Production of palladium nanoparticles supported on multiwalled carbon nanotubes by gamma irradiation

Palladium nanoparticles were produced and supported on multiwalled carbon nanotubes (MWCNT) by gamma irradiation. A solution with a specific ratio of 2:1 of water-isopropanol was prepared and mixed with palladium chloride and the surfactant sodium dodecyl sulfate (SDS). The gamma radiolysis of water ultimately produces Pd metallic particles that serve as nucleation seeds. Isopropanol is used as an ion scavenger to balance the reaction, and the coalescence of the metal nanoparticles was controlled by the addition of SDS as a stabilizer. The size and distribution of nanoparticles on the carbon nanotubes (CNT) were studied at different surfactant concentrations and radiation doses. SEM, STEM and XPS were used for morphological, chemical and structural characterization of the nanostructure. Nanoparticles obtained for doses between 10 and 40 kGy, ranged in size 5-30 nm. The smaller nanoparticles were obtained at the higher doses and vice versa. Histograms of particle size distributions at different doses are presented. - Highlights: → Palladium nanoparticles deposited on multiwalled carbon nanotubes by gamma irradiation. → Dependence of size and distribution of the nanoparticles on dose and surfactant evaluated. → Interaction of Pd and CNTs explained by the formation of Pd-O on the surface of the CNTs. → Distribution of palladium particles with an average size of 5 nm obtained at 40 kGy and 0.07 M SDS.