Direct Fabrication Of Au/Pd(Ii) Colloidal Core-Shell Nanoparticles By Pulsed Laser Ablation Of Gold In Pdcl2 Solution

In this study, Au/Pd(II) core-shell colloidal nanoparticles (NPs) were prepared by pulsed laser (Nd:YAG, lambda = 1064 nm) ablation synthesis in solution (LASiS) of gold target in PdCl2 solution of different concentrations. From X-ray diffraction, metallic Au, PdO, or PdCl2 crystal phases were obtained in this process. Surface plasmon resonance investigations, by means of UV-vis spectrophotometer, revealed damping of Au peak by increasing PdCl2 concentration. Transmission electron microscope showed the bimetallic particles are spherical core Au NPs covered by a Pd(II) shell whose thickness is dependent on PdCl2 concentration. X-ray photoelectron spectroscopy was used for surface chemical analysis. On the basis of the results from the previously described measurements, a mechanism for Au/Pd(II) core-shell formation was given.