KR102561413B1 - Proton-conducting two-dimensional amorphous carbon films for gas membrane and fuel cell applications - Google Patents

Abstract

The present disclosure generally relates to two-dimensional amorphous carbon (2DAC) coating technology. Proton conducting 2DAC films can be used in fuel cell, hydrogen generation and deuterium production applications. More specifically, the present disclosure relates to an electrocatalyst assembly and a fuel cell comprising two-dimensional (2D) amorphous carbon, wherein the 2D amorphous carbon has a crystallinity (C) of 0.8 or less.

Description

Proton-conducting two-dimensional amorphous carbon films for gas membrane and fuel cell applications

The present disclosure relates to two-dimensional amorphous carbon (2DAC) coating technology. More specifically, the present disclosure relates to proton conducting 2DAC films for fuel cell, hydrogen generation and deuterium production applications.

There is a need in the prior art to develop and provide improved performance for fuel cell applications.

According to a first broad aspect, the present invention provides a fuel cell comprising an electrode catalyst assembly and two-dimensional (2D) amorphous carbon, wherein the two-dimensional amorphous carbon has a crystallinity (C) of 0.8 or less.

According to a second broad aspect, the present invention provides a fuel cell comprising an electrocatalyst assembly and two-dimensional (2D) amorphous carbon, wherein the two-dimensional amorphous carbon has a crystallinity (C) of less than 1 and an sp3/sp2 bonding ratio. is less than 0.2.

According to a third broad aspect, the present invention has an electrocatalyst assembly and an atomic structure comprising non-hexagonal carbon rings and hexagonal carbon rings, wherein the ratio of hexagonal carbon rings to non-hexagonal carbon rings is less than 1. A fuel cell comprising two-dimensional (2D) amorphous carbon is provided.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary aspects of the invention and together with the general description given above and the detailed description given below serve to explain the features of the invention.
1 is a schematic representation of the disclosed composite material of an atomically thin film exhibiting random hexagonal rings (not graphene) exhibiting continuity and order in accordance with one aspect of the present invention.
2 shows a TEM image of an amorphous film showing hexagonal and non-hexagonal shapes according to one embodiment of the present invention.
3 shows atomic force microscopy (AFM) measured thickness of a disclosed carbon film on boron nitride according to one aspect of the present disclosure.
4 shows Raman spectra of an amorphous film and nano-crystalline graphene on SiO ₂ according to one aspect of the present disclosure.
5 shows TEM diffraction of atomically thin amorphous carbon (left) and graphene (right) according to one embodiment of the present invention.
6 shows the transmittance of a carbon film disclosed in accordance with one aspect of the present invention.
7 shows a demonstration of the mechanical properties of a 2D amorphous film and a suspended carbon film according to one aspect of the present disclosure.
8 illustrates electrical characteristics of a 2DAC according to one aspect of the present disclosure.
9 shows a composite material grown on different substrates, according to one aspect of the present disclosure.
10 shows X-ray photoelectron spectroscopy (XPS) of 2DAC on copper according to one aspect of the present disclosure.
11 shows a conventional configuration of a proton exchange membrane fuel cell (PEMFC) according to the prior art.
12 shows an embodiment of implementing a 2DAC as a barrier layer between an electrode and a proton exchange membrane, according to one aspect of the present disclosure.
13 shows an implementation of a 2DAC in a configuration between an anode and cathode assembly, according to one aspect of the present disclosure.
14 shows an embodiment in which Nafion® is formed on both sides of an exemplary 2DAC film and encapsulated between electrode and catalyst layers in a fuel cell configuration, in accordance with one aspect of the present disclosure.
15 shows an exemplary fuel cell embodiment having a 2DAC layer between an electrode/catalyst assembly and a proton/deuteron conducting membrane, in accordance with one aspect of the present disclosure.
16 shows an example of a method of using a modified membrane to separate a gas mixture, in accordance with one aspect of the present disclosure.

Justice

Where a definition of a term deviates from the commonly used meaning of the term, Applicant intends the definitions provided below unless otherwise specified.

It is to be understood that both the foregoing general description and the following detailed description are illustrative and explanatory only and do not limit the claimed subject matter. In this application, the use of the singular includes the plural unless specifically stated otherwise. As used in the specification and appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. The use of "or" in this application means "and/or" unless specified otherwise. Also, the use of the term "including" along with other forms such as "includes", "includes" and "included" is not limiting.

For purposes of this invention, the terms "comprising", "having", "including" and variations of these words are intended to be open ended and there may be additional elements other than those listed. means there is

For purposes of the present invention, "top", "bottom", "upper", "lower", "above", "below", "left" Directional terms such as "left", "right", "horizontal", "vertical", "up", "down", etc. merely refer to various aspects of the present invention. It is used for convenience in explaining. Aspects of the invention can be modified in many ways. For example, diagrams, devices, etc. shown in the figures may be turned over, rotated 90° in any direction, or reversed.

For purposes of this invention, a value or attribute is defined as “a value, characteristic, satisfaction of a condition, or other factor” if the value is derived by performing a mathematical calculation or logical decision using the value, attribute, or other factor. be based”.

For purposes of this disclosure, to provide a more concise description, some of the quantitative expressions provided herein are not limited to the term “about”. Regardless of whether or not the term "about" is explicitly used, all quantities provided herein are intended to represent the actual given value, and may also be inferred based on the skill of the art, including approximations due to experimental and/or measurement conditions. It should be understood that it is intended to represent the closest possible approximation to a given value.

For the purpose of the present invention, the term "adhesion strength" means the bond strength between the disclosed 2DAC film and its growth substrate. It directly depends on the adhesion energy between the two materials, which can be measured in units of J/m ² .

For the purposes of this invention, the term “amorphous” means without a definite form, without a specific shape or shape. As a non-crystalline solid, amorphous refers to a solid that lacks the long-range order characteristic of crystals.

For the purposes of this invention, the term “amorphous carbon” means carbon that does not have any long-range crystalline structure.

For the purposes of the present invention, the term “atomically thin amorphous carbon” means amorphous carbon composed of approximately 1 to 5 carbon atom layers in a plane, mainly with sp ² bonds between carbon atoms to form a layer. It should be understood that the layers may be stacked, and stacking of such layers is within the scope of the present invention.

For purposes of the invention, the term "carbon coating" means a layer of carbon deposited on a substrate.

For purposes of this invention, the term "carbon ring size" refers to the size of a ring of carbon atoms. In some disclosed embodiments, the number of atoms within a single carbon ring can vary from 4 to 9 atoms.

For the purposes of the present invention, the term “diamond-like carbon” refers to amorphous carbon composed primarily of sp ³ bonds between carbon atoms.

For purposes of the present invention, the term “differentiating stem cells” refers to the process of transforming unspecialized stem cells into specific types of cells with functional properties. In the disclosed embodiments, differentiation occurs due to a combination of chemical and matrix inducing factors.

For the purposes of the present invention, the term “D/G ratio” means the ratio of the intensities of the D and G peaks in a Raman spectrum.

For the purposes of this invention, the term "electrochemical cell (EC)" means a device capable of generating or facilitating electrical energy from a chemical reaction. Electrochemical cells that generate current are called voltaic cells or galvanic cells, and those used to cause chemical reactions such as electrolysis are called electrolytic cells. A common example of a galvanic cell is the standard 1.5V consumer cell. A battery may consist of one or more cells connected in a parallel or series pattern.

For purposes of this invention, the term “fuel cell” means an electrochemical cell that converts chemical energy from a fuel into electricity through an electrochemical reaction between a hydrogen fuel and oxygen or other oxidizer. A fuel cell may differ from a battery in that it requires a constant source of fuel and oxygen (usually from air) to sustain the chemical reaction, but in a battery the chemical energy comes from chemicals already present in the battery. A fuel cell can continuously generate electricity as long as fuel and oxygen are supplied.

For purposes of this invention, the term "graphene" refers to an allotrope (form) of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice. It is the basic structural element of many other carbon allotropes, such as graphite, charcoal, carbon nanotubes and fullerenes. It can be considered an infinitely large aromatic molecule, the ultimate in the family of planar polycyclic aromatic hydrocarbons. Graphene has many unusual properties, including strong material properties, the ability to efficiently conduct heat and electricity, and being nearly transparent.

For purposes of this invention, the term “membrane” means a layer that acts as a selective barrier that allows some elements to pass through but blocks others, such as molecules, ions or other small particles.

For the purposes of the present invention, the term “Nafion®” means a fluoropolymer-copolymer based on sulfonated tetrafluoroethylene. These are the first class of synthetic polymers with ionic properties, called ionomers. The unique ionic properties of Nafion® result from the incorporation of perfluorovinyl ether groups terminated by sulfonate groups into a tetrafluoroethylene (Teflon) base. Nafion® serves as a proton conductor for proton exchange membrane (PEM) fuel cells and has excellent thermal and mechanical stability.

For purposes of this invention, the term "proton exchange membrane" or "polymer electrolyte membrane" (PEM) is generally made of ionomers and is an electronic insulator and reactant, such as oxygen and hydrogen gas. Refers to a semipermeable membrane designed to conduct protons while acting as a barrier.In some embodiments, a proton exchange membrane or polymer electrolyte membrane may also be referred to as a proton conducting membrane.Some of the essential functions of PEMs are to block the direct electron path through the membrane, while reactants separation and transport of protons.PEMs can be made of pure polymeric membranes or composite membranes in which other materials are embedded in a polymeric matrix.In some disclosed embodiments, PEMs are primarily composed of proton conductivity (σ), methanol It can be characterized by permeability (P) and thermal stability PEM fuel cells can use a solid polymer membrane (thin plastic film) as an electrolyte, which when saturated with water is permeable to protons, but does not transport electrons. don't

For the purposes of the present invention, the term "proton exchange membrane fuel cell (PEMFC)" refers to a type of fuel cell that is being developed primarily for transportation applications, but also for stationary fuel cell applications and portable fuel cell applications. used Their distinctive features include a low temperature/pressure range (50 to 100 °C) and a special proton conducting polymer electrolyte membrane. PEMFCs generate electricity and operate on the opposite principle to polymer electrolyte membrane (PEM) electrolysis, which consumes electricity. They are leading candidates to replace aging alkaline fuel cell technology. In some applications, PEMFCs are also known as polymer electrolyte membrane fuel cells.

For the purposes of the present invention, the term "proton transport" means the transport of protons across an electrically insulating film.

For purposes of this invention, the term "Raman spectroscopy" refers to a spectroscopic technique used to observe vibrational, rotational and other low-frequency modes in a system. Raman spectroscopy is commonly used in chemistry to provide a structural fingerprint by which molecules can be identified. It relies on inelastic or Raman scattering of monochromatic light, typically from lasers in the visible, near-infrared, or near-ultraviolet range. The laser light interacts with molecular vibrations, phonons, or other excitations in the system resulting in an upward or downward movement of the energy of the laser photons. The transfer of energy provides information about the vibrational modes of the system.

For the purposes of the present invention, the term “Raman spectrum” refers to the phenomenon of scattering intensity as a function of frequency shift dependent on the rovibronic state of a molecule. In order for a molecule to exhibit the Raman effect, there must be a change in electric dipole-electric dipole polarizability of the molecule with respect to the vibrational coordinates corresponding to the rotational vibration state. The intensity of Raman scattering is proportional to this polarizability change.

For the purposes of this invention, the term “self-assembled” refers to the self-organization of polymer chains in a regular lattice structure covering the disclosed 2DAC surface. In the disclosed aspect, self-assembly allows the formation of ultra-thin films with different properties compared to bulk properties.

For the purposes of the present invention, the term “ratio sp ³ /sp ² ” refers to the type of carbon bond found in 2DAC. sp ² binding allows higher growth factor binding.

For purposes of this invention, the term “substrate” refers to a structural support for the disclosed two-dimensional (2D) amorphous carbon film. In an optional application, the disclosed aspect provides a substrate for mechanically supporting the 2DAC film, for example, as otherwise the 2DAC film may be too thin to perform its function without being damaged. A substrate can be considered a material used for growth of a 2DAC or 2DAC film disclosed on the surface of the substrate.

For purposes of this invention, the term "two-dimensional (2D) amorphous carbon film" refers to atomically thin amorphous carbon to, for example, metal, glass, and oxide surfaces, including low melting temperatures, non-catalytic (non-catalytic) -catalytic) means the thinnest possible amorphous carbon (eg single atom thick) that can be grown directly on substrates. Growth on other substrates is feasible due to the low temperatures at which the disclosed 2DAC films grow. The disclosed embodiments of the 2DAC film may exist as a free-standing film or as a coating on a substrate, as disclosed herein. Although the disclosed 2DAC film is amorphous, carbon atoms combine with several neighboring carbon atoms in a plane to form a strong network, and it is very stable even when released from the growth substrate (free-standing). The carbon material also has the property of adhering well to metal surfaces, ensuring full coverage across the substrate. The inherent thinness and high strength of the disclosed 2DAC thin films also allow them to withstand bending of metal substrates without breaking.

For the purposes of this invention, the term "two-dimensional (2D) amorphous carbon coating" means a 2DAC film grown and/or deposited directly on a substrate. The disclosed aspects may also include where the 2DAC coating is transferred onto or from a substrate.

explanation

While the present invention is capable of many modifications and alternative forms, certain aspects thereof have been shown by way of example in the drawings and will be described in detail below. However, it should be understood that the present invention is not intended to be limited to the specific forms disclosed, but on the contrary, the present invention is intended to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention.

Fuel cells provide clean and efficient energy conversion of hydrogen and oxygen sources providing power and clean water as waste. One of the most promising fuel cell types is the proton exchange membrane fuel cell (PEMFC), which is already commercially available. ¹ In a conventional configuration, a PEMFC can consist essentially of three components: an anode, a cathode and a proton exchange membrane. 11 shows the working principle of a preferred conventional PEMFC 1100. Hydrogen splits into protons and electrons at the anode 1106 and the protons pass through the proton exchange membrane 1104 to the cathode 1108; Electrons are forced through external circuit 1110 to reach cathode 1108 . At cathode 1108, protons interact with electrons and oxygen to produce water waste (H ₂ O). Power is generated by electrons in the external circuit 1110 .

The performance of the PEMFC 1100 relies on the proton exchange membrane 1104 to conduct protons and prevent hydrogen, methanol, oxygen, nitrogen and other gases that may be present in the system from crossing the membrane. The electrode/catalyst layer or electrode catalyst assembly 1102 typically consists of electrodes made of carbon decorated with catalyst particles made of platinum, ruthenium or other catalytically active materials. Electrocatalyst assembly 1102 has a porous structure that allows gases to diffuse through the layer. The hydrogen fuel diffusing through the anode electrode catalyst assembly reacts with the catalyst particles to dissociate into protons and electrons. In the cathode electrode catalyst assembly, oxygen gases diffuse through the assembly and react with protons and electrons to form water. Often an inert gas such as nitrogen is flowed through the system to help stabilize the operating pressure, fuel supply and carry excess gases and liquids to the exhaust.

Gases crossing the proton exchange membrane 1104 are of concern because they not only reduce the net efficiency but also form hydrogen peroxide at the electrodes, causing pinholes and thinning of the proton exchange membrane 1104. This phenomenon enhances gas crossover and accelerates failure of the fuel cell. ²

Gas crossover can also affect the efficiency of catalyst particles to promote chemical reactions at the anode and cathode. The proton exchange membrane 1104 can be further damaged by ionic contaminants such as alkali metals and ammonium ions. ²

To prevent gas crossover and degradation of the exchange membrane, aspects of the disclosed invention provide a 2DAC layer that can be incorporated as an anti-gas crossover layer. In some embodiments, the disclosed 2DAC is provided as a film layer. In an exemplary configuration, the disclosed 2DAC film may be attached to the proton exchange membrane 1104. The disclosed 2DAC film does not limit the proton conductivity due to its excellent proton conductivity and extremely thin thickness. The disclosed 2DAC film is a barrier to all other gases and ions and thus increases the lifetime of the substituted PEMFC. Further discussion of the disclosed 2DAC films is provided as follows.

The disclosed aspect relates to a new composite material composed of atomically thin (single layer) amorphous carbon over a substrate (metal, glass, oxide). Amorphous carbon adheres very well to the substrate on which it grows. Thus, amorphous carbon materials offer unique properties. For example, the disclosed amorphous carbon material is suitable for applications utilizing a substrate that requires a coating for a specific purpose(s). Exemplary applications may include, but are not limited to, biomedical applications.

The present disclosure provides a new form of carbon referred to as two-dimensional (2D) amorphous carbon (2DAC). The disclosed embodiment is the thinnest possible amorphous carbon (e.g., approximately single atom thick) in 2DAC that can be grown directly on, for example, metal substrates that have a low melting temperature and are non-catalytic, as well as substrates that include glass and oxide surfaces. ) is provided. In one selected aspect, having a single atomic thickness is a preferred material and can establish a lower thickness limit for 2DAC. The disclosed aspects can include thicknesses that can range up to several atoms thick (eg, 10 atoms thick, or about 3+ nm). The disclosed 2DAC may be provided as a two-dimensional (2D) amorphous carbon film. However, it is important to note that as the thickness of the disclosed 2DAC increases, it remains structurally different (eg, sp ³ to sp ² ratio) from other existing amorphous carbon material thicknesses, as disclosed herein. .

The low temperature at which the disclosed 2DAC films grow allows growth on other substrates. Although the disclosed 2DAC film is amorphous, the carbon atoms combine with several adjacent carbon atoms in a plane to form a strong network and are very stable even when released from the growth substrate (free-standing). Thus, each carbon atom is bonded to a large number of carbon atoms, resulting in a high bonding (connection) density. The disclosed 2DAC also has the property of adhering well to metal surfaces, ensuring full coverage. The material properties such as inherent thinness and high strength of the disclosed 2DAC thin film (eg, described below) also allow it to withstand bending of a metal substrate without breaking.

According to the disclosed aspects, amorphous carbon can be defined as a form of carbon that lacks a long-range structural order. It exists in several forms and is often referred to by different names, such as diamondoid carbon, glassy carbon, and soot, depending on the form. Amorphous carbon can be produced by several techniques including, for example, chemical vapor deposition, sputter deposition and cathodic arc deposition among others. In conventional applications, amorphous carbon has always been present in a three-dimensional form (or bulk). The two-dimensional equivalent form of carbon is graphene. However, graphene exists only as a crystalline material (single or polycrystalline). The synthesis of graphene requires high temperatures and is mostly grown on copper. In accordance with the present disclosure, the disclosed aspects have produced a continuous two-dimensional morphology of amorphous carbon that is grown on any substrate at much lower temperatures. The disclosed 2DAC film and substrate composite material has properties significantly different from bulk amorphous carbon and also from single layer graphene.

Embodiments of the disclosed 2DAC are, for example, substrate coatings, films coating the inner surfaces of porous structures, suspension films, rolled films, tubes, fibers, or hollow balls. , may exist as a film. The mechanical, electrical, optical, thermal and other properties of the disclosed 2DAC are expected to vary depending on, for example, the shape of the 2DAC. For example, a tube comprising the disclosed 2DAC will have high mechanical strength in the axial direction and smooth response in the radial direction. The published 2DAC can be prepared in various forms to exploit different properties for different applications.

1 shows a schematic diagram 100 of the disclosed composite material with a TEM image of the carbon material on the top surface of the substrate. The disclosed material configuration is a new composite material of atomically thin amorphous carbon 102 over a substrate 104 (eg, metal or glass, oxide).

The disclosed composite material may refer to atomically thin 2D amorphous carbon (2DAC) on any substrate. According to the disclosed aspects, the disclosed 2DAC film on the disclosed substrate may be defined in terms of its atomic structure and its properties.

A closer examination and definition of the atomic structure can be presented as follows. 2 shows a TEM image of an amorphous film showing hexagons and non-hexagons according to one aspect of the present disclosure. The top left image of FIG. 2 shows a high resolution TEM image of the disclosed 2DAC film comprising hexagonal and non-hexagonal. A schematic diagram of the lower left of the TEM image in the upper left image is provided for viewing aid. Hexagons are colored green, and non-hexagons are colored red or blue. The top right display is the FFT showing the ring structure without a clear diffraction pattern.

Referring to the TEM image of FIG. 2, the 2DAC film is a single atom thick carbon film having a mixture of hexagonal and non-hexagonal rings in its structure. The rings are fully connected to each other, forming a network of polygons in large-area films that are on the order of microns in scale. The ratio of hexagonal rings to non-hexagonal rings is a measure of crystallinity (or amorphousity), C. Non-hexagons are in the form of 4-, 5-, 7-, 8- and 9-membered rings. The 2D amorphous film has a C of 0.8 or less (C ≤ 0.8) when measured at a minimum image area of about 8.0 nm ² . The C value in FIG. 2 is about 0.65. The disclosed aspects may support a range of C values of greater than 0.5 and less than or equal to 0.8. This is different from graphene with C=1 in a pure hexagonal network. Non-hexagons may be randomly distributed within the hexagonal matrix, or may be formed along the boundaries of hexagonal domains. The regions cannot be larger than 5 nm. A fast Fourier transform (FFT) of the image should not reveal diffraction spots (Figure 2, top right). The 2DAC can be detached from the substrate and become a stand-alone or moved to another substrate. Thus, in some aspects, the disclosed 2DAC can be separated from the surface of a substrate to obtain a free-standing 2DAC film.

Figure 3 shows the measured thickness (i.e., height) of the disclosed 2DAC films separated on boron nitride (BN) by AFM. Based on the disclosed invention, the following characteristics apply. Figure 3 shows the AFM of the disclosed boron nitride (BN) transferred 2DAC film. The disclosed thickness of 2DAC is about 6 Å, which is comparable to graphene, which is only one atom thick (thickness ranges from 3.3 Å to less than 10 Å as measured on BN). The thickness is also evidenced by the TEM images in FIG. 1 . Also, the film is found to be homogenous.

4 shows Raman spectra 400 of an amorphous film and nano-crystalline graphene on SiO ₂ . Raman spectroscopy of the isolated film did not reveal a 2D peak (~2700 cm ⁻¹ ), but instead showed broad G (at ˜1600 cm ⁻¹ ) and D peaks (at ˜1350 cm ⁻¹ ). Broadening of the D and G peaks generally indicates a transition from nano-crystalline graphene to amorphous film as previously reported. From the intensity ratio of the ³ D and G peaks, the region size is estimated to be approximately 1-5 nm. ³ Raman spectroscopy serves as a characterization tool to reveal the TEM image of FIG. 2 over a large area.

5 provides a TEM diffraction comparison 500 of atomically thin amorphous carbon (left) and graphene (right), in accordance with one aspect of the present disclosure. Further evidence of the amorphous nature of the disclosed isolated film is evidenced by TEM diffraction in which no clear diffraction spots are detected, in contrast to graphene where diffraction spots indicative of crystallinity are clearly visible. The diffraction rings in Fig. 7 (top) show domain sizes <5 nm. The diffraction data of the amorphous film are consistent with the FFT image in Fig. 2. In this case, the 2DAC film is self-supporting.

Turning to Fig. 6. Graph 600 depicts the transparency of the disclosed carbon film according to one aspect of the present disclosure. The optical transparency is ~98% at 550 nm light wavelength, and the transparency increases with increasing wavelength. Thus, selected embodiments provide optical transparency of 98% or greater at wavelengths of 550 nm or greater. In other words, the disclosed carbon film differs from graphene because the transparency of graphene in a single layer is up to 97.7% across visible wavelengths (400 nm to less than 700 nm) in a single layer and decreases as the number of layers increases. In particular, the transparency of the 2DAC film does not show the characteristic of rapidly decreasing at short wavelengths (less than 400 nm, <400 nm) seen in graphene.

The elastic modulus E of the suspension film is higher than 200 GPa and higher than bulk glassy carbon (E=60 GPa). ⁴ The highest strain before mechanical failure is 10%, much higher than other reported amorphous carbons. 7 shows the nano-indentation of the suspended carbon film after extreme stressing by means of a suspended carbon film and an Atomic Force Microscope (AFM) (eg, Bruker model number: MPP-11120) tip. do. The amorphous nature of the disclosed 2DAC film prevents collapse of the suspension film of FIG. 7 (bottom). Instead, the film exhibits a ductile response to extreme stress levels.

The 2DAC thin film of the disclosed invention has a high resistivity with an electrical resistance ranging from 0.01 to 1000 Ω-cm (including the boundary value of this range) depending on the value of C adjusted by the growth conditions. 8 is a schematic diagram 800 of the electrical properties of 2D amorphous carbon, showing an IV curve 802 of the 2D amorphous film and a histogram 804 of the measured resistivity values for specific C values. Measurement techniques/methods are used to generate resistivity values. The ratio is used in the calculation from the data of the IV curve 802 to obtain each resistivity data point in the histogram 804. Accordingly, the length:width ratio of 2D amorphous carbon in the left side of FIG. 8 is 1:100. By comparison, graphene has a resistivity of ~ 10 ⁻⁶ Ω-cm and bulk glassy carbon (also 100% CC sp ² ) has a resistivity ranging from 0.01 to 0.001 Ω-cm.

A monolayer film comprising more than 6 n-membered rings naturally passes selectively through gaseous components, ions, liquids or other species that are small enough to pass through the 7-, 8-, and 9-membered rings. It is a barrier that can be In particular, the disclosed 2DAC films can pass protons 10 times more efficiently than crystalline monolayer boron nitride at room temperature. ⁵ For the disclosed 2DAC films, the resistivity for proton flow across the membrane is 1-10 Ω-cm ² at room temperature.

9 illustrates composite materials grown on different substrates, according to one aspect of the present disclosure. On the left, pictures of titanium, glass and copper coated with atomically thin amorphous carbon are shown. Shown at the top right is the Raman spectrum of the coated areas showing a similar response regardless of the substrate. Finally, shown at the bottom right is a Raman map of the G/D peak ratio of the 2DAC film on titanium, showing full coverage. The disclosed composite materials (ie, the disclosed 2DACs and substrates) can be produced from any metal (catalytic or non-catalytic) or glass or oxide phase. Thus, the disclosed aspects indicate that 2DAC can be grown directly on any desired substrate material disclosed. This differs from graphene, which can only be grown on catalytic substrates such as copper and must be transferred to other substrates. Thus, compared to methods for depositing amorphous or diamond-like carbon, which cannot be considered continuous because the thickness cannot exist below 1 nm, the disclosed composite material is a two-dimensional amorphous carbon layer that can be strongly bonded to a host substrate. It contains atomically thin (less than 1 nm, <1 nm) and continuous layers.

In general, if the adhesion of the film on the substrate is insufficient, areas of the film may separate from the substrate, and thus there may be insufficient or no protection of the substrate. Accordingly, aspects of the present disclosure provide improved films that provide uniformity and strong adhesion across the applied surface of a substrate. Accordingly, the disclosed 2DAC film is preferably formed as a continuous film on substantially the entire substrate surface or at least the applied surface. Unlike conventional designs, such as graphene on copper, which can be easily separated (eg, adhesion is 10-100 J/m2), the disclosed atomically thin 2DAC disposed on copper, for example, The film adheres very well to the substrate with an adhesion energy greater than 200 J/m2. ⁶ This example provides further evidence to distinguish the disclosed 2DAC films from graphene. (While an exemplary aspect of a copper substrate has been described, any aspect of applying the disclosed 2DAC to any substrate can be applied in accordance with the disclosed aspects of the present invention.) In addition, adhesion energy can be applied to the substrate on which the disclosed 2DAC is grown, such as stainless steel. It is evident in all substrate materials including steel, titanium, glass, nickel and aluminum substrates. It should be understood that the above substrates are exemplary and that the teachings of this disclosure can be applied to any substrate desired.

In general, attempts to transfer any 2D material to material by conventional materials and processes have previously resulted in, for example, defects and cracks in the transferred material(s) and reduced coverage on the substrate. This is due, at least in part, to the fact that the transfer process typically uses many mechanical steps and uses chemicals that cause cracks and defects in existing film applications. However, the disclosed 2DAC film need not be transferred, for example from a growth substrate to a target substrate. In addition to the improved adhesive properties of the disclosed 2DAC films, the improved properties of the disclosed 2DAC films provide and ensure consistent and complete coverage directly across the substrate. Because the disclosed 2DAC films can be consistently and successfully fully grown directly on a host substrate, at least there is no need to transfer the disclosed 2DAC films, so that consistent and complete coverage can be obtained.

Designed to provide such reliable coverage along with excellent mechanical properties for adhesion to substrates, the disclosed 2DAC film (such as carbon) is well suited for applications requiring additional physical properties/requirements of the 2DAC film and composite. can be trusted These physical properties may include the ability of the disclosed 2DAC films and/or composites to bend and/or stretch. The adhesion properties and ability of the disclosed 2DACs to substrates ensure that this is the case. As with transferred films, if there is non-uniform adhesion to the substrate, cracks in the film may form in areas of poor adhesion, making them susceptible to breakage.

Thus, an aspect of the disclosed invention provides a top amorphous carbon film 102 (Raman map in FIG. 9 ) that covers the entire substrate 104 on which it grows, making it very useful, for example, in applications requiring a carbon coating. . The top amorphous carbon film 102 also serves as a defect-free diffusion barrier to prevent oxidation and corrosion of the underlying substrate. Due to its electrically insulating properties, the disclosed amorphous carbon film 102 prevents galvanic corrosion of the substrate 104 . The low electrical conductivity of the disclosed 2DAC is favorable for cell attachment and proliferation as observed in a recent report. ⁷ On conductive substrates, cells adhere to the surface via electrostatic interactions without producing focal adhesions. Focal adhesion is important for cell proliferation and growth, and low electrical conductivity is preferred for focal adhesion development and cell proliferation. The low electrical conductivity is a result of the amorphous nature of the disclosed 2DAC as observed through Raman spectroscopy D/G peak intensity and sp ³ /sp ² ratio.

On the other hand, graphene is known to exacerbate long-term corrosion. ⁸ The transfer of graphene makes it nearly impossible to make a flat continuous film without creating cracks and defects along the surface. The disclosed amorphous carbon film 102 material is composite with the substrate 104, thereby eliminating the risk of cracking in the film 102 as well as eliminating the need for transfer.

The disclosed 2DAC films consist of sp ² -bonded carbon similar to glassy carbon; However, it is only a single atomic layer thick (6 Å), thinner than any previously reported amorphous carbon structure. 10 shows an X-ray photoelectron spectroscopy (XPS) measurement of 2D amorphous carbon on copper, where the peak position indicates the sp ² or sp ³ bond type and the peak intensity indicates the proportion of each type of bonds. Although the maximum CC sp ³ content is set at 20%, mixed concentrations of CC sp ² and sp ³ bonds are possible without sacrificing thickness. The thin structure and strong adhesion of the disclosed 2DAC always inherently protects the underlying substrate, unlike thick films with obvious delamination potential. ⁹

According to disclosed aspects, a laser-based growth process using hydrocarbons as precursors (such as CH ₄ , C ₂ H ₂ , etc.) produces the disclosed composite film. Hydrogen gas (H ₂ ) and argon gas (Ar) may also be mixed with the precursor. In this process, the laser plays two roles. (1) an energy source that decomposes the precursor gas in a process called photolysis; and (2) as a local heat source. Assuming that one or both of the aforementioned roles result in the disclosed 2DAC film: in the first case, the substrate 104 can be said to be at room temperature during growth; In the second case, the laser can heat the substrate 104 up to 500°C. Typically, a pulsed excimer UV laser (eg 193, 248 or 308 nm) is applied to the substrate with a fluence of about 50-1000 mJ/cm ² at different growth times depending on the substrate used. It can be directed upwards or parallel to the substrate. Other possible combinations for producing the disclosed composites may include using any combination of laser, plasma and/or substrate heater. A heater may be used to heat the substrate 104 up to 500°C. Plasma power can be used in the range including 1-100W. Typical combinations using hydrocarbons as precursors are: (i) laser only; (ii) laser + low power plasma (5 W); (iii) laser + low power plasma (5W) + heater (300°C-500°C); (iv) low power plasma (5W) + 500°C heater; (v) High power plasma (100 W) only.

According to the disclosed aspects, the entire growth/deposition of the disclosed 2DAC and 2DAC composite may be performed in a chamber. Modules for heating, plasma, gas flow and pressure control can all be set up and established within the chamber for a controlled growth environment. According to one aspect, the process pressure of the chamber may be established in the range including 10 to 1E-4 mbar.

Process parameters for the disclosed 2DAC may include: (i) process gas: CH ₄ (ii) chamber pressure: 2.0 E-2 mbar; (iii) laser fluence: 70 mJ/cm ² ; (iv) growth time: 1 min; (v) plasma power: 5 W; (vi) Substrate: Cu foil.

The process for manufacturing the disclosed 2DAC film may use methane (CH ₄ ) in a growth chamber for a growth process. During growth, the gas pressure in the chamber is controlled to 2 E-2 mbar overall. This gas is present in a plasma generator operating at 5 W power. Growth begins when a 248 nm excimer laser is exposed to the surface of the copper foil substrate with a pulse frequency of 50 Hz and a fluence of 70 mJ/cm ² . The laser exposure time (i.e. growth period) is set to 1 min to obtain a continuous 2DAC coating on the substrate. In this growth, no stage heater is used. Includes hydrocarbons as precursors, precursor mixtures, adjustments to photolysis processes and equipment, temperature regulation, substrate temperature adjustments, C value changes, atomic layer number changes, sp ² to sp ³ ratio changes, and adhesion to substrate changes. A number of parameters disclosed herein, including but not limited to, may be adjusted to control and/or change the characteristics of the disclosed 2DAC.

The disclosed carbon films can be constructed to a minimum thickness and thus ensure that the disclosed metal surfaces of the substrate are consistently and completely covered over the life of the applied use. In one aspect, the disclosed 2DAC thickness can be designed to be approximately one atomic layer thick. The disclosed carbon film 102 can be grown directly on various substrates 104, such as stainless steel and titanium materials, for example. Because growth occurs at much lower temperatures than, for example, graphene synthesis, the disclosed 2DACs can be grown directly on glass and other substrates 104 that cannot withstand high temperatures, such as hard disks. ¹⁰ The disclosed 2DAC film 102 is very strong and strongly bonded to the substrate 104 making it suitable for applications requiring deformation such as bending and stretching. The strong mechanical properties of the disclosed 2DAC films are attributed to the sub-existence of grain boundaries. The insulating properties of the disclosed carbon film 102 prevent galvanic corrosion of the substrate 104 unlike graphene which enhances corrosion. As seen in the TEM images, the 7-, 8- and 9-membered rings of the carbon film are useful as efficient membranes for gas or proton transport. ⁵

According to selected aspects of the disclosed subject matter, the disclosed 2DAC may be created stand-alone, for example when the disclosed 2DAC needs to be transferred because the substrate is not suitable for growth. Appropriate methods and techniques for transferring the disclosed 2DAC 1202 include patent application: Defect-free direct dry delamination of cvd graphene using a polarized ferroelectric polymer WO2016126208A1 Dry transfer such as described can be used. Other transfer methods include, but are not limited to, thermal release tape, pressure-sensitive adhesive, spin coating, spray coating, and Langmuir-Blodgett techniques.

However, additional advantages of the present disclosure indicate that in some aspects the disclosed 2DAC 1202 can be grown directly on a substrate. These advantages of the disclosed 2DAC films compared to, for example, graphene for the transfer process are that the disclosed 2DAC films do not require a sacrificial support layer for transfer (unlike graphene). In the case of graphene, a film layer is needed to prevent cracks and defects during transfer and the film layer must then be removed. Even if removed, residues that cannot be completely removed from the sacrificial layer remain. Using the disclosed 2DAC, transfer can be performed without a sacrificial layer, without introducing defects, processing residues or damaging the structure.

The advantages of the disclosed aspect of the 2DAC layer may be implemented in a variety of applications including, but not limited to, fuel cell, hydrogen generation and deuterium production applications. These applications take advantage of the disclosed 2DAC layers, which include, for example, an exemplary single layer of carbon atoms in a non-crystalline structure with a C-value of 0.8 or less. Referring back to the amorphous nature of the disclosed 2DAC layers, such as ^the 2DAC film shown in FIG. conductance). The conductivity of a deuteron (the nucleus of deuterium) is 0.01-1 S/cm ² , about 10 times lower than that of protons. The conductivity of triton (the nucleus of tritium) is about 0.003-0.3 S/cm ² . Due to the difference in transmission rate, the disclosed 2DAC is an efficient separation membrane for hydrogen isotopes. At the same time the membrane is impermeable to other molecules such as H ₂ , O ₂ and CH ₄ .

Proton transport through the membrane is limited by the electron cloud density. ^{The 5} C-value describes the crystallinity of the disclosed 2DAC and can be controlled/tuned between about 0.5 and 0.8 by changing the growth parameters. Modifying the C-value can modify the electron cloud in the film, increasing or decreasing the proton conductivity. For example, applied techniques may include adjusting the power, pulse and/or angle of the laser used in the disclosed 2DAC.

In selected embodiments, the elastic modulus E of the disclosed 2DAC suspension film is greater than 200 GPa and the fracture energy is greater than 20 J/m ² (>20 J/m ² ), which is more than twice that of graphene. Evidence of the same is shown, for example, in Figure 7, where the nanoindentation on the disclosed suspended 2DAC film exhibits an elastic modulus E (>200 GPa) (right) in excess of 200 GPa, and the suspended 2DAC film undergoes ultimate stress by the AFM tip. shows a breaking energy exceeding 20 J/m ² after application. Thus, characterizing these mechanical properties of the disclosed 2DAC layer increases the lifetime of the application. For example, the disclosed barrier prevents gas crossover and thus prevents corrosion of the electrolyte and catalyst layers. The strong mechanical properties and particularly high fracture toughness of the disclosed 2DAC layer ensure a long lifetime of the barrier used and thus increase the overall performance of the fuel cell.

The disclosed 2DAC layer or film may be further modified during growth or post-treatment by other non-limiting techniques including, for example, reactive oxygen ion plasma, argon sputtering, ozone treatment or electron beam exposure. The atomic structure of the disclosed 2DAC can be modified to allow larger molecules to pass through. It is used to make gas separators.

Exemplary subject

Example 1

2DAC in a fuel cell as an anti-gas crossover layer:

12 shows an exemplary embodiment of an improved PEMFC 1200 according to one disclosed aspect, wherein the disclosed 2DAC functions as a proton conducting barrier layer. The PEMFC 1200 includes the disclosed 2DAC 1202 used as a barrier layer between the electrode catalyst assembly 1102 and the proton exchange membrane 1104. The disclosed 2DAC 1202 allows only protons to cross the 2DAC layer 1202 and prevents other gases and liquids from contacting the proton exchange membrane 1104 .

In this exemplary configuration, a plurality of electrocatalyst assemblies 1102 are arranged to encapsulate the disclosed 2DAC 1202 and proton exchange membrane 1104. The disclosed 2DAC 1202 may be disposed between each electrode catalyst assembly 1102 and the proton exchange membrane 1104 . Acting as a barrier, the 2DAC 1202 prevents fuel, waste and ionic contaminants from leaking into the proton exchange membrane 1104 and crossing over to the opposing electrode catalyst assembly 1102. These leaks are known to cause destruction of the proton exchange membrane 1104 and degradation of PEMFC performance. It can be readily appreciated that the disclosed 2DAC can be used as such or in other configurations such as layers, membranes, films, and the like.

Hydrogen and oxygen across the proton conducting membrane 1104 can be directly accounted for as a loss of fuel and a direct loss to fuel cell efficiency. The disclosed 2DAC 1202 can avoid this loss and significantly improve the efficiency of the fuel cell. Without the 2DAC 1202, other gases such as nitrogen can also pass through the proton conducting membrane 1104. This in turn can lead to fuel starvation, for example at catalyst sites. Such deficiencies are known to lead to catalyst degradation and thus loss of performance and reliability. ¹¹ The disclosed 2DAC 1202 will prevent other gases from crossing the proton conducting membrane 1104 and will prevent the aforementioned catalyst decomposition.

The proton exchange membrane 1104 often requires a high degree of hydration to conduct protons. By encapsulating the proton conductive film 1104 with an impermeable barrier, dehydration and death of the proton conductive film 1104 can be prevented. This will lead to long-term stability of the PEMFC 1200 performance.

One skilled in the art will readily appreciate that the disclosed technology is not limited to PEMFC applications, and may be implemented in other applications, such as redox flow batteries.

Example 2

2DAC as a single atomic layer proton exchange membrane:

13 shows an exemplary embodiment of an improved PEMFC 1300 in accordance with the disclosed aspects, wherein the disclosed 2DAC is used as a single atom proton conducting film. This aspect places the disclosed 2DAC 1202 in a configuration between the anode and cathode assemblies. In this configuration, the proton exchange membrane has been replaced with a single atomic layer of 2DAC (1202).

The single atomic layer of the disclosed 2DAC 1202 conducts protons and prevents fuel gases and liquids from passing through. This reduces the need for hydration of conventional proton exchange membranes. The high proton conductivity across the ultra-thin 2DAC 1202 produces high power with less ohmic losses than observed in conventional proton exchange membranes. The 2DAC layer 1202 is mechanically strong and has high fracture toughness providing long-term stability. The flexibility of 2DAC 1202 enables new creation of thin and flexible fuel cells.

Example 3

Self-assembled ultrathin homogeneous proton exchange membrane on 2DAC:

14 shows an exemplary embodiment of an improved PEMFC 1400 in accordance with the disclosed aspects, wherein the proton conducting film 1104 is a self-assembled Nafion® proton conducting film or coating 1104 formed on the disclosed 2DAC 1202. ) is used as Thus, the proton exchange membrane 1104 may be composed of a fluoropolymer such as Nafion®. The proton exchange membrane 1104 is generally formed with a minimum thickness of about tens of microns to prevent gas crossover and a maximum thickness of about several hundred microns to reduce transport loss across the proton exchange membrane 1104.

The disclosed 2DAC 1202 can act as a template for polymer assembly due to its unoccupied pi-orbitals. The amorphous structure of the disclosed 2DAC 1202 serves as a template for forming a thin film of Nafion® polymer. Despite the low crystallinity of the disclosed 2DAC, the pi orbitals of the carbon rings allow alignment of the Nafion® polymer to the surface. Thus, the 2DAC 1202 can be used to create an ultra-thin uniform layer of Nafion® coating 1104 on the surface of the 2DAC. The aforementioned Nafion® coating 1104 does not have pinholes. The proton conductivity of the ultrathin Nafion® coating 1104 is increased, while leakage and gas crossover are reduced due to the self-assembly of the disclosed 2DAC (1202).

Thus, as shown in the aspect of FIG. 14 , the electrocatalyst assembly 1102 may include a plurality of electrocatalyst assemblies. The proton exchange membrane 1104 may include a plurality of proton exchange membranes. The disclosed 2DAC 1202 may be disposed between a plurality of proton exchange membranes 1104, and the plurality of proton exchange membranes 1104 may be disposed between a plurality of electrode catalyst assemblies 1102.

To serve as the proton exchange membrane 1104, FIG. 14 shows that a Nafion® coating can be formed on either side of the 2DAC layer 1202 or film and can be configured to be encapsulated between the electrocatalyst assemblies 1102 in a fuel cell configuration. shows Thus, the disclosed 2DAC 1202 can be transferred to a Nafion® film, for example, by wet transfer similar to the case of CVD graphene. ¹²

In another exemplary embodiment, the disclosed 2DAC 1202 is also described in Patent Application: Defect-free direct dry delamination of cvd graphene using a polarized ferroelectric polymer WO2016126208A1 It can be transferred to Nafion® membrane by dry transfer as described above. As mentioned above, other transfer methods include, but are not limited to, thermal release tape, pressure-sensitive adhesive, spin coating, spray coating, and Langmuir-Blodgett techniques.

Example 4

Hydrogen Isotope Separation:

FIG. 15 shows an exemplary embodiment of an improved PEMFC according to the disclosed aspects wherein the fuel cell 1500 is configured to operate in reverse to separate hydrogen isotopes. The disclosed 2DAC 1202 promotes the transport of the nuclei of the hydrogen isotopes deuterium and tritium, albeit at a much lower rate than proton transport. The difference in transmission rate of 2DAC 1202 is used to separate hydrogen isotopes from protium (standard hydrogen). Such separation can be used, for example, in the production of heavy water for use in research and nuclear reactors, as well as in the removal of tritium from heavy water reactors used in, for example, nuclear reactors to maintain performance.

FIG. 15 shows a fuel cell 1500 with a 2DAC 1202 between an electrode catalyst assembly 1102 and a proton/deuteron conducting membrane 1502 . The fuel cell 1500 is operated in reverse mode by applying a bias across the proton/deuteron conducting membrane 1502. In this mode, fuel cell 1500 consumes electricity and produces hydrogen and deuterium. Hydrogen and deuterium are dissociated into protons and deuterium and transported across the disclosed 2DAC layer 1202 and proton/deuterium conducting membrane 1502.

As noted above, the atomic structure and carbon ring size of the disclosed 2DAC 1202 may be altered (eg, through exposure to plasma, e-beam, or other irradiation techniques). Thus, the structure of the disclosed 2DAC 1202 can be tuned by changing the ring size to affect the different rates of transport of protons and deuterons across the disclosed 2DAC layer 1202. The result may include a higher content of hydrogen compared to deuterium.

Thus, in one embodiment, a H ₂ /D ₂ :source ratio of 50% may result in a H ₂ /D ₂ :product ratio of 90%. However, in some disclosed embodiments the H ₂ /D ₂ source ratio and product ratio may vary. For example, if the transport rate of H+ is 10 times that of D+, the source ratio is H ₂ /D ₂ =1 and the product ratio is H ₂ /D ₂ =10.

Example 5

Gas Selective Membrane:

16 illustrates an exemplary system 1600 for gas separation by the disclosed modified 2DAC 1202 in accordance with the disclosed aspects. The disclosed 2DAC 1202 can be modified by irradiation techniques such as electron beam and ion plasma to allow larger molecules to pass through, thereby enabling a gas selective film. Thus, the disclosed 2DAC 1202 remains a barrier to all molecules larger than those specified by the strain parameters.

16 shows an example of how the disclosed modified 2DAC 1202 can be used as a membrane or layer used, for example, to separate gas mixtures. For example, the modified 2DAC film 1602 between the first stage 1604 and the second stage 1606 can be modified to allow H ₂ and O ₂ to pass through; The modified 2DAC film 1604 between the second stage 1606 and the third stage 1608 may be modified so that only H ₂ can pass therethrough. Applying a negative pressure gradient from stage 1 to stage 3 and recycling the gas through the system 1600, stage 1 contains only CO ₂ , stage 2 contains only O ₂ , and stage 3 contains only H ₂ . Thus, there is gas separation in system 1600.

In summary, the two-dimensional amorphous carbon (2DAC) of the disclosed embodiment may include a single atomic layer of carbon atoms in a non-crystalline amorphous structure. In their pristine state, the random arrangement of the atoms enables high transverse proton conductivity and a barrier to all large atoms and molecules (eg H ₂ , O ₂ , CH ₄ ). This highly proton conducting membrane can be implemented in fuel cell, hydrogen generation and deuterium production applications, for example.

The atomic structure and carbon ring size of the disclosed 2DAC can be modified through exposure to plasma, e-beam or other irradiation techniques. This allows larger molecules to pass through, extending the use of the disclosed 2DAC to numerous gas separation applications. The disclosed 2DAC is unique in that it possesses high proton conductivity while introducing only a very single atomic layer thickness. Compared to other two-dimensional materials, for example, mechanical toughness means that the disclosed 2DAC requires about three times more energy to propagate a crack in the disclosed 2DAC. The disclosed 2DAC is impermeable to molecular hydrogen and larger molecules. Thus, the disclosed 2DAC prevents gases from fouling the electrode catalyst assembly 1102 across the proton exchange membrane. The disclosed 2DAC has a proton transport rate of approximately 0.1-10 S/cm ² . This high transport rate improves performance over existing fuel cells. The disclosed 2DAC provides selective transport of hydrogen nuclear isotopes. Thus, the difference in transport rate makes the disclosed 2DAC a more efficient separator for hydrogen isotopes.

While many aspects of the present disclosure have been described in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention as defined in the appended claims. Further, it should be understood that all examples of this disclosure, while illustrative of many aspects of the invention, are provided as non-limiting examples and, therefore, are not intended to limit the various aspects to those described.

references

The following references are mentioned above and are incorporated herein by reference:

1. Sharaf, OZ & Orhan, MF “An overview of fuel cell technology: Fundamentals and applications.” Renewable and Sustainable Energy Reviews 32, 810-853 (2014).

2. Schmittinger, W. & Vahidi, A. “A review of the main parameters influencing long-term performance and durability of PEM fuel cells. ” Journal of Power Sources 180, 1-14 (2008).

3. Ferrari, AC et al . “Interpretation of Raman spectra of disordered and amorphous carbon.” Physical Review B 61 , 14095-14107 (2000).

4. Robertson, J. “Ultrathin carbon coatings for magnetic storage technology.” Thin Solid Films 383 , 81-88 (2001).

5. Hu, S. et al . “Proton transport through one-atom-thick crystals.” Nature 516 , 227-230 (2014).

6. Das, S. et al . “Measurements of adhesion energy of graphene to metallic substrates.” Carbon 59 , 121-129 (2013).

7. Choi, WJ et al. “Effects of substrate conductivity on cell morphogenesis and proliferation using tailored, atomic layer deposition-grown ZnO thin films.” Scientific Reports 5 , 9974 (2015).

8. Schriver, M. et al . “Graphene as a Long-Term Metal Oxidation Barrier: Worse Than Nothing” ACS Nano 7 , 5763-5768 (2013).

9. Wang, JS et al . “The mechanical performance of DLC films on steel substrates.” Thin Solid Films 325 , 163-174 (1998).

10. Marcon, et. al . “The head-disk interface roadmap to an areal density of 4 Tbit/ ^{in 2} .” Advances in Tribology 2013 , 1-8 (2013).

11. Reiser, CA “A reverse-current decay mechanism for fuel cells.” J Electrochem Solid-State Letters 8 , A273-A276 (2005).

12. Li, XS et al. Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils Science 324 , 1312-1314 (2009).

All documents, patents, journal articles and other materials cited in this application are incorporated herein by reference.

Any reference in this specification to any prior publication (or information derived therefrom) or known matter constitutes a part of the general knowledge in the field of which an earlier publication (or information derived therefrom) or known matter was attempted with respect to this specification. It should not be taken as an acknowledgment or admission, or any form of suggestion, that it constitutes.

Although the invention has been disclosed with reference to particular aspects, various modifications, alterations and changes to the described aspects may be made without departing from the spirit and scope of the invention as defined in the appended claims. this is possible Accordingly, the present invention is not intended to be limited to the described aspects, but is intended to have the full scope defined by the language of the following claims and equivalents thereof.

Claims (31)

As a fuel cell, the fuel cell comprises:
an electrode catalyst assembly;
two-dimensional (2D) amorphous carbon having a crystallinity (C) of 0.8 or less, wherein the two-dimensional (2D) amorphous carbon has a fracture energy of greater than 20 J/m2; and
A proton exchange membrane;
Wherein the two-dimensional amorphous carbon is disposed between the electrode catalyst assembly and the proton exchange membrane, and is configured to conduct protons and prevent gas crossover.
According to claim 1,
Wherein the two-dimensional amorphous carbon is a membrane. According to claim 1,
Wherein the two-dimensional amorphous carbon is a film. According to claim 1,
The two-dimensional amorphous carbon has a resistivity of 0.01 to 1000 Ω-cm (including the boundary value of this range), a fuel cell. According to claim 1,
The electrode catalyst assembly includes a plurality of electrode catalyst assemblies,
Wherein the proton exchange membrane is disposed between the plurality of electrode catalyst assemblies, and the two-dimensional amorphous carbon is disposed between each electrode catalyst assembly and the proton exchange membrane to encapsulate the proton exchange membrane.
According to claim 1,
The electrode catalyst assembly includes a plurality of electrode catalyst assemblies,
The proton exchange membrane includes a plurality of proton exchange membranes,
The two-dimensional amorphous carbon is disposed between the plurality of proton exchange membranes, and the plurality of proton exchange membranes are disposed between the plurality of electrode catalyst assemblies.
According to claim 1,
The proton exchange membrane is a fluoropolymer, fuel cell.
According to claim 7,
The fuel cell, wherein the fluoropolymer is Nafion®.
As a fuel cell, the fuel cell comprises:
an electrode catalyst assembly; and
Two-dimensional (2D) amorphous carbon having an atomic structure consisting of non-hexagonal carbon rings and hexagonal carbon rings, wherein the two-dimensional amorphous carbon has a break energy greater than 20 J/m2; ,
the ratio of hexagonal carbon rings to non-hexagonal carbon rings is less than 1;
wherein the two-dimensional amorphous carbon has a crystallinity (C) of less than 1, an sp ³ /sp ² bonding ratio of 0.2 or less, and is configured to conduct protons and prevent gas crossover.
According to claim 9,
The two-dimensional amorphous carbon is a film, a fuel cell.
According to claim 9,
Wherein the two-dimensional amorphous carbon is a film.
According to claim 9,
The two-dimensional amorphous carbon has a resistivity of 0.01 to 1000 Ω-cm (including the boundary value of this range), a fuel cell.
According to claim 9,
A fuel cell, further comprising a proton exchange membrane.
According to claim 13,
The two-dimensional amorphous carbon is disposed between the electrode catalyst assembly and the proton exchange membrane, the fuel cell.
According to claim 13,
The electrode catalyst assembly includes a plurality of electrode catalyst assemblies,
Wherein the proton exchange membrane is disposed between the plurality of electrode catalyst assemblies, and the two-dimensional amorphous carbon is disposed between each electrode catalyst assembly and the proton exchange membrane to encapsulate the proton exchange membrane.
According to claim 13,
The electrode catalyst assembly includes a plurality of electrode catalyst assemblies,
The proton exchange membrane includes a plurality of proton exchange membranes,
The two-dimensional amorphous carbon is disposed between the plurality of proton exchange membranes, and the plurality of proton exchange membranes are disposed between the plurality of electrode catalyst assemblies.
According to claim 13,
The proton exchange membrane is a fluoropolymer, fuel cell.
According to claim 17,
The fuel cell, wherein the fluoropolymer is Nafion®.
According to claim 1,
The two-dimensional amorphous carbon has an sp ³ /sp ² bonding ratio of 0.2 or less, a fuel cell.
delete delete delete delete delete delete delete delete delete delete delete delete