Surfactant-Free Synthesis of Single-Crystalline Bi4Ti3O12 Nanosheets with Excellent Visible-Light Photocatalytic Activity

Single-crystalline Bi4Ti3O12 nanosheets with a thickness less than 10 nm and a lateral size larger than 20 mu m have successfully synthesized via a surfactant-free hydrothermal route by employing K2Ti6O13 nanofibers prepared in advance as titanium sources. The as-prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and selected area electron diffraction, respectively. The results revealed that the single-crystalline Bi4Ti3O12 nanosheets are dominated with (010) facets. In general, the slow exfoliation of TiO6 octahedron lamella and the fast combination of the subnitrate radicals with the Bi3+ ions situated in (010) planes induce the crystallization of the single-crystalline Bi4Ti3O12 nanosheets. In addition, the as-prepared single-crystalline Bi4Ti3O12 nanosheets propose a narrowed gap of ca. 2.41 eV and after modified by Pt-quantum-dots exhibit excellent visible-light photocatalytic activity. It is believed that the surfactant-free in the hydrothermal induce more amount of surface state responsible for the narrowed gap and the excellent visible-light photocatalytic activity.