Dielectric constant controlled solvothermal synthesis of a TiO2 photocatalyst with tunable crystallinity: A strategy for solvent selection

Phase-pure anatase TiO₂ nanocrystals with a tunable crystallinity have been prepared by a one-step solvothermal method in the absence of any templates or additives. 2-Propanol, which has the lowest dielectric constant of those studied, favors the crystallization of TiO₂ nanocrystals with the best crystallinity, and highest photocatalytic efficiency. The effect of the dielectric constant on the processes of nucleation and crystal growth is discussed in detail. The photocatalytic activity of the as-prepared samples has also been investigated with respect to crystallinity.