Preparation of metal olefins

Abstract

A method for synthesizing metalenes is disclosed, which involves providing a MAX phase, intercalating a noble metal A' into the MAX phase to produce a MA'X phase, and etching away the MX layers from the MA'X phase to produce free-standing 2D monatomic thickness noble metal A' sheets. The resulting metalenes have unique properties and potential applications in various fields such as electronics, catalysis, photonics, sensing, and biomedical.

Description

Technical Field

[0001] This technology relates to the field of materials science, particularly the synthesis and production of self-supporting 2D single-atom-thickness materials (metallenes) of metallic elements. These materials exhibit unique electronic properties and a high surface area to volume ratio, making them suitable for a variety of applications in electronics, catalysis, photonics, sensing, and biomedicine. Background Technology

[0002] Noble metals such as gold, silver, platinum, palladium, iridium, and rhodium possess superior properties in a wide range of applications in electronics, catalysis, photonics, sensing, and biomedicine. Compared to their bulk counterparts, these metals have become the subject of extensive research due to their unique plasmon, electronic, and catalytic properties. The anisotropic structures of noble metals, particularly the self-supported 2D single-atom-thickness structures known as metalenes (e.g., goldene for gold), have attracted significant interest because they offer not only exceptional properties but also a high surface-to-volume ratio. This allows for applications requiring significantly less volume and cost compared to conventional noble metal materials.

[0003] Despite the beneficial properties and practical demand for precious metals, they are scarce and expensive on Earth. Furthermore, only a handful of precious metal metal alkenes have been experimentally synthesized, and scalable synthetic methods for their production have not yet been developed. This lack of progress in the production of metal alkenes hinders their potential use in a wide range of applications.

[0004] Another key challenge in the production of metalloalkenes is their structural stability. Due to the nature of 3D metallic bonding, noble metals are thermodynamically unstable in 2D structures. Developing novel synthetic methods will be essential; in particular, surfactants that stabilize the 2D structure will play a crucial role. To address the stability issue, interdisciplinary factors, such as the physical properties of atomic bonding and the chemical inertness of the noble metal elements, must be considered.

[0005] Many types of vapor deposition have demonstrated the epitaxial growth of metal films on lattice-matched substrates. However, during deposition, noble metals have inevitably formed three-dimensional or multi-layered islands due to their strong thermodynamic tendency to coalesce. This produces at most continuous noble metal layers of nanometer thickness. In the case of Au, unique synthetic routes for atomically thin sheets have been developed, such as the synthesis of Au sheets with 1-2 atom-thickness layers diffused into layered double hydroxide templates, self-supporting single-atom-thickness Au with a framework constructed in bulk Au-Ag alloys by electron beam irradiation, and single-atom-thickness gold quantum dots (QDs) stabilized on hexagonal boron nitride surfaces.

[0006] However, these gold flakes were produced under impractical, extreme conditions and physical limitations. Therefore, for Au, truly self-supporting, single-atom-thickness 2D metallene structures have not yet been achieved on a large scale. Similarly, methods for synthesizing self-supporting metallenes of other noble metals using practical and scalable techniques have not yet been developed. The lack of efficient synthetic or other methods for producing stable metallenes is a major technical challenge that needs to be addressed. Summary of the Invention

[0007] According to a first aspect of this disclosure, a method for synthesizing metalloalkenes is provided, the method comprising providing a MAX phase material, intercalating a noble metal A' into the MAX phase to generate an MA'X phase, and etching away the MX layer from the MA'X phase to generate a self-supporting 2D single-atom-thick noble metal A' sheet. This method allows for the production of metalloalkenes with unique properties and potential applications in various fields such as electronics, catalysis, photonics, sensing, and biomedicine.

[0008] Alternatively, in some embodiments, the MAX phase is provided in the form of a film, particles, or bulk. This flexibility in the MAX phase format allows for the synthesis of metalloenes with different sizes and shapes to meet specific application requirements.

[0009] Optionally, in some embodiments, the intercalated noble metal A' layer can be two, three, four, or five atoms thick. This variation enables the production of multilayer metalenes with varying thicknesses, each possessing unique properties and potential applications.

[0010] Optionally, in some embodiments, the film has a thickness of up to 100 nm or greater. This variation in film thickness enables the production of metalloolefins with different volumes, areas, and layer thicknesses, which can affect their properties and potential applications.

[0011] Optionally, in some embodiments, the MAX phase comprises Mn+1Xn layers, where M is a transition metal, X is selected from the group consisting of carbon, nitrogen, and boron, and n is an integer from 1 to 5. This diversity in the composition of the MAX phase allows for the synthesis of metalloalkenes with different properties and characteristics.

[0012] Optionally, in some embodiments, the method further includes removing any remaining noble metals from the MA'X phase before etching away the MX layer. This step ensures the purity of the resulting metalloenes, which can improve their performance in a variety of applications.

[0013] Alternatively, in some embodiments, the removal of residual precious metals is performed using chemical mechanical polishing. This technique provides a precise and efficient method for removing unwanted precious metals from the MA'X phase.

[0014] Optionally, in some embodiments, the noble metal A' is selected from the group consisting of gold, platinum, iridium, rhodium, palladium, and silver. This series of noble metals allows for the synthesis of various types of metal olefins, each with unique properties and potential applications.

[0015] Alternatively, in some embodiments, etching is performed using an etching mixture comprising Murakami's reagent and a surfactant. This etching mixture ensures efficient removal of the MX layer from the MA'X phase, resulting in high-quality metalloolefins.

[0016] Optionally, in some embodiments, the Murakami reagent comprises potassium ferricyanide, potassium hydroxide, and water, preferably ranging from 2 to 5 mg of potassium ferricyanide and potassium hydroxide per 10 mL of water. This specific composition of the Murakami reagent ensures effective etching of the MAX phase.

[0017] Optionally, in some embodiments, the chemical used in the reagent is one of the following: potassium cuprous cyanide, potassium silver cyanide, potassium tetracyanonitrile, potassium tetracyanoplatinate, potassium dicyanofuranate, potassium tetracyanopallate, or potassium permanganate.

[0018] Optionally, in some embodiments, the surfactant is one of the following: hexadecyltrimethylammonium bromide (CTAB), cetrimonium chloride (CTAC), myristyltrimethylammonium bromide, (16-mercaptohexadecyl)trimethylammonium bromide, or cysteine, wherein the concentration is in the range of 1 to 10 mmol / L. Using a surfactant as a stabilizer during etching helps prevent the aggregation of the 2D noble metal structure of the metal olefin, thereby ensuring its stability and quality.

[0019] Optionally, in some embodiments, the etching is performed in the dark and lasts for 2 to 60 days. Etching in the dark ensures the stability of the 2D noble metal structure of the metallene and prevents undesirable reactions or processes that may occur in the presence of light.

[0020] Optionally, in some embodiments, the metal ene has a composition comprising a noble metal selected from the group consisting of gold, platinum, iridium, rhodium, palladium, and silver. This diversity in the composition of metal enes allows for the synthesis of different types of metal enes, each with unique properties and potential applications.

[0021] Optionally, in some embodiments, the goldene is a goldene produced from the Ti3AuC2 MAX phase and / or the Ti4AuC3 MAX phase. Goldene, as a single-atom-thick gold sheet, exhibits unique electronic properties and a high surface area to volume ratio, making it ideal for a variety of applications such as catalysis, sensing, and electronics.

[0022] According to the second aspect of this disclosure, metal olefins synthesized by the above-described method are provided, wherein the metal olefin is one of the following: goldene, platinumene, iridiumene, rhodiumene, palladiumene, and silverene. These metal olefins, with their unique properties and characteristics, have potential applications in various fields such as electronics, catalysis, photonics, sensing, and biomedicine. Attached Figure Description

[0023] The embodiments are described in more detail below with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the synthesis process of a) self-supporting 2D single-atom-thickness noble metal sheet (metalene) and b) self-supporting 2D single-atom-thickness Au sheet (goldene).

[0025] Figure 2 The X-ray photoelectron spectra of Au 4f emitted by goldene and bulk reference Au are shown. Detailed Implementation

[0026] The detailed description set forth below provides information and embodiments of the disclosed technology in sufficient detail to enable those skilled in the art to practice this disclosure.

[0027] Figure 1 Schematic diagrams illustrate the synthesis processes of (a) self-supported 2D single-atom-thickness noble metal sheets (metallene) and (b) self-supported 2D single-atom-thickness Au sheets (goldene). In the case of goldene, the deposition of a Ti3SiC2 film is depicted in Part 1. In Part 2, the intercalation of Au into Ti3SiC2 to produce Ti3AuC2 is shown. In Part 3, the selective etching of Ti3C2 sheets is depicted to produce goldene. This diagram illustrates the overall process of synthesizing metallenes, beginning with the deposition of a MAX phase film, followed by the intercalation of the noble metal, and finally the production of the desired metallene.

[0028] Figure 2 X-ray photoelectron spectroscopy (XPS) spectra of Au 4f emissions from goldene and bulk reference Au are presented. Due to its 2D structure, the binding energy of Au 4f emissions from goldene is 0.9 eV higher than that of bulk Au used as a reference. This figure highlights the unique electronic properties of the synthesized goldene compared to bulk gold, demonstrating the successful fabrication of a single-atom-thick noble metal sheet with unique properties.

[0029] 1. Provides MAX phase

[0030] The method for producing metalloalkenes begins with the availability of MAX phase materials. MAX phases are characterized by the presence of M... n+1 A layered material with a unique structure composed of Xn layers, where M represents a transition metal, X is an element such as carbon (C), nitrogen (N), or boron (B), and n is an integer from 1 to 5. The MAX phase can be provided in various forms, including films, particles, or bulk materials. The MAX phase can contain layers of element A; in a MAX phase film, these layers are connected to M... n+1 X n The layers are interleaved. Layer A determines the specific noble metal that can be intercalated into the MAX phase material.

[0031] 1.1. Selection of MAX phase materials

[0032] In some embodiments, the selection of the MAX phase material is a step in the synthesis of metal alkenes. The MAX phase material can comprise various transition metals (M), such as scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), hafnium (Hf), tantalum (Ta), and tungsten (W). The X layer in the MAX phase can comprise carbon (C), nitrogen (N), or boron (B). The A layer can comprise elements such as aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), gallium (Ga), germanium (Ge), arsenic (As), cadmium (Cd), indium (In), tin (Sn), and lead (Pb). The selection of the MAX phase material can influence the types of noble metals that can be intercalated into the MAX phase, thereby affecting the types of metal alkenes that can be synthesized.

[0033] 1.2 Preparation of MAX phase films

[0034] In some embodiments, the MAX phase is provided in the form of a membrane.

[0035] 1.2.1. Consideration of membrane thickness

[0036] The thickness of the MAX phase film can be controlled during the deposition process to achieve the desired thickness. The thickness of the MAX phase film can affect the intercalation of noble metals into the MAX phase, as well as the resulting thickness, layer thickness, area, and volume of metallene sheets.

[0037] 1.2.2. Deposition Technology

[0038] In some embodiments, the deposition of MAX phase films can be achieved using various techniques. Physical vapor deposition (PVD) techniques, such as sputtering or evaporation, can be used to deposit MAX phase films. Chemical vapor deposition (CVD) techniques, which involve the reaction of gaseous precursors to form MAX phase films on a substrate, can also be used. Atomic layer deposition (ALD) techniques, which involve the sequential reaction of gaseous precursors to form MAX phase films layer by layer, can also be used. The choice of deposition technique can affect the quality and properties of the MAX phase film, and thus the quality and properties of the resulting metalloolefin sheets.

[0039] 1.3. MAX phase particle and bulk forms

[0040] In some embodiments, the MAX phase can be provided in particulate or bulk form. MAX phase particles can be synthesized using various techniques such as ball milling, sol-gel synthesis, or other suitable techniques. MAX phase bulks can be synthesized using techniques such as hot pressing, spark plasma sintering solid-state reaction, or other suitable techniques. The form of the MAX phase can affect the intercalation of noble metals into the MAX phase and the resulting form of metalloolefin sheets.

[0041] 2. Intercalation of precious metals

[0042] The method for synthesizing metalloalkenes involves intercalating a noble metal A' into a provided MAX phase. This step is crucial because it leads to the formation of the MA'X phase, an intermediate structure in the synthesis of metalloalkenes. The noble metal A' can be selected from, but is not limited to, the group consisting of, gold (Au), platinum (Pt), iridium (Ir), rhodium (Rh), palladium (Pd), and silver (Ag). The intercalation process may involve several steps, including cleaning and preparing the MAX phase film, applying the noble metal layer, and annealing.

[0043] 2.1. Selection of Precious Metals

[0044] In some embodiments, the selection of the noble metal A' for intercalation into the MAX phase is a step in the synthesis of metalloalkenes. The noble metal A' can be selected based on its chemical properties, its compatibility with the selected MAX phase, and the desired properties of the resulting metalloalkene. The noble metal A' can include gold (Au), platinum (Pt), iridium (Ir), rhodium (Rh), palladium (Pd), silver (Ag), or alloys thereof containing multiple elements. The selection of the noble metal A' can affect the properties of the resulting metalloalkene, including its chemical stability, electronic properties, and potential applications.

[0045] 2.2. Intercalation process

[0046] In some embodiments, intercalating a noble metal A' into a MAX phase involves several steps. These steps may include cleaning and preparing the MAX phase film, applying the noble metal layer, and an annealing process including interdiffusion. The intercalation process can be carefully controlled to ensure successful formation of the MA'X phase and the desired properties of the resulting metallene. In some embodiments, the intercalated noble metal A' layer may be two-atom, three-atom, four-atom, or five-atom thick. This variation enables the production of multilayer metallenes with different thicknesses, each possessing unique properties and potential applications.

[0047] 2.2.1. Cleaning and Preparation of MAX Phase Films

[0048] In some embodiments, the MAX phase film is cleaned and prepared prior to the intercalation of the noble metal A'. The cleaning process may involve using a cleaning solution, such as buffered hydrofluoric acid (HF), to remove residual oxides from the surface of the MAX phase film. A rinsing step may follow the cleaning process to remove any remaining cleaning solution. The preparation of the MAX phase film may involve applying a noble metal layer onto the cleaned MAX phase film. The noble metal layer may be applied at room temperature and may have a thickness of twice or more than the thickness of the MAX phase film. Some noble metals may have a thickness less than twice the thickness of the MAX phase film.

[0049] 2.2.2. Application of the noble metal layer

[0050] In some embodiments, a noble metal layer is applied to a clean MAX phase film. The noble metal layer may comprise a selected noble metal A', which may be gold (Au), platinum (Pt), iridium (Ir), rhodium (Rh), palladium (Pd), silver (Ag), or an alloy thereof containing multiple elements. The noble metal layer may be applied at room temperature and may have a thickness twice or more than the MAX phase film thickness. Some noble metals may have a thickness less than twice the MAX phase film thickness. The application of the noble metal layer can be achieved using various techniques such as physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), or other suitable techniques.

[0051] 2.2.3. Annealing process

[0052] In some embodiments, a noble metal-coated MAX phase film is annealed to promote the intercalation of noble metal A' into the MAX phase. The annealing process may involve heating the noble metal-coated MAX phase film at a specific temperature for a specific duration. For example, the annealing process may involve heating an Au-coated Ti3SiC2 phase film at 670°C for 12 hours. Suitable annealing temperatures and durations can be applied to other combinations of noble metals and MAX phases. The annealing process can be carried out in an inert gas atmosphere to avoid oxidation. During the annealing process, an exchange reaction can occur between the noble metal A' and the atom in the MAX phase film, resulting in the formation of the MA'X phase. The annealing process can be carefully controlled to ensure successful intercalation of the noble metal A' into the MAX phase and the formation of an MA'X phase with the desired properties.

[0053] 3. Removal of residual precious metals

[0054] The preparation of metalloalkenes involves intercalating a noble metal A' into a MAX phase to form an MA'X phase. Following this intercalation process, residual noble metal may remain on the surface of the MA'X phase. In some embodiments, this residual noble metal is removed before proceeding to the next step of the preparation process, which involves etching away the MX layer from the MA'X phase to produce the desired metalloalkene. Removal of the residual noble metal can help ensure the purity and quality of the resulting metalloalkene.

[0055] 3.1. Chemical Mechanical Polishing

[0056] In some embodiments, the removal of residual noble metals from the MA'X phase is performed using a process known as chemical mechanical polishing (CMP). This process involves using a polishing slurry, which may contain various components that work together to remove residual noble metals from the surface of the MA'X phase. The CMP process can be carefully controlled to ensure effective removal of residual noble metals without damaging the MA'X phase or the resulting metalloolefin.

[0057] 3.1.1. Composition of polishing slurry

[0058] In some embodiments, the polishing slurry used in the chemical mechanical polishing process may contain various components. These components may include fumed silica, iodine, potassium iodide, citric acid, trisodium citrate, and deionized water for removing residual Au. The specific composition of the polishing slurry may be tailored based on the specific requirements of the chemical mechanical polishing process and the characteristics of the MA'X phase and residual noble metals. For example, the polishing slurry may contain 0.1-3.5 g of fumed silica, 0.15-1.5 g of iodine, 0.15-15 g of potassium iodide, 10-20 g of citric acid, 2.5-5 g of trisodium citrate, and 150-250 mL of deionized water for removing residual Au.

[0059] 3.1.2. Polishing process

[0060] In some embodiments, the chemical mechanical polishing process involves applying a polishing slurry to the surface of the MA'X phase. The polishing slurry can be applied using a suitable applicator, and the MA'X phase can be polished using a suitable polishing tool. The polishing process can be performed under controlled conditions to ensure effective removal of any remaining noble metals from the surface of the MA'X phase. After the polishing process, the MA'X phase can be rinsed to remove any remaining polishing slurry and the removed noble metals. The polished MA'X phase can then be dried and prepared for the next step in the synthesis process, which involves etching away the MX layers to produce the desired metalloalkene.

[0061] 4. Etching process

[0062] The method for preparing metalloalenes involves an etching process, a key step in the production of self-supported 2D single-atom-thick noble metal A' sheets. This process involves applying an etching mixture onto the MA'X phase, causing the mixture to react with the MX layers within the MA'X phase to remove them. The etching process can be carefully controlled to ensure the successful production of the desired metalloalenes.

[0063] 4.1. Preparation of Etching Mixture

[0064] Etching mixtures may contain various components including Murakami reagents and surfactants. Etching mixtures may also contain derivative chemicals and surfactants. Derivative chemicals may be selected from the group consisting of: potassium cuprous cyanide, potassium silver cyanide, potassium tetracyanonitrile, potassium tetracyanoplate, potassium dicyanosulfate, potassium tetracyanoplate, or potassium permanganate.

[0065] 4.1.1. Murakami Reagent

[0066] In some embodiments, the Murakami reagent is a key component of the etching mixture. The Murakami reagent may be contained in 1 part potassium ferricyanide and 1 part potassium hydroxide in water. Alternatively, the Murakami reagent may be contained in 10 mL of water at a concentration of 2 to 5 mg of potassium ferricyanide and potassium hydroxide. The Murakami reagent can be made to react effectively with the MX layers within the MA'X phase to remove them, thereby promoting the formation of the desired metalloalkenes.

[0067] In some embodiments, the etching mixture containing potassium ferrocyanide may be replaced by a derivative chemical. The derivative chemical may be one of the following: potassium cuprous cyanide, potassium silver cyanide, potassium nickel tetracyanide, potassium platinum tetracyanide, potassium dicyanosulfate, potassium palladium tetracyanide, or potassium permanganate.

[0068] 4.1.2. Surfactants

[0069] In some embodiments, the etching mixture may contain a surfactant. The surfactant may be hexadecyltrimethylammonium bromide (CTAB), cetrimonium chloride (CTAC), myristyltrimethylammonium bromide, (16-mercaptohexadecyl)trimethylammonium bromide, or cysteine. The surfactant may have a concentration in the range of 1 to 10 mmol / L. For some combinations of surfactant and noble metal, this concentration may be below 1 mmol / L. The surfactant can act as a stabilizer during etching, preventing the aggregation of the 2D noble metal structure of the metalloalkene. This can help ensure the successful production of a self-supporting 2D single-atom-thickness noble metal A' sheet.

[0070] 4.2. Etching Procedure

[0071] In some embodiments, the etching process involves several steps. These steps may include applying an etching mixture to the MA'X phase, allowing the etching mixture to react with the MX layers within the MA'X phase, monitoring the etching process to ensure that the desired etching duration is reached, removing the etching mixture after the desired duration, rinsing the metallene sheet with water or a suitable solvent to remove any remaining etchant, and drying the resulting metallene sheet.

[0072] 4.2.1. Application of Etching Mixture

[0073] In some embodiments, the etching process begins by applying an etching mixture to the MA'X phase. The etching mixture can be applied using a suitable applicator, and the MA'X phase can be exposed to the etching mixture for a specific duration. The application of the etching mixture can be carefully controlled to ensure efficient removal of the MX layer from the MA'X phase.

[0074] 4.2.2. Etching Duration and Conditions

[0075] In some embodiments, the etching process can be performed under specific conditions for a specific duration. The etching process can be carried out in darkness, which can help ensure the stability of the 2D noble metal structure of the metalloene and prevent undesirable reactions or processes that may occur in the presence of light. The etching process can have a duration of 1 to 60 days, which can be adjusted based on the specific requirements of the etching process and the characteristics of the MA'X phase and MX layers.

[0076] 4.2.3. Removal and rinsing of the etching mixture

[0077] In some embodiments, after the desired etching duration has been reached, the etch mixture is removed from the MA'X phase. The MA'X phase can then be rinsed with water or a suitable solvent to remove any remaining etchant. The rinsing process can help ensure the purity and quality of the resulting metalene sheet. After the rinsing process, the resulting metalene sheet can be dried to obtain a self-supporting 2D single-atom-thickness noble metal A' sheet.

[0078] 5. Properties and Characterization of Metal olefins

[0079] The methods used to synthesize metalenes result in the production of self-supported 2D single-atom-thick noble metal A' sheets (also known as metalenes). These metalenes exhibit unique properties that distinguish them from their bulk metallic counterparts. The properties of metalenes can be characterized using various techniques to confirm their structure, composition, and other attributes.

[0080] 5.1. Structure and Chemical Stability

[0081] In some embodiments, metalenes synthesized using the disclosed methods exhibit high structural and chemical stability. This stability is a key property that enables metalenes to retain their unique structure and composition under various conditions. The structural stability of metalenes refers to their ability to maintain their 2D single-atom-thick sheet structure without undergoing deformation or disintegration. The chemical stability of metalenes refers to their resistance to chemical reactions that may alter their composition or structure. The structural and chemical stability of metalenes can be confirmed using various characterization techniques, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning force microscopy (SFM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS).

[0082] 5.2. Electronic properties

[0083] In some embodiments, metalenes exhibit unique electronic properties that differ from their bulk metallic counterparts. These unique electronic properties are a result of the 2D single-atom-thick sheet structure of metalenes, which can influence the behavior of electrons within the material. The electronic properties of metalenes can be characterized using various techniques such as X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and electron energy loss spectroscopy (EELS). For example, the binding energy of Au 4f emitted from goldenes (a type of metalene composed of gold) is 0.9 eV higher than that of bulk Au, which serves as a reference, due to its 2D structure.

[0084] 5.3. Surface area to volume ratio

[0085] In some embodiments, metalloalenes exhibit a high surface area to volume ratio due to their 2D single-atom-thick sheet structure. This property is advantageous because it enhances the performance of metalloalenes in a variety of applications. For example, a higher surface area to volume ratio can enhance catalytic activity, making metalloalenes ideal for catalytic applications. A larger surface area can also enhance sensitivity in sensing applications, allowing the detection of smaller concentrations of analytes. An improved surface area to volume ratio can lead to higher efficiency in electronic devices, enabling faster and more precise electronic processes. The surface area to volume ratio of metalloalenes can be determined using various characterization techniques, such as Brunauer-Emmett-Teller (BET) analysis and atomic force microscopy (AFM).

[0086] 5.4. Scalability and Size Considerations

[0087] In some embodiments, the method for synthesizing metalloalenes is scalable and can be performed at an industry-standard 12-inch size. This scalability is advantageous because it allows for the production of large quantities of metalloalenes, making the method suitable for industrial applications. The size of the metalloalenes can be controlled during the synthesis process to achieve the desired dimensionality. The size of the metalloalenes can be characterized using various techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM). The scalability and size considerations of this method can influence the potential applications of metalloalenes in various fields such as electronics, catalysis, photonics, sensing, and biomedicine.

[0088] 6. Applications of metalenes

[0089] The methods for synthesizing metalenes described in this disclosure result in the production of self-supporting 2D single-atom-thick noble metal A' sheets (also known as metalenes). These metalenes exhibit unique properties that make them suitable for a variety of applications in different fields. Applications of metalenes can include electronics, catalysis, photonics, sensing, and biomedicine. Specific applications of metalenes can be determined based on their unique properties, such as their high surface area to volume ratio, their unique electronic properties, and their high structural and chemical stability.

[0090] 6.1. Electronics

[0091] In some embodiments, metalenes can be used in a variety of electronic applications. The unique electronic properties of metalenes, such as their high conductivity and unique electronic band structure, make them ideal for use in electronic devices. Metalenes can be used to manufacture electronic components such as transistors, diodes, and capacitors. Metalenes can also be used to produce electronic circuits in which they serve as conductive paths for current flow. The high surface area to volume ratio of metalenes can lead to higher efficiency in electronic devices, enabling faster and more precise electronic processes. The scalability of the methods used to synthesize metalenes (which can be performed in industrial standard 12-inch sizes) makes them suitable for mass production of electronic components and circuits.

[0092] 6.2. Catalysis

[0093] In some embodiments, metal alkenes can be used in catalytic applications. The high surface area to volume ratio of metal alkenes can enhance their catalytic activity, making them ideal for a wide variety of catalytic processes. Metal alkenes can be used as catalysts in chemical reactions, where they can increase the rate of the reaction without being consumed in the process. Metal alkenes can be used to catalyze various types of reactions, including oxidation, reduction, and other types of chemical transformations. The unique electronic properties of metal alkenes, such as their ability to donate or accept electrons, can influence their catalytic activity and selectivity. The unique plasmon properties of metal alkenes can also influence their catalytic activity and selectivity.

[0094] 6.3. Photonics

[0095] In some embodiments, metalenes can be used in photonic applications. The unique optical properties of metalenes, such as their ability to interact with light at the nanoscale, make them ideal for use in photonic devices. Metalenes can be used to fabricate photonic components such as waveguides, photodetectors, and light-emitting diodes (LEDs). Metalenes can also be used to produce photonic circuits in which they serve as channels for light flow. The high surface area to volume ratio of metalenes can enhance their interaction with light, leading to improved performance in photonic devices. The unique electronic and plasmon properties of metalenes can also influence their optical and photonic properties.

[0096] 6.4. Sensing

[0097] In some embodiments, metalenes can be used in sensing applications. The high surface area to volume ratio of metalenes can enhance their sensitivity, allowing the detection of small concentrations of analytes. Metalenes can be used to fabricate sensors in which they serve as sensing elements that respond to changes in their environment. Metalenes can be used in a wide variety of sensor types, including chemical sensors, biosensors, and physical sensors. The unique electronic and plasmon properties of metalenes, such as their ability to change their resistance in response to changes in their environment, can influence their sensing performance.

[0098] 6.5. Biomedicine

[0099] In some embodiments, metalenes can be used in biomedical applications. The biocompatibility of metalenes (combined with their unique physical and chemical properties) makes them ideal for a wide range of biomedical applications. Metalenes can be used to manufacture biomedical devices such as implants, prostheses, and drug delivery systems. Metalenes can also be used in biomedical imaging, where they can serve as contrast agents that enhance the visibility of biological structures in imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT). Metalenes can also be used to treat diseases such as cancer, where they can be activated due to their unique plasmon properties. The high surface area to volume ratio of metalenes can enhance their interactions with biological systems, leading to improved performance in biomedical applications.

[0100] 6.6. Decoration

[0101] In some embodiments, metalenes can be used to color liquids by suspension or to color surfaces by coating, thanks to their unique photonic and plasmonic properties.

[0102] 7. Alternative metal alkenes and MAX phases

[0103] The disclosed method for synthesizing metalloalkenes is not limited to producing a specific type of metalloalkene or using a specific type of MAX phase. In some embodiments, the method can be adapted to synthesize alternative types of metalloalkenes and to use alternative types of MAX phases. This adaptability of the method can extend its applicability and versatility, allowing the production of a wide range of metalloalkenes with diverse properties and potential applications.

[0104] 7.1. Other precious metals

[0105] In some embodiments, the noble metal A' intercalated into the MAX phase to produce the MA'X phase may comprise other noble metals and their alloys besides those specifically mentioned in the foregoing sections. These other noble metals may include, but are not limited to, ruthenium (Ru), osmium (Os), and rhenium (Re). The selection of noble metal A' may be based on various factors, including the desired properties of the resulting metalene, the compatibility of the noble metal with the selected MAX phase, and the specific requirements of the intended application of the metalene. The use of other noble metals can expand the range of metalenes that can be synthesized using the disclosed methods, thereby enhancing its versatility and applicability.

[0106] 7.2. Hybrid Superstructure MAX Phase

[0107] In some embodiments, the MAX phase provided for the synthesis of metalloalkenes may include a hybrid superstructure MAX phase. These hybrid superstructure MAX phases may contain M... n+1Xn layers, where M represents a transition metal, X is an element such as carbon (C), nitrogen (N), or boron (B), and n is an integer from 1 to 5. The hybrid superstructure MAX phase can also contain layers of element A; in the MAX phase film, these layers are connected to M... n+1 The Xn layers are interleaved. The A layer determines the specific noble metal that can be intercalated into the MAX phase film. The use of hybrid superstructure MAX phases can influence the properties of the resulting metalenes, including their structure, composition, and electronic properties. The use of hybrid superstructure MAX phases can also expand the range of MAX phases that can be used in the disclosed methods, thereby enhancing their versatility and applicability.

[0108] Example 1: A method for synthesizing metal olefins, the method comprising providing a MAX phase, intercalating a noble metal A' into the MAX phase to generate a MA'X phase, and etching away the MX layer from the MA'X phase to generate a self-supporting 2D single-atom-thickness noble metal A' sheet.

[0109] Example 2: The method as described in Example 1, wherein the MAX phase is provided in the form of a film, particles or bulk.

[0110] Example 3: The method is as described in Example 2, wherein the film has a thickness of up to 100 nm.

[0111] Example 4: The method described in Example 2, wherein the film has a thickness greater than 100 nm.

[0112] Example 5: The method as described in any of the foregoing embodiments, wherein the MAX phase comprises M n+1 Xn layers, where M is a transition metal, X is selected from the group consisting of carbon, nitrogen, and boron, and n is an integer from 1 to 5.

[0113] Example 6: The method as described in any of the preceding embodiments, further comprising removing the remaining noble metal on the MA'X phase before etching away the MX layers.

[0114] Example 7: The method described in Example 6, wherein the removal of the remaining precious metal is performed using chemical mechanical polishing.

[0115] Example 8: The method as described in any of the preceding embodiments, wherein the precious metal A' is selected from the group consisting of: gold, platinum, iridium, rhodium, palladium and silver.

[0116] Example 9: The method as described in any of the preceding examples, wherein the etching is performed using an etching mixture comprising Murakami reagent and a surfactant.

[0117] Example 10: The method described in Example 9, wherein the Murakami reagent comprises potassium ferricyanide, potassium hydroxide and water.

[0118] Example 11: The method as described in Example 10, wherein the Murakami reagent contains 2 to 5 mg of potassium ferricyanide and potassium hydroxide in 10 mL of water.

[0119] Example 12: The method as described in Example 10, wherein the alternative chemical for potassium ferrocyanide in the etching mixture is one of the following: potassium cuprous cyanide, potassium silver cyanide, potassium tetracyanonitrile, potassium tetracyanoplatinate, potassium dicyanofuranate, potassium tetracyanopallate, or potassium permanganate.

[0120] Example 13: The method as described in Example 10 or Example 11, wherein the surfactant is one of the following: hexadecyltrimethylammonium bromide (CTAB), cetrimonium chloride (TAC), myristyltrimethylammonium bromide, (16-mercaptohexadecyl)trimethylammonium bromide, or cysteine.

[0121] Example 14: The method as described in Example 13, wherein the surfactant has a concentration in the range of 1 to 10 mmol / L.

[0122] Example 15: The method as described in Example 13, wherein the surfactant has a concentration of less than 1 mmol / L.

[0123] Example 16: The method as described in any one of Examples 9 to 15, wherein the etching is performed in the dark.

[0124] Example 17: The method as described in any one of Examples 9 to 16, wherein the etching has a duration of 1 to 60 days.

[0125] Example 18: The method as described in any of the preceding embodiments, wherein the metal olefins have a composition comprising a noble metal selected from the group consisting of: gold, platinum, iridium, rhodium, palladium, silver, and alloys thereof comprising multiple elements.

[0126] Example 19: The method as described in any of the preceding examples, wherein these metalenes are goldenes produced from Ti3AuC2 and Ti4AuC3MAX phases.

[0127] Example 20: The method as described in any of the preceding embodiments, wherein the multilayer metal olefin is a gold olefin having a layer of two, three, four, or five atoms thick, generated from Ti3Au2C2 (or Ti4Au2C3), Ti3Au3C2 (or Ti4Au3C3), Ti3Au4C2 (or Ti4Au4C3), and Ti3Au5C2 (or Ti4Au5C3)MAX phases.

[0128] Example 21: A metal alkene synthesized by the method according to any of the preceding examples, wherein the metal alkene is one of the following: gold alkene, platinumene (or platinene), iridiumene (or iridene), rhodiumene (or rhodene), palladiumene (or palladene), silver alkene, and alloys thereof containing multiple elements.

[0129] The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this disclosure. Unless the context clearly indicates otherwise, the singular forms “a / an” and “the” as used herein are intended to include the plural forms as well. As used herein, the term “and / or” includes any and all combinations of one or more of the associated enumerated items. It should be further understood that the terms “comprises / comprising” and “includes / including” as used herein specify the presence of the stated features, integers, actions, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and / or groups thereof.

[0130] It should be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0131] In this document, relative terms such as “below,” “above,” “upper,” “lower,” “horizontal,” or “vertical” may be used to describe the relationship between one element and another, as shown in the figure. It should be understood that these terms, and those discussed above, are intended to cover different orientations in the device besides those depicted in the figure. It should be understood that when an element is referred to as “connected” or “coupled” to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements present. Conversely, when an element is referred to as “directly connected” or “directly coupled” to another element, there are no intermediate elements present.

[0132] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that the terms used herein shall be interpreted as having the same meaning as they have in the context of this specification and the relevant field, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0133] It should be understood that this disclosure is not limited to the aspects described above and shown in the figures; rather, those skilled in the art will recognize that many changes and modifications can be made within the scope of this disclosure and the appended claims. Aspects have been disclosed in the drawings and specification for illustrative purposes only and not for limiting purposes, and the scope of this disclosure is set forth in the following claims.

Claims

1. A method for synthesizing metal alkenes, the method comprising: Provides MAX phase; The noble metal A' is intercalated into the MAX phase to generate the MA'X phase; as well as The MX layer is etched away from the MA'X phase to produce a self-supporting 2D single-atom-thickness noble metal A' sheet.

2. The method according to claim 1, wherein, The MAX phase is provided in the form of a film, particles, or bulk.

3. The method according to any one of the preceding claims, wherein, The MAX phase contains M n+1 Xn layers, where M is a transition metal, X is selected from the group consisting of carbon, nitrogen, and boron, and n is an integer from 1 to 5.

4. The method according to any of the preceding claims, further comprising removing any remaining noble metal on the MA'X phase before etching away the MX layers.

5. The method according to claim 4, wherein, The removal of the remaining precious metals is carried out using chemical mechanical polishing.

6. The method according to any one of the preceding claims, wherein, The etching process, which strips away these metallenes, is performed using an etching mixture containing Murakami reagent and a surfactant.

7. The method according to claim 6, wherein, The Murakami reagent contains 2 to 5 mg of potassium ferricyanide and potassium hydroxide in 10 mL of water.

8. The method according to claim 6 or claim 7, wherein, The surfactant is one of the following: hexadecyltrimethylammonium bromide (CTAB), cetrimonium chloride (CTAC), myristyltrimethylammonium bromide, (16-mercaptohexadecyl)trimethylammonium bromide, or cysteine.

9. The method according to claim 8, wherein, The surfactant has a concentration in the range of 1 to 10 mmol / L.

10. The method according to any one of claims 1 to 5, wherein, The etching process that strips these metallenes is performed using an etching mixture containing derivative chemicals selected from the group consisting of: potassium cuprous cyanide, potassium silver cyanide, potassium tetracyanonitrile, potassium tetracyanoplastate, potassium dicyanosulfate, potassium tetracyanoplastate, or potassium permanganate.

11. The method according to any one of the preceding claims, wherein, The etching was performed in the dark.

12. The method according to any of the preceding claims, wherein, The etching process can last from 1 to 60 days.

13. The method according to any one of the preceding claims, wherein, These multilayered metalloenes have layers with a thickness of two, three, four, or five atoms, and are generated from the MA'X phase having a noble metal A' layer with a thickness of two, three, four, or five atoms.

14. The method according to any one of the preceding claims, wherein, These metalenes are goldenes produced from the Ti3AuC2 MAX phase and / or the Ti4AuC3 MAX phase.

15. A metal alkene synthesized by the method according to any one of the preceding claims, wherein, The metal olefin is one of the following: gold olefin, platinumene (or platinene), iridiumene (or iridiumene), rhodiumene (or rhodene), palladiumene (or palladene), silver olefin, and alloys thereof containing multiple elements.

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