The microstructure of Ni layer on single-walled carbon nanotubes prepared by an electroless coating process

Abstract

The single-walled carbon nanotubes (SWNTs, diameter: 2∼3nm), which were obtained in the suspension of purification solution, with Ni-P coating layers were obtained by an electroless deposition process. The SWNTs before and after coating were characterized by transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). An Ni-P layer on individual nanotube with thickness of 20nm can be obtained after the deposition process. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) analysis of Ni-P SWNTs before and after heat treatment show that the heat treatment caused the transformation of the amorphous Ni-P layer to the nanocrystalline Ni-P (crystalline Ni and Ni3 P intermetallic compound) layer. The XRD pattern of SWNTs with Ni-P layers after heat treatment revealed that the crystal structures of Ni in plating layer contained: hexagonal close-packed (hcp) structure and face-centered cubic (fcc) structure. The lattice parameters of Ni (fcc) and Ni3P are larger than the bulk's, indicting that the lattice expansion has taken place. However, the lattice parameter of Ni (hcp) has no difference from the bulk's. Copyright © 2011 Weixue Li et al.