Preparation Of Coating Of Carbon Nanotube With Nickel

The discovery of carbon nanotubes attracts many scientists' s attention. Carbon nanotubes can be used in many fields due to its excellent physical, chemical properties. The coating carbon nanotubes have a number of ways. Electroless plating is one of methods by the reducing agent to reduce metal ions and to deposite them on the surface of carbon nanotube. Electroless plating is an effect way to obtain coating which has the high dense, the small gap and high hardness. After plating, dispersion of carbon nanotubes can be improved. The study use electroless plating process to coat Ni on the surface of carbon nanotubes to improve carbon Nanotubes surface structure and properties. So to enhance the interface connection of carbon nanotube with metal, ceramic and polymer matrix materials and to expand carbon nanotube applications and effective utilization of carbon nanotubes excellent performance.The carbon nanotubes are treated by microwave heat treatment to remove amorphous carbon in carbon nanotubes to improve the crystallinity. Then the microwave-treated carbon nanotubes are further purified by using 4 mol/L of sodium hydroxide solution, concentrated HCl and concentrated HNO3 respectively to remove the Si, Fe, Al, and other impurities by ultrasound process .After being treated by concentrated HNO3, the surface of carbon nanotubes are grafted carbonyl and hydroxyl, carboxyl, and other organic functional groups. The surface properties of carbon nanotubes is improved. These organic functional groups on the carbon nanotubes are benifical to sensitization and activation treatment. Carbon nanotubes are sensitized in SnCl₂ solution and activated in PdCl₂ solution by ultrasound process. The surface of carbon nanotubes is activated and high density activated sites are obtained. The sites is very important to electroless plating of Ni on carbon nanotube. The continuous metal Ni layer is gained. Electroless plating is done on condition of constant temperature and stirring. The complete, uniform, dense metal coating layer on the surface of carbon nanotubes is obtained by regulating formula, temperature, PH, time. Using infrared spectroscopy, transmission electron microscopy, scanning electron microscopy,X-ray diffraction, energy spectrum and other modern means to study coating' s micro-structure of coated carbon nanotubes. The results show that the use of the third formula and at 85℃, PH 5.6, plating 30 minutes obtained the best coating. The energy spectrum shows that Ni metal is coated on the surface of carbon nanotubes. XRD further confirm the Ni coated on the surface of carbon nanotube is amorphous structure.