Low-temperature metallic alloying of copper and silver nanoparticles with gold nanoparticles through digestive ripening.
We describe a remarkable and simple alloying procedure in which noble metal intermetallic nanoparticles are produced in gram quantities via digestive ripening. This process involves mixing of separately prepared colloids of pure Au and pure Ag or Cu particles and then heating in the presence of an alkanethiol under reflux. The result after 1 h is alloy nanoparticles. Particles synthesized according to this procedure were characterized by UV-vis spectroscopy, EDX analysis, and high-resolution electron microscopy, the results of which confirm the formation of alloy particles. The particles of 5.6+/-0.5 nm diameter for Au/Ag and 4.8+/-1.0 nm diameter for Cu/Au undergo facile self-assembly to form 3-D superlattice ordering. It appears that during this digestive ripening process, the organic ligands display an extraordinary chemistry in which atom transfer between atomically pure copper, silver, and gold metal nanoparticles yields monodisperse alloy nanoparticles.
Department of Chemistry, Kansas State University, 111 Willard Hall, Manhattan, Kansas 66506, USA.
Alexander B
AB
Smetana
Kenneth J
KJ
Klabunde
Christopher M
CM
Sorensen
Audaldo A
AA
Ponce
Benny
B
Mwale
D000497:Alloys / Q000737:chemistry*; D003080:Cold Temperature; D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006361:Heating; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D009930:Organic Chemicals / Q000737:chemistry; D010316:Particle Size; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D000497:Alloys; D009930:Organic Chemicals; D012834:Silver; D006046:Gold; D003300:Copper