Controllable synthesis of ultrathin monolayer titanate nanosheet via osmotic swelling to exfoliation of layered titanate

Abstract Ultrathin titanate nanosheet is one kind of important material for wide applications, but the efficient strategy and lucid mechanism for controllable preparing ultrathin titanate nanosheet with considerable size is still a challenge. Herein, an improved strategy is described for the production of ultrathin titanate nanosheets using macromolecule tetrabutylammonium hydroxide (TBAOH) intercalation. Reaction parameters such as alkali carbonate source, molar ratio of Cs2CO3 and TiO2, calcination temperature are studied systematically. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible absorbance (UV–vis), Fourier-transform infrared (FT-IR), and Raman spectroscopic. The formation mechanism of titanate nanosheet is investigated. The host layer is of lepidocrocite-type in which TiO6 octahedral are combined via edge sharing to produce a two-dimensional sheet of composition Ti2−x/4□x/4O4x- (x ~0.7; □, vacancy), while Cs+ is located interlayer. The elevated calcined temperature can promote the degree of solid-state reaction, enabling the lateral size of the two-dimensional sheet to become larger, therefore the exfoliated nanosheet has a larger considerable size. It has been found that when the calcination temperature is 1100 °C, the alkali carbonate is Cs2CO3, the molar ratio of Cs2CO3 and TiO2 is 1:5.3, ultrathin monolayer titante nanosheet with a considerable size is prepared successfully. Three variable systems of alkali carbonate source, molar ratio of Cs2CO3 and TiO2, calcined temperature are studied systematically and the ultrathin monolayer titante nanosheet with a considerable size is prepared successfully, which is benefit of in-depth theoretical research and application for ultrathin 2D titanate nanosheet in the future.