Ionic liquid of [Bmim]+Cl− for the preparation of hierarchical nanostructured rutile titania

The rutile titania with hierarchical nanostructure was conveniently prepared in a room temperature ionic liquid (RTIL) of [Bmim]+Cl− system. The obtained materials were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption–desorption analysis. XRD patterns revealed that only rutile phase was formed in the ionic liquid of [Bmim]+Cl−. The SEM and TEM micrographs as well as N2 adsorption–desorption measurements showed that the nanorods of rutile titania were interaggregated to fabricate a large mesoporous structure and the voids packed in the nanorods formed a small mesostructure. It was proposed that the formation of rutile crystal phase was due to high acidity and high Cl− content in the special reaction media, and also the combination of ionic liquid-templated effects with so-called reaction limited aggregation resulted in the hierarchical nanostructure.