Synthesis of Core–Shell Magnetic Nanoparticles Containing Ultrasmall Domains of Silicalite‐1

Abstract

Synthesis of core-shell nanostructures with magnetic core and zeolitic shell is an ongoing challenge. Herein, we present a strategy for preparation of -Fe2O3@mesoporous silica (mSiO2) core-shell nanoparticles containing ultra-small domains of silicalite-1 in the shell (-Fe2O3@mSiO2/Silicalite-1). The strategy consists in a solid-state reorganization of the precursor amorphous mSiO2 shell into silicalite-1 using a tetrapropylammonium hydroxide (TPAOH) as an organic structure-directing agent (OSDA) under mild hydrothermal (HT) 2 conditions. The formation of sililicalite-1 crystalline domains has been investigated through the detailed characterization of products obtained at different times of HT treatment by XRD, Raman spectroscopy, FTIR, SEM with EDS, TEM and nitrogen physisorption. By careful tuning the time of HT treatment, the -Fe2O3@mSiO2/Silicalite-1 nanostructures are prepared.