One-pot co-condensation strategy for dendritic mesoporous organosilica nanospheres with fine size and morphology control

Abstract

Dendritic mesoporous organosilica nanospheres (DMOSNs) with tunable organic functions and finely controlled particle size and morphology have been prepared by a one-pot co-condensation strategy using a mix of tetraethoxysilane (TEOS) and a silane coupling agent as silica sources. The size and morphology of the final DMOSNs are strongly dependent on the structure and the hydrophobicity of the silane coupling agents used. In particular, when a more easily hydrolyzed monopodal trialkoxysilane was used, the basic building units for the assembly of DMOSNs, such as single micelles partially coated with silica and their blocks, were captured at the initial stage of the reaction, suggesting a completely different formation mechanism with MCM-41 and SBA-15. Due to the presence of unique dendritic pore channel networks, Au NP immobilized DMOSNs exhibited excellent catalytic performance for the vapor phase selective oxidation of benzyl alcohol to benzaldehyde, compared with those confined within classical MCM-41 and SBA-15 silica matrices.