Chiral film and method of fabricating same

Abstract

A solid film comprises at least two different metals spatially distributed to form a plurality of amorphous structures exhibiting chirality.

Description

[0001] CHIRAL FILM AND METHOD OF FABRICATING SAME

[0002] RELATED APPLICATION

[0003] This application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 724,442 filed on November 25, 2024, the contents of which are incorporated herein by reference in their entirety.

[0004] FIELD AND BACKGROUND OF THE INVENTION

[0005] The present invention, in some embodiments thereof, relates to chirality and, more particularly, but not exclusively, to a chiral film and a method of fabricating a chiral film.

[0006] Chiral-induced spin selectivity (CISS) effect is a phenomenon observed in chiral molecules and materials, where the electron spin orientation becomes correlated with the direction of electron movement through a chiral system. CISS may also occur in non-molecular chiral structures, whereby the chirality is exhibited at scales larger than individual molecules. The CISS effect allows chiral molecules and materials to act as spin filters, allowing electrons with a specific spin orientation to pass through more easily than those with the opposite spin. The effect has implications in fields like spintronics, catalysis, bio-recognition and the like.

[0007] Several methods that utilize metallic chiral structures have been reported. Vadakkayil et al. describes synthesis of chiral cobalt oxide nanoparticles and their application in electrocatalysis. Cysteine was used as a capping ligand to induce chirality in the nanoparticles, which were then used as electrocatalysts for water splitting [Vadakkayil et al., Nat Commun 2023, 14, 1067]. Behar- Levy et al. describes the doping of gold and silver with such as L-glutathione, L-quinine, and D- or L-tryptophan, producing metallic structures exhibiting differences in the emission efficiency of photoelectrons when irradiated with circularly polarized UV light Behar-Levy et al., Adv. Mat. 2007, 19, 1207-1211. Ma et al. describes the synthesis, properties, and applications of chiral nanostructures made from metals, semiconductors, ceramics, and nanocarbons. Described are several techniques for inducing chirality in inorganic materials, including chirality transfer from bioorganic molecules, three-dimensional lithography, and multiphoton chirality transfer.

[0008] SUMMARY OF THE INVENTION

[0009] According to some embodiments of the invention the present invention there is provided a solid film. The solid film comprises at least two different metal atoms spatially distributed to form a plurality of amorphous structures exhibiting chirality. According to some embodiments of the invention the amorphous structures comprise a chiral molecule.

[0010] According to some embodiments of the invention the each of the at least two different metal atoms is distributed generally uniformly over the film.

[0011] According to some embodiments of the invention an atomic ratio of two of the different metal atoms is from about 1: 1 to about 100: 1.

[0012] According to some embodiments of the invention at least one of the metal atoms is present at a plurality of different oxidation states.

[0013] According to some embodiments of the invention the different metal atoms comprise a first metal atom and a second metal atom, wherein a predominant portion of the first metal atom forms ceramic compounds by bonding with oxygen and / or hydroxide ions to create metal oxides and / or metal hydroxides, and the second metal atom is in a metallic state.

[0014] According to some embodiments of the invention the solid film comprises a ceramic composite layer containing metallic phases, wherein the ceramic compounds constitute a predominant phase in the layer and the metallic phases are formed by the second metal atom and are distributed in the layer.

[0015] According to some embodiments of the invention a minor portion of the first metal atom is in a metallic state.

[0016] According to some embodiments of the invention at least one of the metal atoms is a Group

[0017] 10 metal atom.

[0018] According to some embodiments of the invention at least one of the metal atoms is nickel.

[0019] According to some embodiments of the invention at least one of the metal atoms is a Group

[0020] 11 metal atom.

[0021] According to some embodiments of the invention at least one of the metal atoms is gold.

[0022] According to an aspect of some embodiments of the present invention there is provided a coated structure. The coated structure comprises a substrate having a surface at least partially coated by the solid film as delineated above and optionally and preferably as further detailed below.

[0023] According to some embodiments of the invention the surface is flat.

[0024] According to some embodiments of the invention the substrate is foamed.

[0025] According to some embodiments of the invention the substrate is metallic.

[0026] According to some embodiments of the invention the substrate comprises one of the at least two different metal atoms of the film. According to some embodiments of the invention the substrate comprises nickel and the at least two different metal atoms of the film is nickel.

[0027] According to an aspect of some embodiments of the present invention there is provided an electrochemical apparatus. The electrochemical apparatus comprises a reaction chamber at least partially filled with an electrolyte solution, and a pair of electrodes, wherein at least one of the electrodes comprises the coated structure as delineated above and optionally and preferably as further detailed below.

[0028] According to some embodiments of the invention the electrochemical apparatus is an electrolysis apparatus for executing electrolysis.

[0029] According to some embodiments of the invention the electrochemical apparatus is a fuel cell for converting chemical energy into electrical energy.

[0030] According to an aspect of some embodiments of the present invention there is provided a method of electrolysis. The method comprises applying voltage between a cathode and an anode immersed in an electrolyte solution, wherein at least one of the anode and the cathode comprises the coated structure as delineated above and optionally and preferably as further detailed below.

[0031] According to an aspect of some embodiments of the present invention there is provided a method of electroplating. The method comprises electrochemically depositing a film on a surface of a substrate in the presence of an electrolyte solution comprising salts of at least two different metal atoms and a chiral molecule.

[0032] According to some embodiments of the invention the chiral molecule is a chiral organic molecule.

[0033] According to some embodiments of the invention the electrolyte solution is acidic.

[0034] According to some embodiments of the invention the salts are at a ratio of from about 1 : 1 to about 1: 100.

[0035] According to some embodiments of the invention the electrochemically depositing is by an electrochemical cell having an inert counter electrode.

[0036] According to some embodiments of the invention at least one of the salts is a salt containing Group 10 metal atoms.

[0037] According to some embodiments of the invention at least one of the salts is a nickel salt.

[0038] According to some embodiments of the invention at least one of the salts is a salt containing Group 11 metal atoms.

[0039] According to some embodiments of the invention at least one of the salts is a gold salt. According to some embodiments of the invention the salts comprise a nickel salt and a gold salt, and the electrochemically depositing is under a voltage of from about -1.0 V to about -0.8 V.

[0040] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0041] Implementation of the method and / or system of embodiments of the invention can involve performing or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of embodiments of the method and / or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware or by a combination thereof using an operating system.

[0042] For example, hardware for performing selected tasks according to embodiments of the invention could be implemented as a chip or a circuit. As software, selected tasks according to embodiments of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In an exemplary embodiment of the invention, one or more tasks according to exemplary embodiments of method and / or system as described herein are performed by a data processor, such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes a volatile memory for storing instructions and / or data and / or a non-volatile storage, for example, a magnetic hard-disk and / or removable media, for storing instructions and / or data. Optionally, a network connection is provided as well. A display and / or a user input device such as a keyboard or mouse are optionally provided as well.

[0043] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0044] Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. In the drawings:

[0045] FIG. 1A is a schematic illustration of a perspective view of a solid film, according to some embodiments of the present invention;

[0046] FIG. IB is a top view electron microscope image showing a solid film, according to some embodiments of the present invention;

[0047] FIG. 2 is a schematic illustration of a coated structure, according to some embodiments of the present invention;

[0048] FIG. 3 is a schematic illustration showing an example of an electrochemical apparatus, according to some embodiments of the present invention;

[0049] FIG. 4 is a schematic illustration of an electroplating system according to some embodiments of the present invention;

[0050] FIGs. 5A and 5B show SEM images of a chiral Ni-Au layer on a flat Ni layer of a surface area (20x20) pm2(FIG. 5 A), and a surface area (2x2) pm2(FIG. 5B), as obtained in experiments performed according to some embodiments of the present invention;

[0051] FIG. 5C shows a SAM image of chiral Ni-Au coated Ni-foam of a surface area (2.5x2.5) mm2as obtained in experiments performed according to some embodiments of the present invention;

[0052] FIG. 5D shows an EDX spectrum of the chiral Ni-Au layer on a flat Ni layer as obtained in experiments performed according to some embodiments of the present invention;

[0053] FIGs. 5E-G show EDX mapping of the Ni, Au, and C elements of the chiral Ni-Au layer on a flat Ni layer, respectively, as obtained in experiments performed according to some embodiments of the present invention;

[0054] FIGs. 6A-D show deconvoluted high-resolution XPS spectra of Ni 2p, Au 4f, O ls, and C Is, respectively, as obtained in experiments performed according to some embodiments of the present invention;

[0055] FIG. 7 shows circular dichroism spectra of chiral, achiral, and racemic Ni-Au layers in solid state as thin film on an ITO surface as obtained in experiments performed according to some embodiments of the present invention for qualitative probing of the surface chirality;

[0056] FIGs. 8A-C show electrochemical measurements on flat Si(100) with coating, where FIG. 8A shows cyclic voltammetry, FIG. 8B shows overpotential at 10 and 20 mA- cm-2current density, and FIG. 8C shows current density at 2.23V vs RHE (overpotential at 1.0V) for an electrode coated with only Au, only Ni, achiral Ni-Au (only metal), and chiral Ni-Au (with L-tartaric acid), as obtained in experiments performed according to some embodiments of the present invention; FIGs. 9A-C show electrochemical measurements on Ni-foam, where FIG. 9A shows cyclic voltammetry, FIG. 9B shows overpotential at current densities of 100 and 200 mA- cm-2, and FIG. 9C shows current density at a potential of 2.03V vs RHE (overpotential of 0.8V) of a bare Ni-foam electrode and an electrode coated with achiral Ni-Au (only metal), achiral Ni-Au (Racemic-tartaric acid), and chiral Ni-Au (L-tartaric acid) as obtained in experiments performed according to some embodiments of the present invention;

[0057] FIGs. 10A-C show electrochemical measurements of metal coated with proline, cysteine, and glutamic acid on Ni-foam, where FIG. 10A shows CV measurements of the coated electrodes, FIG. 10B shows calculated overpotential at 400 and 600 mA- cm-2, and FIG. 10C shows current density at 2.03V vs RHE, as obtained in experiments performed according to some embodiments of the present invention;

[0058] FIG. 11 shows chronopotentiometry measurement of the current during OER, as obtained in experiments performed according to some embodiments of the present invention;

[0059] FIGs. 12A-C show electrodeposition of Ni Au (Only Metal), acemic Tartaric acid Ni Au, and L-Tartaric acid Ni Au (Chiral Metal), respectively, as obtained in experiments performed according to some embodiments of the present invention;

[0060] FIG. 13 shows EASA measurements of untreated Ni-Foam, Achiral Ni-Au on Ni-Foam (Metal Only), Achiral Ni-Au on Ni-Foam (Rac-Tartaric acid), and Chiral Ni-Au on Ni-Foam (L- Tartaric acid), as obtained in experiments performed according to some embodiments of the present invention;

[0061] FIGs. 14A-H show CV curves (FIGs. 14A, 14C, 14E, and 14G) and linear fitting (FIGs. 14B, 14D, 14F, and 14H) of untreated Ni-Foam (FIGs. 14A-B), Achiral Ni-Au on Ni-Foam (Metal Only) (FIGs. 14C-D), Achiral Ni-Au on Ni-Foam (Rac-Tartaric acid) (FIGs. 14E-F), and Chiral Ni-Au on Ni-Foam (L-Tartaric acid) (FIGs. 14G-H), as obtained in experiments performed according to some embodiments of the present invention;

[0062] FIGs. 15A-D show CV curves of 2 samples of untreated Ni-Foam (FIG. 15A), Achiral Ni- Au on Ni-Foam (Metal Only) (FIG. 15B), Achiral Ni-Au on Ni-Foam (Rac-Tartaric acid) (FIG. 15C), and Chiral Ni-Au on Ni-Foam (L-Tartaric acid) (FIG. 15D), as obtained in experiments performed according to some embodiments of the present invention;

[0063] FIG. 16 is a Scanning electron microscopy (SEM) cross section of chiral Ni-Au (L-Tartaric acid) done by focused ion beam (FIB), as obtained in experiments performed according to some embodiments of the present invention; FIGs. 17A-D show electrochemical measurements obtained on Ni-foam in experiments performed according to some embodiments of the present invention;

[0064] FIGs. 18A and 18B are SEM images of Achiral Ni-Au on Ni-Foam (Only Metal) and Chiral Ni-Au on Ni-Foam (L-Tartaric Acid), respectively, as obtained in experiments performed according to some embodiments of the present invention; and

[0065] FIG. 18C is a SEM image showing a zoom out of a Ni foam coated with chiral Ni / Au, as obtained in experiments performed according to some embodiments of the present invention.

[0066] DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

[0067] The present invention, in some embodiments thereof, relates to chirality and, more particularly, but not exclusively, to a chiral film and a method of fabricating a chiral film.

[0068] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and / or methods set forth in the following description and / or illustrated in the drawings and / or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

[0069] The present embodiments comprise a solid film having a chiral property. The chiral property of the film according to some embodiments of the present invention can be exploited in a wide range of potential applications across various industries. For example, in the field of electrolysis, the chiral film of the present embodiments can be used as an electrode coating to enhance selectivity and efficiency in electrochemical processes. Such an electrode can control the spin alignment of electrons in order to affect the energetic condition of splitting the molecules of the electrolyte. In particular, such a control can reduce the required overpotential compared to conventional systems. The optical properties of film of the present embodiments make it valuable also in the field of materials science, where it can be employed in the fabrication of advanced liquid crystal displays, polarized lenses, and other optical devices. In the field of nanotechnology, the film of the present embodiments can be used to fabricate nanomaterials for use in sensors, molecular recognition systems, and other electronic components.

[0070] Referring now to the drawings, FIG. 1A illustrates a perspective view of a solid film 10, according to some embodiments of the present invention. The thickness of film 10 is preferably from about 10 nm to about 500 microns, or from about 10 nm to about 100 microns, or from about 50 nm to about 100 microns. Film 10 comprises two or more different types of metal atoms 12, 14, spatially distributed to form a plurality of amorphous structures exhibiting chirality. The amorphous structures 16 are better shown in FIG. IB, which is a top view electron microscope image of film 10. Preferably, one or more of the metal atoms 12, 14, more preferably each of the metal atoms 12, 14, is distributed generally uniformly over film 10.

[0071] In some embodiments of the present invention the thickness of the film has variations which are at most 50%.

[0072] As used herein, "metal atom" refers to a population of metal atoms of the same type, unless the context indicates reference to an individual atom.

[0073] One or more of metal atoms 12, 14 is optionally and preferably a Group 10 metal atom. For example, one or more of metal atoms 12, 14 can be nickel atom, or metal atoms from metals such as, cobalt, palladium and others. One or more of metal atoms 12, 14 can be a Group 11 metal atom, such as, but not limited to, metal atom of gold, silver, or copper. In some embodiments of the present invention metal atoms 12 are nickel atoms and metal atoms 14 are gold atoms.

[0074] In some embodiments of the present invention the atomic ratio of metal atoms 12, 14 is from about 1: 1 to about 100: 1, more preferably from about 10: 1 to about 100: 1, more preferably from about 20: 1 to about 100: 1, more preferably from about 30: 1 to about 100: 1, more preferably from about 40: 1 to about 100: 1, more preferably from about 50: 1 to about 100: 1. For example, in experiments performed by the Inventors using nickel and gold atoms, the atomic ratio of nickel atoms and gold atoms was about 80: 1.

[0075] One or more of metal atoms 12, 14 can be present in film 10 at more than one, or more than two, or more than three different oxidation states. Thus, in these embodiments, film 10 is a multivalent film. Such a film offers distinct advantages over single-oxidation- state films, including improved electrical conductivity, corrosion resistance, and catalytic properties. The presence of metal atoms in different oxidation states within film 10 creates a complex electronic structure, resulting in unique physicochemical properties.

[0076] In some embodiments of the invention, a predominant portion (e.g. , more than 50% or more than 60% or more than 70% or more than 80%) of metal atoms 12 form ceramic compounds by bonding with oxygen and / or hydroxide ions to create metal oxides and / or metal hydroxides, and metal atoms 14 and, optionally and preferably, also a minor portion (e.g., less than 50% or less than 40% or less than 30% or less than 20%) of metal atoms 12, remain in their metallic state (zero oxidation state). In these embodiments, film 10 can comprise a ceramic composite layer containing metallic phases and optionally and preferably also metallic components in which the ceramic compounds constitute the predominant phase with the metallic phases and the optional metallic components distributed within the same deposited layer. In some embodiments, the predominant ceramic phase formed by metal atoms 12 comprises at least one of: nickel oxides (such as NiO, hfeCh) and nickel hydroxides (such as Ni(0H)2), the metallic phases formed by metal atoms 14 comprise gold atoms in their metallic state, and the optional metallic components formed by metal atoms 12 comprise residual metallic nickel.

[0077] In some embodiments of the present invention the amorphous structures 16 comprise a chiral molecule 18, which is preferably a chiral organic molecule. Chiral molecule 18 may be characterized by certain spatial and geometrical asymmetries, otherwise known as chirality or handedness. Chiral molecules exist in two forms called enantiomers, which are mirror images of each other and have identical physical properties except for their interaction with polarized light. Chirality can arise from various structural features. For example, molecule 18 can have a tetrahedral center, e.g., carbon atoms with four different substituents, or other atoms such as, but not limited to, silicon or phosphorus. Molecule 18 can possess planar chirality, such as the chirality found in molecules with restricted rotation, e.g., substituted paracyclophanes. Molecule 18 can possess axial chirality, such as the chirality found in compounds with hindered rotation, e.g., allenes or biphenyl. Molecule 18 can possess helical chirality, such as the chirality found in helicenes or certain polymers.

[0078] Representative examples of chiral organic molecules suitable for the present embodiments, include, without limitation, chiral amino acids, sugars and other synthetic molecules. Among the molecules one can mention tartaric acid, lactic acid, alanine or limonene, glucose, and menthol. Molecule 18 can be in an L form or in a D form, as desired. Preferably, film 10 is homo-chiral, wherein all the chiral molecules in film 10 have the same chirality. Also contemplated, are embodiments in which molecule 18 is present in both L and D forms, except that the population of molecules in film 10 that are in one of these forms is larger than the population of molecules that are in the other one of these forms.

[0079] Film 10 can be used as a coating for various coated structures. FIG. 2 is a schematic illustration of a coated structure 20, according to some embodiments of the present invention. Coated structure 20 comprises a substrate 22 having a surface 24 coated by solid film 10. While FIG. 2 illustrates a configuration in which surface 24 is completely coated by film 10, this need not necessarily be the case, since, for some applications, film 10 only partially coats surface 24, leaving one or more regions of surface 24 which are not coated by film 10 e.g., exposed to the environment, or coated by another substance).

[0080] Substrate 22 can be made of any material. Preferably, substrate 22 is electrically conductive. For example, substrate can be metallic or semiconductor, or be made of a conductive polymer, such as, but not limited to, polyacetylene, polyaniline, polypyrrole, polythiophene, poly(p-phenylene), poly(phenylene vinylene), polyfuran, and poly(3,4-ethylenedioxythiophene). When substrate 22 is metallic it optionally and preferably comprises at least one type of metal atoms 12, 14. In experiments performed by the Inventors a film comprising nickel atoms and gold atoms was used for coating a surface of a nickel substrate.

[0081] Use of an electrically conductive material(s) for substrate 22 is particularly advantageous when structure 20 is used as an electrode for use in water splitting via electrolysis. The incorporation of film 10 as the coating of the electrode provides a specific spin correlation between electrons transferred by the electrode, enabling the formation of the triplet. Film 10 acts as a spin filter and reduces the over-potential in the reaction chamber performing the electrolysis. This allows a spin alignment controlled water oxidation. The inventors found that use of film 10 as an electrode coating allows electrons to leave or enter the electrode's surface at a lower potential than for another surface such as a bare electrode or an electrode coated with an achiral film. Thus, the utilization of film 10 in structure 20 may reduce its work function.

[0082] Surface 24 can be flat or curved, as desired. In some embodiments of the present invention surface 24 is foamed. A foamed surface refers to a porous surface that comprises gas bubbles dispersed in a solid matrix. For example, surface 24 can be a metallic foam made, e.g., by incorporating gas bubbles into molten metal. A foamed surface is particularly useful when the coated structure is an electrode, because it provides a three-dimensional structure that enhances the electrochemical interaction between the electrode and other substances e.g., electrolyte).

[0083] The coated structure of the present embodiments can be used with another electrode to form an anode-cathode pair through which voltage can be applied, for example, for hydrogen production, or though which voltage is generated, e.g., by converting chemical energy into electrical energy. FIG. 3 is a schematic illustration showing an example of an electrochemical apparatus 30, according to some embodiments of the present invention. Apparatus 30 can be used for executing a method of electrolysis, for example, for the purpose of water splitting. Apparatus 30 can also be used as a fuel cell for converting chemical energy into electrical energy.

[0084] Apparatus 30 comprises a reaction chamber 32 at least partially filled with an electrolyte solution 34 which can be acidic, alkaline, or neutral, depending on the specific application requirements. Electrolyte solution 34 facilitates ionic conduction, and may include common ionic compounds such as sodium sulfate, potassium hydroxide, sulfuric acid, or other suitable ionic media. Apparatus 30 also comprises a pair of electrodes, including an anode 36 and a cathode 38. Anode 36 can comprise, or be, coated structure 20 as further detailed hereinabove. Cathode 38 can be made of any material that is known to provide stability under electrochemical conditions, such as platinum, iridium oxide, or other catalytic materials. Electrodes 36, 38 are immersed in electrolyte solution 34. Also contemplated, are embodiments in which cathode 38 comprises, or is, coated structure 20, and anode 36 is made of a material that provides stability under electrochemical conditions. Further contemplated, are embodiments in which both anode 36 and cathode 38 comprise, or are, coated structure 20.

[0085] In some embodiments of the present invention, apparatus 30 also comprises an ionconducting membrane 40, positioned between anode 36 and cathode 38 and being selected to selectively permit the passage of ions while suppressing mixing of gaseous products. Membrane 40 can be a proton exchange membrane or an anion exchange membrane, depending on the electrolyte and operational conditions.

[0086] Apparatus 30 can further comprise a power source 42, electrically connected to the electrodes 36, 38 to provide a controlled voltage therebetween. The voltage drives an electrochemical reaction, causing the dissociation of molecules in the electrolyte into gases. For example, when apparatus 30 is used for water splitting, the voltage causes water molecules to dissociate into hydrogen and oxygen gases.

[0087] When apparatus 30 is used for electrolysis, voltage (typically DC voltage) is applied between electrodes 36 and 38, causing the oxidation of molecules of the electrolyte at the anode 36 and the reduction of molecules at the cathode 38. For example, when apparatus 30 is used for water splitting, the water is oxidized at anode 36 to form oxygen gas O2 and OH“ ions. The negatively charged ions migrate to the cathode 38, e.g., via through the ion-conducting membrane 40 (when present), at which they are combined with electrons to produce hydrogen gas H2. One or more of the produced gases can be collected in respective gas collection chambers 44.

[0088] When apparatus 30 is used as a fuel cell for converting chemical energy into electrical energy, a fuel (e.g., hydrogen) is supplied to anode 36 and an oxidant (for example, oxygen from air) is supplied to cathode 38. At anode 36, the fuel is oxidized, releasing electrons and positively charged ions. The electrons travel through an external circuit (not shown), providing electrical power, while the ions pass through the electrolyte 34 to cathode 38. At cathode 38, the ions combine with oxygen and the electrons from the external circuit to form a byproduct (e.g., water).

[0089] Film 10 of the present embodiments can be fabricated by electroplating. FIG. 4 is a schematic illustration of an electroplating system 50 according to some embodiments of the present invention. System 50 comprises an electrochemical cell 52 containing an electrolyte solution 54 comprising salts of two or more different types of metal atoms (e.g., salts containing metal atoms 12, 14) and a chiral molecule (e.g., chiral molecule 18). Preferably, but not necessarily, electrolyte solution 54 is acidic. The salts in electrolyte solution 54 can be at a ratio of from about 1 : 1 to about 1: 100.

[0090] System 50 also comprises a substrate 56 immersed within the electrolyte solution 54. Substrate 56 typically comprises a conductive material, such as a metal or conductive polymer. For example, substrate 56 can be the same as substrate 22 as further detailed hereinabove. System 50 further comprises a counter electrode 58 which is immersed in the electrolyte solution 54. Counter electrode 58 can be made of a metal such as, but not limited to, an inert metal, e.g., platinum, graphite, titanium, gold, and the like. Alternatively, counter electrode 58 can serve as a metal source, in which case counter electrode 58 can comprise a sacrificial metal that provides the ions required for deposition of film 10 onto substrate 56. The sacrificial metal can be any of metal atoms 12, 14 described above. For example, the sacrificial metal of counter electrode 58 can be nickel.

[0091] In some embodiments of the present invention system 50 also comprises a reference electrode 60 which is immersed in the electrolyte solution, and which can be used to provide a reference potential during the electrochemical process in cell 52. Reference electrode 60 can be made of any composition known to be suitable for use as a reference electrode, including, without limitation, a calomel electrode, a silver / silver chloride electrode, and the like. Reference electrode 60 allows better control of the potential difference between the substrate 56 and the reference electrode 60 improving the deposition process in cell 52.

[0092] System 50 further comprises a powering and controlling system 62, which is connected to the counter electrode 58 and the substrate 56, and which applies a controlled voltage or current to drive an electrochemical deposition process in cell 52. Powering and controlling system 62 may feature programmable settings to control the deposition rate, current density, and applied voltage, allowing for precise metal layer thickness and quality. Upon application of voltage between counter electrode 58 and substrate 56, the metal ions in electrolyte 54 are reduced at substrate 56, leading to the deposition of film 10 onto substrate 56. When the salts comprise a nickel salt and a gold salt, system 62 is preferably, but not exclusively, programmed to apply voltage of from about -1.0 V to about -0.8 V.

[0093] As used herein the term “about” refers to ± 10 %. The terms "comprises", "comprising", "includes", "including", “having” and their conjugates mean "including but not limited to".

[0094] The term “consisting of’ means “including and limited to”.

[0095] The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and / or parts, but only if the additional ingredients, steps and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0096] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

[0097] Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0098] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging / ranges between” a first indicate number and a second indicate number and “ranging / ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.

[0099] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples.

[0100] EXAMPLES

[0101] Reference is now made to the following examples, which together with the above descriptions illustrate some embodiments of the invention in a non limiting fashion.

[0102] Chiral Metal Coating for Enhancing W ater Electrolysis

[0103] This Example presents a simple method for coating Ni-based electrodes with chiral Ni-Au film, using electroplating, thus enhancing its efficiency. Chirality is introduced to the electroplating layer by incorporating an enantiopure chiral reagent into the electroplating solution. The chiral layer enhances the oxygen evolution reaction (OER) due to the chiral-induced spin selectivity (CISS) effect. The reduction of the overpotential and the increase in the reaction efficiency by 95% at 1 M KOH at room temperature are demonstrated by optimizing the chiral electroplating process.

[0104] Significant attention has been garnered by hydrogen as a clean and renewable energy source recently due to its high gravimetric energy density (142 MJ kg 1), eco-friendly nature, the potential to reduce reliance on fossil fuels, and to mitigate climate change [1,2, 3, 4]. One of the most promising methods for hydrogen production is by water splitting, a process in which water is electrolyzed to produce hydrogen and oxygen [5,6]. However, the efficiency of the water splitting process is limited by overpotentials, particularly at the anode; this increases the energy required for the reaction and reduces the overall efficiency of hydrogen production.

[0105] At present, Ir / Ru oxides and Pt are considered the primary materials for electrocatalysis in the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). However, the scarce abundance of these materials and their low chemical stability hinder reducing the cost of hydrogen production.

[0106] Recent advancements in materials science have led to the development of foam metals as electrodes in electrolyzers. Foam metals, such as nickel foam, offer a high surface area, which increases the active sites for the electrochemical reaction and allows for the use of zero-gap electrolyzers, further enhancing the process's efficiency. Despite these improvements, the issue of overpotential remains a significant challenge.

[0107] It has been shown that overpotential occurs because the OER is a spin-forbidden process. Whereas water has a singlet ground state, the product, oxygen, has a triplet ground state. Hence, formally this reaction is forbidden, namely, it has a spin-related potential barrier. Recent studies demonstrated a link between the formation of the oxygen triplet state, the overpotential, and the spin alignment [4, 10, 11, 12]. In the OER, two pairs of electrons are transferred [13,14]. If the electrons in each pair have the same spin state, the reaction is enhanced, and the spin-related barrier is reduced. One method to obtain this spin co-alignment is by coating the anode with chiral material that serves as a spin filter, due to the chiral-induced spin selectivity (CISS) effect. The CISS effect refers to spin- selective electron transport through chiral systems [15-17].

[0108] In recent years, several methods for preparing chiral metal films have been reported [4, 18- 21]. Among others, the films of chiral gold and chiral Ni have been produced.

[0109] In this Example, electroplating is applied as a simple method for coating nickel foam and flat Ni-substrates electrodes with a chiral Ni-Au coating. Chirality is induced in the electrodeposited composite metal layers by adding enantiopure chiral acids to the electroplating solution. The chiral layer formed on the anode induces the CISS effect, leading to higher efficiency in the OER. The chiral electroplating process was optimized and the impact of the chiral metal coating on the overpotential and efficiency of the OER with various organic chiral acids was investigated. New insights into designing more efficient and cost-effective electrodes for hydrogen production by electrolysis are provided by the findings.

[0110] Several substrates were probed. In the first case, Ni-Au layers were deposited electrochemically using a solution of various salt mixtures, specifically Na3[Au(S2O3)2]-2H2O, NiSO4, NiCh, Na2S2O3, Na2SO3, and chiral / racemic tartaric acid at pH 6.5. The layer was grown chronoamperometrically on the flat Ni surface at a constant voltage of -0.9V using Pt as the counter and Hg / HgCl (SCE) as the reference electrode.

[0111] The morphologies of the Ni-Au layers were measured by scanning electron microscopy (SEM). The low-magnification SEM image of chiral Ni-Au on a flat Ni surface (FIG. 5A) shows the formation of a compact electrodeposited layer. The high-resolution SEM image (FIG. 5B) shows amorphous structures with a high surface area. FIG. 5C represents the SEM image of Ni-Au coated on another substrate, Nickel foam. The image shows the highly porous structure with a larger surface area than the flat surface. Furthermore, the energy-dispersive X-ray (EDX) presents a substantial abundance of Ni, Au, and C signals in the chiral Ni- Au-deposited layers (FIG. 5D). Elemental mapping confirms the uniform distribution of the Ni, Au, and C elements on the entire surface (FIGs. 5E-F). The thickness of the deposited layer varies between 0.5 to 1 micron (see FIG. 16) and the chiral and no effect of the thickness on the activity was detected. The achiral layers have the same properties as the chiral one.

[0112] X-ray photoemission spectroscopy (XPS) was carried out to determine the surface chemical state of the Ni-Au layers. FIGs. 6A-D show the high-resolution XPS spectrum of Ni 2p, Au 4f, C Is, and O ls. The Ni 2p peak (FIG. 6A) consists of two spin-orbit doublets at binding energies (BE) of 856.3 eV and 874.0 eV, with a spin energy separation of 17.7 eV, corresponding to Ni 3p3 / 2 and Ni 3p 1 / 2, respectively. The binding energies indicate that these two peaks correspond to a combination of Ni2+and Ni3+states. Ni 2p and Ni2+peaks appear at 857.3 and 875 eV and the peaks corresponding to Ni3+appear at 856.1 and 873.6 eV

[0022] . Small peaks at binding energies of 853 and 870 eV are observed in the Ni° state, related to the nickel substrate. The peaks at a BE of 861.7 and 879.6 eV correspond to the shake-up peaks of Ni 2p3 / 2 and Ni 2pi / 2. Ni3+arises from Ni(0H)2 oxidation upon exposure to air. FIG. 6B presents a high-resolution XPS spectrum of Au 4f with two spin-doublets at 83.8 and 87.4 eV corresponding to 4f 7 / 2 and 4f 5 / 2. The presence of an Au 4f signal confirms the deposition of gold along with Ni. The atomic ratio of Ni and Au in the deposited layer is around 80: 1 near the surface. FIG. 6C presents the XPS profile of O Is, where the peak is centered at 531.7 eV. The de-convoluted peak indicates that it is composed of three components. The peak at 529.5 eV corresponds to the band of oxygen in metal oxides (M-O), and the peak at 531.6 eV corresponds to hydroxides (M-OH). Here it is Ni(0H)2, and the peak at 332.7 eV corresponds to the oxygen in the carboxylic acid group of tartaric acid. FIG. 6D represents the C is high-resolution XPS spectrum, which gives rise to four de-convolute peaks corresponding to C-C at 284.9 eV from adventitious C, C-OH at 286.1 eV, O-C=O- from carboxylic of tartaric acid at 287.8 eV, and COOH carboxylic acid of tartaric acid at 288.8 eV [23, 24]. The experiments described herein confirm that the electrodeposited layer consists of Ni and Au, where Ni is present in various oxidation states. Also, tartaric acid is present within the electrodeposited chiral metal layer.

[0113] Solid-state circular dichroism (CD) measurements were performed on the Ni-Au layer to confirm the chirality of the electrodeposited layers. For this purpose, a thin Ni-Au composite layer was grown on an ITO surface, so that the surface remains semitransparent. FIG. 7 presents the CD spectra of different systems. The chiral Ni-Au layer, grown in the presence of either L- or D- tartaric acid, shows CD signals ranging from 330 to 800 nm that are mirror images of each other. The racemic mixture shows no CD signal and bisects the CD signals that arise from the chiral layers. These results confirm that enantiopure tartaric acid induces chirality in the Ni-Au composite layer during electrodeposition.

[0114] All electrochemical results are presented with respect to a reversible hydrogen electrode (RHE). An electrode of 1x1 cm was used for electrochemical studies. The electrocatalytic performances of the Ni-Au layer-modified electrodes were studied in 1.0 M KOH solution using cyclic voltammetry (CV). Electrochemical Studies on flat surfaces

[0115] All the electrochemical studies were performed at least on four different samples with the same coating and the error bars represent the deviations in their performance. FIG. 8A presents the CV spectra obtained with various films grown on the Si(100) surface. Shown is an apparent current enhancement and an overpotential reduction as the film changes from Au to Ni to achiral Ni-Au, and it changes the chiral Ni-Au surface. Along with the enhancement, the CV spectra show nickel oxidation and reduction peaks at 1.4 V and 1.25 V vs RHE due to the transformation of Ni2+-> Ni3+and Ni3+-> Ni2+, respectively. The conversion of Ni2+to Ni3+preactivates the composite layer, consequently catalyzing the water splitting. The higher the surface density of the Ni3+species, the higher the current associated with water splitting. Following preactivation, the flat Ni surface requires an overpotential of 0.69V and 0.8V to obtain a current density of 10 and 20 mA / cm2, respectively (FIG. 8B). The overpotential is defined as the potential above 1.23 V vs. RHE. In contrast, the achiral Ni-Au layer requires an overpotential of only 0.53 and 0.59 V, and the chiral Ni-Au layer requires 0.34 and 0.38 V, respectively (FIG. 8B). The overpotential is reduced by about 25% from Ni to the achiral Ni-Au surface and is reduced further by 35% from achiral Ni-Au to chiral Ni-Au. However, as shown in FIG. 8C, a significant current enhancement is observed in the achiral Ni-Au and chiral Ni-Au, with around 200% and 400% improvement, respectively, compared with flat Ni surfaces. These results confirm that introducing Au in the grown Ni oxide layer improves the catalytic efficiency of Ni3+for the water splitting reaction. Introducing chirality to the system improves the OER efficiency even more, which is attributed to the CISS effect.

[0116] Electrochemical Studies on Ni foam

[0117] FIG. 9A presents the cyclic voltammetry (CV) measurements for chiral metal, racemic metal, and metal only, corresponding to samples with E-Tartaric acid, L+D Tartaric acid, and no chiral molecules, respectively. The study of the racemic mixture was introduced to determine whether the effect of the organic molecules results only from increasing the surface area. In general, an increase in current was observed in the Ni-Au-coated nickel foam electrodes, compared with the flat metals. This may result from increasing the surface area. FIGs. 9B and 9C present the overpotentials and current densities, respectively. The electrode coated with chiral Ni-Au provides the best results with 95% and 40% improvement in current density, compared with the untreated and only metal samples, respectively. A similar trend was observed in the overpotentials, where the chiral Ni-Au electrode provides the lower overpotential. Electrochemically active surface area (EASA) measurements were conducted for Ni foam, achiral Ni-Au (metal only), achiral Ni-Au (racemic tartaric acid), and chiral Ni-Au (L-tartaric acid) coatings. The results are shown in FIG. 13 with an average of 3 samples in each batch. The achiral Ni-Au surface showed a 10% increase in surface area as compared to the chiral surface. This supports the Inventor's conclusion that the primary effect, on the efficiency of the OER, arises from the CISS effect and its catalytic properties, rather than from changes in the electrode's surface area.

[0118] In further experiments, several amino acids were used in the electrodeposition process, at the same concentration as tartaric acid. The molecules studied were proline, cysteine, and glutamic acid. FIG. 10A presents the CV plot for those molecules. FIG. 10B shows the overpotentials obtained for these three chiral Ni-Au layers at two different current densities of 400 and 600 mA

[0119] All amino acid-modified chiral layers show a reduction of overpotential compared with bare Ni-foam, whereas glutamic acid shows the lowest overpotential. FIG. 10C 6c shows the current improvement at 2.03V vs RHE based on the CV measurements. All the Au-Ni layers with the amino acids show an improvement in current density compared with the values obtained before treatment, and the chiral Ni-Au sample showed a 60% increase in current density with glutamic acid, compared with the result with the bare electrode. The results with tartaric acid surpass those obtained with glutamic acid.

[0120] The stability of the chiral metal coating was probed for 11.5 days and compared to that of the bare electrode. A chronopotentiometry measurement was conducted on untreated Ni foam and chiral Ni-Au (E-tartaric acid). The chiral Ni-Au stabilized after one day at 2.45 V vs. RHE and, after 11 days, settled around 2.53 V vs. RHE, reflecting an 80 mV increase over 10 days. In contrast, the untreated Ni foam reached 2.87 V vs. RHE after one day and rose to 3.08 V after 11 days, showing a 210 mV increase over the same period. These findings indicate that the chiral Ni- Au coating provides protection to the Ni foam substrate in addition to enhancing its performance. It shows that beyond reducing the potential, the chiral coating improves the time stability of the electrode without significant deterioration of the electrode's performance. FIG. 11 shows chronopotentiometry measurement of the current during OER. The current was set to 250mA / cm2in 5M KOH solution. The anode was either untreated Ni foam (black) or Ni foam coated with chiral Ni-Au (L-Tartaric acid) film.

[0121] The improved performance of the chiral Ni-Au coatings can be attributed to the chiral- induced spin selectivity (CISS) effect. The CISS effect occurs when chiral molecules or structures preferentially transmit electrons with one spin state. In the context of water electrolysis, the chiral layer on the anode enables the transfer of electrons with one specific spin state from the OH- in the solution, leaving the OH radicals with unpaired electrons in the same spin state. Therefore, when two radicals interact to form oxygen, they do so on a triplet spin state potential, which allows the formation of oxygen in its triplet ground state

[0010] . This selective interaction reduces the overpotential required for OER by facilitating more efficient electron transfer.

[0122] This Example demonstrates the significant potential of chiral metal coatings in enhancing the efficiency of water electrolysis for hydrogen production. Chirality was successfully introduced into Ni-Au coatings on nickel foam and flat nickel electrodes by employing a straightforward electroplating method; this chirality introduces the CISS effect. The enhancement in the OER reaction is expressed in a substantial reduction in the overpotential and a notable increase in the OER efficiency. The feasibility of using chiral metal coatings to address the challenges of overpotential and efficiency in water splitting technologies is highlighted by the findings, paving the way for more cost-effective and sustainable hydrogen production methods.

[0123] Following is a description regarding the layer deposition, the electrochemical measurements' procedure, and the characterization methods

[0124] Laver Depositions

[0125] Electrochemical depositions have been performed mainly with two types of substrates: flat substrates, where metal layers are grown on Si(100) surfaces, and another system, nickel foam. Four types of metal-coated layers were used for the OER studies on flat surfaces.

[0126] Si(100) wafers were cut into rectangular shapes of (1x4) cm2, and then 100 nm Gold or 120 nm Nickel were grown using an E-beam evaporator. Furthermore, Ni-coated surfaces were used for electroplating the Ni-Au composite materials. In that case, the Ni-coated surfaces were cleaned in boiling acetone and ethanol, each for 10 min before electrodeposition.

[0127] The Ni foam was cut into lx 1+0.1 cm2squares and then subjected to a thorough cleaning process prior to any pretesting and electroplating. The cleaning procedure involved washing the foam with pure ethanol, followed by a 2-minute exposure to O2 plasma at 100W for each side, a 5- minute sonication in 37% (v / v) HC1, rinsing with distilled water to remove any residues, and a final 5-minute sonication in ethanol.

[0128] The electroplating was conducted using a three-electrode system, comprising the Ni-Foam as the working electrode, a Pt wire as the counter electrode, and an Ag / AgCl reference electrode. Cyclic voltammetry was performed, scanning from -1.4V to -0.6V at a rate of 50 mV / s. The electroplating solution contained 0.02M Nas Au SiCb , 0.25M Ni(S04)2’6H20,0.05M NiCh ,0.42M Na2S20s, 0.42M Na2 SO3, and a 0.6M chiral molecule in distilled water; the final pH of the solution was adjusted using NaOH resulting in 6.5+0.1. A reference anode was made, using a racemic chiral in the same concentration, and without organic chiral material (metal only) to determine the effect of CISS in the process.

[0129] FIGs. 12A-C show electrodeposition of Ni Au (Only Metal), acemic Tartaric acid Ni Au, and L-Tartaric acid Ni Au (Chiral Metal), respectively.

[0130] Electrochemical Study

[0131] The electrochemical characterizations were conducted in two separate systems. Initially, cyclic voltammetry (CV) was performed in a three-electrode setup with a Ti net as the counter electrode for the Ni foam substrates, Pt as a counter electrode for flat substrates, and an Hg / HgO electrode (purchased from ALC Co.) as the reference electrode. A pretesting CV was carried out for all electrodes before the deposition process (and after cleaning) to minimize potential errors arising from variations in electrode size. Subsequently, the coated electrodes were tested for longterm constant voltage measurements. This setup tests the coating's stability under prolonged and harsh conditions. Both measurements were done in IM KOH.

[0132] All the experiments were performed at 24-25 °C under ambient conditions. In this Example, all potentials reported were adjusted to the reversible hydrogen electrode (RHE). For RHE conversion at different pH, the following equation was used.

[0133] E(RHE) = E(Hg / HgO) + E^(Hg / HgO) + 0.059 pH

[0134] At pH 14,

[0135] E° (Hg / HgO) + 0.059pH = 0.936

[0136] The overpotential at a specific current density was defined as the extra potential required to achieve that current density with respect to the minimum potential required by the thermodynamic potential, whose reversible thermodynamic potential is 1.23V vs RHE for OER.

[0137] Characterization

[0138] X-ray photoelectron spectroscopy (XPS):

[0139] XPS measurements were carried out using a KratosAxis Ultra DLD spectrometer equipped with a monochromatic Al Ka X-ray source (hv = 1486.6 eV) operating at 75 W. Measurements were performed at the surface normal. Elemental concentrations were measured from the relative intensities of different elements. XPS spectra were analyzed using CASA XPS software using a Shirley background correction. The spectra were fitted with the minimum number of peaks needed to reproduce the spectral features using Gaussian Lorentzian product function. Scanning, electron microscopy (SEM}'.

[0140] Morphological investigations were performed on a high-resolution scanning electron microscope (HRSEM, Carl Zeiss Ultra Plus). Energy-dispersive X-ray spectroscopy (EDS) was performed using a spectrometer (Oxford Instruments X-MaxN) attached to a SEM.

[0141] X-ray Diffraction (XRDy.

[0142] The powder X-ray diffraction pattern (PXRD) was recorded using a Bruker AXS with D8 advance with Cu Ka radiation (1.54 A), and with a step size of 0.02 in a 20 range of 5-800.

[0143] Circular Dichroism (CD} Spectroscopy.

[0144] The Circular Dichroism spectroscopy measurements were performed using a Chirascan spectrometer with a thermoelectric ally controlled single-cell holder. The measurements were performed at 1 s time per point, a 1 nm step size and with a bandwidth of 1 nm.

[0145] An EASA measurement done on Ni-Foam for understanding the changes in the active surface area of the Ni-Foam after treatment. The measurements done in a three-electrode setup in 0. IM KOH, Ni-Foam and Hg / HgO sat. as counter and reference electrodes, respectively. The cyclic voltammetry scan done +0.1V around the OCP. Rate scan are 10, 20, 30, 40, 50, 60, 70, 80, 90 mV / s.

[0146] FIGs. 14A-H show CV curves (FIGs. 14A, 14C, 14E, and 14G) and linear fitting (FIGs. 14B, 14D, 14F, and 14H) of untreated Ni-Foam (FIGs. 14A-B), Achiral Ni-Au on Ni-Foam (Metal Only) (FIGs. 14C-D), Achiral Ni-Au on Ni-Foam (Rac-Tartaric acid) (FIGs. 14E-F), and Chiral Ni-Au on Ni-Foam (E-Tartaric acid) (FIGs. 14G-H). Average of 3 samples was taken in each batch.

[0147] FIGs. 15A-D show CV curves of 2 samples of untreated Ni-Foam (FIG. 15A), Achiral Ni- Au on Ni-Foam (Metal Only) (FIG. 15B), Achiral Ni-Au on Ni-Foam (Rac-Tartaric acid) (FIG. 15C), and Chiral Ni-Au on Ni-Foam (L-Tartaric acid) (FIG. 15D).

[0148] FIG. 16 is a Scanning electron microscopy (SEM) cross section of chiral Ni-Au (E-Tartaric acid) done by focused ion beam (FIB). The Chiral Ni-Au average coating size is approximately 0.75pm. Identical images were obtained for the Ni-Au without chiral molecules and with racemic mixture

[0149] FIGs. 17A-D summarizes the various results obtained from the electrochemical measurements conducted on Ni-foam electrode, either bare or coated with achiral or chiral Ni / Au coating. FIG. 17A shows cyclic voltammetry, FIG. 17B shows overpotential at current densities of 100 and 200 mA- cm2, FIG. 17C shows chronopotentiometry measurement at 250mA / cm2in 5M KOH of Untreated Ni foam, and Chiral Ni-Au (L-Tartaric acid), and FIG. 17D shows current density at a potential of 2.03V vs RHE (overpotential of 0.8V) of only Ni-foam, achiral Ni-Au (only metal), achiral Ni-Au (Racemic-tartaric acid), and chiral Ni-Au (L-tartaric acid) coating.

[0150] SEM images of the surfaces prepared are shown in FIGs. 18A-C. Achiral Ni-Au on Ni- Foam (Only Metal) is shown in FIG. 18 A, Chiral Ni-Au on Ni-Foam (E-Tartaric Acid) is shown in FIG. 18A, and a zoom out of the Ni foam coated with the chiral Ni / Au is shown in FIG. 18C.

[0151] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. It is the intent of the applicant(s) that all publications, patents and patent applications referred to in this specification are to be incorporated in their entirety by reference into the specification, as if each individual publication, patent or patent application was specifically and individually noted when referenced that it is to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is / are hereby incorporated herein by reference in its / their entirety.

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Claims

WHAT IS CLAIMED IS:

1. A solid film, comprising at least two different metal atoms spatially distributed to form a plurality of amorphous structures exhibiting chirality.

2. The solid film according to claim 1, wherein said amorphous structures comprise a chiral molecule.

3. The solid film according to claim 1, wherein said chiral molecule is a chiral organic molecule.

4. The solid film according to any of claims 1 and 2, wherein each of said at least two different metal atoms is distributed generally uniformly over the film.

5. The solid film according to claim 1, wherein an atomic ratio of two of said different metal atoms is from about 1: 1 to about 100: 1.

6. The solid film according to any of claims 2-4, wherein an atomic ratio of two of said different metal atoms is from about 1: 1 to about 100: 1.

7. The solid film according to claim 1, wherein at least one of said metal atoms is present at a plurality of different oxidation states.

8. The solid film according to any of claims 2-6, wherein at least one of said metal atoms is present at a plurality of different oxidation states.

9. The solid film according to claim 7, wherein said at least two different metal atoms comprise a first metal atom and a second metal atom, wherein a predominant portion of said first metal atom forms ceramic compounds by bonding with oxygen and / or hydroxide ions to create metal oxides and / or metal hydroxides, and said second metal atom is in a metallic state.

10. The solid film according to claim 8, wherein said at least two different metal atoms comprise a first metal atom and a second metal atom, wherein a predominant portion of said firstmetal atom forms ceramic compounds by bonding with oxygen and / or hydroxide ions to create metal oxides and / or metal hydroxides, and said second metal atom is in a metallic state.

11. The solid film according to claim 9, comprising a ceramic composite layer containing metallic phases, wherein said ceramic compounds constitute a predominant phase in said layer and said metallic phases are form by said second metal atom and are distributed in said layer.

12. The solid film according to claim 10, comprising a ceramic composite layer containing metallic phases, wherein said ceramic compounds constitute a predominant phase in said layer and said metallic phases are form by said second metal atom and are distributed in said layer.

13. The solid film according to claim 9, wherein a minor portion of said first metal atom is in a metallic state.

14. The solid film according to any of claims 10-12, wherein a minor portion of said first metal atom is in a metallic state.

15. The solid film according to claim 1, wherein at least one of said metal atoms is a Group 10 metal atom.

16. The solid film according to any of claims 2-14, wherein at least one of said metal atoms is a Group 10 metal atom.

17. The solid film according to claim 1, wherein at least one of said metal atoms is nickel.

18. The solid film according to any of claims 2-16, wherein at least one of said metal atoms is nickel.

19. The solid film according to claim 1, wherein at least one of said metal atoms is a Group 11 metal.

20. The solid film according to any of claims 2-19, wherein at least one of said metal atoms is a Group 11 metal.

21. The solid film according to claim 1, wherein at least one of said metal atoms is gold.

22. The solid film according to any of claims 2-20, wherein at least one of said metal atoms is gold.

23. A coated structure, comprising a substrate having a surface at least partially coated by the solid film according to claim 1.

24. A coated structure, comprising a substrate having a surface at least partially coated by the solid film according to any of claims 2-22.

25. The coated structure according to claim 23, wherein said surface is flat.

26. The coated structure according to claim 24, wherein said surface is flat.

27. The coated structure according to claim 23, wherein said substrate is foamed.

28. The coated structure according to claim 24, wherein said substrate is foamed.

29. The coated structure according to claim 23, wherein said substrate is metallic.

30. The coated structure according to any of claims 24-28, wherein said substrate is metallic.

31. The coated structure according to claim 29, wherein said substrate comprises one of said at least two different metal atoms of the film.

32. The coated structure according to claim 30, wherein said substrate comprises one of said at least two different metal atoms of the film.

33. The coated structure according to claim 29, wherein said substrate comprises nickel and said at least two different metal atoms of the film is nickel.

34. The coated structure according to claim 30, wherein said substrate comprises nickel and said at least two different metal atoms of the film is nickel.

35. An electrochemical apparatus, comprising a reaction chamber at least partially filled with an electrolyte solution, and a pair of electrodes, wherein at least one of said electrode comprises the coated structure according claim 23.

36. An electrochemical apparatus, comprising a reaction chamber at least partially filled with an electrolyte solution, and a pair of electrodes, wherein at least one of said electrode comprises the coated structure according to any of claims 24-33.

37. The electrochemical apparatus according to claim 35, being an electrolysis apparatus.

38. The electrochemical apparatus according to claim 36, being an electrolysis apparatus.

39. The electrochemical apparatus according to claim 35, being a fuel cell.

40. The electrochemical apparatus according to claim 36, being a fuel cell.

41. A method of electrolysis, comprising applying voltage between a cathode and an anode immersed in an electrolyte solution, wherein at least one of said anode and said cathode comprises the coated structure according to claim 23.

42. A method of electrolysis, comprising applying voltage between a cathode and an anode immersed in an electrolyte solution, wherein at least one of said anode and said cathode comprises the coated structure according to any of claims 24-34.

43. A method of electroplating, comprising electrochemically depositing a film on a surface of a substrate in the presence of an electrolyte solution comprising salts of at least two different metal atoms and a chiral molecule.

44. The method according to claim 43, wherein said chiral molecule is a chiral organic molecule.

45. The method according to claim 43, wherein said electrolyte solution is acidic.

46. The method according to claim 43, wherein said salts are at a ratio of from about 1: 1 to about 1: 100.

47. The method according to any of claims 44-45, wherein said salts are at a ratio of from about 1: 1 to about 1: 100.

48. The method according to claim 43, wherein a said electrochemically depositing is by an electrochemical cell having an inert counter electrode.

49. The method according to any of claims 44-47, wherein a said electrochemically depositing is by an electrochemical cell having an inert counter electrode.

50. The method according to claim 43, wherein at least one of said salts is a salt containing Group 10 metal atoms.

51. The method according to any of claims 44-49, wherein at least one of said salts is a salt containing Group 10 metal atoms.

52. The method according to claim 43, wherein at least one of said salts is a nickel salt.

53. The method according to any of claims 44-51, wherein at least one of said salts is a nickel salt.

54. The method according to claim 43, wherein at least one of said salts is a salt containing Group 11 metal atoms.

55. The method according to any of claims 44-53, wherein at least one of said salts is a salt containing Group 11 metal atoms.

56. The method according to claim 43, wherein at least one of said salts is a gold salt.

57. The method according to any of claims 44-55, wherein at least one of said salts is a gold salt.

58. The method according to claim 43, wherein said salts comprise a nickel salt and a gold salt, and said electrochemically depositing is under a voltage of from about -1.0 V to about -0.8 V.

59. The method according to any of claims 44-57, wherein said salts comprise a nickel salt and a gold salt, and said electrochemically depositing is under a voltage of from about -1.0 V to about -0.8 V.

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