Recently, sol−gel methods employing ionic liquids (ILs) have shown significant implications for the synthesis of well-defined nanostructured inorganic materials. Herein, we synthesized nanocrystalline TiO2 particles via an alkoxide sol−gel method employing a water-immiscible room temperature IL (1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6]) as a new solvent medium and further modified with nonionic surfactant (polyoxyethylenesorbitan monooleate) as a pore templating material. Detailed information on the preparative method, synthesis route and mechanism, crystallographic and structural properties, and photocatalytic activity of the TiO2 particles is described. The possible rationale for the formation of nanocrystalline TiO2 particles with high surface area and activity is discussed with respect to the special characteristics of [bmim][PF6] as well as the role of the surfactant self-assembly in the sol−gel network. Due to its capping effect and water immiscibility, the use of [bmim][PF6] in ...