Size-controlled synthesis of Fe2O3 and Fe3O4 nanoparticles onto zeolite by means of a modified activated-coprecipitation method: effect of the HCl concentration during the activation

摘要

Synthetic sodium type A zeolite bearing Fe2O3 and Fe3O4 nanoparticles composites have been prepared by means of a coprecipitation method with two different activation methodologies, one using Sn and the other using Sn/Pd nanoparticles as activators. Sn activation generates hematite nanoparticles while Sn/Pd produces magnetite nanoparticles. Amount of HCl used during the activation of the zeolite with SnCl2 showed a correlation between the stannous activating species and the particle size. Both Sn and Sn–Pd activated nanocomposites show nearly narrow size distributions but only those iron oxides obtained with Sn–Pd showed supermagnetism.