Effects of cementation factors on the Cu nanoparticle deposit of Cu-multi-wall carbon nanotubes composites

Copper (Cu) coated carbon nanotubes (CNTs) were prepared and investigated by chemical reduction or cementation method. The morphology changes of Cu nanoparticles deposited onto the multiwall carbon nanotubes with metallic zinc (Zn) as a reducing agent have been examined at different cementation factors. The precipitated Cu nanoparticles from the copper ion in the reaction solution were deposited onto and entangled with the CNT substrates. CNTs used were multi-wall carbon nanotubes with average diameter of 10-20 nm and length of 10-50 μm. As-prepared CNTs products were purified by nitric acid solution, and then the CNTs were washed several times with distilled water, and dried in vacuum. The pre-treated CNTs were suspended in solvent. Then, the copper salt was dissolved in the suspension containing the CNTs. The deposited morphology and distribution of copper particles on the CNTs substrate were investigated by changing the solute, solvent and reducing agent. The Cu/CNTs agglomerates were obtained in the presence of copper chloride and copper sulphate salts, and water and ethanol were used as the solvents. And the raw CNTs were pretreated with glacial acetic acid for increasing the coverage rate of copper particles over the CNTs surface at different acid concentrations. The Cu deposited CNTs were characterized in respect of morphology and distribution of CNTs and Cu particles with field emission scanning electron microscopy (FESEM). The copper crystals were identified by X-ray diffraction patterns.