Mesoporous silica materials with hydroxyphosphatoethyl pendant groups (POH-MS) were obtained by a two-step process: (1) block copolymer Pluronic P123-templated synthesis of mesoporous silica with diethylphosphatoethyl groups (DP-MS) by co-condensation of diethylphosphatoethyl triethoxysilane (DPTS) and tetraethylorthosilicate (TEOS) under acidic conditions and (2) conversion of diethylphosphatoethyl into hydroxyphosphatoethyl groups upon suitable treatment with concentrated hydrochloric acid. The DP-MS samples obtained by using up to 20% of DPTS featured hexagonally ordered mesopores, narrow pore size distribution and high specific surface area. Conversion of DP-MS to mesoporous silica with hydroxyphosphatoethyl groups (POH-MS) resulted in the enlargement of the specific surface area, total porosity, and microporosity. High affinity of hydroxyphosphatoethyl groups toward lead ions (Pb(2+)) makes the POH-MS materials attractive sorbents for lead ions, which is reflected by high lead uptake reaching 272 mg of Pb(2+) per gram of POH-MS. This study shows that the simple and effective co-condensation strategy assures high loading of P-containing groups showing high affinity toward lead ions, which is of great importance for removal of highly toxic lead ions from contaminated water.

Titania-incorporated organosilica-mesostructures (Ti-MO) were synthesized using tris [3-(trimethoxysilyl)propyl]isocyanurate, tetraethylorthosilicate as silica precursors, and titanium isopropoxide as the titanium precursor via a co-condensation method in the presence of the triblock copolymer, Pluronic P123. The triblock copolymer was completely removed by extraction with a 95% ethanol solution, followed by a thermal treatment at 350 °C under flowing nitrogen without decomposing isocyanurate bridging groups. The molar ratio of titanium to silica in the mesostructures was gradually changed by increasing the amount of tetraethylorthosilicate in the initial reaction mixture. Our synthesis strategy also allowed us to tailor both adsorption and structural properties, including a well-developed specific surface area, high microporosity, and large pore volume. A portion of the samples was thermally treated at 600 °C to remove both the block copolymer and bridging groups. The thermal treatment at 600 °C was used to convert the amorphous titania into a crystalline anatase form. The Ti-MO materials were characterized using a N2 adsorption desorption analysis, thermogravimetric analysis (TGA), solid state nuclear magnetic resonance (NMR), transmission electron microscope (TEM), and X-ray powder diffraction (XRD). CO2 adsorption studies were also conducted to determine the basicity of the Ti-MO materials. The effect of the surface properties on the CO2 sorption was also identified.