Method for Production of Carbon Nanotube and Method for Purification of the Same

Abstract

The present invention provides a method for producing a carbon nanotube having a high purity and a method for purifying an unpurified carbon nanotube or a carbon nanotube having a low purity. The method for producing a carbon nanotube comprises a step of providing a carbonaceous material containing a carbon nanotube and a step of adding an iron material and hydrogen peroxide to the carbonaceous material to thereby purity a carbon nanotube. It is preferred that an iron powder is used as the iron material. The iron powder is preferably used in a proportion of 0.5 to 20 parts by mass relative to 100 parts by mass of the whole carbonaceous material.

1 - 13 . (canceled) 
     
     
         14 . A method for producing purified carbon nanotube comprising the steps of:
 providing a carbonaceous material comprising carbon nanotube; and   adding iron powder as an iron material and   hydrogen peroxide from outside sources to the carbonaceous material to facilitate removal of impurities present in the carbonaceous material.   
     
     
         15 . The method according to  claim 14 , wherein the carbonaceous material contains essentially no iron (Fe). 
     
     
         16 . The method according to  claim 14 , wherein the carbonaceous material contains no iron (Fe). 
     
     
         17 . The method according to  claim 15 , wherein the carbonaceous material is obtained by striking an arc discharge between a pair of electrodes wherein at least the positive electrode is a carbon molding that contains at least one metal selected from the group consisting of nickel (Ni), cobalt (Co), and the platinum group elements, or an alloy mainly composed thereof; and causing the deposition of evaporated material produced from the positive electrode. 
     
     
         18 . The method according to  claim 14 , wherein the iron powder consists of iron particles having an average particle size of 500 nm or smaller. 
     
     
         19 . The method according to  claim 14 , wherein the iron powder is used in a proportion of 0.5 to 20 mass parts for each 100 mass parts of the total carbonaceous material. 
     
     
         20 . The method according to  claim 14  further comprising adding an inorganic acid component. 
     
     
         21 . A method for producing carbon nanotube comprising:
 providing a carbonaceous material comprising carbon nanotube, but essentially no iron;   providing, as an iron material, an iron-containing carbonaceous material obtained by striking an arc discharge between a pair of electrodes wherein at least the positive electrode is an iron-containing carbon molding and causing the deposition of evaporated material produced from the positive electrode; and   adding the iron-containing carbonaceous material to the carbonaceous material containing essentially no iron.   
     
     
         22 . The method according to  claim 21 , wherein the carbonaceous material contains no iron (Fe). 
     
     
         23 . The method according to  claim 21 , wherein the iron-containing carbonaceous material consists of iron particles with an average particle diameter of 100 nm or smaller. 
     
     
         24 . The method according to  claim 21  further comprising adding an inorganic acid component. 
     
     
         25 . The method according to  claim 21  further comprising adding hydrogen peroxide. 
     
     
         26 . A method for purifying carbon nanotube comprising:
 providing a carbonaceous material comprising carbon nanotube; and   adding iron powder as an iron material and   hydrogen peroxide from outside sources to the carbonaceous material to facilitate removal of impurities present in the carbonaceous material.   
     
     
         27 . A product produced by the method according to  claim 14 . 
     
     
         28 . A product produced by the method according to  claim 21 . 
     
     
         29 . A product produced by the method according to  claim 26 .