Growth of nitrogen-doped carbon nanotubes using Ni/La2Zr2O7 as catalyst: Electrochemical and magnetic studies

Abstract

The combination of different nanomaterials to achieve particular applications is a topic with an increasing impact on diverse areas of nanotechnology. In particular, the material of La2Zr2O7 (LZO) and NiO could be employed as a source of catalyst for carbon nanotube fabrication. In this work, the Ni/LZO material was utilized to fabricate nitrogen-doped multiwalled carbon nanotube (N-MWCNTs). The N-MWCNTs were produced at 850 °C by the aerosol assisted catalytic chemical vapor deposition method using benzylamine as the sole carbon and nitrogen precursor. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and vibrating sample magnetometry. Before the synthesis of N-MWCNTs, NiO was reduced to Ni to act as a catalyst and LZO as support. N-MWCNTs exhibited the typical feature bamboo shape morphology with small nanoparticles anchored inside and on its surface. The electrochemical studies show interesting results about charge capacity and a hydroquinone/quinone redox process of oxygen functionalities. The magnetic properties of N-MWCNTs showed a ferromagnetic behavior with a saturated magnetization of 43 emu/g at 0.2 T.