Method of preparing nickel-coated nanocarbon

Abstract

A method of preparing a nickel-coated nanocarbon using electroless plating is provided. The method includes washing a nanocarbon with a solvent or thermally-oxidizing the nanocarbon to remove impurities from the nanocarbon, immersing the washed or thermally-oxidized nanocarbon into a Pd-containing solution to form an activated Pd seed on a surface of the nanocarbon, treating the nanocarbon having the Pd seed with a strong acid, immersing the strong acid-treated nanocarbon into an electroless nickel plating solution to form a nickel plated layer on a surface of the nanocarbon, and heat-treating the nanocarbon having the nickel plated layer at a high temperature to crystallize the nanocarbon.

What is claimed is: 
     
         1 . A method of preparing a nickel-coated nanocarbon using electroless plating, comprising the steps of:
 1) washing a nanocarbon with a solvent or thermally-oxidizing the nanocarbon to remove impurities from the nanocarbon;   2) immersing the washed or thermally-oxidized nanocarbon into a Pd-containing solution to form an activated palladium (Pd) seed on a surface of the nanocarbon;   3) treating the nanocarbon having the Pd seed with a strong acid;   4) immersing the strong acid-treated nanocarbon into an electroless nickel plating solution to form a nickel plated layer on a surface of the nanocarbon; and   5) heat-treating the nanocarbon having the nickel plated layer at a high temperature to crystallize the nanocarbon.   
     
     
         2 . The method of  claim 1 , wherein the nanocarbon is selected from a carbon nanofiber (CNF), a multi-walled carbon nanotube (MWCNT), a triple-walled carbon nanotube (TWCNT), a double-walled carbon nanotube (DWCNT), a metallic single-walled carbon nanotube (SWCNT), a semiconductive single-walked carbon nanotube (SWCNT) and a semiconductive single-walled carbon nanotube bundle. 
     
     
         3 . The method of  claim 1 , wherein, in the step 1), the nanocarbon is washed with ultrasonic waves in an organic solvent or an aqueous acid solution. 
     
     
         4 . The method of  claim 1 , wherein, in the step 1), the nanocarbon is thermally oxidized at 400˜600° C. for 30 minutes˜5 hours under an air atmosphere. 
     
     
         5 . The method of  claim 1 , wherein the nanocarbon is a semiconductive SWCNT or a SWCNT bundle, and the method further includes, after the step 2), the step of immersing a semiconductive nanocarbon into a tin (Sn)-containing solution to adsorb tin ions (Sn 2+ ) on a surface of the semiconductive nanocarbon and then washing the tin ion-adsorbed semiconductive nanocarbon with wafer. 
     
     
         6 . The method of  claim 1 , wherein, in the step 3), the nanocarbon having the Pd seed is treated with a strong acid to deposit purified palladium (Pd). 
     
     
         7 . The method of  claim 1 , wherein, in the step 4), when the electroless nickel plating solution is a normal temperature type of nickel plating solution, the strong acid-treated nanocarbon is immersed into the electroless nickel plating solution at 20˜40° C. for 5˜20 minutes, and, when the electroless nickel plating solution is a high temperature type of nickel plating solution, the strong acid-treated nanocarbon is immersed into the electroless nickel plating solution at 70˜100° C. for 1˜10 minutes. 
     
     
         8 . The method of  claim 1 , wherein, in the step 4), the pH of the electroless nickel plating solution is maintained at 4˜6. 
     
     
         9 . The method of  claim 1 , wherein the step 4) is conducted under the conditions of a Pd concentration of 0.4˜1 g/L, a nickel plating solution concentration of 5˜10 g/L, a deposition time of 10˜15 minutes, a reaction temperature of 70˜80° C. am a pH of 4˜5, so as to form a fibrous nickel plated layer. 
     
     
         10 . The method of  claim 1 , wherein the step 4) is conducted under the conditions of a Pd concentration of 0.4˜1 g/L, a nickel plating solution concentration of 5˜10 g/L, a deposition time of 5˜10 minutes, a reaction temperature of 80˜100° C. an a pH of 5˜6, so as to form a scalelike nickel plated layer. 
     
     
         11 . The method of  claim 1 , wherein the step 4) is conducted under the conditions of a Pd concentration of 0.125˜0.2 g/L, a nickel plating solution concentration of 5˜10 g/L, a deposition time of 5˜10 minutes, a reaction temperature of 80˜100° C. an a pH of 5˜6, so as to form a spherical nickel plated layer. 
     
     
         12 . The method of  claim 1 , wherein, in the step 5), the nanocarbon having the nickel plated layer is heat-treated at a high temperature of 300˜700° C. for 3 hours under an inert gas atmosphere, a vacuum atmosphere or an air atmosphere.