| The ionic liquid, short for IL, is a green material with excellent characteristics, and it is a hot topic of green chemistry. Because of its special properties and performances, with the supercritical carbon dioxide and aqueous two-phase were known as the three major green solvents. The ionic liquid in organic synthesis, electrochemistry, homogeneous catalysis, especially in heterogeneous catalysis, separation, etc. has broad application prospects.Layered Salts of transition metal oxides drew increasing attention due to its unique structure, especially the layered compounds component of catalytic activity group Nb and Ti. Thus, to build shape-selective catalysts and molecular sieves has drawn wide attention. Because of typical layered and the exchangeable properties of interlayer cations, so the research about the layered compounds focus on their catalytic properties and modification methods in recent years. However, the introduction of organic active ingredients in layered titanoniobate surface and interlayer, especially the ionic liquids is still in infancy.In this study, the layered compound was used as precursors to immobilize ionic liquid, through the means of grafting or intercalating to introduce the imidazole ionic liquid. The interaction between the ionic liquid and layered materialsprovide was explored, which can be provide a reference for the preparation of catalytic materials.H2Ti3O7was prepared through H+ion-exchange reaction of Na2Ti3O7, which was synthesed by a solid reaction. N-sulfonic acid butyl-3-methylimidazolium was synthesized from the Lactone reaction of N-methyl imidazole and1,4-butyl sulfonic acid.Then the ionic liquid N-sulfobutyl-3-methylimidazolium hydrogen sulfate salt was prepared by acidification of sulfuric acid.The immobilized Na2Ti3O7-IL and H2Ti3O7-IL was prepared by the method of ion exchange reaction under certain conditions.The structure and morphology were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visiblediffuse spectroscopy (UV-vis DRS), thermal analysis (TG-DTA). The results showed:1. N-sulfobutyl-3-methylimidazolium hydrogen sulfate can be inserted into the layered Na2Ti3O7and H2Ti3O7through the ion exchange. The d-spacing of (001) plane increases and the laminate overall loosed, and the crystal degree of crystallinity decreased after intercalation.2. The FT-IR results of Na2Ti3O7-IL samples showed that the wavenumber1456cm-1disappeared, Ti=O stretching vibration (927.6cm-1), and472.5cm-1,713.5cm-1were blueshifted to high wavenumber, compared with the precursor Na2Ti3O7. FT-IR samples H2Ti3O7IL1167cm-1disappearance of the1569.8cm-1peak moved to higher frequencies, at the same time appears at the C-H peak (2937.1cm-1). The results showed N-sulfobutyl-3-methylimidazolium cation have inserted into the interlayer, and existed interaction with the laminates composed of groups.3. The spectral characteristics of Na2Ti3O7, H2TiO7existence a continuous wide UV band absorption, the absorption edge at367nm,404nm. The UV absorption bands of immobilized Na2Ti3O7-IL, H2Ti3O7-IL were changed narrow, the absorption edge shifted to the visible region, indicating that N-sulfobutyl-3-methyl imidazolium cation immobilized in the energy of the band gap reduction smaller.Figure[42] Table[2] Reference[65]... |
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