Synthesis of Fe2O3/biochar nanocomposites by microwave method for magnetic energy-storage concentration cells

Abstract

Magnetic nanocomposites have attracted increasing attention due to its widely applications in different areas in recent years. The conventional synthesis of magnetic nanocomposites is usually based on high temperature annealing technique from biomass. In this paper, a microwave method has been developed to prepare iron oxide based magnetic nanocomposites using ferric acetylacetonate ((Fe(acac)3), oleylamine (OAm), oleic acid (OA), and commercial biochar. The reaction is completed in several minutes. Composite structure composed of γ-Fe2O3 nanoparticles with the size of 6–17 nm and biochar is confirmed by TEM, SEM EDX element mapping images. The iron oxide size can be controlled by the microwave time and the ligand ratio. Magnetic properties of the magnetic nanocomposites are studied. The application of the prepared magnetic nanocomposites in magnetic concentration cells are tested with different magnetic fields and different biochar to iron oxide ratios. The method developed in this work on magnetic nanocomposite synthesis will not only facilitate the research progress of magnetic nanocomposite synthesis but also provide an alternative technique to be used in magnetic concentration cells.