Synthesis of nanoparticles using an atmospheric pressure plasma jet

Summary form only given. Nanocrystalline metal oxide particles are synthesized by an atmospheric pressure plasma jet (APPJ). The APPJ is sustained using a repetitive pulse source with O
₂
and N
₂
as the plasma gas. Precursors of several types are used to synthesize simple and complex metal oxides via multiple approaches to assess the potential using such a process to fabricate nanoparticles. The first approach uses Zn(NO
₃
)
₂
and NaNO
₃
solution to fabricate ZnO nanoparticles using the salt-assisted spray pyrolysis-like process. The ultrasonically nebulized precursor is carried into the downstream of the APPJ using a carrier gas. This process is able to fabricate nanocrystalline ZnO particles within a short contact time (a few ms) between the precursor and the plasma jet. When N
₂
plasma is used, N-doped ZnO is formed and the doping level can be controlled using the plasma gas flow rate. The second approach utilizes nebulized the LiNO
₃
and Titanium bis(ammonium lactate)-dehydroxide solution as the precursor to fabricate Li
₄
Ti
₅
O
₁₂
using O
₂
and N
₂
plasmas. The fabricated powders include Li
₄
Ti
₅
O
₁₂
. TiO
₂
, and Li
₂
TiO
₃
. The third approach uses titanium tetraisopropoxide as the precursor. The precursor is injected into the system using a heated bubbler. With this approach, nearly mono-dispersed N-doped TiO
₂
nanoparticles are synthesized using N
₂
plasmas. Preliminary studies show that the first approach is the most stable process while the approach using organic metal precursors exhibits the highest throughput. In this presentation, key features of different approaches and key factors that dominate the fabricated nanoparticle characteristics will be discussed.