Preparation of Phenyl-Bridged Hybrid Organic-Inorganic Mesoporous Vesicles with High Thermal Stability and Hierarchical Buildups

Hollow periodic mesoporous organosilicas have promising applications due to their excellent properties but have difficulty withstanding harsh working conditions, and current synthesis techniques typically require strong acids or strong base substances. In this study, we report an environmentally friendly synthesis technique of phenyl-bridged hybrid organic-inorganic mesoporous vesicles (Ph-HPMOs) with high thermal stability and hydrother-mal stability using 1,4-bis(triethoxysilyl)benzene (BTEB) as an organosilica precursor in alkaline phosphate buffer solution. The Ph-HPMOs were robust with a diameter of 100-200 nm and a shell thickness up to 50 nm. In addition, the Ph-HPMOs had a unique hierarchical pore size distribution of macropores, cavities, mesopores and micropores with a high surface area of 560-930 m2/g and a large pore volume of 0.6-1.3 cm3/g. Also, the effect of different variables on the structural morphologies of the products were investigated. The optimized conditions for the Ph-HPMOs were 1 SDS:1.5 CTAB: 13.575 BTEB: 4.525 TEOS: 316.26 EtOH: 5119.92H2O (molar ratio). Additionally, aluminum ions (Al3+) were doped into Ph-HPMOs, and the catalytic properties were investigated in a fixed bed reactor, highlighting their high practical value as catalysts or adsorbents.