Nanostructured TiO2 thin films were prepared using an amphiphilic PS‐b‐PEO block copolymer as a templating agent. A good–poor solvent pair‐induced pair phase separation process was coupled with sol–gel chemistry to control the morphology of the TiO2 film in a solution of 1,4‐dioxane, concentrated HCl, and titanium tetraisopropoxide (TTIP). By varying the block copolymer concentration from 0.25 to 4.0 wt.‐% while keeping the relative ratios among 1,4‐dioxane, conc. HCl, and TTIP constant, a morphology transition from pores to lamellae was observed. The photoluminescence (PL) properties of the film composed of different morphologies were studied, and the PL properties were found to be independent of the morphologies of the mesoporous films. The mechanism of the morphology evolution with respect to the copolymer concentration is further discussed.
