title: Formation of Au-Pt bimetallic nanoparticles in a two-layer SiO2 films doped with Au and Pt, respectively, through interlayer diffusion.
abstract: Bimetallic Au-Pt nanoparticles have been generated inside a relatively porous SiO2 film matrix by a two-layer (2L) coating methodology. Two overlapping coating layers were deposited on glass substrates from Au- and Pt-doped inorganic-organic hybrid silica sols and air dried at 60 degrees C. The 2L coating assembly was then UV- and followed by heat-treated at 450 and 550 degrees C in air. UV-treatment decomposes AuCl(4)(-) and PtCl(6)(2-) ions in the respective layers and the subsequent heat treatment in air influences the diffusion of Au and Pt nanometals to each other to form bimetallic Au-Pt nanoparticles inside the silica matrix. A UV-visible study showed damping of Au-plasmon after heat treatments. GIXRD and TEM analyses reveal the formation of a partial Au/Pt solid solution with a small fraction of Pt ( approximately 16%), while the major fraction of Pt remains fused with the Au(Pt) solid solution.
authors.affiliation: Sol-Gel Division, Central Glass and Ceramic Research Institute, Jadavpur, Kolkata, India.
authors.forename: Sudipto
authors.initials: S
authors.lastname: Pal
authors.forename: Goutam
authors.initials: G
authors.lastname: De
mesh_terms: D000497:Alloys / Q000737:chemistry*; D003460:Crystallization; D004058:Diffusion; D006046:Gold / Q000737:chemistry*; D006358:Hot Temperature; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010984:Platinum / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D020349:Surface Plasmon Resonance; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D010984:Platinum; D006046:Gold; D012822:Silicon Dioxide