title: Soft purification of N-doped and undoped multi-wall carbon nanotubes.
abstract: A soft method for purifying multi-wall carbon nanotubes (N-doped and undoped) is presented. The technique includes a hydrothermal/ultrasonic treatment of the material in conjunction with other subsequent treatments, including the extraction of polyaromatic compounds, dissolution of metal particles, bundle exfoliation, and uniform dispersion. This method avoids harsh oxidation protocols that burn (via thermal treatments) or functionalize (by introducing chemical groups) the nanotubes. We show a careful analysis of each purification step and demonstrate that the technique is extremely efficient when characterizing the materials using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), scanning tuneling electron microscopy (STEM), x-ray powder diffraction (XRD), diffuse reflectance Fourier transform infrared (DRFTIR) spectroscopy and thermogravimetric analysis (TGA).
authors.affiliation: Instituto de Fisica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, CP 78000, San Luis Potosi, Mexico.
authors.forename: Edgar Rogelio
authors.initials: ER
authors.lastname: Alvizo-Paez
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Romo-Herrera
authors.forename: Humberto
authors.initials: H
authors.lastname: Terrones
authors.forename: Mauricio
authors.initials: M
authors.lastname: Terrones
authors.forename: Jaime
authors.initials: J
authors.lastname: Ruiz-Garcia
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Hernandez-Lopez