Monodisperse magnetic core/shell microspheres with Pd nanoparticles-incorporated-carbon shells

Abstract

This work reports a hard self-template method to synthesize core/shell like Fe₃O₄@C microparticles, in which the Pd nanocrystals can be alternatively incorporated into the carbon shells. The Fe₃O₄@polyaniline core/shell microspheres were first synthesized as the precursor by in situ polymerization of aniline onto the surface of the Fe₃O₄ microspheres. In a subsequent carbonization of the precursor under a vacuum oven, the Fe₃O₄ core was preserved and the polyaniline shell transferred into carbon shells enveloping the magnetic sphere, forming magnetic Fe₃O₄@C microspheres. The Pd ions could be impregnated into the polyaniline shell, and thus the obtained composites were transformed into Fe₃O₄@C/Pd microspheres under the same vacuum heating progress. The as-obtained system demonstrates superparamagnetic characteristics, which would benefit its potential application in nanocatalysts. This strategy provides an efficient approach for tailoring core/shell materials with desired functionalities and structures by adjusting the precursors and structure-directing agents.