Single-crystalline Bi₄Ti₃O₁₂ nanosheets with a thickness less than 10 nm and a lateral size larger than 20 μm 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 system induce more amount of surface state responsible for the narrowed gap and the excellent visible-light photocatalytic activity.

采用预先制备的K ₂ Ti ₆ O ₁₃纳米纤维作为钛源，通过无表面活性剂水热法成功合成了厚度小于10 nm且横向尺寸大于20μm的Bi ₄ Ti ₃ O ₁₂单晶纳米片。。分别通过X射线衍射，场发射扫描电子显微镜，透射电子显微镜（TEM），高分辨率TEM和选择区域电子衍射对制备的样品进行表征。结果表明，单晶Bi ₄ Ti ₃ O ₁₂纳米片以（010）面为主。通常，TiO ₆八面体薄片的缓慢剥落以及亚硝酸根自由基与（010）平面中Bi ³⁺离子的快速结合会诱导Bi ₄ Ti ₃ O ₁₂单晶纳米片的结晶。另外，制备的单晶Bi ₄ Ti ₃ O ₁₂纳米片提出了约一个缩小的差距。经Pt量子点修饰后，其2.41 eV表现出优异的可见光光催化活性。据信在水热体系中不含表面活性剂会引起更多的表面状态，从而导致间隙变窄和优异的可见光光催化活性。