Generation of Charged Nanoparticles during Synthesis of ZnO Nanowires by Carbothermal Reduction

Abstract

We measured the size distribution of positively and negatively charged nanoparticles generated abundantly in the gas phase during the syntheses of ZnO nanowires by a carbothermal reduction process using a differential mobility analyzer. Under the conditions where these charged nanoparticles were not generated, no nanowires could be grown. The evolution of ZnO nanostructures on the substrate was studied with in-situ measurements of the size distribution of charged nanoparticles with varying reactor temperature and oxygen flow rate. The results suggest that the electrostatic energy arising from charged nanoparticles would play a critical role in the growth of ZnO nanowires.