Titania–silica–phosphonate triconstituent hybrid mesoporous materials as adsorbents in gas and liquid phases

Mesoporous titania–silica–phosphonate (TSP) hybrid materials with different Si/Ti molar ratios have been synthesized by triconstituent assembly through oil-in-water microemulsion strategy with the use of Si(OEt)4, TiCl4 and sodium salt of ethylene diamine tetra(methylene phosphonic acid) as Si, Ti and P sources, respectively, and cetyltrimethylammonium bromide as surfactant template. The integration of silica into titania–phosphonate hybrids resulted in the improvement of regularity of mesoporous structure and the enlargement of surface area and pore volume of the hybrid materials, confirmed by low-angle powder X-ray diffraction, transmission electron microscopy and nitrogen adsorption–desorption analysis. The synthesized TSP triconstituent hybrid mesoporous materials have a preferable BET surface area up to 670 m2/g with large pore volume of 1.1 cm3/g. And the adsorption measurements of the synthesized TSP materials for CO2 in gas phase and Cd(II) ions in liquid phase were tested, indicating their potential applications as multifunctional adsorbents for environmental protection.