To increase the productivity of carbon nanotubes of high quality.

The composite carbon structures that contain carbon-coated catalyst nanoparticles, and that are used in subsequent arc-discharge or laser ablation methods to produce carbon nanostructures, particularly single walled nanotubes in an increased amount and of a well-defined quality. Also, a method of making the composite carbon structures, and a method of using the composite carbon structures to produce carbon nanostructures, such as SWNTs. Further, a catalyst support for CVD growth of carbon nanostructures, wherein the catalyst support includes carbon-coated catalyst nanoparticles. Also, a method of making the catalyst support, and a method of using the catalyst support to grow carbon nanostructures by CVD.