Studies of synthesis of ultra-fine nanoparticles using metal arc discharge

The use of single-walled carbon nanotubes (SWCNTs) in structural materials promises significant enhancement in the construction’s life span, mechanical, and even electrical characteristics, and thus—the reduction of the CO₂ emissions. One of the scalable techniques of SWCNTs production is the arc discharge method. Previous efforts mainly focused on the carbon arc, where two graphite electrodes, one of which contained catalyst powder, served as the carbon source [1]. A more scalable and sustainable method is the metal arc in a methane atmosphere in which the metal anode is continuously evaporated to produce catalyst nanoparticles, while methane is decomposed to generate carbon and H₂, with no CO₂ formation. For SWCNT synthesis, a precise control over the catalyst particle size distribution is essential [2]. Here, we start from the argon metal arc discharge to explore how to control the particle size distribution and produce ultra-fine metal nanoparticles. Apart from the process parameters, such as arc voltage, current, pressure, and temperature, we focus on understanding and improving the arc stability [3]. For that, we deploy high-speed imaging and optical emission spectroscopy.