Gas-phase process for purifying single-wall carbon nanotubes and compositions thereof

A method for purifying single-wall carbon nanotubes comprising the steps of:

• (a) oxidizing a single-wall carbon nanotube material comprising single-wall carbon nanotubes, amorphous carbon, and a metallic impurity in an oxidizing gaseous atmosphere;
• (b) reducing the single-wall carbon nanotube material with a reducing gas comprising hydrogen;
• and
• (c) treating the single-wall carbon nanotube material with a halogen-containing gas.

A purified single-wall carbon nanotube material made by the process comprising:

• (a) oxidizing a single-wall carbon nanotube material in an oxidizing gaseous atmosphere, wherein the single-wall carbon nanotube material comprises single-wall carbon nanotubes, amorphous carbon, and a metallic impurity;
• (b) treating the single-wall carbon nanotube material with a halogen-containing gas;
• and
• (c) recovering the single-wall carbon nanotube material to obtain the purified single-wall carbon nanotube material, wherein the amorphous carbon is present in an amount at most about 5 wt % of the purified single-wall carbon nanotube material.

A purified single-wall carbon nanotube material made by the process comprising:

• (a) oxidizing a single-wall carbon nanotube material in an oxidizing gaseous atmosphere, wherein the single-wall carbon nanotube material comprises single-wall carbon nanotubes, amorphous carbon, and a metallic impurity and wherein the metallic impurity comprises metal;
• (b) treating the single-wall carbon nanotube material with a halogen-containing gas;
• and
• (c) recovering the single-wall carbon nanotube material to obtain the purified single-wall carbon nanotube material, wherein the metal is present in an amount at most about 5 wt % of the purified single-wall carbon nanotube material.

A method for purifying carbon nanotubes comprising the steps of:

• (a) oxidizing a carbon nanotube material comprising carbon nanotubes, amorphous carbon, and a metallic impurity in an oxidizing gaseous atmosphere;
• (b) reducing the carbon nanotube material with a reducing gas comprising hydrogen;
• and
• (c) treating the carbon nanotube material with a halogen-containing gas.