Abstract
The synthesis of highly divided anatase TiO2 nanoparticles displaying 300 m(2) g(-1) surface area is achieved by following a two-step synthetic process at room temperature. The particles exhibit a needle-like morphology composed of self-assembled 4 nm nanoparticles. The crystallization process from amorphous TiO2.1.6H(2)O to oriented aggregation of anatase TiO2 proceeds according to a slow solid dehydration process takingplace in a large range of pH in deionized water (1 < pH < 12) or alternatively when including a low amount of NH4F(aq) in solution. Driven by their high surface area enhancing the chemical/electrochemical reactivity, it is reported in the case of the anatase TiO2 that a modification in the lithium insertion mechanism is no longer attributable to a two-phase reaction between the two-end members Li epsilon TiO2 and Li0.5 +/- TiO2 when downsizing the particle size, but instead through a complete solid solution all along the composition range.