WO2022185167A1

WO2022185167A1 - Process for producing a nanocrystalline carbon with 1d, 2d, or 3d structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite and/or a mixture thereof

Info

Publication number: WO2022185167A1
Application number: PCT/IB2022/051665
Authority: WO
Inventors: Rungkiat NGANGLUMPOON
Original assignee: Crystallyte Co., Ltd.
Priority date: 2021-03-04
Filing date: 2022-02-25
Publication date: 2022-09-09
Also published as: WO2022185167A4; WO2022185098A1; WO2022185166A4; WO2022185166A1

Abstract

A new process for producing a nanocrystalline carbon with a 1D, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof, by electrochemically reducing a carbon source which is an oxygenic organic compound or a mixture containing said oxygenic organic compound under ambient conditions at an onset potential not greater than 10 Volt in presence of an electrolyte and at least one electrode, said electrode comprising a metallic material comprising one or more of the following: a post-transition element, a transition element, an oxide, and an alloy thereof. The ambient conditions and the onset potential enabled by embodiments simplify the production, and the nanocrystalline carbon yield can be scaled up to reach a mass production scale. A product obtained from the new process comprises a nanocrystalline carbon with a 1D, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal. Such product can be a mixture that contains various carbon structures, comprising: a nanocrystalline diamond, an amorphous carbon, a graphitic carbon, and a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal. Said product may further comprise a graphite or a graphene. Products according to the embodiments contain substantially more types of structure, and so are more versatile than those currently commercially available.

Description

PROCESS FOR PRODUCING A NANOCRYSTALLINE CARBON WITH ID, 2D, OR 3D

STRUCTURE AND/OR A NANOCRYSTALLINE DIAMOND AND/OR AN AMORPHOUS CARBON AND/OR A METAL-CARBON NANOMATERIAL COMPOSITE

AND/OR A MIXTURE THEREOF

The present disclosure claims priority to the earlier International Application No. PCT/IB2021/051792, filed March 4, 2021, the entire disclosure of which is incorporated into the present disclosure by way of reference.

FIELD OF INVENTION

The present disclosure relates to the production of a carbon nanomaterial, including a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or transition metal, and/or a mixture thereof, particularly when said production of carbon nanomaterials involves electrochemical reduction.

BACKGROUND OF THE INVENTION

Owing to their outstanding properties (e.g. thermal conductivity, electrical conductivity, and mechanical strength), a carbon nanomaterial, including a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or transition metal, and/or a mixture thereof, finds their applications in many fields, such as energy storage, energy management, and medical industries. Therefore, the market size of the carbon nanomaterial has been growing exponentially since the past decade.

The carbon nanomaterial’s scarcity in nature gives rise to the need for their artificial production under different processes which require different carbon sources. Such processes include electrochemical exfoliation, laser ablation, pyrolysis, and chemical vapor deposition (CVD). In any case, these processes are conventionally known as consuming the most energy in formation of carbon allotropes. This is a major problem of the processes in the relevant arts.

For example, US patent publication No. US 9,695,516 B2 discloses a process for preparation of graphene oxide or graphene by electrochemical exfoliation using a plasma electrolytic apparatus having an electrolyte which is in contact with a graphite cathode. A current is provided to the graphite cathode so as to initiate a plasma electrolytic process at a surface of said cathode in order to obtain a graphite oxide and a graphene. This process requires a 40-80 V output for the plasma electrolytic apparatus, and thus high electrical energy.

US patent publication No. US 2016/0115601 A1 discloses a process of producing graphene and/or graphite nanoplate structures by electrochemically reducing carbon oxide in an electrochemical cell comprising a negative electrode, a positive electrode, and an electrolyte. The main object of this process, particularly its selection of carbon source, is to reduce energy consumption. The reduction occurs at 110 °C or below. Nonetheless, the potential difference across the electrodes can be up to 30 V for dissociating the strong C=0 bond, and thus the energy consumption is still considered high.

In addition, US patent publication No. US 2005/0079118 A1 discloses a process of producing single wall carbon nanotube using an oxygenic organic compound brought into contact with a metal catalyst at 500 to 1,500 °C, which consumes high energy.

The most recent attempts to address the energy consumption for producing carbon nanomaterials that are known to the present inventors include the following.

Dai et. al. [Dai 2021] reported the synthesis of almost all types of known carbon nanostructures at ambient conditions by the reaction between KOH and ethanol. A major drawback of this process is the reaction time, which is several days until completion.

Wu et.al. [Wu 2021] reported the electrochemical process to turn chloroacetic acid into carbon nanomaterial using fluorine-doped tin oxide (FTO) glass as a cathode under ambient conditions. Though this process takes an hour or less to complete, it can produce a diamond-like amorphous carbon film only.

Shawky et.al. [Shawky 2012] showed the electrochemical route to produce single wall carbon nanotubes using millisecond electrodeposited Ni on Au substrate as a cathode under ambient conditions. Shawky’ s process requires about half an hour of reaction time; however, constrained by a very limited amount of catalyst, the product yield is low.

Finally, European patent publication No. EP 1,867,758 Al provides a method of electrochemically converting an oxygenic organic compound under ambient conditions in order to produce a nanoplate diamond. This process still involves high electric potentials of 50 V and 10 V for the pre-treatment step and the reaction step. The reaction time is about 3 hours which is still unsatisfactory. Accordingly, it is necessary to provide new method for producing carbon nanomaterials which not only addresses the energy consumption problem, but also mitigates the limitations and trade-offs arising in the prior arts.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a new process for industrially producing a carbon nanomaterial. The inventor has found that embodiments according to the concept of the present invention enable the production of such products at a significantly less energy-intensive condition, as well as satisfactory yield and reaction time.

In the first, second and third aspects, the present invention provides a new process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof. The embodiments’ characterizing features, involving electrochemical reduction of an oxygenic organic compound or a mixture containing said oxygenic organic compound in presence of an electrolyte, allow said process to be carried out under ambient conditions and at an onset potential not greater than 10 Volt. Said conditions, which simplify the production, are effects that distinguishes a process in accordance with the present invention from the currently available ones. The metal-carbon nanomaterial composite product yield per a single run of an embodiment, which depends on the type of metal electrode and reaction time of a batch, is approximately 10 - 100 mg-cm²-h ¹. Such yield is conducive to the scale-up to a mass production scale.

An embodiment in accordance with the first aspect is a process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof. Said process is carried out by electrochemically reducing a carbon source which is an oxygenic organic compound or a mixture containing said oxygenic organic compound. The electrochemical reduction takes place under ambient conditions at an onset potential not greater than 10 Volt in presence of an electrolyte and at least one electrode. Said electrode comprises a metallic material comprising one or more of the following: a post-transition element, a transition element, an oxide, and an alloy thereof.

An embodiment in accordance with the second aspect is a process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof. Said process comprises steps of: (a) depositing a metallic material in the particulate form on a substrate to form a cathode; and (b) electrochemically reducing an oxygenic organic compound or a mixture containing said oxygenic organic compound in presence of: an electrolyte that is separated into an anolyte and a catholyte, an anode submerged in said anolyte, and said cathode submerged in said catholyte. Said catholyte comprises a mixture of 1 -butyl-3 -methylimidazolium tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NFL iSC ) or sodium sulfate (NaiSC ), water, and the oxygenic organic compound or the mixture containing the oxygenic organic compound. Said electrochemically reducing the oxygenic organic compound or the mixture containing said oxygenic organic compound occurs in an ambient condition at an onset potential not greater than 10 Volt.

An embodiment in accordance with the third aspect is a process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof. Said process comprises steps of: (a) depositing a metallic material in the particulate form on a substrate to form a cathode; and (b) electrochemically reducing an oxygenic organic compound or a mixture containing said oxygenic organic compound in presence of: an electrolyte, an anode and said cathode which are submerged in said electrolyte. Said electrolyte comprises a mixture of 1-butyl- 3 -methylimidazolium tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NFL iSC ) or sodium sulfate (NaiSC ), water, and the oxygenic organic compound or the mixture containing the oxygenic organic compound. Said electrochemically reducing the oxygenic organic compound or the mixture containing said oxygenic organic compound occurs in an ambient condition at an onset potential not greater than 10 Volt.

In an embodiment, the oxygenic organic compound or the mixture containing said oxygenic organic compound is dissolved in the electrolyte. In such case, it is preferable that the oxygenic organic compound or the mixture containing said oxygenic organic compound is dissolved at a concentration within a range of 0.01 to 10 M.

Thus, it is preferable that the oxygenic organic compound or the mixture containing said oxygenic organic compound is water-soluble, and even more preferable if the said compound is chemically stable in the electrolyte when there is no electric current passing through the electrolyte. Preferred oxygenic organic compounds include: an alcohol, polyol, carboxylic acid, ketone, aldehyde, agricultural chemical, amino acid, and carbamate.

Preferably, the metallic material comprises one or more of the post-transition element and the transition element. Preferably, the post-transition element is bismuth (Bi) and the transition element is silver (Ag). In an embodiment where the metallic material is deposited on a substrate, said substrate is preferably a tin (Sn) or copper (Cu) foil.

Among possible combinations of metallic materials and substrates, the present inventors found that markedly greater yields are enabled by either the combination of bismuth (Bi) deposited upon a tin (Sn) foil, or silver (Ag) deposited upon a copper (Cu) foil.

Preferably, the electrodeposition method is used to deposit particulate metal upon a substrate. Even more preferably, the electrodeposition time is in a range of 2 to 2000 seconds. Preferably, an onset potential for said electrodeposition method is in a range of -0.1 to -10 Volt. Preferably, said electrodeposition method uses a metal salt in aqueous solution with the concentration in a range of 0.001 to 0.1 M as a precursor.

Preferably, the substrate deposited with the metallic material is exposed to the ambient air with the time in a range of 1 second to 24 hours for the post-treatment of the electrode.

Preferably, the electrolyte is separated into an anolyte and a catholyte. Even more preferably, the electrolyte is separated by a membrane. Preferably, the anolyte is an aqueous solution. Said aqueous solution comprises potassium bicarbonate (KHCO3) and water.

Preferably, the process further comprises a step of agitating the electrolyte, more preferably by way of feeding nitrogen gas (N2) into the electrolyte. The agitation promotes the mixture and hence performance of the process. Nitrogen gas (N2) is preferred due to its availability and inertness.

Preferably, the catholyte is a mixture containing an ionic salt, an oxygenic organic compound, or a mixture of an oxygenic organic compound and water.

Preferably, said ionic salt comprises a cation selected from alkaline metal cation, ammonium cation, imidazolium cation, and a mixture thereof. Preferably, the concentration of said ionic salt in the electrolyte is within a range of 0.01 - 10 M. Preferably, said alkaline metal cation is sodium cation (Na⁺). Preferably, said ammonium cation is ammonium cation (NPLC). Preferably, said imidazolium cation is 1 -butyl-3 -methylimidazolium ([bmim]).

Preferably, the anion of said ionic salt is selected from the group comprising tetrafluoroborate (BF₄ ), hexafluorophosphate (PF₆ ), halides (Cl , Br , F , G), hexafluoroantimonate (SbF₆ ), sulfate (SO₄ ² ), and nitrate (NO₃ ); Optionally, a homogenizing additive may be added to the electrolyte. This additive is particularly useful when the oxygenic organic compound has a viscosity that is substantially different from that of the electrolyte, as will be shown below in examples involving ethanol and glycerol. The homogenizing additive may be a strong acid, preferably HNO3, or a strong base, preferably KOH.

Optionally, the anolyte and catholyte are the same electrolyte, which is the mixture of the ionic salt, the oxygenic organic compound, or the mixture of an oxygenic organic compound and water.

In the fourth and fifth aspects, the present invention provides a new product that is obtainable from the abovementioned first, second or third aspect.

An embodiment in accordance with the fourth aspect is a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal. Said product is obtainable from any embodiment in accordance with the first, second, or third aspect.

Preferably, said product of nanocrystalline carbon with the ID, 2D, or 3D structure and/or the nanocrystalline diamond and/or the amorphous carbon and/or the metal-carbon nanomaterial composite, said composite containing the post-transition metal or the transition metal, also comprises a graphitic carbon.

An embodiment in accordance with the fifth aspect is a product that is a mixture having various carbon structures comprising: a nanocrystalline diamond, an amorphous carbon, a graphitic carbon, and a metal-carbon nanomaterial composite, said composite containing a post transition metal or a transition metal. Said product is obtainable from any embodiment in accordance with the first, second, or third aspect.

Also preferably, the various carbon structures further comprise a graphite or a graphene.

Accordingly, the present disclosure provides examples to illustrate the conditions of such processes and the characteristic properties of such products. The preferred embodiments will be described in detail later on.

BRIEF DESCRIPTION OF DRAWINGS

Fig 1 shows a schematic diagram of an electrochemical cell for electrochemically reducing an oxygenic organic compound in accordance with a preferred embodiment (not to scale). Fig 2 shows a schematic diagram of an electrochemical cell for electrochemically reducing an oxygenic organic compound in accordance with an alternative embodiment (not to scale).

Fig 3 shows a Raman spectrum exhibiting merged peaks of a product of Example 1. Fig 4 shows a Raman spectrum exhibiting merged peaks of a product of Example 2.

Fig 5 shows a Raman spectrum exhibiting merged peaks of a product of Example 3.

Fig 6 shows a Raman spectrum exhibiting merged peaks of a product of Example 4.

Fig 7 shows a Raman spectrum exhibiting merged peaks of a product of Example 5.

Fig 8 shows a Raman spectrum exhibiting merged peaks of a product of Example 6. Fig 9A shows a Raman spectrum exhibiting merged peaks of a product of Example 7.

Fig. 9B shows a first Transmission Electron Microscopy (TEM) image of the product of Example 7.

Fig. 9C shows a second Transmission Electron Microscopy (TEM) image of the product of Example 7. Fig. 9D shows Energy Dispersive X-ray (EDX) peaks of the product of Example 7.

Fig 10 shows a Raman spectrum exhibiting merged peaks of a product of Example 8. Fig 11 shows a Raman spectrum exhibiting merged peaks of a product of Example 9. Fig 12A shows a Raman spectrum exhibiting merged peaks of a product of Example 10. Fig. 12B shows a matching of d-spacing, as obtained from Selected Area Electron Diffraction (SAED), of the product of Example 10.

Fig. 12C shows a first Transmission Electron Microscopy (TEM) image of the product of Example 10.

Fig. 12D shows a second Transmission Electron Microscopy (TEM) image of the product of Example 10. Fig. 12E shows Energy Dispersive X-ray (EDX) peaks of the product of Example 10.

Fig 13 shows a Raman spectrum exhibiting merged peaks of a product of Example 11. Fig 14 shows a Raman spectrum exhibiting merged peaks of a product of Example 12. Fig 15 shows a Raman spectrum exhibiting merged peaks of a product of Example 13. Fig 16 shows a Raman spectrum exhibiting merged peaks of a product of Example 14. Fig 17 shows a Raman spectrum exhibiting merged peaks of a product of Example 15.

Fig 18A shows a Raman spectrum exhibiting merged peaks of a product of Example 16. Fig. 18B shows a matching of d-spacing, as obtained from Selected Area Electron Diffraction (SAED), of the product of Example 16. Fig. 18C shows a first Transmission Electron Microscopy (TEM) image of the product of Example 16.

Fig. 18D shows a second Transmission Electron Microscopy (TEM) image of the product of Example 16.

Fig. 18E shows Energy Dispersive X-ray (EDX) peaks of the product of Example 16.

Fig 19 shows a Raman spectrum exhibiting merged peaks of a product of Example 17.

Fig 20 shows a Raman spectrum exhibiting merged peaks of a product of Example 18.

Fig 21 shows a Raman spectrum exhibiting merged peaks of a product of Example 19.

Fig 22 shows a Raman spectrum exhibiting merged peaks of a product of Example 20.

Fig 23 shows a Raman spectrum exhibiting merged peaks of a product of Example 21.

Fig 24 shows a Raman spectrum exhibiting merged peaks of a product of Example 22.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

It is to be understood that the following detailed description will be directed to embodiments, provided as examples for illustrating the concept of the present invention only. The present invention is in fact not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of this invention will be limited only by the appended claims.

The detailed description of the invention is divided into various sections only for the reader’s convenience and disclosure found in any section may be combined with that in another section.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

The term “about” when used before a numerical designation, e.g., dimensions, time, amount, and such other, including a range, indicates approximations which may vary by ( + ) or ( - ) 10 %, 5 % or 1 %, or any sub-range or sub-value there between.

“Comprising” or “comprises” is intended to mean that the compositions and processes include the recited elements, but not excluding others. “Consisting essentially of’ when used to define compositions and methods, shall mean excluding other elements of any essential significance to the combination for the stated purpose. Thus, a process or product consisting essentially of the elements as defined herein would not exclude other materials or steps that do not materially affect the basic and novel characteristic(s) of the claimed invention. “Consisting of’ shall mean excluding more than trace elements of other ingredients and substantial steps. Embodiments defined by each of these transition terms are within the scope of this invention.

“Oxygenic organic compound” is intended to mean a mono-molecular organic compound having an oxygen atom.

“Agricultural chemical” is intended to mean an organic molecule that can be physically or chemically extracted from an agricultural product.

Electrochemical cell

Fig 1 shows a schematic diagram of an electrochemical cell in which a process for producing a carbon nanomaterial is conducted in accordance with a preferred embodiment. The electrochemical cell (10) comprises a receptacle (100) and a membrane (200) which separates the receptacle (100) into an anode region (300) and a cathode region (400). The receptacle (100) receives and contains an electrolyte which is in turn separated by the membrane (200) into an anolyte (310) and a catholyte (410), contained in the anode region (300) and the cathode region (400), respectively. This arrangement allows options whereby the anolyte (310) and the catholyte (410) may be the same or different substances. Further, this preferred electrochemical cell (10) is a 3-electrode system wherein electrodes (320, 420, 430) are immersed in, and thus in a direct contact with, the electrolyte (310, 410). In the anode region (300), the electrode is an anode (320). The anode region (300) further comprises a vent (350) to provide a passage of oxygen out from the anode region (300). Preferably, the vent (350) is located at the upper part or top of the anode region (300). In the cathode region (400), the electrodes comprise a cathode (420) and a reference electrode (430). The cathode region (400) further comprises a vent (450) to provide a passage of gas byproducts out from the cathode region (400). Preferably, the vent (450) is located at the upper part or top of the cathode region (400). The electrodes (320, 420, 430) are electrically connected to a power supply (500), which according to a preferred embodiment is a source of direct current electricity.

Fig 2 shows a schematic diagram of an electrochemical cell in which a process for producing a carbon nanomaterial is conducted in accordance with an alternative embodiment which does not feature the membrane (200). Thus, the anode and cathode regions (300, 400) which in Fig 1 were separated and defined by the membrane (200), along with the anolyte and catholyte (310, 340) which in Fig 1 were defined by the cathode and anode regions (300, 400), are not present in Fig 2. In this alternative embodiment, the receptacle (100) contains an electrolyte (110) that is a mixture of an ionic salt, an oxygenic organic compound, and water. The other components of the alternative embodiment, as well as their characteristics, connections and reference numbers, are substantially similar to those of the preferred embodiment previously shown and described with respect to Fig 1.

Oxygenic organic compound

In the present invention, the carbon source comprises an oxygenic organic compound. Preferably, a water-soluble oxygenic organic compound is used. Preferably, said oxygenic organic compound is chemically stable in the electrolyte when there is no electric current passing through the electrolyte. Examples of preferred oxygenic organic compounds are: alcohol, polyol, aldehyde, carboxylic acid, ketone, agricultural chemical, amino acid, and carbamate, and the mixture thereof. In addition, the oxygenic organic compound may be supplied to the electrolyte in any desired form, for example, in solid, liquid, gaseous, or solvated form, depending on the phase stability at the operating temperature and pressure. Preferably, the oxygenic organic compound is dissolved in the electrolyte (i.e. supplied in the solvated form).

Pressure

A process according to the concept of the present invention may be carried out in various conditions which may be adjusted according to the circumstantial requirements. The applicable pressure is within a range of about 1 to about 20 atm.

The pressure in accordance with the preferred embodiment is an ambient pressure. The ambient pressure refers to a common or usual condition surrounding any person in a room. An ambient pressure for operating the process is preferably 1 atm. Because a process in accordance with the preferred embodiment allows the electrochemical reduction to occur effectively at such ambient pressure, it obviates the need to pressurize, depressurize, vacuumize or control the pressure at any part of the electrochemical cell (10) and thus substantially simplifies the production.

Temperature

A process according to the concept of the present invention may be carried out in various conditions which may be adjusted according to the circumstantial requirements. The applicable temperature is within a range of about 10 °C to about 60 °C.

The temperature in accordance with the preferred embodiment is an ambient temperature. The ambient temperature refers to a common or usual condition surrounding any person in a room. Preferably, the ambient temperature is within a range of about 15 °C to about 50 °C. More preferably, the ambient temperature is about 30 °C. Because a process in accordance with the preferred embodiment allows the electrochemical reduction to occur effectively at such ambient temperature, it obviates the need to heat, cool or control the temperature at any part of the electrochemical cell (10) and thus substantially simplifies the production.

Onset potential

Generally, the onset potential of the electrochemical cell (10) is at least of the electric potential sufficient to initiate the electrochemical reduction of the oxygenic organic compound. Preferably, the onset potential across the electrodes (320, 420, 430) is substantially constant during the electrochemical reduction.

The onset potential of the electrochemical cell (10) depends on the electrode being selected. In an embodiment, the electrochemical cell (10) comprises a power supply (500) to provide the onset potential, which is preferably within a range of about 0.1 to about 10 V, more preferably within a range of about 0.7 to about 3 V, and even more preferably at about 1.6 V.

Preferably, the power supply (500) is adapted to monitor the onset potential. Even more preferably, the power supply (500) is adapted to regulate the onset potential to accord with a preset value. In the following Examples, the power supply (500) is a potentiostat which is capable of both monitoring and regulating the onset potential. A potentiostat’ s equivalent devices for an industrial scale production include a rectifier which is as well applicable to the concept of the present invention.

Electrolyte

According to the concept of the present invention, an electrolyte, which may be separated into an anolyte (310) and a catholyte (410), is an ion-containing fluid. Preferably, the anolyte (310) is an aqueous electrolyte and the catholyte (410) is a mixture containing an ionic salt, an oxygenic organic compound or the mixture containing the oxygenic organic compound, and water. Optionally, the anolyte (310) and the catholyte (410) are the same electrolyte, which is the mixture of an ionic salt, an oxygenic organic compound or a mixture of an oxygenic organic compound, and water.

According to the concept of the present invention, all known ionic salts may be part of the mixture that forms the electrolyte. Preferably, the ionic salts in an embodiment are compounds represented by Formula (I):

[A]„⁺ [Y]„- (I) wherein: n is 1 or 2;

[Y]_n is selected from the group comprising tetrafluoroborate ([BF₄] ), hexafluorophosphate ([PF₆] ), halides (CF, Br , F , G), hexafluoroantimonate ([SbF₆] ), sulfate ([SO4² ]), and nitrate ([NO3] );

[A]⁺ is selected from —

(a) the group comprising alkali metal cations, ammonium cations represented by Formula

(II):

R¹, R², R³, and R⁴ being selected from hydrogen atom, Cl-C6-alkyl, Cl-C6-alkoxy, Cl- C6-aminoalkyl, C5-C12-aryl, and C5-C12-aryl-Cl-C6-alkyl groups; and

(b) the group comprising imidazolium cations represented by Formula (III):

R, R¹, and R² being selected from Cl-C6-alkyl, Cl-C6-alkoxy, Cl-C6-aminoalkyl, C5- C12-aryl, and C5-C12-aryl-Cl-C6-alkyl groups.

The preferred combination of the ionic salt, the oxygenic organic compound or the mixture of the oxygenic organic compound, and water, is as follows: the ionic salt being a mixture of l-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NFL iS O4) or sodium sulfate ( NaiSC ), an oxygenic organic compound, and water. In some embodiments, the ionic salt also functions as a stabilizer of nanoparticles/carbon nanomaterial formed at the at least one electrode during the electrochemical reduction of the oxygenic organic compound in the electrochemical cell (10). Preferably, the ionic salt is selected from ([bmim][BF4]), (NH₄)₂S0₄, and Na₂S0₄. More preferably, the ionic salt is a mixture of [bmim] [BF₄], (NH₄)₂S04, and Na₂S0₄.

According to the concept of the present invention, the anolyte may also be an aqueous solution. Preferably, the anolyte that is an aqueous solution comprises a salt as a solute and water as a solvent. According to an embodiment, the preferred aqueous solution contains a cation comprising Na⁺, K⁺, or Cs⁺ and an anion comprising HCO3 , S0₄ ² , or Cl .

In some embodiments, the anolyte is an aqueous solution of potassium bicarbonate (KHCO3).

Membrane

In some embodiments, a membrane (200) is present to separate the receptacle (100) into an anode region (300) and a cathode region (400), and thus the electrolyte into the anolyte (310) and the catholyte (410), in order to prevent oxidation of the carbon nanomaterial in the electrolyte (310, 410). The membrane (200) further prevents the gaseous anodic products, such as oxygen, from mixing with the gaseous cathodic products, such as hydrogen, thereby enhancing the transportation of protons (H⁺) from the anode region (300) to the cathode region (400). Preferably, the membrane (200) arranged thus causes the contents of the two regions (300, 400) to have different pH conditions.

In one embodiment, the membrane (200) comprises a polymer film. Preferably, the membrane (200) is a proton-conductive membrane made of a polymer film which allows the transportation of protons only. Preferred examples of such proton-conductive membrane include those commercially available under the tradename of NAFION™, specifically NAFION™ 961, NAFION™ 430, or NAFION™ 117.

Electrode

According to an embodiment, an electrode in the electrochemical cell (10) is categorized into a cathode (420), and/or an anode (320). The cathode (420) is an electrode having more negative potential than the other electrode, while the anode (320) is an electrode having less negative potential than the other electrode.

Preferably, at least one electrode is formed of the metallic material in the particulate form deposited upon a substrate, or formed of the metallic material in the form of metallic foil without further deposition of particulate metal. Preferably, said electrode, being formed of the metallic material in either of the foregoing forms, is the cathode (420).

The metallic material in the particulate form can be deposited upon the substrate by means of any deposition method such as electrodeposition, chemical vapor deposition, and thin- film deposition, carried out in an ambient condition. Preferably, the metallic material in the particulate form is deposited upon the substrate by means of electrodeposition carried out under ambient conditions. Preferably, the solution used in the electrodeposition contains the metallic material intended to be deposited upon the substrate, which may be in any form or derivatives including ions and radicals.

The metallic material being deposited upon the substrate according to an embodiment is selected from one or more of the following: a post-transition element, a transition element, an oxide, and an alloy thereof. Preferably, the metallic material being deposited upon the substrate is selected from one or more of the following: a post-transition element, and a transition element. More preferably, the post-transition element is bismuth (Bi); and the transition element is silver (Ag).

The substrate upon which the metallic material in the particulate form is deposited can also be a metal sheet such as a metal foil, including a copper (Cu) foil, tin (Sn) foil, titanium (Ti) foil, or a non-metal sheet such as glass sheet, or a rigid body of aluminum (Al), silicon (Si), carbon (C), etc. Preferably, the substrate is a metal foil. More preferably, the substrate is a copper (Cu) foil, tin (Sn) foil, bismuth (Bi) foil, aluminum (Al) foil, or titanium (Ti) foil.

As a post-treatment step, the electrode is then exposed to the ambient air or oxygen- containing atmosphere at the room temperature in order to create a thin oxide layer before the start of electrochemical reduction. This post-treatment step is carried out for 1 second - 24 hours.

In some embodiments, at least one electrode is essentially free of a carbon-based material before the oxygenic organic compound is reduced electrochemically. Preferably, said electrode is the cathode (420).

In some embodiments, the substrate is configured to have a certain size, and/or shape in order to provide a greater specific surface area, upon which more metallic material in the particulate form may be deposited.

Preferably, the anode (320) is a platinum foil, platinum mesh, platinum rod, or graphite rod. More preferably, the anode (320) is a platinum foil or platinum mesh. In some embodiments, the electrochemical cell further comprises a reference electrode (430) to provide a 3-electrode cell system. Preferably, the reference electrode (430) is an Ag/AgCl electrode.

Reaction time

According to an embodiment, the electrochemical reduction occurs in the electrochemical cell (10) as a batch operation. The crystal structure and crystal size of the resulting product depends on the nature of electrode used, the energy supplied, and the reaction time, among others. Prolonging the reaction time results in a larger crystallite size being formed. According to the embodiments, the crystallite size is measured by Raman peaks.

According to the embodiments, the reaction time for each batch of production can be ranged from about 5 minutes to 140 minutes. Preferably, the reaction time for each batch of production is about 15 minutes to 75 minutes.

Nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof

In an embodiment, the process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal- carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or mixture thereof in the electrochemical cell (10) is preferably carried out as a batch operation.

The nanocrystalline carbon with the ID, 2D, or 3D structure and/or the nanocrystalline diamond and/or the amorphous carbon and/or the metal-carbon nanomaterial composite, said composite containing a post-transition metal or transition metal, and/or the mixture thereof is formed at at least one electrode. Preferably, said product is formed at the cathode (420).

The carbon product obtained from a process in accordance with a preferred embodiment comprises a graphite and/or a graphene and/or a graphitic carbon having an average crystallite domain size of about 1-100 nm and/or the nanocrystalline diamond and/or the amorphous carbon, and/or the metal-carbon nanomaterial composite, said composite containing the post transition metal or the transition metal, and/or the mixture thereof.

In some embodiments, the carbon product being produced is further separated from the electrode (320, 420) by a known separation process. Preferably, said separation process is a mechanical removal process, such as mechanical abrasion, or ultrasonication. After being separated from the electrode (320, 420), the carbon product may contain residue of the metallic material originally deposited upon the electrode (320, 420). The metallic material can be further removed from the carbon product by means of a conventional chemical removal process, preferably acid leaching. Preferably, said acid leaching involves the use of nitric acid (HNO3), hydrochloric acid (HC1), or a mixture thereof.

In some embodiments, the separation process of the carbon product from the electrode (320, 420) comprises the following steps:

(1) mechanically removing the solid product from the electrode (320, 420)

(2) placing the solid product that was removed by step (1) in a microcentrifuge tube

(3) slowly dropping a mixture of nitric acid and hydrochloric acid into the microcentrifuge tube to perform acid leaching. Preferably, the mixture of nitric acid and hydrochloric acid is in a molar ratio of 1:3 in 0.3 ml of the solution

(4) shaking the solution before ultrasonicating the solution for approximately 5 minutes

(5) centrifuging the solution to separate the solid product from the solution

(6) collecting the solid product and neutralizing the solid product with deionized water (DI water). Preferably, the neutralization is conducted three times.

The abovementioned process results in a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon product and/or a metal- carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof, which is a mixture having various carbon structures. Said structures are inclusive of, and selectable from: an amorphous carbon, a graphite, a graphene, a nanocrystalline diamond, and a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal.

Examples of embodiments

Twenty-two Examples were carried out for the preferred and alternative embodiments. In all of the Examples, the following paragraphs apply:

Electrochemical reductions took place in a three-electrode cell system at a pressure of about 1 atm. and at a temperature of about 30 + 5 °C. If a membrane (200) was used for separating the electrolyte (110) into the anolyte (310) and the catholyte (410), said membrane was NAFION™ 117; and if a reference electrode (430) was used, said reference electrode was Ag/AgCl with a 3.5 mol/L potassium chloride (KC1) solution. The carbon source was mixed with the electrolyte (110) or the catholyte (410), as the case may be. The electrochemical reduction’s onset potentials were measured by a potentiostat. After the reaction time, the carbon nanomaterial product was formed at the cathode (420), which was then removed from the electrolyte (110) or the catholyte (410), as the cases may be, and dried.

Moreover, where a metal element in the particulate form was deposited upon a metal foil substrate, the deposition was carried out by way of electrodeposition at ambient conditions, wherein a solution of nitrate salt at a concentration of 0.001-1 M was used as a precursor. The voltage applied for said electrodeposition was about -0.1 to -10 V. More particularly, where the metal element in the particulate form was silver (Ag), the deposition time was about 2-2,000 seconds; where the metal element in the particulate form was bismuth (Bi), the deposition time was about 60-3,600 seconds. After the said deposition time, the electrode, i.e. the substrate upon which the intended particulate metal element had been deposited, was left in the ambient air for 1-720 minutes as a post-treatment step before being used in the electrochemical reduction.

Further, where an amine solution was saturated with carbon dioxide gas (CO2), such saturation was carried out in order to prepare a carbamate. In such case, CO2 was purged through the amine solution at ambient conditions. The flow rate of CO2 per volume of amine solution was within a range of 0.04 - 40 cm³ CC /cm³ amine solution per minute, and the purging time was within a duration of 1-1,000 minutes.

Table 1 in the next two sheets shows the particulars of Examples 1-22. Description of the product obtained from each Example shall follow Table 1.

Example 1 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 3, as observed from the shown Raman spectrum, the carbon product obtained from Example 1 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 2 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 4, as observed from the shown Raman spectrum, the carbon product obtained from Example 2 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 3 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 5, as observed from the shown Raman spectrum, the carbon product obtained from Example 3 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 4 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 6, as observed from the shown Raman spectrum, the carbon product obtained from Example 4 comprised metastable diamond, graphitic carbon, and amorphous carbon structures.

Example 5 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 7, as observed from the shown Raman spectrum, the carbon product obtained from Example 5 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 6 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 8, as observed from the shown Raman spectrum, the carbon product obtained from Example 6 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 7 produced a metal-carbon composite product in the form of metallic Bi/Bi oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. Fig. 9A shows the Raman spectrum of the product of Example 7. Next, images from the Transmission Electron Microscopy (TEM) are shown in Figs. 9B and 9C. Finally, the peaks from Energy Dispersive X-ray (EDX) analysis, shown in Fig. 9D, revealed the following atomic percentages of said product: 46.30 % carbon; 38.03 % oxygen; 1.12 % silicon; 0.56 % iron; 0.69 % cobalt; 13.2 % tin; and 0.10 % bismuth. All the foregoing results confirmed that the product of Example 7 comprised graphene, graphitic carbon, and amorphous carbon structures. Example 8 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 10, as observed from the shown Raman spectrum, the carbon product obtained from Example 8 comprised graphitic carbon and amorphous carbon structures.

Example 9 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 11, as observed from the shown Raman spectrum, the carbon product obtained from Example 9 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 10 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. Fig. 12A shows the Raman spectrum of the product of Example 10. Moreover, the Selected Area Electron Diffraction (SAED) analysis revealed the d-spacing of said product as 1.28, 1.50, 1.93, 2.09, 2.30, 2.45, and 2.97 Angstrom (A), which, as shown in Fig. 12B, matched the d-spacing references of hexagonal silver, nanodiamond, and hexagonal diamond. Next, images from the Transmission Electron Microscopy (TEM) are shown in Figs. 12C and 12D. Finally, the peaks from Energy Dispersive X-ray (EDX) analysis, shown in Fig. 12E, revealed the following atomic percentages of said product: 33.31 % carbon; 2.61 % nitrogen; 13.46 % oxygen; 1.74 % fluorine; and 14.10 % silver. All the foregoing results confirmed that the product of Example 10 comprised nanocrystalline diamond comprising hexagonal diamond and nanodiamond, metastable diamond, graphitic carbon, and amorphous carbon structures.

Example 11 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 13, as observed from the shown Raman spectrum, the carbon product obtained from Example 11 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 12 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 14, as observed from the shown Raman spectrum, the carbon product obtained from Example 12 comprised metastable diamond, graphitic carbon, and amorphous carbon structures.

Example 13 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 15, as observed from the shown Raman spectrum, the carbon product obtained from Example 13 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures. Example 14 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 16, as observed from the shown Raman spectrum, the carbon product obtained from Example 14 comprised metastable diamond, graphitic carbon, and amorphous carbon structures.

Example 15 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 17, as observed from the shown Raman spectrum, the carbon product obtained from Example 15 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 16 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. Fig. 18A shows the Raman spectrum of the product of Example 16. Moreover, the Selected Area Electron Diffraction (SAED) analysis revealed the d-spacing of said product as 1.15, 1.41, 1.49, 1.92, 2.26, 2.43, and 2.95 Angstrom (A), which, as shown in Fig. 18B, matched the d-spacing references of hexagonal silver and hexagonal diamond. Next, images from the Transmission Electron Microscopy (TEM) are shown in Figs. 18C and 18D. Finally, the peaks from Energy Dispersive X-ray (EDX) analysis, shown in Fig. 18E, revealed the following atomic percentages of said product: 64.42 % carbon; 2.36 % nitrogen; 6.98 % oxygen; 1.42 % fluorine; 15.60 % copper; and 9.02 % silver. All the foregoing results confirmed that the product of Example 16 comprised nanocrystalline diamond comprising hexagonal diamond, graphitic carbon, and amorphous carbon structures.

Example 17 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 19, as observed from the shown Raman spectrum, the carbon product obtained from Example 17 comprised graphitic carbon, and amorphous carbon structures.

Example 18 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 20, as observed from the shown Raman spectrum, the carbon product obtained from Example 18 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 19 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 21, as observed from the shown Raman spectrum, the carbon product obtained from Example 19 comprised nanocrystalline diamond, metastable diamond, graphitic carbon, and amorphous carbon structures. Example 20 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 22, as observed from the shown Raman spectrum, the carbon product obtained from Example 20 comprised nanocrystalline diamond, graphitic carbon, and amorphous carbon structures.

Example 21 produced a metal-carbon composite product in the form of metallic Bi/Bi oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 23, as observed from the shown Raman spectrum, the carbon product obtained from Example 21 comprised graphene, graphitic carbon, and amorphous carbon structures.

Example 22 produced a metal-carbon composite product in the form of metallic Ag/Ag oxides and nanocrystalline carbon with a ID, 2D, and 3D structure. According to Fig. 24, as observed from the shown Raman spectrum, the carbon product obtained from Example 22 comprised graphene, graphitic carbon, and amorphous carbon structures.

References

[Dai 2021] Room-temperature synthesis of various allotropes of carbon nanostructures (graphene, graphene polyhedra, carbon nanotubes and nano-onions, n-diamond nanocrystals) with aid of ultrasonic shock using ethanol and potassium hydroxide, Dai et al., Carbon, 2021, 179, pp 133 - 141;

[Wu 2021] Effect of carbon chain length of chlorinated carboxylic acids on morphology of the carbon films electrodepo sited from aqueous solutions, Wu et al., Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021, 626;

[Shawky 2012] Room- temperature synthesis of single- wall carbon nanotubes by an electrochemical process, Shawky et.ak, Carbon, 2012, 50, pp 4184 - 4191;

List of Drawing References

100 receptacle

110 electrolyte

200 membrane

300 anode region

310 anolyte

320 anode

350 vent

400 cathode region

410 catholyte

420 cathode reference electrode feed vent power supply

Claims

1. A process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof, by electrochemically reducing a carbon source which is an oxygenic organic compound or a mixture containing said oxygenic organic compound under ambient conditions at an onset potential not greater than 10 Volt in presence of an electrolyte and at least one electrode, said electrode comprising a metallic material comprising one or more of the following: a post-transition element, a transition element, an oxide, and an alloy thereof.

2. The process according to claim 1, wherein the oxygenic organic compound or the mixture containing said oxygenic organic compound is dissolved in the electrolyte.

3. The process according to claim 2, wherein the oxygenic organic compound or the mixture containing said oxygenic organic compound is dissolved in the electrolyte at a concentration within a range of 0.01 to 10 M.

4. The process according to claim 1, wherein the oxygenic organic compound or the mixture containing said oxygenic organic compound is water-soluble.

5. The process according to claim 4, wherein said water-soluble oxygenic organic compound or mixture containing said oxygenic organic compound is chemically stable in the electrolyte when there is no electric current passing through the electrolyte.

6. The process according to claim 5, wherein the oxygenic organic compound is an alcohol.

7. The process according to claim 6, wherein the oxygenic organic compound is ethanol or glycerol.

8. The process according to claim 5, wherein the oxygenic organic compound is a carboxylic acid.

9. The process according to claim 8, wherein the oxygenic organic compound is acetic acid, formic acid or acrylic acid.

10. The process according to claim 5, wherein the oxygenic organic compound is a ketone.

11. The process according to claim 10, wherein the oxygenic organic compound is acetone.

12. The process according to claim 5, wherein the oxygenic organic compound is an aldehyde.

13. The process according to claim 12, wherein the oxygenic organic compound is acetaldehyde.

14. The process according to claim 5, wherein the oxygenic organic compound is an agricultural chemical.

15. The process according to claim 14, wherein the agricultural chemical is a monosaccharide or its derivative.

16. The process according to claim 15, wherein said monosaccharide is glucose.

17. The process according to claim 14, wherein the agricultural chemical is lactic acid.

18. The process according to claim 14, wherein the agricultural chemical is pyruvic acid.

19. The process according to claim 14, wherein the agricultural chemical is glycolic acid.

20. The process according to claim 5, wherein the oxygenic organic compound is an amino acid.

21. The process according to claim 20, wherein the oxygenic organic compound is glycine.

22. The process according to claim 5, wherein the oxygenic organic compound is a carbamate.

23. The process according to claim 22, wherein the carbamate is prepared by saturating an amine or a mixture containing said amine with CO2.

24. The process according to claim 23, wherein said amine is mono ethanolamine.

25. The process according to claim 2, wherein a homogenizing additive is added to the electrolyte.

26. The process according to claim 25, wherein the homogenizing additive is a strong acid.

27. The process according to claim 26, wherein the homogenizing additive is HNO3.

28. The process according to claim 25, wherein the homogenizing additive is a strong base.

29. The process according to claim 28, wherein the homogenizing additive is KOH.

30. The process according to claim 1, wherein the metallic material comprises one or more of the following: the post-transition element and the transition element.

31. The process according to claim 1, wherein said at least one electrode is formed of said metallic material in the particulate form deposited upon a substrate.

32. The process according to claim 1, wherein the post-transition element is Bi, and the transition element is Ag.

33. The process according to claim 31, wherein the electrode that is formed of the metallic material in the particulate form deposited upon a substrate is a cathode (420).

34. The process according to claim 33, wherein said metallic material in the particulate form deposited upon a substrate is prepared by an electrodeposition process.

35. The process according to claim 34, wherein said electrodeposition process uses a metal salt aqueous solution as a precursor.

36. The process according to claim 35, wherein said metal salt aqueous solution contains the metal salt at a concentration within a range of 0.001 to 0.1 M.

37. The process according to claim 35, wherein the electrodeposition process was carried out for 2-2,000 seconds.

38. The process according to claim 35, wherein the electrodeposition process uses an electric potential within a range of -0.1 to -10 Volt.

39. The process according to claim 34, wherein the electrodeposition process comprises a post-treatment step which involves exposing said metallic material in the particulate form deposited upon a substrate to the ambient air.

40. The process according to claim 39, wherein said post-treatment step is carried out for 1 second - 24 hours.

41. The process according to claim 1, wherein the electrolyte is separated into an anolyte (310) and a catholyte (410).

42. The process according to claim 41, wherein said catholyte is a mixture containing an ionic salt, the oxygenic organic compound or the mixture containing the oxygenic organic compound, and water, said ionic salt being a compound represented by Formula (I)

[A]n⁺ [Y]„- - (I) wherein, n is 1 or 2;

[Y] is selected from the group comprising tetrafluoroborate ([BF4] ), hexafluorophosphate ([PF₆] ), halides (CT, Br , F , G), hexafluoroantimonate ([SbF₆] ), sulfate ([SO4]² ) and nitrate ([NO3] );

[A]⁺ is selected from (a) the group comprising alkali metal cations, ammonium cations represented by Formula (II):

R¹, R², R³, and R⁴ being selected from hydrogen atom, Cl- C6-alkyl, Cl-C6-alkoxy, Cl-C6-aminoalkyl, C5-C 12-aryl, and C5-C12-aryl-Cl-C6-alkyl groups; and

(b) the group comprising imidazolium cations represented by Formula

(HI):

R, R¹, and R² being selected from Cl-C6-alkyl, C1-C6- alkoxy, Cl-C6-aminoalkyl, C5-C12-aryl, and C5-C12-aryl-Cl- C6-alkyl groups.

43. The process according to claim 42, wherein the catholyte contains the ionic salt at a concentration within a range of 0.01 to 10 M.

44. The process according to claim 42, wherein said ionic salt is l-butyl-3- methylimidazolium tetrafluoroborate ([bmim][BF4]).

45. The process according to claim 42, wherein said ionic salt is ammonium sulfate ((NH4)₂S0₄).

46. The process according to claim 42, wherein said ionic salt is sodium sulfate (NaiSCU)

47. The process according to claim 41, wherein the electrolyte (310, 410) is separated by a membrane (200).

48. The process according to claim 1, further comprising a step of agitating the electrolyte.

49. The process according to claim 48, wherein the agitation of the electrolyte is carried out by feeding a N2 gas flow into the electrolyte.

50. A process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof, said process comprising steps of: depositing a metallic material in the particulate form on a substrate to form a cathode (420); and electrochemically reducing an oxygenic organic compound or a mixture containing said oxygenic organic compound in presence of: an electrolyte that is separated into an anolyte (310) and a catholyte (410), an anode (320) submerged in said anolyte (310), and said cathode (420) submerged in said catholyte (410), wherein said catholyte (410) comprises a mixture of l-butyl-3- methylimidazolium tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NFL 2SO4) or sodium sulfate (NaiSC ), water, and the oxygenic organic compound or the mixture containing the oxygenic organic compound, and wherein said electrochemically reducing the oxygenic organic compound or the mixture containing said oxygenic organic compound occurs under ambient conditions at an onset potential not greater than 10 Volt.

51. A process for producing a nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, and/or a mixture thereof, said process comprising steps of: depositing a metallic material in the particulate form on a substrate to form a cathode (420); and electrochemically reducing an oxygenic organic compound or a mixture containing said oxygenic organic compound in presence of: an electrolyte (110), an anode (320) and said cathode (420) which are submerged in said electrolyte (110), wherein said electrolyte (110) comprises a mixture of l-butyl-3- methylimidazolium tetrafluoroborate ([bmim][BF4]), ammonium sulfate ((NFL 2SO4) or sodium sulfate (Na2S04), water, and the oxygenic organic compound or the mixture containing the oxygenic organic compound, and wherein said electrochemically reducing the oxygenic organic compound or the mixture containing said oxygenic organic compound occurs in an ambient condition at an onset potential not greater than 10 Volt .

52. A process according to claim 50 or 51, wherein said metallic material is Bi, and said substrate is a Sn foil.

53. A process according to claim 50 or 51, wherein said metallic material is Ag, and said substrate is a Cu foil.

54. A nanocrystalline carbon with a ID, 2D, or 3D structure and/or a nanocrystalline diamond and/or an amorphous carbon and/or a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, that is obtained from the process according to claim 1, 50, or 51.

55. A product that is a mixture having various carbon structures comprising: a nanocrystalline diamond, an amorphous carbon, a graphitic carbon, and a metal-carbon nanomaterial composite, said composite containing a post-transition metal or a transition metal, said product being obtained from the process according to claim 1, 50, or 51.

56. The product according to claim 55, wherein the various carbon structures further comprise a graphite or a graphene.