Synthesis of Al-containing mesoporous silica (KSW-2) with semi-squared channels by incorporation of Al into the framework of kanemiteElectronic supplementary information (ESI) available: powder XRD patterns and 29Si MAS NMR spectra of kanemite and Al-kanemite, N2 adsorption isotherm of Al-KSW-2, TEM images of Al-KSW-2. See http://www.rsc.org/suppdata/jm/b2/b211073c/

Incorporation of Al into the framework of single-layered silicate kanemite and the formation of Al-containing mesoporous silica (Al-KSW-2) with semi-squared one-dimensional channels were surveyed. Al-containing δ-Na2Si2O5 was successfully obtained by thermal treatment of an aqueous sodium silicate solution (Na2O/SiO2 = 1 ∶ 2) containing NaAlO2 up to 785–810 °C, depending on the amount of NaAlO2 added. After Al-containing δ-Na2Si2O5 was dispersed in distilled water, Al-containing kanemite (Al-kanemite) was obtained with tetrahedrally coordinated Al. The reaction of Al-kanemite with an aqueous solution of hexadecyltrimethylammonium (C16TMA) surfactant yielded a layered C16TMA–Al-kanemite complex which was converted to a mesostructured precursor of Al-KSW-2 by mild acid treatment. Tetrahedral coordination of Al was retained in the framework of Al-KSW-2 with high surface area (830 m2 g−1) and uniform semi-squared mesopores (2.7 nm), which increased the adsorption ability for cationic dye molecules.