BCN nanotubes are tubular structures with a sub-micrometer diameter and a length much longer than diameter. They are composed of comparable amounts of boron, carbon and nitrogen atoms. First made in 1994, synthesis methods have included: arc-discharge, laser ablation, chemical vapor deposition (CVD), template route, and pyrolysis techniques. Single-walled B–C–N nanotubes have been made with a hot-filament method.