Hetero-nanocapsule and method of preparing the same
Hetero-nanocapsule, which is a carbon nanocapule containing heteroatoms, comprises a closed graphite layer represented by a chemical formula C(D) x , wherein C is carbon atom exhibiting sp 2 hybrid orbital, D is hetero-atom, such as B, N, P, or S atom, bonded to the carbon atom; and X is a molar equivalent ranging from 0.0001 to 0.1, based on the molar equivalent of carbon atom as 1. The hetero-nanocapsules may be hollow or filled with metal or metal compound.
1. A hetero-nanocapsule, which is a carbon cluster constituting a closed multiple graphite layer structure and containing heteroatoms, comprising a closed polyhedral graphite layer constituted by carbon atoms exhibiting sp 2 hybrid orbital and D atoms, wherein D is an atom of Group III or V of the periodic table bonded to the carbon, and the mole ratio between D atoms and carbon atoms is from 0.0001 to 0.1, wherein the closed polyhedral graphite layer is a hollow shell and is made up of pentagonal rings and hexagonal rings, wherein at least one flat outside side of the closed polyhedral graphite layer has a length of larger than 1 nm.
2. The hetero-nanocapsule as claimed in claim 1 , wherein the external diameter thereof is 1 nm to 100 nm.
3. The hetero-nanocapsule as claimed in claim 1 , further comprising a filler M in the hollow closed graphite shell.
4. The hetero-nanocapsule as claimed in claim 3 , wherein M is metal, metal oxide, metal carbide, metal sulfide, metal nitride, metal borate, or alloy.
5. The hetero-nanocapsules as claimed in claim 4 , wherein the metal atom of the metal, metal oxide, metal carbide, metal sulfide, metal nitride, metal borate, or alloy is Sc, V, Cr, Fe, Co, Ni, Cu, Y, Zr, Mo, Ru, Rh, Pd, La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Lu, Ta, Os, Ir, Pt, Au, Th, U or a combination thereof.
6. A method for preparing hetero-nanocapsules, comprising mixing compounds containing atoms of Group III or V of the periodic table and graphite, at a ratio from 1:50 to 1:10; molding the mixture into an electrode by hot-pressing to form a composite graphite anode; providing an arc chamber comprising the composite graphite anode and a graphite cathode; introducing inert gas into the arc chamber; applying voltage across the cathode and the anode by pulse current to generate a carbon arc reaction therebetween, and collecting deposit formed on the cathode.
7. The method as claimed in claim 6 , wherein the compounds containing atoms of Group III or V of the periodic table comprise melamine, ammonium chloride, B 4 C, B 2 O 3 , or P 2 O 5 .
8. A method for preparing hetero-nanocapsules, comprising mixing compounds containing atoms of Group III or V of the periodic table, metal or metalline powders, and graphite, wherein the ratio of atoms of Group III or V to the carbon atoms is from 1:50 to 1:10, and the ratio of metal atoms to carbon atoms is from 1:100 to 1:20; molding the mixture into an electrode by hot-pressing to form a composite graphite anode; providing an arc chamber comprising the composite graphite anode and a graphite cathode; introducing an inert gas into the arc chamber; applying a voltage across the cathode and the anode by pulse current to generate a carbon arc reaction therebetween, and collecting deposit formed on the cathode.
9. The method as claimed in claim 8 , wherein the compounds containing atoms of Group III or V of the periodic table comprise melamine, ammonium chloride, B 4 C, B 2 O 3 , or P 2 O 5 .
10. The method as claimed in claim 9 , wherein the metal atom of the metal or metalline powders are Sc, V, Cr, Fe, Co, Ni, Cu, Y, Zr, Mo, Ru, Rh, Pd, La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Lu, Ta, Os, Ir, Pt, Au, Th, U or a combination thereof.