C. Ergun, S. Parlakyigit
Istanbul Technical University,
Keywords: ZnO, nano particle, ICP, thermal plasma
Summary:Zinc oxide (ZnO) is recognized for its unique optical, semiconducting, photocatalytic, pyroelectric, and piezoelectric properties. Due to the combination of these specific properties, ZnO has received much attention from researchers studying on optoelectronics, light-emitting diodes (LED), energy harvesting devices, actuators, photodetectors, solar cells, transparent conductors, gas sensors, biosensors, cosmetics, medicines, and antibacterial. Thermal plasma process has been recognized as a promising method for rapid and high-yield synthesis of nanostructures with their ability to provide very high temperatures and high energy density. In general, thermal plasmas can be established via high-density DC arcs or high-frequency RF discharges. Particularly, the ICP method has received considerable attention due to its flexibility, versatility and unique features such as no requirement for any internal electrode/s, the capability to permit injection of precursor/s along the central axis, and to provide long residence time in the plasma zone. Furthermore, starting materials in different forms, such as solid, liquid, gas or their combination can be used as precursors. In addition, cold quenching gas can be introduced to attain very high cooling rates. In this method, both the size and size distribution of nanoparticles can be controlled through a number of means such as the degree of supersaturation is the predominant factor determining the size of the particles. In this research, ZnO were synthesized in a lab-built Spray atomization assisted inductively coupled plasma unit operating at 1.5 kW (at 27.12 MHz). As the process parameters, the precursor flow rate was chosen as 2 ml/h and 4 ml/h, carrier gas density as 0.4 and 1 ml/ min, the precursor concentration in a range of 1.6 and 4.8 M. In addition, dry air or oxygen was used as quench gas.