The Activation Of Carbon Nanotubes And The Preparation Of Carbon Nanotubes-nickel Compound Materials

This research was to investigate the preparation carbon nanotubes-nickel compound materials by electrodeposition. The carbon nanotubes having a diameter around tens to hundreds nanometer. The carbon nanotubes of as-prepared must be purification and activation by pretreatment. The as-prepared carbon nanotubes usually contain a large amount of impurities, such as amorphous carbon, multishell carbon nanocapsules and catalyst particles. Furthermore the hydrophobic nature, large surface curvature, small diameter and large aspect ratio, it is difficult to gain a uniform and continuous deposit layer on the surface of carbon nanotubes. In the foundation of each method's merit of carbon nanotubes sample pretreatment, a highly effective carbon nanotubes sample pretreatment method was gained. The pretreatment involves ultro-sonication, acid treatment and calcining. Each factor that affects the pretreatment was discussed. The optimal volume proportion of the mixture acid and the calcining temperature were determined.The carbon nanotubes samples before and after pretreatment were analyzed using scaning electron microscopy (SEM) and thermogravimetry(TG). The result indicated that most of amorphous carbon, multishell carbon nanocapsules as well as the catalyst particles were successfully removed from the carbon nanotubes samples. And enable its surface to include the hydrophilic groups, also, the sample's wetting property and dispersibility had been improved greatly, and the carbon nanotubes sample can disperse stably and homogeneously in the bath. Factors influencing the nickel deposition on carbon nanotubes were inspected . The conditions of the concentration of carbon nanotubes in bath, deposition time and current density had been optimized. The morphology of the Ni coating was examined by SEM and its composition was determined by energy spectrum analysis. The results showed that the surface of carbon nanotubes was successfully coated with continuous and uniform layer of nickel. In this paper, some other testshave done, such as X-ray diffraction (XRD), nickel content, resistivity et al. The mechanism of the carbon nanotubes dispersing agents was discussed. Preliminary investigation has been done to the deposition mechanism on the carbon nanotubes surface.Sensitization and activation steps were not needed in this method, it can be directly deposited by dispersing the carbon nanotubes sample into the bath. This method is simple and inexpensive, and it's friendly to the environment. The amount of Ni deposited on the carbon nanotubes can be controlled by selecting the appropriate deposition conditions.