Abstract: Carbon nanostructure are synthesized by pyrolyzing an organic material. The carbon nanostructures are synthesized on a stainless steel substrate that is reused. After synthesizing the carbon nanostructures, the stainless steel substrate is contacted with an acid, heated, quenched and reused for synthesis of carbon nanostructures.

Abstract: Carbon nanostructures are synthesized from a feedstock that includes polyethylene terephthalate. In a first furnace, the feedstock that includes polyethylene terephthalate and calcium oxide (CaO) or calcium hydroxide (Ca(OH)2) are pyrolyzed to obtain one or more gaseous decomposition products. The gaseous decomposition productions are optionally filtered to remove any solid particles. The one or more gaseous decomposition products are passed across a stainless steel substrate in a second furnace to form the carbon nanostructures.