Controllable synthesis of TiO2 hierarchical nanostructures and their applications in lithium ion batteries

In this article, TiO2 hierarchical nanostructures have been successfully fabricated in the Ti(SO4)(2)-CH3COOH system via a simple hydrothermal method. The formation mechanism of the TiO2 hierarchical nanostructures was also investigated in detail, which involved the complex reaction between Ti(SO4)(2) and CH3COOH, hydrolysis of the complex, nucleation and self-assembly of TiO2 nanocrystals and anisotropic growth of these subunits. SO42- plays an important role in the self-assembly of subunits. In addition, controllable synthesis of TiO2 hierarchical nanostructures with tunable size can be realized just by changing experimental parameters, such as reaction time or Ti(SO4)(2) concentration. When used as the anode in lithium ion batteries, these TiO2 hierarchical nanostructures present much higher specific capacity and better rate performances than TiO2 nanoparticles, which are attributed to the stability of the secondary-structure during the charge and discharge processes.