New Insights into Plasma‐Assisted Dissociation of Organometallic Vapors for Gas‐Phase Synthesis of Metal Nanoparticles

Abstract

Organometallic compounds are a general class of metal precursors that are used for chemical vapor deposition of metal films and nanoparticle nucleation in the gas phase. While there have been numerous studies of metal film deposition, there exist far fewer studies of how organometallic vapors are dissociated in the gas phase to homogeneously nucleate metal nanoparticles, and, most importantly, if the organic components are incorporated in the nanoparticle material. Here, we study the dissociation of organometallic precursors in an atmospheric‐pressure microplasma by optical emission spectroscopy and assess the chemical composition of the as‐grown nanoparticles by X‐ray photoelectron spectroscopy. We find that certain precursors such as Ni(Cp)2 do not form carbon except at higher discharge powers where electron and gas heating are enhanced. In comparison, precursors such as Cu(acac)2 dissociate to form carbon moieties even at low discharge currents. These results should help guide processes that are intended to produce high‐purity metal nanoparticles.

Low‐Temperature Atmospheric Pressure Plasma Processes for “Green” Third Generation Photovoltaics

“…The effect of the solution composition, temperature of electrolyte, presence of a stabilizer, and stirring of solution were studied. Effect of precursor concentration was similar as previously reported . By increasing electrolyte temperature from 25 to 70 °C increased the synthesis rate and there was no effect of stabilizer on particle growth.…”

Synthesis of Ni nanoparticles with controllable magnetic properties by atmospheric pressure microplasma assisted process

“…Based on preceding reports [18][19][20][21][22] and NIST Atomic Spectra Database, 23 detailed radiative transition information of species resulted by Ni(cp) 2 dissociation process is summarized in Supporting Information Table S1. The crystal size and phase composition is derived from the XRD results using Scherrer formula; fcc (face-centered-cubic Ni), hcp (hexagonal-close-packed Ni), C (crystalline carbon).…”

Atmospheric pressure synthesis of diamondoids by plasmas generated inside a microfluidic reactor

“…For example, the rapid continuous gas phase growth of semiconductor nanowires has been demonstrated [28], and the growth speed and morphology were shown to be influenced by the flow rate and precursor size. In addition, continuous flow microplasma reactors operated at atmospheric pressure have been used for the synthesis of metallic nanoparticles [29,30] and nanodiamond [31].…”