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.