Ordered deposition of Pd nanoparticles on sodium dodecyl sulfate-functionalized single-walled carbon nanotubes

We report here a novel chemical solution method to site-selectively deposit and arrange palladium (Pd) nanoparticles (NPs) on single-walled carbon nanotubes (SWCNTs). Sodium dodecyl sulfate (SDS) formed supramolecular self-assemblies on the SWCNTs. The SDS then acted as adsorption sites for Pd(II) ions. Pd(II) was reduced to Pd NPs by photo-reduction, and the NPs formed helices with different helix angles on the surface of the SWCNTs. The pitch of the Pd NPs helix was 4.5 nm. The parameters of the Pd NPs helix (pitch, angle, and chirality) were determined by the supramolecular self-assembly of SDS on the SWCNTs. Increasing the concentration of Pd(II) ions resulted in high-density deposition of Pd NPs on the SDS-functionalized SWCNTs.