### 液相合成超薄TiO2纳米片微结构影响因素研究

1. a 重庆大学材料科学与工程学院 重庆 400045;
b 重庆邮电大学理学院 重庆 400065
• 发布日期:2018-05-21
• 通讯作者: 钱觉时,E-mail:qianjueshi@163.com E-mail:qianjueshi@163.com
• 基金资助:

国家自然科学基金（No.51472037）资助项目.

### Influence Factors on the Microstructure of Ultrathin TiO2 Nanosheets Synthesized by Liquid Phase Method

Chu Wanyia, Tang Xiaob, Li Zhena, Lin Jingchengb, Qian Jueshia

1. a College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China;
b School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
• Published:2018-05-21
• Contact: 10.6023/A18030100 E-mail:qianjueshi@163.com
• Supported by:

Project supported by the National Natural Science Foundation of China (No. 51472037).

Synthesis of large scale ultrathin 2D structural TiO2 is challenging and meaningful in many fields of science and technology, because of their larger surface area and higher electron-hole pairs separation efficiency. In this work, a "bottomup" method is used to synthesize the large-size ultrathin TiO2 nanosheets at low temperature by liquid-phase. The mixture of tetrabutyl titanate and ethanol could hydrolyze in a dilute nitric acid solution with an ice-water bath and the obtained hydrolysates could peptize. After peptized, the hydrolysis products become to be very small TiO2 nanoclusters and they form a two-dimensional network structure via the orientation bonding formed by hydrogen bond. Continue to be aged at low temperature, the crystallization degree of samples will increase, and the networks eventually turn into TiO2 nanosheets. Effects of the concentration of nitric acid, ambient temperature and reactant concentration on the formation of two-dimensional structure TiO2 are studied in this work. The transmission electron microscope (TEM), ultraviolet-visible (UV-Vis) absorbance spectra, X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier Transform infrared spectroscopy (FTIR) are used to analyze the morphology, microstructure and properties of the samples, and the experiment of photocatalytic reduction of Cr(VI) is conducted to observe the photocatalytic activity of samples as well as to verify the effects of system parameters on the microstructure of TiO2 nanosheets. The results show that when the concentration of nitric acid is during 0.0217~0.0721 mol·L-1, the anatase TiO2 nanosheets that thinner than 1 nm could be obtained by peptizing and aging at 0~4℃. Excess nitric acid leads to crystalline and morphology transformation of TiO2, but lower concentration of nitric acid could prolong the peptizing time; increasing the ambient temperature will undermine the formation of two-dimensional structure; improving the amount of ethanol in the reactant will be helpful to disperse the hydrolysis products, and promote the process of the peptizing and formation of the two-dimensional structure.