Au-Pt alloy nanoparticles obtained by nanosecond laser irradiation of gold and platinum bulk targets in an ethylene glycol solution

Au-Pt alloy nanoparticles (NPs) of different compositions (Au0Pt100, Au30Pt70, Au50Pt50, Au70Pt30, and Au100Pt0) were obtained using the nanosecond laser ablation of gold and platinum bulk targets in ethylene glycol, followed by mixing highly monodisperse Au and Pt nanocolloids, for the first time. UV-vis absorption spectra of NPs showed that by increasing the Au content in the Au-Pt NPs, the surface plasmon resonance (SPR) peak red-shifted, from 260 to 573nm in a nonlinear way. In addition, the mean crystalline size, crystal structure, d-spacing, and lattice parameters of NPs were estimated from the XRD spectra. Microscopy studies revealed the most NPs have a spherical or near-spherical shape, and the average sizes of Au0Pt100, Au30Pt70, Au50Pt50, Au70Pt30, and Au100Pt0 NPs were calculated to be 12.50, 14.15, 18.53, 19.29, and 26.38 nm, respectively. Also, the chemical identity of the molecules adhering to the NPs surface was considered by Raman and FT-IR spectroscopy techniques. Among different synthesis methods, the demonstrated technique allows easy synthesis of alloy NPs in aqueous media at room temperature with no formation of by-products.