CN112534611B

CN112534611B - Proton conducting two-dimensional amorphous carbon films for gas membrane and fuel cell applications

Info

Publication number: CN112534611B
Application number: CN201980050734.1A
Authority: CN
Inventors: 巴巴罗斯.欧伊尔迈兹; 亨里克.安德森; 卓志达
Original assignee: National University of Singapore
Current assignee: National University of Singapore
Priority date: 2018-07-30
Filing date: 2019-07-30
Publication date: 2024-07-16
Anticipated expiration: 2039-07-30
Also published as: CN112534611A; JP7217055B2; JP2021533532A; KR102561413B1; KR20210033991A; DE112019003128T5; WO2020027728A1

Abstract

The present disclosure relates generally to two-dimensional amorphous carbon (2 DAC) coating techniques. Proton conducting 2DAC membranes can be used in fuel cell, hydrogen generation, and deuterium manufacturing applications. More particularly, the present disclosure relates to a fuel cell comprising an electrode catalyst assembly and two-dimensional (2D) amorphous carbon, wherein the crystallinity (C) of the 2D amorphous carbon is less than or equal to 0.8.

Description

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

Technical Field

The present disclosure relates generally to two-dimensional amorphous carbon (2 DAC) coating techniques. More particularly, the present disclosure relates to proton conducting 2DAC membranes for fuel cell, hydrogen generation and deuterium manufacturing applications.

Background

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

Disclosure of Invention

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 crystallinity (C) of the 2D amorphous carbon is less than or equal to 0.8.

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

According to a third broad aspect, the present invention provides a fuel cell comprising an electrode catalyst assembly and two-dimensional (2D) amorphous carbon having an atomic structure consisting of non-hexagonal carbon rings and a ratio of hexagonal to non-hexagonal carbon rings of less than 1.0.

Drawings

The accompanying drawings, which are incorporated herein and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with the general description given above and the detailed description given below, serve to explain features of the invention.

Fig. 1 is a schematic diagram showing a composite of the disclosed atomic thin films showing random hexagonal rings (not graphene) that exhibit continuity and ordering, according to one embodiment of the present disclosure.

Fig. 2 shows a TEM image showing hexagonal and non-hexagonal amorphous films according to one embodiment of the present disclosure.

Fig. 3 shows the thickness of the disclosed carbon film measured by Atomic Force Microscopy (AFM) on boron nitride, according to one embodiment of the present disclosure.

Fig. 4 shows raman spectra of amorphous films and nanocrystalline graphene on SiO ₂ according to one embodiment of the present disclosure.

Fig. 5 shows TEM diffraction of atomic thin amorphous carbon (left) and graphene (right) according to one embodiment of the present disclosure.

Fig. 6 shows the transmittance of the disclosed carbon film according to one embodiment of the present disclosure.

Fig. 7 shows a demonstration of mechanical properties of a 2D amorphous film and a suspended carbon film according to one embodiment of the present disclosure.

Fig. 8 illustrates the electrical properties of a 2DAC according to an embodiment of the disclosure.

Fig. 9 illustrates a composite material grown on a different substrate according to one embodiment of the present disclosure.

Fig. 10 shows X-ray photoelectron spectroscopy (XPS) of a 2DAC on Cu according to one embodiment of the present disclosure.

Fig. 11 shows a conventional configuration of a proton exchange membrane (proton exchange membrane ) Fuel Cell (PEMFC) according to the prior art.

Fig. 12 illustrates an embodiment of a 2DAC implemented as a barrier layer between an electrode and a proton exchange membrane according to an embodiment of the disclosure.

Fig. 13 illustrates an embodiment of implementing a 2DAC in a configuration between anode and cathode assemblies according to an embodiment of the disclosure.

FIG. 14 shows a process in which an exemplary 2DAC film is formed on either side, in accordance with one embodiment of the present disclosureAnd encapsulate it between the electrode and the catalyst layer in the fuel cell construction.

Fig. 15 shows an exemplary fuel cell embodiment in which a 2DAC layer is between an electrode/catalyst assembly and a proton/deuteron conductive membrane (conductive membrane sheet, conducting membrane) according to one embodiment of the disclosure.

Fig. 16 is an illustrative example of how a modified membrane may be used to separate a gas mixture in accordance with one embodiment of the present disclosure.

Detailed Description

Definition of the definition

Where a definition of a term deviates from the commonly used meaning of the term, the applicant intends to make use of the definition provided below, unless specifically indicated.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of any subject matter as claimed. In the present application, the use of the singular includes the plural unless specifically stated otherwise. It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. In the present application, the use of "or" means "and/or" unless stated otherwise. Furthermore, the use of the terms "include" and other forms of information, such as "include," include, "and" comprise (included), are not limiting.

For the purposes of this disclosure, the terms "comprising," "having," and variations thereof are intended to be open-ended and mean that there may be additional elements other than the listed elements.

For the purposes of this disclosure, directional terms, such as "top," "bottom," "upper," "lower," "above," "below," "left," "right," "horizontal," "vertical," "upper," "lower," etc., are used for convenience only in describing various embodiments of the present disclosure. Embodiments of the present invention may be oriented in various ways. For example, the figures, devices, etc. shown in the drawings may be flipped, rotated 90 ° in any direction, inverted, etc.

For the purposes of this disclosure, a value or property is "based on" a particular value, property, degree of satisfaction of a condition, or other factor (if the value is derived by mathematical calculation or logical decision using the value, property, or other factor).

For the purposes of the present invention, it should be noted that some quantitative expressions given herein are not modified by the term "about" in order to provide a more concise description. It will be understood that each quantity given herein is intended to refer to an actual given value, whether or not the term "about" is explicitly used, and is also intended to refer to an approximation of that given value based on what one of ordinary skill in the art would reasonably infer, including approximations due to experimental and/or measurement conditions for that given value.

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

For the purposes of the present invention, the term "amorphous" refers to a lack of defined form or to no particular shape or to no shape. Amorphous, as an amorphous solid, refers to a solid that lacks the long range order characteristic of crystals.

For the purposes of the present invention, the term "amorphous carbon" refers to carbon without any long-range crystalline structure.

For the purposes of the present invention, the term "atomically thin amorphous carbon" refers to amorphous carbon consisting of a layer of about one to five carbon atoms in a plane, where the carbon atoms are predominantly sp ² bonds between them and thus form a layer. It should be understood that the layers may be stacked and that such stacking of layers is considered to be within the scope of the present invention.

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

For the purposes of the present invention, the term "carbocycle size" refers to the size of the ring of carbon atoms. In some disclosed embodiments, the number of atoms in a 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 consisting essentially of sp ³ bonds between carbon atoms.

For the purposes of the present invention, the term "differentiated stem cell" refers to a process of directing non-specialized (unspecialized) stem cells to a specific type of cell having a functional trait. In the disclosed embodiments, differentiation occurs due to a combination of chemical and basal inducing factors.

For the purposes of the present invention, the term "D/G ratio" refers to the ratio of the intensities of the D and G peaks in the raman spectrum.

For the purposes of the present invention, the term "Electrochemical Cell (EC)" refers to a device capable of generating electrical energy from a chemical reaction or otherwise facilitating electrical energy. Electrochemical cells that produce electricity are called voltaic cells or galvanic cells, and other cells are called electrolytic cells, which are used to drive chemical reactions such as electrolysis. One common example of a primary cell is a standard 1.5 volt battery for consumer use. The battery (battery) may be composed of one or more cells connected in parallel or in series.

For the purposes of the present invention, the term "fuel cell" refers to an electrochemical cell that converts chemical energy from a fuel into electricity through the electrochemical reaction of hydrogen fuel with oxygen or other oxidizing agents. Fuel cells can be distinguished from batteries in that a continuous source of fuel and oxygen (typically from air) is required to maintain a chemical reaction, whereas in batteries chemical energy comes from chemicals already present in the battery. The fuel cell can continuously generate electricity as long as fuel and oxygen are supplied.

For the purposes of the present invention, the term "graphene" refers to an allotrope (form) of carbon, which consists of a single layer of carbon atoms arranged in a hexagonal lattice. It is the basic structural element of many other allotropes of carbon (e.g., graphite, charcoal, carbon nanotubes, and fullerenes). It can be considered as an infinitely large aromatic molecule (limit of the planar (flat) polycyclic aromatic hydrocarbon family). Graphene has many unusual properties, including its powerful material properties, ability to efficiently conduct heat and electricity, and is also almost transparent.

For the purposes of the present invention, the term "membrane" refers to a layer that acts as a selective barrier that may allow some elements to pass through, but prevent other molecules, ions, or other small particles, for example.

For the purposes of the present invention, the termRefers to sulfonated tetrafluoroethylene-based fluoropolymer-copolymers. It is the first of a class of synthetic polymers with ionic properties called ionomers.The unique ionic nature of (c) is a result of incorporating sulfonate-terminated perfluorovinyl ether groups into the tetrafluoroethylene (Teflon) backbone.Used as proton conductors for Proton Exchange Membrane (PEM) fuel cells and have excellent thermal and mechanical stability.

For the purposes of the present invention, the term "proton exchange membrane" or "polymer electrolyte membrane" (PEM) refers to a semipermeable membrane that is typically made of ionomers and is designed to act as both an electronic insulator and a reactant barrier (e.g., to oxygen and hydrogen gases) while conducting protons. In some embodiments, the proton exchange membrane or polymer electrolyte membrane may also be referred to as a proton conducting membrane. A part of the basic functions of the PEM may include reactant separation and proton transport while blocking the direct electron path through the membrane (sheet). The PEM may be manufactured from a pure polymer membrane or from a composite membrane in which other materials are embedded in a polymer matrix. In some disclosed embodiments, the PEM may be characterized primarily by proton conductivity (σ), methanol permeability (P), and thermal stability. PEM fuel cells may utilize a solid polymer membrane (thin plastic film) as the electrolyte, wherein the polymer is permeable to protons when saturated with water, but it does not conduct electrons.

For the purposes of the present invention, the term "Proton Exchange Membrane Fuel Cell (PEMFC)" refers to one type of fuel cell that has been developed primarily for transportation applications as well as stationary fuel cell applications and portable fuel cell applications. Their notable features include a lower temperature/pressure range (50 to 100 ℃) and a special proton conducting polymer electrolyte membrane. PEMFCs generate electricity and operate on the reverse principle of Polymer Electrolyte Membrane (PEM) electrolysis, which consumes electricity. They are leading candidates for replacement of aged alkaline fuel cell technologies. In some applications, the PEMFC may also be referred to as a polymer electrolyte membrane fuel cell.

For the purposes of the present invention, the term "proton transport" refers to the transport of protons across an electrically insulating membrane.

For the purposes of the present invention, the term "raman spectroscopy" refers to spectroscopic techniques for observing vibrations, rotations, and other low frequency modes in a system. Raman spectroscopy is commonly used in chemistry to provide structural fingerprints that can be used to identify molecules. Which relies on inelastic scattering or raman scattering of monochromatic light (typically from lasers in the visible, near infrared or near ultraviolet range). The laser interacts with molecular vibrations, phonons, or other excitations in the system, causing the energy of the laser photons to move up and down. The movement of energy gives information about the vibration modes in the system.

For the purposes of the present invention, the term "raman spectrum" refers to the phenomenon in which the scattering intensity is a function of the frequency shift (depending on the state of the spin (rovibronic) of the molecule). For molecules exhibiting raman effect, their electric dipole-electric dipole polarizability must be changed with respect to the vibration coordinates corresponding to the state of rotation. The intensity of raman scattering is proportional to this change in polarizability.

For the purposes of the present 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 embodiments, self-assembly allows the formation of ultrathin films having different properties than bulk properties.

For the purposes of the present invention, the term "sp ³/sp² ratio" refers to the type of carbon bond found in a2 DAC. sp ² bonds allow for higher growth factor bonds.

For the purposes of the present invention, the term "substrate" refers to a structural support for the disclosed two-dimensional (2D) amorphous carbon film. In select applications, the disclosed embodiments provide a substrate to mechanically support, for example, a 2DAC film, which may otherwise be too thin to perform its function without damage. The substrate may be considered as a material for: growth of the disclosed 2DAC or 2DAC film on the surface of the substrate.

For the purposes of the present invention, the term "two-dimensional (2D) amorphous carbon film" refers to the atomically thin amorphous carbon to the thinnest amorphous carbon possible (e.g. monoatomically thick) that can be grown directly on, for example, substrates including those with low melting temperatures, non-catalytic, and those substrates also including metal, glass, and oxide surfaces. Growth on other substrates is possible due to the low temperature of the disclosed 2DAC film growth. The disclosed embodiments of the 2DAC film may be presented as an unsupported film (free-STANDING FILM) as disclosed herein or as a coating on a substrate. Although the disclosed 2DAC film is amorphous, the carbon atoms bond with a plurality of adjacent carbon atoms in the plane to form a strong network, which is very stable even when peeled (unsupported) from its growth substrate. The carbon material also has the property of adhering well to the metal surface, thereby ensuring complete coverage over the entire substrate. The inherent thinness (thinness) and high strength of the disclosed 2DAC film also allows it to withstand bending of metal substrates without cracking.

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

Description of the invention

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Fuel cells provide clean and efficient energy conversion of hydrogen and oxygen sources, which provides electrical energy and clean water as waste. One of the more promising types of fuel cells is Proton Exchange Membrane Fuel Cells (PEMFC), which have been commercialized. ¹ In a conventional configuration, the PEMFC can consist essentially of three components: anode, cathode and proton exchange membrane. Fig. 11 illustrates the operation principle of an exemplary conventional PEMFC 1100. The hydrogen dissociates into protons and electrons at the anode 1106, and the protons pass through the proton exchange membrane 1104 to the cathode 108; and electrons are forced through an external circuit 1110 to reach the cathode 1108. Protons interact with electrons and oxygen at the cathode 108, producing wastewater (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 passing through the membrane. The electrode/catalyst layer or electrode catalyst assembly 1102 consists of an electrode, typically made of carbon, decorated with catalyst particles made of platinum, ruthenium or other catalytically active materials. The electrode catalyst assembly 1102 has a porous structure that allows gas diffusion through the layer. The hydrogen fuel that diffuses through the anode electrode catalyst assembly reacts with the catalyst particles and dissociates into protons and electrons. At the cathode electrode catalyst assembly, oxygen diffuses through the assembly and reacts with protons and electrons to form water. Typically, an inert gas (e.g., nitrogen) is flowed through the system to stabilize the operating pressure, fuel supply, and to help bring excess gas and liquid to the exhaust (exhaust).

The gas passing through the proton exchange membrane 1104 is interesting because it not only reduces the net efficiency, but also results in the formation of hydrogen peroxide at the electrodes, which results in pinholes and thinning of the proton exchange membrane 104. These events exacerbate gas crossover and accelerate fuel cell failure. ²

The gas-leaping can also affect the efficiency of the catalyst particles that promote chemical reactions at the anode and cathode. Proton exchange membrane 1104 may be further damaged by ionic contaminants such as alkali metals and ammonium ions. ²

In order to prevent degradation of the gas-leaping and proton exchange membrane, embodiments of the disclosed invention provide a 2DAC layer that may be incorporated as a gas-leaping prevention layer. In some embodiments, the disclosed 2DAC is provided as a film layer. In an exemplary configuration, the disclosed 2DAC membrane may be attached to a proton exchange membrane 1104. The disclosed 2DAC membrane has no limitation of proton conductivity due to its excellent proton conductivity and final thinness. The disclosed 2DAC membrane is a barrier to all other gases and ions and thus increases the lifetime of the PEMFC employed. Further discussion of the disclosed 2DAC film is provided below.

The disclosed embodiments relate to a new composite material comprising an atomically thin (monolayer) amorphous carbon on top of a substrate (metal, glass, oxide). Amorphous carbon adheres very well to the substrate on which it is grown. Thus, amorphous carbon materials provide unique properties. For example, the disclosed amorphous carbon materials are suitable for applications that utilize substrates that require a coating for a specific purpose. Exemplary applications may include, but are not limited to, biomedical applications.

The present disclosure provides a new form of carbon, known as two-dimensional (2D) amorphous carbon (2 DAC). The disclosed embodiments provide the thinnest amorphous carbon possible (e.g., about a single atom thick) within a 2DAC, which can be grown, for example, directly on metal substrates, including those with low melting temperatures, non-catalytic, and also including glass and oxide surfaces. In an alternative embodiment, having a single atomic thickness is the preferred material and a lower thickness limit may be established for a2 DAC. The disclosed embodiments may include thicknesses ranging up to several atomic thicknesses (e.g., 10 atomic thicknesses or about 3+nm). The disclosed 2DAC may be provided as a two-dimensional (2D) amorphous carbon film. However, it is still important to note that as the thickness of the disclosed 2DAC increases, it is still structurally different from any other amorphous carbon material thickness that may be present as disclosed herein (e.g., sp ³ to sp ² ratio).

Growth on other substrates is possible due to the low temperature of the disclosed 2DAC film growth. Although the disclosed 2DAC film is amorphous, the carbon atoms bond to multiple adjacent carbon atoms in the plane to form a strong network, which is very stable even when peeled (unsupported) from its growth substrate. Thus, each carbon atom is bonded to a plurality of carbon atoms so as to have a high density of bonds (linkages). The disclosed 2DAC also has the property of adhering well to metal surfaces, thereby ensuring complete coverage. The material properties (such as those disclosed below) of the disclosed 2DAC films, such as inherent thinness and high strength, also allow them to withstand bending of a metal substrate without cracking.

According to disclosed embodiments, amorphous carbon may be defined as a form of carbon without long range structural order. It exists in several forms and is often referred to by its forms by different names such as diamond-like carbon, glassy carbon, soot, etc. Amorphous carbon can be produced by a variety of techniques including, for example, chemical vapor deposition, sputter deposition, and cathodic arc deposition, among others. In conventional applications, amorphous carbon has been present in three-dimensional form (or bulk). The two-dimensional equivalent form of carbon is graphene; however, graphene exists only as a crystalline material (single crystal or polycrystalline). For graphene to be synthesized, it requires high temperatures and grows mainly on copper. In accordance with the present disclosure, embodiments of the disclosure have sought to produce continuous two-dimensional forms of amorphous carbon that grow at much lower temperatures and on any substrate. The disclosed composite of 2DAC film and substrate has very different properties than bulk amorphous carbon and even single layer graphene.

The disclosed implementations of the 2DAC may exist as follows: a membrane (e.g., a substrate-coated membrane), a membrane coating the inner surface of a porous structure, a suspended membrane, a rolled membrane, a tube, a fiber, or a hollow sphere. It is contemplated that the mechanical, electrical, optical, thermal, and other properties of the disclosed 2DAC vary, for example, depending on the shape of the 2 DAC. For example, a tube comprising the disclosed 2DAC will have high mechanical strength in the axial direction and a softer response in the radial direction. The disclosed 2DAC can be prepared in various forms to use different properties for individual applications.

Fig. 1 shows a schematic 100 of the disclosed composite material with a TEM image of the carbon material on the top surface of the substrate. The composition of matter disclosed is a new composite of atomically thin amorphous carbon 102 on top of a substrate 104 (e.g. metal or glass, oxide).

The disclosed composite material may refer to an atomically thin 2D amorphous carbon (2 DAC) on top of any substrate. According to disclosed embodiments, the disclosed 2DAC films on top of the disclosed substrates may be defined in terms of their atomic structure and their properties.

A more careful examination and definition of atomic structure can be presented as follows: fig. 2 shows a TEM image showing hexagonal and non-hexagonal amorphous films according to one embodiment of the present disclosure. The upper left image of fig. 2 shows a high resolution TEM image of the disclosed 2DAC film including hexagonal and non-hexagonal shapes. A lower left schematic of the TEM image of the upper left image is provided to aid viewing. The hexagons are colored green instead of red or blue. The upper right display is an FFT showing a ring structure without a clear diffraction pattern.

Referring to the TEM image of fig. 2, the 2DAC film is a monoatomic thick carbon film having a mixture of hexagonal rings and non-hexagonal rings in its structure. The rings are fully connected to each other, forming a network of polygons in a large area film on the scale of at least microns. The ratio of hexagonal to non-hexagonal is a measure of crystallinity (or amorphous) C. Non-hexagonal is in the form of a 4, 5, 7,8, 9 membered ring. C.ltoreq.0.8 for 2D amorphous films taken over a minimum imaging area of about 8.0nm ². The C value in fig. 2 is about 0.65. The disclosed embodiments may support a C value range between 0.5 and 0.8 and include 0.5 to 0.8. This is different from graphene where c=1 for a pure hexagonal network. The non-hexagons may be randomly distributed within the hexagonal matrix or formed along the boundaries of hexagonal domains (domains). The domains must not be larger than 5nm. The Fast Fourier Transform (FFT) of the image must not show diffraction points (fig. 2, top right). The 2DAC may be peeled from the substrate without support or may be transferred to another substrate. Thus, in some embodiments, the disclosed 2DAC may be separated from the surface of the substrate to obtain an unsupported 2DAC film.

Fig. 3 shows the thickness (i.e., height) of the separated disclosed 2DAC film measured by AFM on Boron Nitride (BN). Based on the disclosed invention, the following properties apply: fig. 3 shows an AFM of the disclosed 2DAC film transferred to Boron Nitride (BN). The thickness of the disclosed 2DAC is aboutCorresponding to graphene of only one atom thickness (thickness range when measured on BNTo the point ofAnd comprisesTo the point of). The thickness was also confirmed by the TEM image in fig. 1. In addition, the film was found to be uniform.

Fig. 4 shows raman spectra 400 of amorphous films and nanocrystalline graphene on SiO ₂. The Raman spectrum of the separated film showed no 2D peak (-2700 cm-1), but a broad G peak (-1600 cm-1) and D peak (-1350 cm-1). The broadening of the D and G peaks generally indicates the transition from nanocrystalline graphene to amorphous film, as previously reported. ³ The domain size was estimated to be about 1-5nm based on the intensity ratio of the D and G peaks. ³ Raman spectroscopy is used as a characterization tool to represent the TEM image in fig. 2 in large areas.

Fig. 5 provides a comparison 500 of TEM diffraction of atomic thin amorphous carbon (left) and graphene (right) according to one embodiment of the present disclosure. Further evidence regarding the amorphous nature of the disclosed isolated films was confirmed by TEM diffraction, where no sharp diffraction spots were detected, as opposed to graphene, where diffraction spots indicative of crystallinity were clearly seen. The diffraction rings in fig. 7 (top) indicate domain sizes of <5 nm. The diffraction data for the amorphous film is consistent with the FFT image in fig. 2. In this case, the 2DAC film is unsupported.

Turning to fig. 6, a graph 600 illustrates the transparency of the disclosed carbon film according to one embodiment of the present disclosure. At a wavelength of 550nm, the optical transparency is 98%, and as the wavelength increases, the transparency increases. Thus, selected embodiments provide an optical transparency of 98% or greater at a wavelength of 550nm or greater. Again, the disclosed carbon films differ from graphene in that the transparency of graphene of a monolayer is at most 97.7% throughout the visible wavelength (400 nm-700nm, inclusive) and decreases with increasing number of layers. Notably, the transparency of the 2DAC film does not decrease rapidly at short wavelengths (< 400 nm) as seen in graphene.

The elastic modulus E of the suspended film is higher than 200GPa, which is higher than bulk glassy carbon (e=60 GPa). ⁴ The limit strain before mechanical failure was 10% much higher than the reported limit strain for other amorphous carbon. FIG. 7 shows nanoindentation on a suspended carbon film by an Atomic Force Microscope (AFM) (e.g., bruker model: MPP-11120) tip and the suspended carbon film after application of extreme stress. The amorphous nature of the disclosed 2DAC film prevents collapse of the suspended film in fig. 7 (bottom). Instead, the film exhibits a ductile response to a limited stress level.

The 2DAC thin film of the disclosed invention has a high resistance, whose resistivity ranges from 0.01 to 1000 Ω -cm, depending on the C value adjusted by the growth conditions. Fig. 8 is a schematic 800 of the electrical properties of 2D amorphous carbon showing an I-V curve 802 of a 2D amorphous film and a histogram 804 of measured resistivity values for a particular C value. Measurement techniques/methods are used to generate resistivity values. In the calculation, the ratio of the data from the I-V curve 802 is used to obtain each resistivity data point in the histogram 804. Accordingly, the length to width ratio of 2D amorphous carbon in fig. 8 (left) is 1:100. In contrast, graphene has a resistivity value of 10 ^-6 Ω -cm, while bulk glassy carbon (also 100% C-C sp ²) has a value in the range of 0.01 to 0.001 Ω -cm.

A monolayer film containing an n-membered ring of >6 is naturally a membrane that can selectively pass a gas, ion, liquid or other substance of sufficiently small size to pass through the 7, 8, 9 membered ring. In particular, the disclosed 2DAC films can pass protons 10 times as efficiently at room temperature than crystalline monolayer boron nitride. ⁵ For the disclosed 2DAC membranes, the resistivity of protons flowing across the membrane at room temperature is 1-10Ω -cm ².

Fig. 9 illustrates a composite material grown on a different substrate according to one embodiment of the present disclosure. The left side shows pictures of titanium, glass and copper coated with atomically thin amorphous carbon. In the upper right, raman spectra from the coated areas are shown, showing similar responses independent of the substrate. Finally, in the lower right, a raman plot of the G/D peak ratio of the 2DAC film on top of titanium is shown, showing its complete coverage. The disclosed composite materials (i.e., the disclosed 2DAC and substrate) may be produced from any metal (catalytic or non-catalytic) or on glass or oxide. Thus, the disclosed embodiments provide that the 2DAC can be grown directly on any of the disclosed desired substrate materials. This is different from graphene, which can only be grown on catalytic substrates (e.g. copper) and needs to be transferred to all other substrates. Accordingly, in contrast to deposition methods of amorphous or diamond-like carbon (which cannot exist in such a thickness: less than 1nm and still be considered continuous), the disclosed composite material comprises an atomically thin (< 1 nm) and continuous layer of two-dimensional amorphous carbon firmly bonded to a host substrate.

In general, when the adhesion of a film on a substrate is poor, the area of the film may become detached from the substrate and thus will provide poor or little protection to the substrate. Accordingly, embodiments of the present disclosure provide an improved film that provides uniformity and strong adhesion across the applied surface of the substrate. Accordingly, the disclosed 2DAC film is preferably formed as a continuous film over substantially the entire substrate surface or at least over the applied surface. Unlike conventional designs, such as graphene (which can be easily detached (e.g., adhesion of 10-100J/m 2) in Cu, the disclosed atomically thin 2DAC films disposed on Cu, for example, adhere very well to substrates with an adhesion of >200J/m 2. ⁶ This example provides further evidence to distinguish the disclosed 2DAC film from graphene. (although exemplary embodiments of Cu substrates are described, embodiments of applying the disclosed 2DAC to any substrate may be applied in accordance with the disclosed embodiments of the invention.) furthermore, adhesion energy is evident in all substrate materials on which the disclosed 2DAC film is grown (including, for example, stainless steel, titanium, glass, nickel, and aluminum substrates). It should be appreciated that the above substrates are exemplary and that the teachings of the present disclosure may be applied to any substrate desired.

Generally, any attempt to transfer any 2D material to a material by conventional materials and methods has previously resulted in defects and cracks in the transferred material(s) and reduced coverage on the substrate, for example. This is due at least in part to the fact that: the transfer process typically takes many mechanical steps and may use chemicals that can cause cracks and defects in conventional film applications. However, the disclosed 2DAC films do not require transfer from a growth substrate to a target substrate, for example. In addition to the improved adhesion properties of the disclosed 2DAC films, the enhanced properties of the disclosed 2DAC films also provide and ensure consistent and complete coverage directly across/on the substrate. Whereby a uniform and complete coverage is obtained at least because there is no need to transfer the disclosed 2DAC film, as it is fully capable of being grown uniformly and successfully directly on its bulk substrate.

The disclosed 2DAC films are designed to provide such reliable coverage and their excellent mechanical properties for adhering to a substrate (e.g. carbon), so the 2DAC films are well suited and reliable for applications requiring that the 2DAC films and composites have additional physical properties/requirements. Such physical characteristics may include the ability of the disclosed 2DAC films and/or composites to bend and/or stretch. This is ensured by the adhesion properties and capabilities of the disclosed 2DAC to the substrate. If there is non-uniform adhesion to the substrate (as for the transferred film), cracks in the film can form at areas of poor adhesion and are a cause of failure.

Accordingly, embodiments of the disclosed invention provide such a top amorphous carbon film 102: which covers the entire substrate 104 (raman plot of fig. 9) over which it is grown, making it very useful for applications requiring, for example, carbon coatings. The top amorphous carbon film 102 also acts as a defect-free diffusion barrier, thereby preventing oxidation and corrosion of the underlying substrate. The disclosed amorphous carbon film 102 prevents any galvanic corrosion of the substrate 104 due to the electrically insulating properties. The low conductivity of the disclosed 2DAC is beneficial for cell attachment and proliferation, as observed in recent reports. ⁷ Cells on the conductive substrate adhere to the surface by electrostatic interactions without focal adhesion. Focal adhesion is critical for cell proliferation and growth, and low conductivity is preferred for focal adhesion development and cell proliferation. The low conductivity is a result of the amorphous nature of the disclosed 2DAC (as observed by raman spectrum D/G peak intensity and sp ³/sp² ratio).

In contrast, graphene is known to deteriorate long-term corrosion. ⁸ The transfer of graphene makes it almost impossible to produce a flat continuous film without generating cracks and defects along the surface. The disclosed amorphous carbon film 102 material is a composite with the substrate 104, eliminating the need for transfer and the risk of cracks in the film 102.

The disclosed 2DAC film consists of sp ² -bonded carbon similar to glassy carbon; however, its thickness is only about one atomic layer thickThinner than any conventional reported amorphous carbon structure. Fig. 10 shows X-ray photoelectron spectroscopy (XPS) measurements of 2D amorphous carbon on Cu, with peak positions indicating sp ² or sp ³ bond types and peak intensities indicating fractions of the respective types of bonds. Although the maximum C-C sp ³ content is set to 20%, mixed concentrations of C-C sp ² and sp ³ bonds are also possible without sacrificing thickness. The thin structure and strong adhesion of the disclosed 2DAC always inherently protects the underlying substrate, unlike in thicker films where the possibility of peeling is apparent. ⁹

According to the disclosed embodiments, a laser-based growth process using hydrocarbons as precursors (e.g., CH ₄、C₂H₂, etc.) produces the disclosed composite films. Hydrogen (H ₂) and argon (Ar) may also be mixed with the precursor. In this process, the laser has two roles: (1) An energy source that decomposes the precursor gas in a process known as photolytic decomposition; and (2) as a localized heat source. It is assumed that one or both of the foregoing effects produce the disclosed 2DAC film: in the first case, the substrate 104 is said to be at room temperature throughout the growth; in the second case, the laser may heat the substrate 104 up to 500 ℃. Typically, pulsed excitonic UV lasers (e.g., 193, 248 or 308 nm) may be directed onto or parallel to the substrate at different growth times with fluence (fluence) of about 50-1000mJ/cm ², depending on the substrate employed. Other possible combinations of producing the disclosed composites may include any combination utilizing a laser, plasma, and/or substrate heater. A heater may be used to heat the substrate 104 up to 500 ℃. Plasma powers in the range of 1-100W and including 1-100W may be used. A typical combination using hydrocarbons as precursors is as follows: (i) laser only; (ii) laser + low power plasma (5W); (iii) Laser + low power plasma (5W) +heater (300 ℃ -500 ℃); (iv) a low power plasma (5W) +500 ℃ heater; (v) high power plasma only (100W).

According to the disclosed embodiments, the entire growth/deposition of the disclosed 2DAC and 2DAC complexes may be performed within the chamber. Modules for heating, plasma, gas flow and pressure control may all be placed and established within a chamber for a controlled growth environment. According to one embodiment, the process pressure of the chamber may be established in the range of 10 to 1E-4mbar and comprises 10 to 1E-4mbar.

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

The method (process) of producing the disclosed 2DAC film may utilize the use of methane (CH ₄) within a growth chamber for the growth process. During growth, the gas pressure in the chamber was always controlled at 2E-2mbar. The gas is in the presence of a plasma generator operating at 5W power. Growth begins when 248nm excitonic laser is exposed on the surface of the copper foil substrate at a fluence of 70mJ/cm ² and a pulse frequency of 50 Hz. The laser exposure time (i.e., growth duration) was set to 1min to obtain a continuous 2DAC coating on the substrate. In this growth, a stage heater is not used. The various parameters disclosed herein may be adjusted to control and/or alter the properties of the disclosed 2DAC, including, but not limited to, hydrocarbons as precursors, precursor mixtures, adjustments to photolytic decomposition processes and equipment, temperature adjustments, substrate temperature adjustments, changes in C values, changes in the number of atomic layers, changes in the sp ² to sp ³ ratio, and changes in adhesion to the substrate.

The disclosed carbon films may be configured to have a minimum thickness, thereby ensuring that the disclosed base metal surface is consistently and completely covered during the applied service life. In one exemplary embodiment, the disclosed 2DAC thickness may be designed to be approximately one atomic layer thickness. The disclosed carbon film 102 may be grown directly on, for example, several substrates 104 (e.g., stainless steel and titanium materials). Since growth is accomplished at much lower temperatures than, for example, graphene synthesis, the disclosed 2DAC can be grown directly to other substrates 104 that are not tolerant of high temperatures, such as glass and hard disks (hard disks). ¹⁰ The disclosed 2DAC film 102 is strong and firmly bonded to the substrate 104, making it suitable for applications that may require deformation (e.g., bending and stretching). The strong mechanical properties of the disclosed 2DAC films are due to their lack of grain boundaries. The insulating properties of the disclosed carbon film 102 prevent galvanic corrosion of the substrate 104, unlike graphene, which enhances the corrosion. As seen in TEM images, the 7,8, and 9 membered rings of carbon films can be used as efficient membranes for gas or proton transport. ⁵

According to alternative embodiments of the disclosed invention, the disclosed 2DAC may be produced as an unsupported situation, for example when the substrate is not suitable for growth thereon and thus the disclosed 2DAC needs to be transferred. Other transfer methods of the disclosed 2dac 1202, such as the dry transfer ：Defect-free direct dry delamination of cvd graphene using a polarized ferroelectric polymer WO2016126208A1. described in the following patent applications, may include, but are not limited to, thermal release tape, pressure sensitive adhesives, spin coating, spray coating, and Langmuir-Blodgett (Langmuir-Blodgett) techniques, using suitable methods and techniques.

However, additional advantages of the present disclosure provide: in some embodiments, the disclosed 2dac 1202 may be grown directly on a substrate. Such benefit of the disclosed 2DAC films over, for example, graphene for the transfer process is that the disclosed 2DAC films do not require a sacrificial carrier layer for transfer (unlike graphene). For graphene, a film layer is required to prevent cracks and defects from occurring during transfer, after which the film layer needs to be removed. Even if removed, there is a residue remaining from the sacrificial layer that cannot be completely removed. For the disclosed 2DAC, the transfer can be done without a sacrificial layer, without causing defects, and without having to process residues or make a back-off to the structure.

Advantages of the disclosed embodiments of the 2DAC layer may be realized in a variety of applications, including, but not limited to: fuel cells, hydrogen generation and deuterium production applications. Such applications take advantage of the disclosed 2DAC layers that include an exemplary monolayer of carbon atoms in an amorphous structure, for example, having a C value of less than or equal to 0.8. Referring again to the amorphous nature of the disclosed 2DAC layer, such as the 2DAC film shown in fig. 2, the continuous carbon film is arranged in a random pattern that allows for an ultra-high lateral conductivity of protons between about 0.1-10S/cm ². The conductivity of deuterons (nuclei of deuterium) is 0.01-1S/cm ², approximately an order of magnitude lower than the conductivity of protons. The conductivity of tritium nuclei (trition) (nuclei of tritium (tritrium)) is about 0.003-0.3S/cm ². The difference in transport rates makes the disclosed 2DAC an effective separation membrane for hydrogen isotopes. At the same time, the membrane is impermeable to other molecules (e.g., H ₂、O₂ and CH ₄).

Proton transport through the membrane is limited by the electron cloud density. ⁵ The C value describes the crystallinity of the disclosed 2DAC and can be controlled/adjusted between about 0.5 and 0.8 by varying the growth parameters. By changing the C value, the electron cloud in the membrane is changed and the proton conductivity can be increased or decreased. For example, the applied techniques may include adjusting the power, pulse, and/or angle of the employed laser for the disclosed 2 DAC.

In selected embodiments, the disclosed 2DAC suspended films have an elastic modulus E of greater than 200GPa and an energy-to-break of >20J/m2, twice that of graphene. Evidence is shown, for example, in fig. 7, where nanoindentation on the disclosed suspended 2DAC film shows an elastic modulus E >200GPa (right), and the suspended 2DAC film after application of extreme stress by the AFM tip shows an energy of rupture >20J/m ². Thus, the disclosed features of these mechanical properties of the 2DAC layer increase the lifetime of the application. For example, the disclosed barriers prevent gassing and thus corrosion of the electrolyte and catalyst layers. The strong mechanical properties of the disclosed 2DAC layer and its particularly high fracture toughness ensure long life of the barrier employed, thereby yielding longer overall performance of the fuel cell.

The disclosed 2DAC layers or films may be further modified (modified) during growth or post-processing 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 may be modified to allow larger molecules to pass through. This is used to create a gas separator.

Example subject matter

Example 1

2DAC in fuel cell as anti-gassing layer:

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

In this exemplary configuration, a plurality of electrode catalyst 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. The 2dac 1202, acting as a barrier, prevents fuel, waste and ionic contaminants from leaking into the proton exchange membrane 1104 and passing through to the opposing electrode catalyst assembly 1102. Such leakage is known to cause damage to the proton exchange membrane 1104 and degradation of PEMFC performance. It is readily understood that the disclosed 2DAC may be used as such or in other configurations such as layers, films, membranes, etc.

Hydrogen and oxygen passing through proton-conducting membrane 1104 can be directly seen as a loss of fuel and a direct loss of fuel cell efficiency. The disclosed 2DAC 1202 will prevent such losses and can significantly improve the efficiency of the fuel cell. Without the 2dac 1202, other gases (e.g., nitrogen) may also pass through the proton-conducting membrane 1104. This in turn may lead to fuel starvation, for example at the catalyst sites. This deficiency is known to lead to catalyst degradation and thus to a loss of performance and reliability. ¹¹ The disclosed 2dac 1202 will prevent other gases from passing through the proton conducting membrane 1104 and prevent the catalyst degradation described above.

Proton exchange membrane 1104 typically requires a high level of hydration to conduct protons. By encapsulating proton-conducting membrane 1104 in an impermeable barrier, dehydration and failure (dying) of proton-conducting membrane 1104 may be prevented. This will lead to long-term stability of the performance of the PEMFC 1200.

Those skilled in the art will readily appreciate that the disclosed technology is not limited to PEMFC applications, but may also be implemented in other applications (e.g., redox flow batteries).

Example 2

2DAC as monoatomic layer proton exchange membrane:

fig. 13 shows an exemplary embodiment of an improved PEMFC 1300 according to a disclosed embodiment, wherein the disclosed 2DAC is used as a monoatomic proton conducting membrane. This embodiment places the disclosed 2dac 1202 in a configuration between the anode and cathode assemblies. In this configuration, the proton exchange membrane has been replaced by a monoatomic layer of the 2dac 1202.

The monoatomic layer of the disclosed 2dac 1202 conducts protons and prevents fuel gas and liquid from passing therethrough. 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 ohmic losses smaller than those realized and 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 the 2dac 1202 allows for innovation of thin flexible fuel cells.

Example 3

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

Fig. 14 shows an exemplary embodiment of an improved PEMFC 1400 in accordance with a disclosed embodiment, wherein a proton conducting membrane 1104 is used as a self-assembled formed over a disclosed 2dac 1202 Proton conducting membrane or coating 1104. Thus, the proton exchange membrane 1104 may include a fluoropolymer (e.g.). The proton exchange membrane 1104 is typically formed to a minimum thickness of about tens of microns to avoid gas bouncing, and a maximum thickness of about hundreds of microns to reduce transmission losses across the proton exchange membrane 1104.

The disclosed 2dac 1202 can be used as a template for polymer assembly due to its unoccupied pi orbitals. The amorphous structure of the disclosed 2dac 1202 functions asThe polymer forms a template for the film. The pi orbitals in the carbocycle allow for even the disclosed 2DAC with low crystallinityThe polymer is aligned with the surface. Thus, the 2DAC 1202 may be used to generate a signal on a 2DAC surfaceUltra-thin uniform layers of coating 1104. Above-mentionedCoating 1104 is pinhole free. Due to self-assembly on the disclosed 2dac 1202, ultra-thinThe proton conductivity of the coating 1104 increases while leakage and gas leaping decrease.

Thus, as shown in the illustrative embodiment of fig. 14, the electrode catalyst assembly 1102 may include a plurality of electrode catalyst 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 a plurality of proton exchange membranes 1104 may be disposed between a plurality of electrode catalyst assemblies 1102.

Acting as proton exchange membrane 1104, FIG. 14 showsThe coating may be formed on either side of the 2DAC layer 1202 or the membrane and is configured to be encapsulated between the electrode catalyst assemblies 1102 in a fuel cell configuration. Thus, the disclosed 2dac 1202 may be transferred, for example, to by wet transfer similar to CVD grapheneAnd (3) a film. ¹²

In another exemplary embodiment, the disclosed 2dac 1202 may also be transferred to by dry transferFilms, dry transfer as described above at ：Defect-free direct dry delamination of cvd graphene using a polarized ferroelectric polymer WO2016126208A1. in the following patent applications, other transfer methods may include, but are not limited to, thermal release tape, pressure sensitive adhesives, spin coating, spray coating, and Langmuir-Blodgett (Langmuir-Blodgett) techniques.

Example 4

Separation of hydrogen isotopes:

Fig. 15 shows an exemplary embodiment of an improved PEMFC according to the disclosed embodiment, wherein a fuel cell 1500 is configured to operate in reverse, thereby separating hydrogen isotopes. The disclosed 2dac 1202 facilitates the transport of the nuclei of the hydrogen isotopes deuterium and tritium, although at a much slower rate than proton transport. The difference in transfer rates across the 2dac 1202 is used to separate the hydrogen isotopes from protium (standard hydrogen). Such separations can be used in heavy water production, for example, in research and nuclear reactors, and for example, to remove tritium from heavy water used in nuclear reactors to maintain performance.

Fig. 15 shows a fuel cell 1500 with a 2dac 1202 between an electrode catalyst assembly 1102 assembly and a proton/deuteron conductive membrane 1502. The fuel cell 1500 operates in a reverse mode by applying a bias across the proton/deuteron conductive membrane 1502. In this mode, the fuel cell 1500 consumes electricity and produces hydrogen and deuterium. The hydrogen and deuterium dissociate into protons and deuterons and are transported across the disclosed 2DAC layer 1202 and proton/deuteron conductive film 1502.

As disclosed above, the atomic structure and carbon ring dimensions of the disclosed 2dac 1202 may be modified (e.g., by exposure to plasma, electron beam, or other radiation techniques). Thus, the structure of the disclosed 2DAC 1202 can be tuned by modifying the dimensions of the ring, thereby affecting the different rates of proton and deuteron transport across the disclosed 2DAC layer 1202. The result may include a higher content of hydrogen than deuterium.

Thus, in one embodiment, a source ratio of 50% H ₂/D₂ can produce a product ratio of 90% H ₂/D₂. However, in some disclosed embodiments, the source and product ratios of H ₂/D₂ may vary. For example, if the transmission rate of h+ is 10 times that of d+, the source ratio of H ₂/D₂ =1 and the product ratio of H ₂/D₂ =10.

Example 5

Gas selective membrane:

Fig. 16 illustrates an exemplary system 1600 for gas separation by the disclosed modified 2dac 1202 in accordance with the disclosed embodiments. The disclosed 2dac 1202 can be modified by radiation techniques (e.g., electron beam and ion plasma) to allow larger molecules to pass through, thereby enabling a gas selective membrane. Thus, the disclosed 2dac 1202 remains a barrier to all molecules larger than specified by modifying the parameters.

Fig. 16 shows an example of how the disclosed modified 2dac 1202 may be used as a membrane or layer, for example, for separating a gas mixture. For example, the modified 2DAC film 1602 between stage 1 1604 and stage 2 1606 may be modified to allow H ₂ and O ₂ to pass through; and the modified 2DAC film 1604 between stage 2 1606 and stage 3 1608 may be modified to allow only H ₂ to pass through. By applying a negative pressure gradient from stage 1 to stage 3, and recirculating the gas through system 1600, stage 1 will contain only CO ₂, stage 2 will contain only O ₂, and stage 3 will contain only H ₂. Thus, gas separation is achieved in system 1600.

In summary, the two-dimensional amorphous carbon (2 DAC) of the disclosed embodiments may include a monoatomic layer of carbon atoms in an amorphous structure. In its original state, the random arrangement of atoms allows for high transverse proton conductivity and blocks all larger atoms and molecules (e.g., H ₂、O₂、CH₄). Such high proton conducting membranes may be implemented in, for example, fuel cell, hydrogen generation, and deuterium manufacturing applications.

The atomic structure and carbon ring size of the disclosed 2DAC may be modified by exposure to plasma, electron beam, or other radiation techniques. This allows larger molecules to pass through, thereby expanding the use of the disclosed 2DAC into many gas separation applications. The disclosed 2DAC is unique in that it has extremely high proton conductivity while introducing only a single atomic layer thickness. For example, mechanical toughness means that the disclosed 2DAC requires about three times as much energy to propagate a crack in the disclosed 2DAC as compared to other two-dimensional materials. The disclosed 2DAC is impermeable to molecular hydrogen and larger molecules. Thus, the disclosed 2DAC prevents gas from passing through the proton exchange membrane and thus poisoning the electrode catalyst assembly 1102. The disclosed 2DAC has a proton transfer rate of about 0.1-10S/cm ². Such high transfer rates improve performance relative to conventional fuel cells. The disclosed 2DAC provides selective transport of hydrogen nuclear isotopes. Thus, the difference in transport rates makes the disclosed 2DAC a more efficient separation membrane for hydrogen isotopes.

Having described in detail many embodiments of the present disclosure, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. Furthermore, it should be understood that while many embodiments of the present invention are illustrated, all examples in this disclosure are provided as non-limiting examples and, therefore, should not be taken as limiting the various aspects so illustrated.

Reference to

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

1.Sharaf,O.Z.&Orhan,M.F."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,A.C.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,W.J.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,J.S.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 4Tbit/in²."Advances in Tribology 2013,1-8(2013).

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

12.Li,X.S.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 disclosure are incorporated herein by reference.

In this specification, reference to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgement or any form of suggestion that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour (endeavour) to which this specification relates.

Although the present invention has been disclosed with reference to certain embodiments, numerous modifications, alterations and changes to the described embodiments are possible without departing from the metes and bounds of the invention as defined in the appended claims. Accordingly, it is intended that the invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims and equivalents thereof.

Claims

1. A fuel cell, comprising:

An electrode catalyst assembly;

Two-dimensional (2D) amorphous carbon, wherein the crystallinity (C). Ltoreq. 0.8,2D amorphous carbon of 2D amorphous carbon is continuous and uniform, has a thickness up to 10 atoms thick and a domain size of less than 5nm, and has a breaking energy of more than 20J/m ² and an adhesion energy of more than 200J/m ², and

A proton exchange membrane,

Wherein the 2D amorphous carbon is disposed between the electrode catalyst assembly and the proton exchange membrane, and the 2D amorphous carbon is configured to conduct protons and prevent gas bouncing.

2. The fuel cell of claim 1, wherein the 2D amorphous carbon is a membrane.

3. The fuel cell of claim 1, wherein the 2D amorphous carbon is a film.

4. The fuel cell of claim 1, wherein the 2D amorphous carbon has a resistivity of 0.01 to 1000 Ω -cm, inclusive.

5. The fuel cell according to claim 1,

Wherein the electrode catalyst assembly comprises a plurality of electrode catalyst assemblies, and

Wherein a proton exchange membrane is disposed between the plurality of electrode catalyst assemblies and 2D amorphous carbon is disposed between each electrode catalyst assembly and the proton exchange membrane to encapsulate the proton exchange membrane.

6. The fuel cell according to claim 1,

Wherein the electrode catalyst assembly comprises a plurality of electrode catalyst assemblies,

Wherein the proton exchange membrane comprises a plurality of proton exchange membranes,

Wherein the 2D amorphous carbon is disposed between the plurality of proton exchange membranes and the plurality of proton exchange membranes is disposed between the plurality of electrode catalyst assemblies.

7. The fuel cell of claim 1 wherein the proton exchange membrane is a fluoropolymer.

8. The fuel cell of claim 7 wherein the fluoropolymer is

9. The fuel cell of claim 1, wherein the 2D amorphous carbon has an sp ³/sp² bond ratio of 0.2 or less.