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 O₂ and N₂ 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(NO₃)₂ and NaNO₃ 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 N₂ 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 LiNO₃ and Titanium bis(ammonium lactate)-dehydroxide solution as the precursor to fabricate Li₄Ti₅O₁₂ using O₂ and N₂ plasmas. The fabricated powders include Li₄Ti₅O₁₂. TiO₂, and Li₂TiO₃. 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 TiO₂ nanoparticles are synthesized using N₂ 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.