J. Phys. Chem. C 2008, 112, 15647–15655
15647
Laser-Induced Fragmentative Decomposition of Ketone-Suspended Ag2O Micropowders to Novel Self-Stabilized Ag Nanoparticles Mitsuo Kawasaki* and Naoya Nishimura Department of Molecular Engineering, Graduate School of Engineering, Kyoto UniVersity, Katsura, Kyoto 615-8510, Japan ReceiVed: June 28, 2008; ReVised Manuscript ReceiVed: August 7, 2008
The fragmentative decomposition of ketone-suspended Ag2O micropowders (most preferably in acetone), induced by 1064 nm nanosecond laser irradiation as a single-pulse event at the required minimum laser fluence as low as ∼0.1 J/cm2, proved to offer a highly productive pathway to novel Ag nanoparticles (AgNPs) with many unique properties. The maximum NP production rate reached 2.5 mg/min at the input laser power of only ∼0.5 W, and the product AgNPs, typically 10-20 nm in diameter, exhibited excellent dispersity in ketone without any intentional addenda, thus being self-stabilized for concentrations up to ∼5 wt % (in acetone) or to more than 20 wt % (in γ-butyrolactone). The novelty of the present AgNPs was corroborated further by unusual properties that their film coatings manifested, such as a distinct coloring resembling that of bulk gold and a high electric conductivity gained by low-temperature (
