Single-Walled Carbon Nanotubes Coated by Fe_2O_3 Nanoparticles with Enhanced Magnetic Properties

摘要

Carbon nanotubes (CNTs) continue to attract significant interests due to their unique combination of extraordinary thermal, electrical, optical, and mechanical properties. The preparation of CNTs coated with magnetically sensitive Fe_2O_3 nanoparticles has implications to the development of advanced heat transfer nanofluids and high capacity lithium ion batteries. In this paper, various characterization methods confirm that single-walled carbon nanotubes (SWNTs) were uniformly coated with Fe_2O_3 nanoparticles through solution mixture. Scanning and transmission electron microscopy were used to compare the morphology of pristine SWNTs and as-prepared SWNTs coated with Fe_2O_3 nanoparticles. Raman spectroscopy and thermo gravimetric analysis presented the extent of defects and the amount of Fe_2O_3 nanoparticles present in the sample. Near edge X-ray absorption fine structure spectroscopy was used to probe the electronic band structure of as-prepared core-shell structures. Magnetization measurements indicate that the coercive field of SWNTs coated with Fe_2O_3 nanoparticles was twice that of pristine SWNTs.