Micelle-mediated UV-photoactivation route for the evolution of Pdcore–Aushell and Pdcore–Agshell bimetallics from photogenerated Pd nanoparticles

UV-photoactivation of aqueous PdCl2 evolves palladium nanoparticles with narrow size distribution (∼5 nm) in TX-100 [poly(oxyethylene)isooctyl phenyl ether] micelles. Here, TX-100 molecules serve as a stabilizer as well as a reducing agent. The layered core–shell bimetallic palladium–gold and palladium–silver colloids in the size range 10–30 nm have been prepared through successive ion loading by seed-mediated method where Pd particles act as seeds. By varying the seed to gold or silver ion ratios, palladium seeds are successfully covered by gold or silver shells of various compositions of Pd:Au and Pd:Ag. Thus, core–shell nanoparticles of various sizes are generated having tunable thickness of the shells. Optical plasmon absorption bands, transmission electron micrographs (TEM) and energy dispersive X-ray (EDX) studies characterize the particles.