Formation of silicalite-1 hollow spheres by the self-assembly of nanocrystals

A simple approach is reported for the preparation of hollow spheres with a 10-20-nm-thick shell of silicalite-1 nanocrystals. The nanocrystals were produced by the steaming of silicalite-1 nanoprecursors (NPs), collected with the help of surfactant from a clear synthesis solution immediately following the induction period. The nanocrystals produced were approximate to10-20 nm with a BET surface area of 440-470 m(2)/g and an external surface area > 112 m(2)/g. A water adsorption isotherm confirmed that the nanocrystals were hydrophobic in nature. These nanocrystals self-assembled into hollow spheres of 100-300-nm diameter when ultrasonicated in ammoniac ethanol.