Preparation Of TiO₂ Nanosheets Using A Liquid Phase Shearing Exfoliation Method

TiO₂ materials have attracted considerable attention due to their extensive prospect in biomedical engineering, energy fields and environment. Many researches have suggested that morphologies of materials have significant effects on their properties. Although two-dimensional TiO₂ nanosheets share many properties with their bulk counterparts, they have more unique specific-surface-area and excellent photoelectric characteristic. Liquid-shearing exfoliation becomes an important technology recent years in the field of two-dimensional materials synthesis especially for graphene. It is a scalable and easy method for the exfoliation of materials and can produce dispersed nanosheets.Here we demonstrate liquid-shearing exfoliation for the preparation of TiO₂ nanosheets with exposed {001} facets, including indirect and direct ways: 1) layered NH4 TiOF3 crystals were sheared in liquid exfoliation and then were topotactically transformed into TiO₂ nanosheets; 2) Various types of TiO₂ crystals were sheared in liquid exfoliation directly and TiO₂ nanosheets were obtained.This paper mainly includes: Relatively uniform sized NH4 TiOF3 particles were obtained via optimal experimental conditions; NH4 TiOF3 nanosheets were obtained from liquid-shearing exfoliation and were characterized in detail, the influences of different solvents?such as ethanol, hexylamine, isopropanol, and NMP? on properties of nanosheets were compared at the same time; With topotactic transformation reaction, NH4 TiOF3 nanosheets transformed into TiO₂ nanosheets, TiO₂ nanosheets were characterized; TiO₂ mesocrystals and TiO₂ particles were synthesized and were sheared in liquid exfoliation directly in order to find an easier method to obtain TiO₂ nanosheets; The widely used Zn O, Li2 TiO3 were also sheared in liquid exfoliation in order to expand the applicability of original materials for liquid-shearing exfoliation.The results indicate: Liquid-shearing exfoliation is capable of synthesizing layered NH4 TiOF3 nanosheets, and then NH4 TiOF3 nanosheets can be transformed into TiO₂ nanosheets with largely exposed {001} facets via topotactic transformation reaction; Liquid-shearing exfoliation can be used of synthesizing non-layer materials?TiO₂, Zn O, Li2 TiO3? nanosheets at a certain degree. Experiments in alcohol solvent are environmentally-friendly, and extraordinary thin nanosheets are with a well soft morphology, which are promising in composite lamellar materials synthesis and applications.