Removal of surfactant template from mesoporous titania

We have reported the synthesis of mesoporous titania with crystalline walls using hexadecyltrimethylammonium bromide (CTAB), a typical cationic surfactant, as a template and titanium sulfoxide as a reactant in aqueous solution (Shibata et al., 2005 [1]). In this study, the removal method of CTAB from the mesopores without calcination or collapsing the ordered porous structure is described. First, CTAB molecules in the pore were replaced by acetic acid molecules under moderate reaction conditions. FT-IR spectra confirmed the removal of CTAB and adsorption of acetic acid. Removal of the adsorbed acetic acid was then performed by addition of carbonate ions that desorbed the acetate ions on the surface of the mesoporous titania. Mesoporous titania after removal of CTAB by the present method was found to have a more uniform pore structure compared with that after removal of CTAB by calcination treatment.