Synthesis of TiO2 nanosheets via an exfoliation route assisted by a surfactant.

Titanium dioxide (TiO2) is an important material for photovoltaics, photocatalysis, sensors and lithium ion batteries. Various morphologies of TiO2 nanomaterials have been synthesized, including zero-dimensional (0D) nanoparticles, one-dimensional (1D) nanowires and nanotubes, as well as three-dimensional (3D) nanostructures. But the two-dimensional (2D) TiO2 nanostructures, which are expected to have more promising properties and applications, are rarely reported. Herein, we report a surfactant-assisted exfoliation method to synthesize TiO2 2D nanosheets. It has been revealed that tetrabutylammonium hydroxide (hereafter TBAOH) as a surfactant plays a crucial role in retaining the 2D nanosheet structures. Compared with TiO2 nanotubes and anatase TiO2 nanoparticles, the as-prepared TiO2 single layered nanosheets delivered much higher capacities as anodes of the coin-type Li ion cells, with a reversible capacity of 82.2 mA h g(-1) at the 630th cycle at a current density of 2000 mA g(-1).