AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
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Nanoparticle Synthesis by Laser Pyrolysis: Recent Advances in Production and Application of Multicomponent Materials
Parham Rohani, Seongbeom Kim, MARK SWIHART, University at Buffalo (SUNY)
Abstract Number: 584 Working Group: Nanoparticles and Materials Synthesis
Abstract Laser pyrolysis is a versatile aerosol process that has been used to prepare many types of nanoparticles (NPs) since its development more than 30 years ago. In this approach, a CO$_2 laser beam is used to very rapidly heat a gas mixture, initiating decomposition of precursor molecules from which solid particles then nucleate. Rapid cooling of the particles by mixing with unheated gases quenches particle growth and sintering. If the precursor does not absorb the laser beam, a photosensitizer (e.g. SF$_6) can be added to the precursor mixture. Even for gases that adsorb at the laser wavelength, a photosensitizer can be used to provide additional control of the reaction temperature. Precursor flow rates, laser power, and carrier gas flow rates determine the residence time, reaction temperature, and reactant concentrations. By varying these parameters, primary particle diameters can typically be tuned from about 5 to 50 nm. Alloy and doped nanoparticles can often by prepared using mixed precursor gases. Here, we will present recent results from our laboratory on synthesis of silicon, boron, carbon, and germanium-containing NPs. Silane-germane, silane-diborane, silane-ethylene and silane-germane-ethylene mixtures are being employed to produce Si-Ge alloy NPs, boron-doped Si NPs, silicon carbide NPs and Si-Ge-C ternary alloy NPs respectively. With proper control of size, composition, and surface chemistry, these NPs can be used as reagents for chemical water splitting to produce hydrogen, as anode materials in lithium-ion batteries, as photoluminescent contrast agents for biological imaging, and as light absorbers or emitters in printable electronics. In this presentation, we will summarize our recent progress in producing binary and ternary alloy NPs by laser pyrolysis and present examples of their use in select applications.