Effect of π–π stacking of water miscible ionic liquid template with different cation chain length and content on morphology of mesoporous TiO 2 prepared via sol–gel method and the applications

Abstract

In this study, the imidazolium π–π stacking of two water miscible imidazolium ionic liquids (ILs) in the TiO 2 matrix formed during the sol–gel polymerization was studied by FT-IR, XRD, TEM and BET measurements. It was found that the mesoporous morphology, including surface area, average pore size and wormhole-like structure, and thermal stability of the as-prepared TiO 2 particle were varied with the imidazolium chain length and content of the IL used due to different extent of imidazolium π–π stacking. Besides, the wormhole-like mesoporous anatase TiO 2 particles with high surface area exhibited higher photodegradation efficiencies of methylene blue (MB) under 1 h UV irradiation, while those with large pore size used for the electrode materials showed higher efficiency in dye-sensitized solar cells.