Nanoengineering of iron oxide and iron oxide/silica hollow spheres by sequential layering combined with a sol-gel process

Fe2O3 and Fe2O3/SiO2 hollow spheres with tailored dimensions and compositions were created by consecutively coating polystyrene (PS) latices either with Fe3+ alternately adsorbed with Nafion or combining a sol-gel process based on the hydrolysis of tetraethoxysilane (TEOS), and subsequently removing the cores upon pyrolysis. (c) 2005 Published by Elsevier Inc.