LAUSR

The metastable titania phase, bronze, has great potential as photocatalyst or as anode material in Li-ion batteries. Here, we report the first synthesis of colloidally stable, size-tunable TiO2-bronze (TiO2–B) nanocrystals, via a hydrothermal process. By employing definitive screening design, the experimental parameters affecting the size and agglomeration of the nanocrystals are identified. The size is mostly determined by the reaction temperature, resulting in 3–8 nm NCs in the range of 130–180 °C. To avoid irreversible aggregation, short reaction times are desired, and in this respect, microwave heating proved essential due to its fast heating and cooling rates. The resulting nanocrystals are deaggregated and stabilized in polar solvents using either positive or negative surface charges. In nonpolar solvents, steric stabilization is provided by long chain amines and carboxylic acids. Furthermore, we study this peculiar postsynthetic surface modification through solution 1H NMR and elemental analysis. S...