Synthesis of micron-sized hollow silica spheres with a novel mesoporous shell of MCF

Micron-sized hollow silica spheres whose shells are made up of mesocellular silica foams (MCFs) have been synthesized by one-pot sol–gel method in benzene/water/P123 emulsion. The material is characterized with SEM, TEM, BET and 29Si MAS NMR. The results show that the MCFs of the unique shell of hollow silica spheres were connected by large windows with a narrow distribution of ∼10 nm in diameter, the inner space of the hollow sphere is accessible. And the formation mechanism of the hollow silica spheres is proposed.