Synthesis and Optical Properties of Iodinated Multi-walled Carbon Nanotubes

This paper reports synthesis and optical properties of iodinated multi-walled carbon nanotubes (MWCNT). Multi-walled carbon nanotubes were synthesized by aerosol – assisted chemical vapor deposition method and iodinated by crystalline iodine under increased pressure (approximately ~20 bar) at 400°C. X-ray diffraction analysis, Raman and Fourier transform infrared spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy were applied to characterize the iodinated MWCNTs.The results proved the presence of iodine atoms in iodinated MWCNTs. UV-VIS absorption and photoluminescence properties have been studied in pristine MWCNTs and iodinated MWCNTs suspensions in ethanol. Firstly, photoluminescence intensity of the iodinated MWCNTs remarkably enhanced with the appearance of C–I bonds on the surface of MWCNTs, due to the high concentration of intercalated iodine atoms (approximately 30 wt %). The photoluminescence intensity enhancement of peaks at 430 and 520 nm is highly dependent on defects formed by C–I bonds.