The appearance of hydrocarbons on carbon nanotube (CNT) structures occurs often. It means that some of the carbon source that is being used to grow the CNTs (for example acetylene or hexane or ethanol etc) is not doing the right thing. Instead of all the carbon source cracking on the catalyst surfaces and being incorporated into CNT growth, some of it is decomposing thermally and forming other compounds such as hydrocarbons, badly graphitised carbon platelets etc. These can then deposit on the surfaces of the growing CNTs.

The appearance of hydrocarbons on carbon nanotube (CNT) structures occurs often. It means that some of the carbon source that is being used to grow the CNTs (for example acetylene or hexane or ethanol etc) is not doing the right thing. Instead of all the carbon source cracking on the catalyst surfaces and being incorporated into CNT growth, some of it is decomposing thermally and forming other compounds such as hydrocarbons, badly graphitised carbon platelets etc. These can then deposit on the surfaces of the growing CNTs.

Thanks for the clarification!

This problem may be due to the unstable nature or incomplete burning of starting hydrocarbon material at elevated temperatures which may causes a deposition of hydrocarbons compounds instead of the carbon nanotubes.

Thank you!