Syntheses and characterizations of multiwalled carbon nanotubes-supported palladium nanocomposites

Multiwalled carbon nanotubes/Pd nanoparticles (CNT/Pd) were prepared by different four synthesis techniques. After the chemical oxidation of CNTs, the infrared absorption data indicated the existence of several functional groups loaded on the CNTs surfaces. The first Pd deposition technique went through the processes of Sn sensitization and Pd deposition on the functionalized surfaces of CNTs. The second method was Pd deposition by polyol process. The third method was Pd deposition using hydrazine in acidic media. In the fourth method, fourth generation poly(amidoamine) dendrimer and sodium borohydride were used as an intermediator between Pd and the surfaces of CNTs and as a reducing agent of the palladium chloride, respectively. It was observed from transmission electron microscope analysis of the produced CNT/Pd nanoparticles that the Pd particles on the CNTs prepared by the fourth method had the smallest average particle size of 3 nm. The Pd contents in the produced CNT/Pd nanocomposite powders were determined by thermogravimetric analysis.