The preparation of multi-walled carbon nanotubes with a Ni–P coating by an electroless deposition process Original Research Article

The multi-walled carbon nanotubes (MWCNTs, mean diameter: 100–200 nm) with nickel–phosphorous (Ni–P) coatings were obtained by an electroless deposition process. To prepare the MWCNTs covered with continual Ni–P layers, a pre-treatment procedure comprised of acid-cleaning, sensitization and activation has been developed. The resulting MWCNTs have a uniform distribution of the Ni–P layers coated on the MWCNTs with the fibrous appearance maintained. X-ray diffraction (XRD) and transmission electron microscopy (TEM) observations revealed that the as-coated MWCNTs were comprised of the amorphous Ni–P layers and inner carbon nanotubes covered with the Ni–P layers. These amorphous Ni–P-coated MWCNTs were used as precursors for preparing MWCNTs with nanocrystalline Ni–P(crystalline Ni and Ni3P intermetallic compound) layers by the heat-treatment above 400 °C, which were determined by differential scanning calorimeter (DSC) and XRD studies. The results of this work provide an effective electrochemical method for preparing powdery MWCNTs with Ni–P layer as new composite materials from the aqueous solution.