Generation of charged nanoparticles during the synthesis of carbon nanotubes by chemical vapor deposition

Generation of charged nanoparticles in the gas phase has been frequently reported during the synthesis of thin films and nanostructures, such as nanowires, using chemical vapor deposition (CVD). In an effort to confirm whether charged carbon nanoparticles were also generated during the synthesis of carbon nanotubes (CNTs) by CVD, a differential mobility analyzer combined with a Faraday cup electrometer was connected to an atmospheric-pressure CVD reactor under typical conditions for CNT growth. The size distribution of positively and negatively charged nanoparticles abundantly generated in the gas phase could be measured. Under conditions in which charged nanoparticles were not generated, no nanotubes could be grown.