WO2022093377A2 - Graphitic carbon with boron incorporated into the graphite lattice and method for preparing the same - Google Patents

Abstract

Disclosed is a boron doped mesoscopic graphite and a method for preparing a boron doped mesoscopic graphite. The boron doped mesoscopic graphite is characterized as an open and closed tubular filament having wall thicknesses between about 50 nm and about 100 nm. The disclosed method is an atmospheric pressure chemical vapor deposition method where the reactants undergo pyrolysis within a reaction chamber leading to growth of the boron doped mesoscopic graphite on a substrate.

Description

Graphitic Carbon with Boron Incorporated into the Graphite Lattice and Method for Preparing the Same

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to U.S. Provisional Application No. 63/107,273 filed on October 29, 2020, incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED

RESEARCH OR DEVELOPMENT

[0002] This invention was made with government support under N00014-20-1-2433 awarded by Office of Naval Research. The government has certain rights in the invention.

BACKGROUND

[0003] The properties of carbon-based materials are highly dependent on their morphology and carbon bonding, i.e., sp2, sp3, or a mixture thereof. For example, graphite with sp2 bonding is conductive, while diamond with sp3 bonding is a wide bandgap insulator. Similarly, the chirality of a carbon nanotube and/or its geometrical structure determines whether it will be a semiconductor or a conductor. In the field of conductive carbons, graphite is one option for Li- ion batteries; however, fast charging of the battery can lead to swelling and flaking or breaking of the graphite particles into smaller particles diminishing its storage capacity, cycle life or leading to catastrophic failure. Therefore, a more stable conductive carbon structure would be beneficial to several industrial applications.

SUMMARY

[0004] In one aspect, the present disclosure provides a method of preparing a boron doped carbon mesoscopic structure. The method comprises: providing a reaction chamber containing a substrate, said substrate having a melting point greater than 1100°C and said reaction chamber and substrate are free of any metal catalyst; heating said reaction chamber to a temperature between about 700°C and about 1100°C; providing a housing containing a carbon source and a boron source, said housing having a fluid inlet and a fluid outlet; heating the solution to a temperature between about 80°C and about 130°C; passing a non-reactive gas into said housing through said fluid inlet and passing the non- reactive gas through the solution at a rate sufficient to carry said solution out of said housing through the fluid outlet as a vapor; passing said non-reactive gas carrying said vapor to said reaction chamber; passing said non-reactive gas carrying said vapor over said substrate; and, growing graphite layers on said substrate by decomposing said carbon source on said substrate to yield boron doped carbon mesoscopic structures on said substrate.

The resulting boron doped carbon mesoscopic structures are free of sulfur.

[0005] In another aspect, the present disclosure describes a boron doped carbon mesoscopic structure characterized as open and closed tubular filaments having wall thicknesses between about 20 nm and about 100 nm. The boron doped carbon mesoscopic structure further characterized as comprising an atomic concentration of boron between about 0.1% and about 15%. Additionally, the boron doped carbon mesoscopic has a length between about 9 pm and about 20 pm.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIGS. 1 A - ID depict images of the graphitic carbon with boron incorporated into the graphite lattice at different magnifications. FIG. 1 A is at a magnification of 2000X. FIG. IB is at a magnification of 10000X. FIG. 1C is at a magnification of 27000X. FIG. ID is at a magnification of 58000X.

[0007] FIGS. 2A - 2D provide transmission electron microscopy images of a bundle of graphitic carbon with boron incorporated into the graphite lattice. FIG. 2A is at a magnification of 60000X. FIG. 2B is at a magnification of 200000X. FIG. 2C is at a magnification of 400000X. FIG. 2D is at a magnification of 500000X.

[0008] FIG. 3A is a scanning electron microscope image of graphitic carbon with boron incorporated into the graphite lattice at the early stage of formation and FIG. 3B is a scanning electron microscope image of a fully formed filament of graphitic carbon with boron incorporated into the graphite lattice.

[0009] FIG. 4A depicts the surface morphology of a pseudo-graphite.

[0010] FIG. 4B depicts the surface morphology of graphitic carbon with boron incorporated into the graphite lattice.

[0011] FIG. 5 provides a theoretical model of the incorporation of boron into the graphite lattice of the graphitic carbon.

[0012] FIG. 6A is a schematic representation of the pseudo-graphite of FIG. 4A. [0013] FIG. 6B is a schematic representation of the tubular form of the graphitic carbon with boron incorporated into the graphite lattice.

[0014] FIG. 7 is a schematic representation of the equipment and method suitable for preparing the graphitic carbon with boron incorporated into the graphite lattice.

DETAILED DESCRIPTION

[0015] The drawings included with this application illustrate certain aspects of the embodiments described herein. However, the drawings should not be viewed as exclusive embodiments. Throughout this disclosure, the terms “about”, “approximate”, and variations thereof, are used to indicate that a value includes the inherent variation or error for the device, system, the method being employed to determine the value, or the variation that exists among the study subjects. Finally, the following description is not to be considered as limiting the scope of the embodiments described herein.

[0016] For the purposes of the following discussion, the boron doped carbon mesoscopic structures will be referred to as BOD-Carbon. As used herein, the term “doped” refers to the inclusion of boron in the lattice structure of the resulting carbon form. See FIG. 5. As used herein, the term carbon mesoscopic structure refers to carbon structures that have physical dimensions that are between microscopic and macroscopic. Typically, the disclosed BOD- Carbon has diameters between about 1 pm and about 2 pm with wall thicknesses between about 20 nm and about 100 nm. The final dimensions can be varied depending on how the following method is fine tuned. Additionally, the filament typically tapers from a narrow open end to a broader closed base. The disclosed BOD-Carbon is depicted in FIGS. 1-4 and 6. FIGS. 1A - ID depict the BOD-Carbon under scanning electron microscopy. In FIG. 1A, the tubular filaments can be seen as a medium density array under magnification of 2000X. FIG. IB, taken at a magnification of 10000X, reveals open ended tubular filaments having lengths of about 9 pm to about 20 pm with some filaments having closed ends. If an open second end is desired, then the overall length will typically be 10 pm or less. However, the lengths can be significantly longer depending on fine tuning of the following method. FIG. 1C, taken at a magnification of 27000X, depicts many filaments in a top down view revealing the hollow nature of the BOD- Carbon. Finally, FIG. ID, taken at a magnification of 58000X, reveals that the BOD-Carbon filaments have outer diameters between about ten nanometers and about 5 pm and have wall thicknesses of about 50 nm to about 100 nm. Thus, the BOD-Carbon filaments are significantly larger than single wall and multi-wall carbon nanotubes.

[0017] Analysis of the BOD-Carbon filaments using X-ray photoelectron spectroscopic methods determined that the atomic concentration of boron in the graphite lattice of the BOD- Carbon is between about 0.1% and about 15%. In most instances, the atomic concentration of boron was found to be about 3.0±0.6%.

[0018] The transmission electron micrographs of FIGS. 2A-B confirm that the BOD-Carbon filaments are hollow but lack the concentric cylinders type morphology common to multi-wall carbon nanotubes. As such, the BOD-Carbon filaments represent a new mesoscopic morphology of carbon. Additionally, FIGS. 2A and 2B depict three types of terminations for the BOD- Carbon filaments: flared outward, straight and closed. Additionally, the inner diameter of the filament typically increases while the outer diameter typically remains constant. FIG. 2A was taken at a magnification of 60000X while FIG. 2B was taken at a magnification of 200000X. With reference to FIGS. 2C and 2D, these images indicate that the walls of individual BOD- Carbon filaments are composed of disordered layers of nanographite. Without being limited by theory, the graphitic layering of the filaments may explain why the filaments are hollow as opposed to solid carbon microfibers. The unique configuration of the BOD-Carbon filaments is likely due to the boron inclusion within and at the edges of the carbon graphitic lattice.

[0019] Further characterization of the BOD-Carbon filaments can be made by determining the energy state of the resulting boron substituted graphitic lattice. Without being limited by theory, the resulting BOD-Carbon is believed to be a consequence of boron induced strain of the hexagonal sp2 bonded carbon lattice and disorder associated with increased sp3 bonded carbon. The modeling of the inclusion of boron in the lattice structure and the resulting lattice distortions supports this conclusion. The lowest energy state of the graphitic structure with substituted boron was determined using an open source three-dimensional molecular structure editing software known as Avogadro to determine the corresponding geometry. The resulting modeled structure of the BOD-Carbon is depicted in FIG. 6.

[0020] Further, FIG. 5 depicts the reduced energy state for the three calculated geometries of graphitic lattice with boron substitution. As reflected in FIG. 5, boron substitution reduced the energy state of structure A from 4828.1 kJ/mole to 1204.4 kJ/mole in the substituted structure D. Likewise, boron substitution of structure B reduced the energy state from 1610.1 kJ/mole to 289.7 kJ/mole for substituted structure E. Finally, boron substitution of structure C reduced the energy state from 2174.3 kJ/mole to 761.8 kJ/mole for substituted structure F. In the case of the two flat graphene structures A, B, the distortion of the lattice and a corresponding curvature of the graphene sheet resulting from the boron substitution produces the lowering of the energy of the corresponding structures D and E. In the case of the already curved graphene sheet C, Boron inclusion alone does not invert the curvature of the resulting substituted graphene sheet F. However, the interaction between planes will invert the curvature of the substituted graphene sheet F due to the crosslinking between layers facilitated by the increase of sp3 carbon bonds.

[0021] Thus, as represented in FIG. 5, the presence of boron in the lattice structure of BOD- Carbon produces an upward curving morphology relative to the substrate. The upward curve results from the additional strain, out of plane or between planes, generated by the sp3 carbon sites. The Raman spectrum of BOD-Carbon supports the conclusion of Boron induced strain. Specifically, the G band of BOD-Carbon is at 1593 cm'¹. As known to those skilled in the art, tensile strain produces a shift of the G band of graphite and graphene related materials.

[0022] To demonstrate the impact of boron doping on the carbon structure, FIGS. 4A and 6A compare a non-doped pseudo-graphite to the newly developed BOD-Carbon. As used herein, the term pseudo-graphite refers to a carbon structure that has the hexagonal atomic lattice structure of graphite. However, the pseudo-graphite structure is highly disordered which differs from the long range order commonly associated with graphite. The non-doped pseudo-graphite used for comparison to the BOD-Carbon can be exfoliated in the same manner as graphite. However, BOD-Carbon cannot be exfoliated and further differs structurally from the non-doped pseudographite as discussed herein.

[0023] The non-doped pseudo-graphite was prepared using a pressure chemical vapor deposition (APCVD) process. As depicted in FIG. 6A, the pseudo-graphite has overlapping downward curving structures. The pseudo-graphite is characterized as a layered structure that exfoliates; however, unlike graphite, the thickness of the exfoliated layers is on the order of microns. Further, as depicted in FIG. 6A, the pseudo-graphite in an agglomeration of carbon hemispheres having diameters ranging from 50 nm to 100 nm. Using substrate 14 supporting the growth of the pseudo-graphite as the reference point, the carbon hemispheres have a downward curve toward the substrate, as depicted in FIG. 6A. When grown and subsequently delaminated from a substrate, the backside of the pseudo-graphite has a relatively smooth structure with a few circular pits when examined using an atomic force microscope (AFM). See FIG. 4A. The RMS roughness of the backside of the pseudo-graphite is 0.3 nm in the pit free regions and the average diameter of the pits is 58 ± 12 nm. In FIG. 4A, the isolated top corner of the FIG. depicts the line analysis for that region. As used herein, line analysis refers to the practice of removing noise and artifacts from an image.

[0024] In contrast to the non-boron doped pseudo-graphite, preparation of BOD-Carbon, using the method described below, produces an upwardly curved structure away from the substrate 14, which continues into a filament. See FIG. 6B. With reference to FIG. 4B, AFM mapping of the backside of the delaminated films of BOD-Carbon (Fig. 4B) reveals an extremely rough surface consisting of clusters of hemispherical bumps, with an RMS roughness of 8.5 nm or 28 times rougher than the backside of the pseudo-graphite. The average diameter of the bumps is 105 ± 15 nm. The resulting filament structure is believed to be a result of the influence of the boron doping on the structure of the BOD-Carbon. In FIG. 4B, the isolated top comer of the FIG. depicts the line analysis for that region.

[0025] Without being limited by theory, we believe that tensile strain within the graphene sheets forming the nanographite of BOD-carbon produces a curvature growth direction normal to the substrate. Support for this conclusion is found by the reduction of the Raman G band of BOD-carbon relative to the observed Raman G band of pseudo-graphite. As a consequence of the growth normal to the substrate, the carbon hemispheres of BOD-carbon continue to grow. However, because of the tensile strain, the carbon hemispheres attempt to close. We believe that the radius of the inner core of the hemisphere can accomplish this feat due to the combination of the tensile stress and the Van der Waals attraction between graphene sheets. However, at larger radii, the tensile stress and the Van der Waals attraction is insufficient for closure leading to the decoupling of the outer layers of the carbon hemisphere from the inner core. As a result, the outer layers continue to grow vertically to form the tubular filament. Further support for this conclusion is found in FIGS. 3A and 3B which depict the closed core and ellipsoidal follicle (3 A) that tapers prior to formation of the hollow filament of FIG. 3B.

[0026] The BOD-carbon structures disclosed above can be prepared according to the following atmospheric pressure chemical vapor deposition method. The following method will also be described with reference to FIG. 7. As depicted schematically in FIG. 7, the method may be carried out in a heated reaction chamber or furnace 10. The interior of reaction chamber 10 contains a clean substrate 14 suitable for supporting growth of the BOD-carbon. Reaction chamber 10 also has a fluid inlet 16 and a fluid outlet 18. A housing 20 contains the solution or suspension of reaction materials. Housing 20 has a fluid inlet 22, fluid outlet 24, a heating mechanism (not shown) and an agitation mechanism (not shown). Reaction materials may be added to housing 20 through fluid inlet 22, fluid outlet 24 or through another opening not shown. Typically, fluid inlet 22 extends downward into housing 20 such that the fluid level of reactants in housing 20 is above the exit point of fluid inlet 22. Additionally, housing 20 will preferably provide for the continuous agitation or stirring of the reaction materials. A carrier gas source, not shown, is in fluid communication with fluid inlet 22 of housing 20 and fluid outlet 24 is in fluid communication with fluid inlet 16 of reaction chamber 10. Substrate 14 is selected to withstand the reaction temperature. Typically, substrate 14 may be any suitable material having a melting point in excess of 900°C. More typically, the material will have a melting point greater than 1100°C. Common substrates include but are not limited to: silicon, alumina, quartz, sapphire, carbon. Reaction chamber 10 can have any shape. For example, a tube furnace having a fluid inlet and fluid outlet may be used as reaction chamber 10.

[0027] With continued reference to FIG. 7, the atmospheric pressure chemical vapor deposition method for forming BOD-carbon will be described. The method begins by placing the reactants in housing 20. The reactants include a carbon source, a boron source and optionally a sulfur source. The carbon source may be a liquid or gaseous hydrocarbon such as, but not limited to: aliphatic alcohols, alicyclic alcohols, aromatic alcohols, heterocyclic alcohols, ethylene and acetylene. Typically, the carbon source is an organic compound, such as cyclohexanol. Suitable boron sources included but are not limited to: ortho-carborane (also known as ortho-closo-dicarbadodecaborane), meta-closo-dicarbadodecaborane, para-closo- dicarbadodecaborane, boric acid, metaboric acid, decaborane, tri ethylborane, borazane and borazine. Typically, the source of sulfur will be elemental sulfur; however, other sources such as but not limited to thiols, mercaptans, hydrogen sulfide (H2S), dimethyl sulfoxide (DMSO) will also perform satisfactorily. The agitation mechanism of housing 20 provides sufficient movement of the carbon source to convert the mixture of reactants into a homogeneous dispersion or suspension or when components are soluble into a solution. Thus, when using a liquid carbon source, the reactants are present in housing 20 as a suspension, dispersion or solution. For the purposes of the remaining discussion, we will use the term solution; however, one skilled in the art will recognize that nature of the mixture will be based on the components used. When using a gaseous hydrocarbon, the boron source will typically be diborane (B2H6) in which case the sulfur source can be H2S.

[0028] In general, the final solution of reactants in housing 20 will contain a sufficient concentration of the boron source to supply the equivalent of approximately 2% to about 50% by weight of elemental boron in the solution. If sulfur is included in the final solution of reactants, the source of sulfur shall provide the equivalent of about 1% to about 30% sulfur by weight in the solution. The remaining portion of the suspension is the carbon source.

[0029] The atmospheric pressure chemical vapor deposition begins by preheating the reactants in housing 20 to a temperature between about 80°C and about 130°C and heating reaction chamber 10 to a temperature between 700°C and about 1100°C. The minimum temperature within reaction chamber 10 is that temperature sufficient to decompose the carbon and boron sources. Following the initial heating of the reactants and achieving the desired temperature in reaction chamber 10, a second optional heating step of housing 20 takes place. In this second heating step, the suspension of reactants is heated to a temperature sufficient to aid in the entrainment of the reactant solution as a vapor in a non-reactive gas passing through the solution of reactants. Typically, the reactant solution will be heated to a temperature between about 80°C and about 200°C, more typically 80°C to about 120°C. In most instances, the final temperature of the reactant solution is about 120°C.

[0030] Upon achievement of the desired reactant solution temperature and ensuring that reaction chamber is at a temperature between 700°C and about 1100°C, a non-reactive gas is passed through housing 20 via inlet 22. Thus, due to the configuration of inlet 22, the non- reactive gas passes directly into and through the solution of reactants acting as a bubbler or vaporizer, thereby vaporizing the reactants. The vaporized reactants carried by the non-reactive gas subsequently pass out of housing 20 through outlet 24. The flow rate of the non-reactive gas through housing 20 will vary depending on the size of housing 20 and the size of reaction chamber 10. In the laboratory scale equipment used to demonstrate the disclosed method, the non-reactive gas passed into housing 20 at a flow rate between about 130 seem and 160 seem (standard cubic centimeter per minute). Thus, the flow rate necessary to entrain and carry the reactants from housing 20 to reaction chamber 10 will be readily determinable by those skilled in the art using conventional fluid dynamics calculations. Suitable gases are gases which are non- reactive with the reactants in housing 20. Non-limiting examples would include common carrier gases such as nitrogen, argon and helium.

[0031] In the lab scale demonstration, the carrier gas, flowed at a rate of about 130 seem and 160 seem, to carry the vaporized reactants from housing 20 into reaction chamber 10. The flow rate remained within this range as the reactants passed over substrate 14. Within reaction chamber 10, the boron source and carbon source decomposed through pyrolysis on the surface of substrate 14 initiating the growth of the BOD-carbon.

[0032] Thus, in the disclosed method, the decomposition of both the carbon source and the boron source on the surface of the substrate will produce a carbon lattice structure with boron incorporated into the lattice of the mesoscopic structure of BOD-Carbon. As a result, the interfacial energy at the carbon-silicon interface, i.e. the interface with substrate 14, is modified leading to the upward curved structures relative to the upper surface of substrate 14. In general, the growth of the BOD-Carbon continues for a period between about 5 minutes and about 120 minutes. More typically, the time allowed for growth will be between about 15 minutes and about 30 minutes. Upon completion of the growth cycle of the BOD-Carbon, the flow of the non-reactive gas through housing 20 and reaction chamber 10 ceases.

[0033] Without intending to be limited by theory, we believe that as the resulting BOD- Carbon structure grows, the deformation of the carbon layers due to boron substitution, i.e. boron doping, causes tensile strain and the carbon hemispheres attempt to close. The radius of the inner core of the hemisphere can accomplish this feat. The closure of the inner core is likely due to the combination of the tensile stress and the Van der Waals attraction between graphene sheets. However, at larger radii, the tensile stress and the Van der Waals attraction is insufficient. As a result, the outer layers of the carbon hemisphere decouple from the inner core and continue to grow vertically to form the tubular filament. When sulfur is included in the reactant suspension, the sulfur acts as a promoter of carbon nucleation to enhance formation of the resulting structure. However, sulfur does not become part of the resulting BOD-Carbon mesoscopic carbon structure. Rather, the BOD-Carbon is free of sulfur and does not contain any other catalyst material. The final BOD-Carbon structure has the characteristics discussed above.

[0034] Other embodiments of the present invention will be apparent to one skilled in the art. As such, the foregoing description merely enables and describes the general uses and methods of the present invention. Accordingly, the following claims define the true scope of the present invention.

Claims

We claim:

1. A method of preparing a boron doped carbon mesoscopic structure comprising: providing a reaction chamber containing a substrate, said substrate having a melting point greater than 900°C and said reaction chamber and substrate are free of any metal catalyst; heating said reaction chamber to a temperature between about 700°C and about 1100°C; providing a housing containing a carbon source and a boron source, said housing having a fluid inlet and a fluid outlet; passing a non-reactive gas into said housing through said fluid inlet and passing the non- reactive gas through the carbon source and boron source at a rate sufficient to carry said carbon source and said boron source out of said housing through the fluid outlet as a vapor; passing said non-reactive gas carrying said vapor to said reaction chamber; passing said non-reactive gas carrying said vapor over said substrate; and, growing graphite layers on said substrate by decomposing said carbon source on said substrate to yield boron doped carbon mesoscopic structures on said substrate.

2. The method of claim 1, further comprising: heating the carbon source and the boron source within said housing to a temperature sufficient to increase entrainment of the boron source and carbon source within said non-reactive gas passing through the carbon source and the boron source.

3. The method of claim 1, further comprising: the step of adding elemental sulfur or a sulfur compound to said solution containing a carbon source and a boron source.

4. The method of claim 3, wherein said sulfur compound is selected from the group consisting of: thiols, mercaptans, hydrogen sulfide (H2S), dimethyl sulfoxide (DMSO).

5. The method of claim 3, wherein said solution comprises up to about 30% elemental sulfur or when using a sulfur compound the equivalent of 30% elemental sulfur by weight and a sufficient concentration of said boron source to provide between about 2% and about 50% elemental boron by weight.

6. The method of claim 1, wherein said step of growing graphite layers on said substrate continues for a period of about 5 minutes to about 120 minutes and wherein said boron doped carbon mesoscopic structures are characterized as upward curving structures relative to the substrate surface.

7. The method of claim 1, wherein said step of growing graphite layers on said substrate continues for a period of about 15 minutes to about 30 minutes and wherein said boron doped carbon mesoscopic structures grow vertically as a tubular filament.

8. The method of claim 7, wherein said tubular filaments are characterized as having wall thicknesses of about 20 nm to about 100 nm.

9. The method of claim 7, wherein said tubular filaments are characterized as having lengths of about 9 pm to about 20 pm.

10. The method of claim 1, wherein said boron source is selected from the group consisting of ortho-carborane, ortho-closo-dicarbadodecaborane, meta-closo-dicarbadodecaborane, para- closo-dicarbadodecaborane, boric acid, metaboric acid, decaborane, tri ethylborane, borazane or borazine.

11. The method of claim 1, wherein said carbon source is selected from the group consisting of aliphatic alcohols, alicyclic alcohols, aromatic alcohols, heterocyclic alcohols, ethylene and acetylene.

12. The method of claim 1, wherein said non-reactive gas passes through said solution and through said reaction chamber at a rate between about 130 seem and 160 seem.

13. The method of claim 1, wherein said step of heating said solution, heats said solution to a temperature between about 80°C and about 100°C for 15 minutes followed by further heating said solution to a temperature between about 115°C and about 125°C.

14. The method of claim 1, wherein the resulting boron doped carbon mesoscopic structures are substantially free of sulfur.

15. A method of preparing a boron doped carbon mesoscopic structure comprising: providing a reaction chamber containing a substrate; providing a housing containing a carbon source and a boron source, said housing having a fluid inlet and a fluid outlet; heating said reaction chamber to a temperature sufficient to decompose the carbon source and the boron source; passing a non-reactive gas into said housing through said fluid inlet and passing the non- reactive gas through the solution at a rate sufficient to carry said solution out of said housing through the fluid outlet as a vapor; passing said non-reactive gas carrying said vapor to said reaction chamber; passing said non-reactive gas carrying said vapor over said substrate; and, growing graphite layers on said substrate by decomposing said carbon source on said substrate to yield boron doped carbon mesoscopic structures on said substrate.

16. The method of claim 15, further comprising: heating the carbon source and the boron source within said housing to a temperature sufficient to increase entrainment of the boron source and carbon source within said non-reactive gas passing through the carbon source and the boron source.

17. The method of claim 15, further comprising: the step of adding elemental sulfur or a sulfur compound to said solution containing a carbon source and a boron source.

18. The method of claim 17, wherein said sulfur compound is selected from the group consisting of: thiols, mercaptans, hydrogen sulfide (H2S), dimethyl sulfoxide (DMSO).

19. The method of claim 17, wherein said solution comprises up to about 30% elemental sulfur or when using a sulfur compound the equivalent of 30% elemental sulfur by weight and a sufficient concentration of said boron source to provide between about 2% and about 50% elemental boron by weight.

20. The method of claim 15, wherein said step of growing graphite layers on said substrate continues for a period of about 5 minutes to about 120 minutes and wherein said boron doped carbon mesoscopic structures are characterized as upward curving structures relative to the substrate surface.

21. The method of claim 15, wherein said step of growing graphite layers on said substrate continues for a period of about 15 minutes to about 30 minutes and wherein said boron doped carbon mesoscopic structures grow vertically as a tubular filament.

22. The method of claim 21, wherein said tubular filaments are characterized as having wall thicknesses of about 20 nm to about 100 nm.

23. The method of claim 22, wherein said tubular filaments are characterized as having lengths of about 9 gm to about 20 gm.

24. The method of claim 15, wherein said boron source is selected from the group consisting of: ortho-carborane, ortho-closo-dicarbadodecaborane, meta-closo-dicarbadodecaborane, para- closo-dicarbadodecaborane, boric acid, metaboric acid, decaborane, tri ethylborane, borazane or borazine.

25. The method of claim 15, wherein said carbon source is selected from the group consisting of: aliphatic alcohols, alicyclic alcohols, aromatic alcohols, heterocyclic alcohols, ethylene and acetylene.

26. The method of claim 15, wherein said non-reactive gas passes through said solution and through said reaction chamber at a rate between about 130 seem and 160 seem.

27. The method of claim 15, wherein said step of heating said solution, heats said solution to a temperature between about 80°C and about 100°C for 15 minutes followed by further heating said solution to a temperature between about 115°C and about 135°C.

28. The method of claim 15, wherein the resulting boron doped carbon mesoscopic structures are substantially free of sulfur.

29. A boron doped carbon mesoscopic structure characterized as tubular filaments having one open end and one closed end, said tubular filaments having wall thicknesses between about 20 nm and about 100 nm.

30. The boron doped carbon mesoscopic structure of claim 29, further characterized as comprising an atomic concentration of boron between about 0.1% and about 15%.

31. The boron doped carbon mesoscopic structure of claim 29, further characterized as having a length between about 9 pm and about 20 pm.

32. The boron doped carbon mesoscopic structure of claim 29, further characterized as being free of sulfur.

33. A boron doped carbon mesoscopic structure characterized as hollow tubular filaments having disordered layers of nanographite where said disordered layers of nanographite are not in the form of concentric cylinder layers.

34. The boron doped carbon mesoscopic structure of claim 33, further characterized as comprising an atomic concentration of boron between about 0.1% and about 15%.

35. The boron doped carbon mesoscopic structure of claim 33, further characterized as having a length between about 9 pm and about 20 pm.

36. The boron doped carbon mesoscopic structure of claim 33, further characterized as being free of sulfur.

37. The boron doped carbon mesoscopic structure of claim 33, further characterized as having a length of less than about 10 pm and having a first closed end and a second open end.

38. The boron doped carbon mesoscopic structure of claim 35, wherein said filament tapers from said first open end to said second closed end, wherein said second closed end has a diameter greater than said first open end.