Super-microporous TiO2 synthesized by using new designed chelating structure directing agents

Amphiphilic chelating structure directing agents (SDAs) dodecyl-2-pyridinyl-methylamine (L12) and hexadecyl-2-pyridinyl-methylamine (L16) were prepared through condensation between pyridine-2-carboxaldehyde and C12 or C16 long chain primary amines followed by reduction of the corresponding imines with NaBH4. These tailor made SDAs were used to synthesize novel super-microporous titania materials, TiO2–L12 and TiO2–L16 under mild hydrothermal conditions. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope attached with energy dispersive X-ray spectroscopy (SEM–EDS), CHN chemical analysis, N2-sorption, 1H and 13C NMR, high resolution mass spectroscopy (HR MS), Fourier transformed infrared (FT IR), UV–visible absorption and emission spectroscopic tools were employed to characterize the SDAs and the super-microporous TiO2 materials. XRD and TEM image analysis suggested the nanostructure with wormhole-like disordered arrangement of super-micropores of ca. 1.4–1.68 nm width in these samples. The as-synthesized titania composites showed deep blue emissions at room temperature. On removal of the surfactants these materials showed very high surface areas (604–634 m2 g−1) and good micropore volumes (0.26–0.29 cc g−1).