Application of Flying Jet Plasma Torch for the Synthesis of Iron-Based Nanostructures

Abstract

Synthesizing iron-based nanostructures through a simple direct way is investigated. A jet plasma was imposed, at several time durations, on a metal foil dipped inside alkaline/salty solution (pH≈ 12.5) to examine the formation of nanoscale metal dendrites. Scanning electron microscopy (SEM) pictures showed considerable changes in the metal surface topography after the plasma effect. The effect was further assured through measuring the surface contact angle, which is found to be 85o and 40o before and after the plasma effect, respectively. The changes in the topography denoted the removal of a surface layer and formation of a precipitate, which was ascertained via formed colloids. Upon elaboration of plasma reactions for 10 min, the liquid solution color was changed to a mild green and precipitated colloids of mild whitish color were observed in the bottom of the reaction cell. The colloids (aggregated and dispersed) were filtered and dried in a furnace for 2 hrs., and the collected dried solid was extra cleaned with ethanol and analyzed after dryness. Energy dispersive X-Ray spectroscopy (EDS) results proved a presence of 55.5 mass% iron in the precipitated composite. The formation of nano-pine dendrites, was detected through transmission electron microscopy (TEM) pictures. The magnetic properties of the nanoparticles were examined through generating the magnetic hysteresis loop, and hence, the existence of Fe3O4 dendrites was concluded. Lastly, a conceptual reaction mechanism was proposed for the formation of iron oxides/iron hydroxide in the examined system.