Synthesis and characterization of large mesoporous silica SBA-15 sheets with ordered accessible 18 nm pores

Abstract

Mesoporous silica SBA-15 in the form of 10-30 μm sized sheets with unusually large ordered pores has been synthesized using heptane as a cosolvent in the presence of NH4F. The resulting morphology of 400 nm thick sheets that contain easily accessed, hexagonally arranged, 18 nm sized pores running parallel to sheet normal has not been previously reported. The material has a BET surface area of 541 m2/g, large pore volume of 1.69 cm3/g and ordered mesopore structure with a narrow pore size distribution around 18 nm. A mechanism for sheet formation based on heptane droplets acting as sites for self assembling of silica crystallites is suggested. © 2009 Elsevier B.V. All rights reserved.