Production of carbonaceous nanostructures from a silver-carbon ambient spark

Using silver-carbon ambient sparks, hollow carbon nanospheres or multiwall carbon nanotubes were produced separately from carbon encapsulated silver nanoparticles (−1,400 K s−1) during relatively slow (−800 K s−1) or fast (−2,900 K s−1) cooling process. Different cooling processes (i.e., different exposures within high temperature) caused the formation of different carbon precipitates in the process of silver mediated graphitization: for −2,900 K s−1 and <−1,400 K s−1, respectively, obtained tubelike and sphere (encapsulated and hollow)-like carbonaceous nanostructures.