Patent ID: 7601321

Claim:
A method for synthesizing hollow carbon nanospheres and nanometer-scale metallic particles from a carbon-based substrate doped with a metal salt, and for recovering either one or both of these products, comprising the sequential steps of: (a) doping a carbon-based substrate with about 1-99 wt. % of a metal salt; (b) heating the doped substrate in an inert gas atmosphere to a first heating temperature of about 200° C. to about 400° C. for a period sufficient to produce initial charring of the substrate to form amorphous carbon and metal nanoparticles; (c) cooling the charred substrate; (d) optionally separating a first portion of the charred substrate from the remaining charred substrate and recovering metal nanoparticles if desired from said first portion of the charred substrate; and, (e) pyrolyzing at least a portion of the remaining charred substrate by heating it to a second heating temperature of 2000° C. or higher in an inert gas atmosphere for a period sufficient to produce graphitic nanostructures having the properties of being almost totally homogeneous and substantially resistant to attack by acid.