopy measurements confirm that the composition of the as-fabricated sample is Bi(12)TiO(20)/TiO(2) composite. Scanning and transmission electron microscopy observation reveals that the as-synthesized sample is microsized flower-like hierarchical networks consisted of Bi(12)TiO(20) nanorods decorated with the primary TiO(2) nanoparticles. Extension of the light absorption from the ultraviolet region to the visible-light region was confirmed by UV-vis absorption spectra. Due to the structure-property relationships, the 3D Bi(12)TiO(20)/TiO(2) heterostructure exhibited enhanced visible photocatalytic activity over that of Bi(12)TiO(20) and TiO(2) samples in the decomposition of Rhodamine B in water which is a typical model pollutant. The enhanced photocatalytic activity can be attributed to the extended absorption in the visible light region resulting from the 3D Bi(12)TiO(20)/TiO(2) heterostructures, and the effective separation of photogenerated carriers driven by the photoinduced potential difference generated at the Bi(12)TiO(20)/TiO(2) junction interface, demonstrating that the Bi(12)TiO(20)/TiO(2) heterostructure is a promising candidate as a visible light photocatalyst.