Silica nanospheres as a key process element in the Green engineering for the synthesis of carbon nanotubes as a supercapacitors additives

Abstract

In our study, we got carbon nanotubes by the Green engineering method. In this approach, the key element is silica nanospheres, that act as a catalyst carriers, prepared from the recycled ethanol-ammonia solution and copper wire from used cables. We used copper wires as a source of metal ions that were adsorbed by the silica nanospheres and then serve as a catalyst. Copper particles after synthesis of carbon nanotubes were reused for synthesis of new carbon nanotubes after re-deposition on pristine silica particles. The second material recovered from the waste cable was a polymer sheath, which at high temperature can served as a carbon source in carbon nanotubes growth. Ethanol was main source of carbon used for the chemical vapor deposition process. The synthesized carbon nanotubes were compared to commercial carbon nanotubes in terms of their electrochemical properties when used as a conductive material in supercapacitors electrodes.