Anode material, preparation method, electrolytic device and application thereof

Abstract

The application relates to the technical field of electrolytic hydrogen production, and particularly discloses an anode material, a preparation method thereof and application of the anode material in a proton exchange membrane electrolytic cell. The anode material comprises a titanium or titanium alloy base and a surface composite coating, the total thickness of the coating is 0.7-1.5 microns, and the coating comprises, in sequence along the direction away from the base, a first layer (containing at least two kinds of titanium oxides, the total oxygen content is gradually decreased), a transition layer (containing titanium oxides and titanium nitride, the oxygen content is gradually decreased and the nitrogen content is gradually increased), a second layer (containing titanium nitride) and a third layer (containing a precious metal catalytic material such as Pt / Ir, the porosity is 25-50%). The anode material is prepared by using magnetron sputtering, the composition gradient control is realized by dynamically adjusting the argon / oxygen / nitrogen ratio, and the deposition is subjected to annealing treatment in an argon atmosphere. The structure is synergistically optimized through the composition and gradient between the layers, the corrosion resistance, the electrical conductivity and the service life of the anode material are significantly enhanced, and the problems of easy passivation and short service life of the traditional anode are solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogen production by water electrolysis, and particularly relates to an anode material, a preparation method, an electrolysis device and application. BACKGROUND

[0002] Proton exchange membrane water electrolysis technology (PEMWE) is a hydrogen production technology by water electrolysis based on a proton exchange membrane (PEM) as an electrolyte. The principle is to separate the anode and the cathode by the proton exchange membrane, and water molecules are decomposed into hydrogen ions, electrons and oxygen at the anode. The hydrogen ions migrate to the cathode through the membrane and combine with the electrons to generate hydrogen. The anode material, including the anode electrode, gas diffusion layer and bipolar plate, is a key component of PEMWE. Metal anode materials are widely used in PEMWE due to their mature processing technology, excellent mechanical properties, electrical and thermal conductivity, high porosity and other characteristics. However, bare metal anode materials are prone to corrosion in the acidic environment of PEMWE. The release of corrosion ions during corrosion has a toxic effect on the catalyst, and the oxide film generated on the surface of the metal anode increases the interfacial contact resistance, which reduces the output power of PEMWE. Preparing a coating on the surface of the metal anode has become a mainstream method to solve the corrosion problem. In the prior art, patent CN117364121A discloses a method of setting multiple layers of coating (oxide layer to nitride layer to noble metal layer) on a metal substrate, which can improve the corrosion resistance of the anode material. However, it still has problems such as poor electrical conductivity of the oxide layer and insufficient interlayer adhesion. SUMMARY

[0003] In view of the problems existing in the prior art, the purpose of the present application is to improve the corrosion resistance, electrical conductivity and interfacial adhesion of the metal anode for PEMWE.

[0004] To achieve the above-mentioned purpose, the present application provides an anode material, comprising a substrate and a composite coating arranged on the surface of the substrate, the substrate comprising titanium or titanium alloy; the composite coating comprises a first layer, a transition layer, a second layer and a third layer from the side close to the substrate to the side away from the substrate, wherein the first layer contains at least two oxides of titanium, and the first layer has a decreasing oxygen content gradient in the direction away from the substrate; the transition layer contains titanium nitride and titanium oxide, and the transition layer has an increasing nitrogen content gradient and a decreasing oxygen content gradient in the direction away from the substrate; the second layer contains titanium nitride; the third layer contains a catalytic material; and the total thickness of the composite coating is 0.7-1.5 μm.

[0005] Optionally, the thickness ratio of the first layer, the transition layer, the second layer and the third layer of the anode material is (1-2):(1-1.5):(8-15):(0.5-1).

[0006] Optionally, the first layer has a thickness of 80-200 nm, and the oxide of titanium in the first layer comprises TiO2 and Ti4O7.

[0007] Optionally, the first layer has a total oxygen content of 65.0-66.0 at%.

[0008] Optionally, the first layer has an oxygen content of 66.5-67.0 at% near the substrate side, and an oxygen content of 63.6-65.0 at% near the transition layer side.

[0009] Optionally, the transition layer has a thickness of 80-150 nm, and the oxide of titanium in the transition layer comprises one or both of TiO2 and Ti4O7.

[0010] Optionally, the transition layer has a total oxygen content of 30-45 at%.

[0011] Optionally, the second layer has a thickness of 500-1000 nm.

[0012] Optionally, the third layer has a thickness of 50-100 nm.

[0013] Optionally, the catalytic material in the third layer comprises a noble metal or a noble metal alloy, and the noble metal is selected from one or more of Pt, Ir, Au, and Ru.

[0014] Optionally, the third layer has a porosity of 25-50%.

[0015] The present application provides a method for preparing the anode material described above, comprising:

[0016] Step 1: pretreating the surface of the substrate;

[0017] Step 2: preparing the first layer on the surface of the substrate by magnetron sputtering in an atmosphere of a mixture of argon and oxygen at a pressure of 0.5-1.5 Pa, and gradually reducing the proportion of oxygen in the mixture during the magnetron sputtering process;

[0018] Step 3: preparing the transition layer on the surface of the first layer by magnetron sputtering in an atmosphere of a mixture of argon, oxygen, and nitrogen at a pressure of 0.5-1.5 Pa, and gradually reducing the proportion of oxygen and gradually increasing the proportion of nitrogen in the mixture during the magnetron sputtering process;

[0019] Step 4: preparing the second layer on the surface of the transition layer by magnetron sputtering in an atmosphere of a mixture of argon and nitrogen at a pressure of 0.5-1.0 Pa;

[0020] Step five, in the argon atmosphere with pressure of 0.6-1.0 Pa, a third layer is prepared on the surface of the second layer by magnetron sputtering.

[0021] Optionally, the roughness of the pretreated substrate surface is 0.5-2.0 μm.

[0022] Optionally, during the preparation of the first layer, the substrate temperature is 200-300 DEG C, the power is 100-200 W, the deposition rate is 0.2-0.35 nm / s, the oxygen flow rate is 15-20 sccm and the argon flow rate is 20-30 sccm in the initial stage; and the oxygen flow rate is 7-15 sccm and the argon flow rate is 30-40 sccm in the final stage.

[0023] Optionally, during the preparation of the transition layer, the substrate temperature is 250-350 DEG C, the power is 200-300 W, the deposition rate is 0.25-0.45 nm / s, the oxygen flow rate is 15-25 sccm, the nitrogen flow rate is 5-10 sccm and the argon flow rate is 30-40 sccm in the initial stage; and the oxygen flow rate is 2-5 sccm, the nitrogen flow rate is 20-30 sccm and the argon flow rate is 30-40 sccm in the final stage.

[0024] Optionally, during the preparation of the second layer, the substrate temperature is 300-400 DEG C, the power is 300-400 W, the deposition rate is 0.3-0.55 nm / s, the nitrogen flow rate is 1-5 sccm and the argon flow rate is 2-40 sccm, and the total pressure is 0.5-1.0 Pa.

[0025] Optionally, during the preparation of the third layer, the substrate temperature is normal temperature, the power is 100-150 W, the deposition rate is 0.2-0.3 nm / s, and the argon flow rate is 20-40 sccm.

[0026] Optionally, after the preparation of any one of the first layer, the transition layer or the second layer is completed, the oxygen and / or nitrogen sources are closed, the argon flow rate is adjusted to 20-40 sccm, the plasma is turned on and the power is maintained at 200-300 W for 2-6 min, and then the next layer is prepared.

[0027] Optionally, after the preparation of the third layer is completed, the anode material is subjected to an annealing treatment in an argon atmosphere, the annealing temperature is 300-450 DEG C, and the holding time is 1-3 h.

[0028] The application provides a proton exchange membrane electrolyzer comprising the anode material of the aforementioned technical solution.

[0029] The application provides a method for preparing hydrogen by electrolyzing water with a proton exchange membrane, wherein the anode material of the aforementioned technical solution is used as an anode.

[0030] The application provides a method for hydrogen production by electrolysis of water using a proton exchange membrane electrolyzer.

[0031] The anode material provided by the application has the following beneficial effects: the first layer contains at least two titanium oxides, and the oxygen content is limited to decrease in the direction away from the substrate, which can improve the corrosion resistance of the substrate and balance the electrical conductivity of the first layer; the transition layer arranged between the first layer and the second layer can improve the bonding force between the first layer and the second layer; the second layer can provide a low-resistance electron transmission path to reduce the overall coating resistance; and the third layer can provide an oxygen evolution reaction active site. Therefore, the application can improve the corrosion resistance, electrical conductivity, interlayer bonding force and service life of the anode material.

[0032] The preparation method provided by the application realizes the integrated construction of the composite coating from "composition gradient to interface compatibility to function synergy" through accurate control of the proportion of the gas and the synergistic design of the preparation process of each layer, thereby guaranteeing the systematic optimization of the corrosion resistance, electrical conductivity, bonding strength and catalytic activity of the anode material from the preparation end. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 FIG. 2 is a cross-sectional SEM image of the anode material composite coating of Example 2 of the application. DETAILED DESCRIPTION

[0034] The application will be described in detail below with reference to specific embodiments. The embodiments shown below do not have any limiting effect on the content of the invention described in the claims. In addition, the entire content of the configuration represented by the following embodiments is not limited to being necessary as a solution to the invention described in the claims.

[0035] As used herein, the term "comprising" should be interpreted as inclusive and open-ended, rather than exclusive. Specifically, when used in the specification and claims, the term "comprising" and variations thereof mean including the features, steps or components specified. These terms are not to be interpreted to exclude the presence of other features, steps or components.

[0036] In this document, the terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or a specific number of the technical features indicated. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features.

[0037] Where a range of values is given, the range is inclusive of the recited values, and of all intermediate integers and fractions thereof, and also includes each narrower range that falls within the broader range, to the same extent as if each narrower range were expressly stated herein.

[0038] The first aspect of the present application provides an anode material, comprising a substrate and a composite coating arranged on the surface of the substrate, the substrate comprising titanium materials or titanium alloy materials such as titanium felt, titanium sheet, titanium mesh, titanium plate, etc.; the composite coating at least comprises a first layer, a transition layer, a second layer and a third layer in sequence away from the substrate, wherein the first layer comprises at least two titanium oxides, and the oxygen content in the first layer decreases away from the substrate; the transition layer comprises titanium nitride and titanium oxide, and the nitrogen content in the transition layer increases and the oxygen content decreases away from the substrate; the second layer comprises titanium nitride; and the third layer comprises a catalyst. The anode material of the present application breaks through the inherent contradiction between corrosion resistance, electrical conductivity and bonding strength of traditional anode materials through the multi-dimensional design of "composition gradient to interface compatibility to functional synergy" of the composite coating, and can improve the service life and electrochemical performance.

[0039] The first layer of the anode material of the present application is a titanium oxide layer, which contains at least two titanium oxides. Compared with titanium oxides with low oxygen content (such as Ti4O7), titanium oxides with high oxygen content (such as TiO2) have higher matching degree of lattice parameters and thermal expansion coefficients with titanium or titanium alloy substrates, and thus have stronger interface bonding strength with the substrates. At the same time, the crystal structure of titanium oxides with high oxygen content is more dense, which can effectively hinder the penetration of corrosive media, thereby significantly improving the corrosion resistance of the substrate; and titanium oxides with low oxygen content (such as Ti4O7) have significantly better electrical conductivity due to the existence of more oxygen vacancies and electronic defects, which can optimize the electrical conductivity of the first layer. In addition, the present application designs the oxygen content of the first layer to decrease away from the substrate, forming a gradient distribution structure. This gradient design can gradually transition the thermal expansion coefficient inside the coating from the substrate to the surface, avoiding interface stress concentration caused by performance mutation, thereby further improving the structural stability of the coating.

[0040] The transition layer has increasing nitrogen content and decreasing oxygen content away from the substrate, which can form an atomic-level mixed transition zone between the oxide and the nitride, eliminate stress concentration caused by hard interface mutation, and promote atomic diffusion between layers, thereby improving the bonding strength through chemical compatibility and mechanical interlocking effect. Moreover, the increase in nitrogen content can gradually activate the conductive phase, which can realize low-resistance transition from oxide to nitride.

[0041] The second layer of titanium nitride, as a high-conductivity phase, can form a continuous electron transport path, and its high conductivity can reduce the overall resistance of the coating.

[0042] The third layer of catalyst can provide active sites for the reaction, and relying on the rigid support of the lower layer of titanium nitride and the stress buffering effect of the gradient structure, it can delay the shedding and dissolution of the catalyst at high potential, achieving a synergistic optimization of catalytic activity and structural stability.

[0043] In some embodiments, the thickness ratio of the first layer, the transition layer, the second layer, and the third layer is (1-2):(1-1.5):(8-15):(0.5-1). In this way, the service life and electrochemical performance can be further improved.

[0044] In some embodiments, the thickness of the first layer is 80-200 nm. Satisfying this thickness range can further form a continuous and dense corrosion-resistant barrier, and further relieve interface stress, thereby further improving corrosion resistance and structural stability.

[0045] In some embodiments, the oxygen content in the first layer gradually decreases in the direction away from the substrate. The present application further limits the gradual change of the oxygen content in the first layer, which can further form a continuous lattice parameter transition zone, avoid stress concentration caused by composition mutation, and at the same time ensure the smoothness of the electron conduction path from the substrate to the coating, further synergistically optimizing the corrosion resistance and conductivity.

[0046] In some embodiments, the titanium oxide in the first layer includes TiO2 and Ti4O7. TiO2 can provide high corrosion resistance, and Ti4O7 can contribute good conductivity. The two work together to form a "corrosion-resistant to conductive" dual-functional layer, further protecting the substrate while reducing electron transport resistance.

[0047] In some embodiments, the total oxygen content in the first layer is 66.5-67.0 at%, which can keep the titanium oxide in the preferred ratio range of TiO2 and Ti4O7, further balancing the density and electron conductivity of the passivation film, and further improving the matching of corrosion resistance and conductivity. The oxygen content on the side of the first layer close to the substrate is 66.5-67.0 at%, which can form a high-density oxide layer close to the substrate, which can further effectively inhibit the oxidation and corrosion of the substrate; and can further improve the adhesion between the first layer and the substrate.

[0048] In some embodiments, the oxygen content on the side of the first layer close to the transition layer is 63.6-65.0 at%, which can improve the interlayer conductivity and smoothly connect the nitride conductive phase of the transition layer, further reducing the interface resistance.

[0049] In some embodiments, the thickness of the transition layer is 80 nm to 150 nm, which can further form an atomic mixed transition region with sufficient width, further relieving the stress mutation between the oxide and the nitride, while providing a continuous percolation path for electron conduction, thereby further enhancing the bonding strength and electrical conductivity.

[0050] In some embodiments, the content of nitrogen elements in the transition layer gradually increases and the content of oxygen elements gradually decreases in a direction away from the substrate. The present application further limits the transition layer to meet the above conditions, which can further make the interlayer chemical bond type (from Ti to O to Ti to N) smoothly transition, further eliminating interface charge accumulation, thereby further reducing the contact resistance and improving the structural stability.

[0051] In some embodiments, the oxide of titanium in the transition layer includes one or both of TiO2 and Ti4O7. The present application further limits the transition layer to meet the above conditions, which can further form a functional synergy with the first layer and the second layer, further optimizing the overall performance of the coating.

[0052] In some embodiments, the total oxygen content in the transition layer is 30 at% to 45 at%. The present application further limits the transition layer to meet the above conditions, which can further improve the electrical conductivity while maintaining the structural integrity.

[0053] In some embodiments, the thickness of the second layer is 500 nm to 1000 nm. The present application further limits the second layer to meet the above conditions, which can further promote the formation of a continuous three-dimensional conductive network of titanium nitride, further reducing the overall resistance of the coating, while further providing sufficient mechanical support for the upper layer of catalyst, thereby further inhibiting structural deformation during service.

[0054] In some embodiments, the thickness of the third layer is 50 nm to 100 nm. The present application further limits the third layer to meet the above conditions, which can further provide sufficient catalytically active sites for the reaction, and further avoid internal stress cracking of the catalyst layer due to excessive thickness through the stress buffering effect of the gradient structure, thereby further prolonging the service life of the catalyst.

[0055] In some embodiments, the catalyst includes a noble metal. Thus, the performance of the anode material can be further improved.

[0056] In some embodiments, the noble metal includes one or more of Pt, Ir, Au, and Ru. Thus, the performance of the anode material can be further improved.

[0057] In some embodiments, the porosity of the third layer is 25% to 50%, which can further enable the third layer to form a multi-level pore structure that balances reactant transport and active site exposure, while further inhibiting electrolyte penetration through capillary forces of the pore walls, thereby further extending the service life of the catalyst layer.

[0058] It should be noted that the shape of the anode and the substrate in the present application can be various, such as flat plate, rod or any other desired shape, which is not limited herein; the composite coating can cover the entire outer surface of the substrate, or can cover part of the outer surface, which can be adjusted according to actual needs, which is not limited herein.

[0059] The present application provides some methods for measuring the thickness and composition of the anode material coating, which are only for reference and do not limit the present application, and specifically include:

[0060] Cutting: for anode material products, the anode material can be cut to expose the longitudinal section of the composite coating before detecting the composite coating, the cutting method can be selected according to actual needs, such as mechanical cutting plus ion beam polishing, FIB cutting, neutral ion beam cutting, FIB+STEM to EELS, etc., other methods can also be selected, which are not limited herein;

[0061] Layer detection: the cross section of the composite coating can be detected by EDS area scanning, the spatial distribution of each element in the layer can be directly displayed by the area distribution image, and the thickness data of each layer can be obtained by measurement; other methods can also be used, which are not limited herein;

[0062] Titanium oxide species detection: XRD, XPS and other methods can be used to analyze the titanium oxide species, and other methods can also be used, which are not limited herein.

[0063] The second aspect of the present application provides a method for preparing an anode material, comprising: pretreating the surface of a substrate; preparing a first layer on the surface of the substrate by magnetron sputtering in a mixed gas atmosphere of argon and oxygen with a pressure of 0.5 to 1.5 Pa, and gradually reducing the proportion of oxygen in the mixed gas during the magnetron sputtering process; preparing a transition layer on the surface of the first layer by magnetron sputtering in a mixed gas atmosphere of argon, oxygen and nitrogen with a pressure of 0.5 to 1.5 Pa, and gradually reducing the proportion of oxygen and increasing the proportion of nitrogen in the mixed gas during the magnetron sputtering process; preparing a second layer on the surface of the transition layer by magnetron sputtering in a mixed gas atmosphere of argon and nitrogen with a pressure of 0.5 to 1.0 Pa; and preparing a third layer on the surface of the second layer by magnetron sputtering in an argon atmosphere with a pressure of 0.6 to 1.0 Pa.

[0064] The anode material preparation method provided by the application can systematically improve the comprehensive performance of the material through dynamic regulation of the gas atmosphere in the magnetron sputtering process and a layered preparation strategy. The specific action mechanism is as follows: (1) first, the surface of the substrate is pretreated to remove the oxide layer and optimize the surface roughness, thereby providing a high-activity attachment interface for the coating and enhancing the initial bonding capacity of the substrate and the coating. During the preparation of the first layer, the oxygen content in the Ar / oxygen mixed gas atmosphere is dynamically reduced, so that the titanium oxide gradually transitions from high oxygen content to low oxygen content. In combination with the temperature / power synergistic effect, not less than two kinds of titanium oxides are generated in the first layer, thereby forming a functional layer with gradually matched lattice parameters and thermal expansion coefficients. The dense oxide structure in the high-oxygen region can effectively block the penetration of the electrolyte and improve the corrosion resistance; the low-valence oxide in the low-oxygen region improves the conductivity within the layer, realizes the functional balance of "corrosion resistance to conductivity", and relieves the stress concentration between the substrate and the coating; (2) during the preparation of the transition layer, the oxygen and nitrogen ratios are simultaneously adjusted, so that the nitrogen content increases and the oxygen content decreases, thereby constructing a transition region of titanium oxide-nitride solid solution with a nitrogen-oxygen element gradient. This gradual structure eliminates the "hard interface" mutation of the oxide and the nitride, promotes atomic diffusion and chemical bonding between the layers, enhances the interface compatibility, significantly improves the interfacial bonding strength and reduces the internal stress; (3) the second layer is deposited in an Ar / nitrogen atmosphere to form a continuous high-conductivity phase, thereby constructing a low-resistance electron transport path and ensuring efficient conduction of electrons from the substrate to the catalyst layer; (4) the third layer is formed in pure argon by controlling the sputtering parameters, thereby forming a catalyst layer with a suitable thickness and pore structure, which not only increases the exposure area of active sites to improve the catalytic reaction efficiency, but also relies on the rigid support of the lower layer and the stress buffering effect of the gradient structure to enhance the stability of the catalyst in a high-potential environment.

[0065] In some embodiments, during the preparation of the first layer: the substrate temperature is 200-300°C, the power is 200-300W, and the deposition rate is 0.2-0.35 nm / s; the oxygen flow rate is 15-20 sccm and the argon flow rate is 20-30 sccm in the initial stage; and the oxygen flow rate is 7-15 sccm and the argon flow rate is 30-40 sccm in the end stage. Through dynamic regulation of the oxygen flow rate and temperature / power synergistic optimization, the coexistence of TiO2 and Ti4O7 in the first layer is ensured from the aspects of thermodynamics and kinetics, thereby further improving the performance of the anode material.

[0066] In some embodiments, during the preparation of the transition layer: the substrate temperature is 250-350°C, the power is 200-300 W, and the deposition rate is 0.25-0.45 nm / s; in the initial stage, the oxygen flow rate is 15-25 sccm, the nitrogen flow rate is 5-10 sccm, and the argon flow rate is 30-40 sccm; in the final stage, the oxygen flow rate is 2-5 sccm, the nitrogen flow rate is 20-30 sccm, and the argon flow rate is 30-40 sccm. In this way, the performance of the anode material can be further improved.

[0067] In some embodiments, during the preparation of the second layer: the substrate temperature is 300-400°C, the power is 300-400 W, the deposition rate is 0.3-0.55 nm / s, and the ratio of nitrogen flow rate to argon flow rate is 1:(2-5), and the total pressure is 0.5-1.0 Pa. In this way, the performance of the anode material can be further improved.

[0068] In some embodiments, during the preparation of the third layer: the substrate temperature is 150-250°C, the power is 100-150 W, the deposition rate is 0.2-0.3 nm / s, and the argon flow rate is 20-40 sccm. In this way, the performance of the anode material can be further improved.

[0069] In some embodiments, after the preparation of the first layer, the transition layer, or the second layer is completed, the oxygen and / or nitrogen gas sources are turned off, the argon flow rate is adjusted to 20-40 sccm, the plasma is turned on and the power is maintained at 200-300 W for 2-6 min, and then the next layer is prepared. High-energy argon plasma bombardment can effectively remove adsorbed impurities, loose layers, and residual reaction gases on the surface of the layer, increase the surface roughness, and activate the surface atomic activity, which can enhance the mechanical interlocking and chemical bonding of the interface and improve the interfacial bonding strength.

[0070] In some embodiments, the method further comprises annealing the anode material after the preparation of the third layer is completed in an argon atmosphere, and the annealing temperature is 300-450°C and the holding time is 1-3 h. High-temperature annealing can promote the transition of the catalyst layer from an amorphous state to a crystalline state, which can increase the density of catalytically active sites. It can also promote the release of internal stress in the coating, enhance the atomic diffusion between the layers, and form a more stable interfacial layer. In addition, the annealing process can also optimize the uniformity of the pore structure, improve the connectivity of the pores while maintaining the porosity, and further improve the catalytic activity, structural stability, and long-term service life of the anode material.

[0071] Example 1

[0072] In this example, the anode material is prepared by the following steps:

[0073] (1) Substrate pretreatment

[0074] A titanium alloy substrate was selected and sandblasted to achieve a surface roughness of 1.2 μm.

[0075] (2) Preparation of the first layer by magnetron sputtering

[0076] A pure titanium target was used as the source material, and the substrate temperature was set to 250°C, the power was 200 W, and the deposition rate was 0.25 nm / s in a mixed gas atmosphere of argon and oxygen at a pressure of 1.0 Pa. The oxygen flow rate was 18 sccm and the argon flow rate was 25 sccm at the beginning, and the oxygen flow rate was 10 sccm and the argon flow rate was 35 sccm at the end. The first layer was prepared on the substrate surface by magnetron sputtering, and the thickness of the first layer was controlled to be 150 nm.

[0077] Detection showed that the titanium oxide in the first layer was TiO2 and Ti4O7, the oxygen content near the substrate side was about 66.75 at%, the oxygen content near the transition layer side was about 64.3 at%, and the total oxygen content was about 65.5 at%. The oxygen content gradually decreased away from the substrate.

[0078] (3) Preparation of the transition layer by magnetron sputtering

[0079] After the preparation of the first layer was completed, the oxygen source was turned off, the argon flow rate was adjusted to 30 sccm, the plasma was turned on and the power was maintained at 250 W for 4 min.

[0080] Then, a pure titanium target was used as the source material, and the transition layer was prepared by magnetron sputtering in a mixed gas atmosphere of argon, oxygen, and nitrogen at a pressure of 1.0 Pa. The substrate temperature was set to 300°C, the power was 250 W, and the deposition rate was 0.35 nm / s. The oxygen flow rate was 20 sccm, the nitrogen flow rate was 7.5 sccm, and the argon flow rate was 35 sccm at the beginning. The oxygen flow rate was 3 sccm, the nitrogen flow rate was 25 sccm, and the argon flow rate was 35 sccm at the end. The thickness of the transition layer was controlled to be 115 nm.

[0081] Detection showed that the titanium oxide in the transition layer was TiO2 and Ti4O7, the nitrogen content gradually increased and the oxygen content gradually decreased away from the substrate, and the total oxygen content was about 37.5 at%.

[0082] (4) Preparation of the second layer by magnetron sputtering

[0083] After the preparation of the transition layer was completed, the oxygen and nitrogen sources were turned off, the argon flow rate was adjusted to 30 sccm, the plasma was turned on and the power was maintained at 250 W for 4 min.

[0084] Then, the second layer is prepared by magnetron sputtering with a pure titanium target as a source material in an atmosphere of mixed argon and nitrogen gas at a pressure of 0.75 Pa, a substrate temperature of 350 ℃, a power of 350 W, a deposition rate of 0.3 nm / s, and a flow ratio of nitrogen to argon of 1:3, and the thickness of the second layer is controlled to be 750 nm.

[0085] The second layer is detected to be titanium nitride.

[0086] (5) Preparation of the third layer by magnetron sputtering

[0087] After the preparation of the second layer is completed, the nitrogen source is closed, the argon flow is adjusted to 30 sccm, the plasma is turned on and the power is kept at 250 W for 4 min.

[0088] Then, the third layer is prepared by magnetron sputtering with a Pt target as a source material in an atmosphere of argon gas at a pressure of 0.8 Pa, a substrate temperature of room temperature, a power of 70 W, a deposition rate of 0.25 nm / s, and an argon flow of 55 sccm, and the thickness of the third layer is controlled to be 75 nm.

[0089] The third layer is detected to have a porosity of 37.5%.

[0090] (6) Annealing treatment

[0091] The anode material after the preparation of the third layer is annealed in an argon atmosphere at an annealing temperature of 400 ℃ for 1.5 h.

[0092] Example 2

[0093] The anode material is prepared by the following steps:

[0094] (1) Substrate pretreatment

[0095] A titanium substrate is selected and sandblasted to have a surface roughness of 0.5 μm.

[0096] (2) Preparation of the first layer by magnetron sputtering

[0097] The first layer is prepared by magnetron sputtering with a pure titanium target as a source material in an atmosphere of mixed argon and oxygen gas at a pressure of 0.5 Pa. The substrate temperature is set to be 200 ℃, the power is 100 W, and the deposition rate is 0.2 nm / s. The initial stage is controlled to have an oxygen flow of 15 sccm and an argon flow of 20 sccm, and the end stage is controlled to have an oxygen flow of 7 sccm and an argon flow of 30 sccm. The thickness of the first layer is controlled to be 80 nm.

[0098] The first layer is detected to have titanium oxides of TiO2 and Ti4O7, and the oxygen content near the substrate side is about 66.5 at%, the oxygen content near the transition layer side is about 63.6 at%, the total oxygen content is about 65.0 at%, and the oxygen content gradually decreases along the direction away from the substrate.

[0099] (3) Preparation of the transition layer by magnetron sputtering

[0100] After the preparation of the first layer is completed, the oxygen source is closed, the argon flow is adjusted to 20 sccm, the plasma is turned on and the power is kept at 200 W for 2 min.

[0101] Then, the pure titanium target is used as the source material to prepare the transition layer by magnetron sputtering in a mixed gas atmosphere of argon, oxygen and nitrogen at a pressure of 0.5 Pa. The substrate temperature is set to 250℃, the power is 200 W, and the deposition rate is 0.25 nm / s. The initial stage is controlled as follows: oxygen flow 15 sccm, nitrogen flow 5 sccm, and argon flow 30 sccm; the end stage is controlled as follows: oxygen flow 2 sccm, nitrogen flow 20 sccm, and argon flow 30 sccm. The thickness is controlled to be 80 nm.

[0102] After detection, the oxide of titanium in the transition layer is TiO2, the content of nitrogen element gradually increases and the content of oxygen element gradually decreases in the direction away from the substrate, and the total oxygen content is about 30 at%.

[0103] (4) Preparation of the second layer by magnetron sputtering

[0104] After the preparation of the transition layer is completed, the oxygen and nitrogen sources are closed, the argon flow is adjusted to 20 sccm, the plasma is turned on and the power is kept at 200 W for 2 min.

[0105] Then, the pure titanium target is used as the source material to prepare the second layer by magnetron sputtering in a mixed gas atmosphere of argon and nitrogen at a pressure of 0.5 Pa. The substrate temperature is 300℃, the power is 300 W, the deposition rate is 0.3 nm / s, the nitrogen to argon flow ratio is 1:2, and the thickness is controlled to be 750 nm.

[0106] After detection, the second layer is composed of titanium nitride.

[0107] (5) Preparation of the third layer by magnetron sputtering

[0108] After the preparation of the second layer is completed, the nitrogen source is closed, the argon flow is adjusted to 20 sccm, the plasma is turned on and the power is kept at 200 W for 2 min.

[0109] Then, the Ir target is used as the source material to prepare the third layer by magnetron sputtering in an argon atmosphere at a pressure of 0.6 Pa. The substrate is at room temperature, the power is 100 W, the deposition rate is 0.2 nm / s, the argon flow is 20 sccm, and the thickness of the third layer is 50 nm. The catalyst is Ir. After detection, the porosity of the third layer is 25%.

[0110] (6) Annealing treatment

[0111] The third layer of the prepared anode material is annealed in an argon atmosphere, the annealing temperature is 300°C, and the holding time is 1h.

[0112] Example 3

[0113] The anode material is prepared by the following steps:

[0114] (1) Pretreatment of the substrate

[0115] A titanium alloy substrate is selected, and the surface thereof is subjected to sand blasting treatment so that the surface roughness reaches 2.0 μm.

[0116] (2) Preparation of the first layer by magnetron sputtering

[0117] The first layer is prepared by magnetron sputtering using a pure titanium target as the source material in a mixed gas atmosphere of argon and oxygen at a pressure of 1.5 Pa, the substrate temperature is set to 300°C, the power is 200 W, and the deposition rate is 0.35 nm / s. In the initial stage, the oxygen flow rate is 20 sccm, the argon flow rate is 30 sccm; in the final stage, the oxygen flow rate is 15 sccm, the argon flow rate is 40 sccm, and the thickness is controlled to be 200 nm.

[0118] It is detected that the titanium oxides in the first layer are TiO2 and Ti4O7, the oxygen content near the substrate side is about 67.0 at%, the oxygen content near the transition layer side is about 65.0 at%, the total oxygen content is about 66.0 at%, and the oxygen content gradually decreases along the direction away from the substrate.

[0119] (3) Preparation of the transition layer by magnetron sputtering

[0120] After the preparation of the first layer is completed, the oxygen source is closed, the argon flow rate is adjusted to 40 sccm, the plasma is turned on, and the power is maintained at 300 W for 6 min.

[0121] Then, the transition layer is prepared by magnetron sputtering using a pure titanium target as the source material in a mixed gas atmosphere of argon, oxygen, and nitrogen at a pressure of 1.5 Pa, the substrate temperature is 350°C, the power is 300 W, and the deposition rate is 0.45 nm / s. In the initial stage, the oxygen flow rate is 25 sccm, the nitrogen flow rate is 10 sccm, and the argon flow rate is 40 sccm; in the final stage, the oxygen flow rate is 5 sccm, the nitrogen flow rate is 30 sccm, and the argon flow rate is 40 sccm, and the thickness is controlled to be 150 nm.

[0122] It is detected that the titanium oxide in the transition layer is Ti4O7, the nitrogen content gradually increases and the oxygen content gradually decreases along the direction away from the substrate, and the total oxygen content is about 45 at%.

[0123] (4) Preparation of the second layer by magnetron sputtering

[0124] After the preparation of the transition layer is completed, the oxygen and nitrogen gas sources are closed, the argon flow is adjusted to 40sccm, the plasma is turned on and the power is kept at 300W for 6min.

[0125] Then, a second layer is prepared by magnetron sputtering with a pure titanium target as the source material in a mixed gas atmosphere of argon and nitrogen at a pressure of 1.0Pa, a substrate temperature of 400℃, a power of 400W, a deposition rate of 0.55nm / s, a nitrogen to argon flow ratio of 1:5, and a thickness of 1000nm.

[0126] It is detected that the second layer is composed of titanium nitride.

[0127] (5) Preparation of a third layer by magnetron sputtering

[0128] After the preparation of the second layer is completed, the nitrogen gas source is closed, the argon flow is adjusted to 40sccm, the plasma is turned on and the power is kept at 300W for 6min.

[0129] Then, a third layer is prepared by magnetron sputtering with a Ru target as the source material in an argon atmosphere at a pressure of 1.0Pa, a substrate temperature of room temperature, a power of 150W, a deposition rate of 0.3nm / s, an argon flow of 40sccm, and a thickness of 100nm. It is detected that the porosity of the third layer is 50%.

[0130] (6) Annealing treatment

[0131] The anode material after the preparation of the third layer is subjected to annealing treatment in an argon atmosphere at an annealing temperature of 450℃ for 3h.

[0132] Example 4

[0133] The anode material is prepared by the following steps:

[0134] (1) Substrate pretreatment

[0135] A titanium substrate is selected and subjected to sandblasting treatment to make the surface roughness reach 1.0μm.

[0136] (2) Preparation of a first layer by magnetron sputtering

[0137] A first layer is prepared by magnetron sputtering with a pure titanium target as the source material in a mixed gas atmosphere of argon and oxygen at a pressure of 0.8Pa, a substrate temperature of 220℃, a power of 120W, and a deposition rate of 0.25nm / s. In the initial stage, the oxygen flow is 16sccm and the argon flow is 22sccm; in the final stage, the oxygen flow is 10sccm and the argon flow is 32sccm, and the thickness is controlled to be 100nm.

[0138] The oxide of titanium in the first layer is TiO2 and Ti4O7, the oxygen content is about 66.6at% near the substrate side, the oxygen content is 64.0at% near the transition layer side, and the total oxygen content is 65.3at%, which gradually decreases away from the substrate.

[0139] (3) Preparation of the transition layer by magnetron sputtering

[0140] After the preparation of the first layer is completed, the oxygen source is closed, the argon flow is adjusted to 25sccm, the plasma is turned on and the power is kept at 220W for 3min.

[0141] Then, a pure titanium target is used as the source material to prepare the transition layer by magnetron sputtering in a mixed gas atmosphere of argon, oxygen and nitrogen at a pressure of 0.8Pa, the substrate temperature is 280℃, the power is 230W, and the deposition rate is 0.30nm / s. In the initial stage, the oxygen flow is 18sccm, the nitrogen flow is 6sccm, and the argon flow is 32sccm; in the final stage, the oxygen flow is 4sccm, the nitrogen flow is 22sccm, and the argon flow is 32sccm, and the thickness is controlled to be 120nm.

[0142] The oxide of titanium in the transition layer is TiO2, the nitrogen content gradually increases and the oxygen content gradually decreases away from the substrate, and the total oxygen content is about 35at%.

[0143] (4) Preparation of the second layer by magnetron sputtering

[0144] After the preparation of the transition layer is completed, the oxygen and nitrogen sources are closed, the argon flow is adjusted to 25sccm, the plasma is turned on and the power is kept at 220W for 3min.

[0145] Then, a pure titanium target is used as the source material to prepare the second layer by magnetron sputtering in a mixed gas atmosphere of argon and nitrogen at a pressure of 0.6Pa, the substrate temperature is 320℃, the power is 320W, the deposition rate is 0.4nm / s, the nitrogen and argon flow ratio is 1:2.5, and the thickness is controlled to be 650nm.

[0146] The second layer is composed of titanium nitride.

[0147] (5) Preparation of the third layer by magnetron sputtering

[0148] After the preparation of the second layer is completed, the nitrogen source is closed, the argon flow is adjusted to 25sccm, the plasma is turned on and the power is kept at 220W for 3min.

[0149] Then, the third layer was prepared by magnetron sputtering with a Pt target as a source material in an argon atmosphere with a pressure of 0.7 Pa, a substrate temperature of room temperature, a power of 110 W, a deposition rate of 0.22 nm / s, an argon flow rate of 22 sccm, and a thickness of 60 nm.

[0150] It was detected that the porosity of the third layer was 30%.

[0151] (6) Annealing treatment

[0152] The anode material after preparation of the third layer was annealed in an argon atmosphere, with an annealing temperature of 350℃ and an annealing time of 1.5 h.

[0153] Example 5

[0154] The anode material was prepared by the following steps:

[0155] (1) Substrate pretreatment

[0156] A titanium alloy substrate was selected, and the surface thereof was sandblasted to have a surface roughness of 1.8 μm.

[0157] (2) Preparation of the first layer by magnetron sputtering

[0158] The first layer was prepared by magnetron sputtering with a pure titanium target as a source material in a mixed gas atmosphere of argon and oxygen with a pressure of 1.2 Pa, a substrate temperature of 280℃, a power of 180 W, a deposition rate of 0.28 nm / s, an oxygen flow rate of 16 sccm and an argon flow rate of 28 sccm in the initial stage, an oxygen flow rate of 12 sccm and an argon flow rate of 38 sccm in the end stage, and a thickness of 180 nm.

[0159] It was detected that the oxides of the first layer of titanium were TiO2 and Ti4O7, the oxygen content near the substrate side was about 66.8 at%, the oxygen content near the transition layer side was about 64.5 at%, the total oxygen content was about 65.8 at%, and the oxygen content gradually decreased along the direction away from the substrate.

[0160] (3) Preparation of the transition layer by magnetron sputtering

[0161] After the preparation of the first layer was completed, the oxygen source was closed, the argon flow rate was adjusted to 35 sccm, the plasma was turned on with a power of 280 W, and the process was continued for 5 min.

[0162] Then, the transition layer is prepared by magnetron sputtering with a pure titanium target as a source material in a mixed gas atmosphere of argon, oxygen and nitrogen at a pressure of 1.2 Pa, a substrate temperature of 330 ℃, a power of 280 W and a deposition rate of 0.4 nm / s. In the initial stage, the oxygen flow rate is 22 sccm, the nitrogen flow rate is 8 sccm and the argon flow rate is 38 sccm; in the final stage, the oxygen flow rate is 4.5 sccm, the nitrogen flow rate is 28 sccm and the argon flow rate is 38 sccm, and the thickness is controlled to be 140 nm.

[0163] It is detected that the oxide of the transition layer titanium is Ti4O7, the nitrogen content gradually increases and the oxygen content gradually decreases in the direction away from the substrate, and the total oxygen content is about 40 at%.

[0164] (4) Preparation of the second layer by magnetron sputtering

[0165] After the preparation of the transition layer is completed, the oxygen and nitrogen sources are closed, the argon flow rate is adjusted to 35 sccm, the plasma is turned on and the power is kept at 280 W for 5 min.

[0166] Then, the second layer is prepared by magnetron sputtering with a pure titanium target as a source material in a mixed gas atmosphere of argon and nitrogen at a pressure of 0.9 Pa, a substrate temperature of 380 ℃, a power of 380 W and a deposition rate of 0.45 nm / s, the nitrogen and argon flow rate ratio is 1:4.5, and the thickness is controlled to be 800 nm.

[0167] It is detected that the second layer is composed of titanium nitride.

[0168] (5) Preparation of the third layer by magnetron sputtering

[0169] After the preparation of the second layer is completed, the nitrogen source is closed, the argon flow rate is adjusted to 35 sccm, the plasma is turned on and the power is kept at 280 W for 5 min.

[0170] Then, the third layer is prepared by magnetron sputtering with an Au target as a source material in an argon atmosphere at a pressure of 0.9 Pa, a substrate temperature of room temperature, a power of 125 W and a deposition rate of 0.28 nm / s, the argon flow rate is 35 sccm, and the thickness is controlled to be 90 nm.

[0171] It is detected that the porosity of the third layer is 45%.

[0172] (6) Annealing treatment

[0173] The anode material after the preparation of the third layer is subjected to annealing in an argon atmosphere, the annealing temperature is 430 ℃ and the holding time is 2 h.

[0174] Comparative Example 1

[0175] The difference between the present comparative example and Example 2 is that the substrate is not pretreated and no coating is prepared on the substrate.

[0176] Comparative Example 2

[0177] The difference between the present comparative example and Example 2 is that the constant oxygen is 30 ccm when preparing the first layer, and other conditions are the same.

[0178] Comparative Example 3

[0179] The difference between the present comparative example and Example 2 is that no transition layer is prepared between the first layer and the second, and other conditions are the same.

[0180] Comparative Example 4

[0181] The difference between the present comparative example and Example 2 is that no first layer is prepared, and other conditions are the same.

[0182] The anode materials of Examples 1 to 5 and Comparative Examples 1 to 3 are tested for constant potential electrochemical polarization curve by EIS Swiss Autolab under the condition of 80℃ water bath in 0.5 mol / L H2SO4+5ppm HF solution by using a three-electrode system, the contact resistance is tested by using a contact resistance tester, the adhesion is tested according to GB / T 5210-2006 standard by using a digital display pull development tester BGD500, and the coating hardness is measured by using a Durometer. The test data of adhesion, hardness, corrosion current density, corrosion current density after 100h constant potential operation, contact resistance, and contact resistance after 100h constant potential operation are shown in Table 1.

[0183]

[0184] As shown in Table 1, the comprehensive performance of the composite coating of the anode material prepared in Examples 1 to 5 of the present application is obviously better than that of Comparative Examples 1 to 4. According to the test results in Table 1, the adhesion between the anode material of the present application and the substrate is more than 11 MPa, the coating hardness is not less than 21 GPa, the corrosion current density is ≤0.025 μA / cm², and the contact resistance is ≤2 mΩ·cm, and after 100h constant potential use, the increase ratio of the corrosion current density and the contact resistance of the anode material of the present application is obviously lower than that of the comparative examples. Therefore, the anode material prepared in the examples of the present application has better comprehensive performance.

[0185] Note that the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having substantially the same configuration, function, and effect as the technical idea of the present application are included in the technical scope of the present application. Furthermore, other modes constructed by applying various modifications to the embodiments, or by combining part of the configurations of the embodiments, which can be conceived by those skilled in the art, without departing from the spirit of the present application, are also included in the scope of the present application.

Claims

1. An anode material, characterized by, A composite coating layer is provided on a substrate, the substrate comprising titanium or titanium alloy, the composite coating layer comprising, in order from the side proximal to the substrate to the side distal to the substrate, a first layer, a transition layer, a second layer, and a third layer, wherein: the first layer comprises at least two oxides of titanium, and the first layer has a gradient of decreasing oxygen content in the direction distal to the substrate; the transition layer comprises titanium nitride and oxides of titanium, and the transition layer has a gradient of increasing nitrogen content and a gradient of decreasing oxygen content in the direction distal to the substrate; the second layer comprises titanium nitride; the third layer comprises a catalytic material; the total thickness of the composite coating layer is 0.7 μm to 1.5 μm.

2. The anode material of claim 1, characterized in that The anode material according to claim 1, wherein the thickness ratio of the first layer, the transition layer, the second layer, and the third layer is (1-2):(1-1.5):(8-15):(0.5-1).

3. The anode material of claim 1, wherein The thickness of the first layer is 80 nm to 200 nm, and the oxides of titanium in the first layer comprise TiO2 and Ti4O7.

4. The anode material according to claim 1 or 3, characterized in that The total oxygen content of the first layer is 65.0 at% to 66.0 at%.

5. The anode material according to claim 1 or 3, characterized in that The oxygen content of the first layer proximal to the substrate is 66.5 at% to 67.0 at%, and the oxygen content of the first layer proximal to the transition layer is 63.6 at% to 65.0 at%.

6. The anode material of claim 1, wherein The thickness of the transition layer is 80 nm to 150 nm, and the oxides of titanium in the transition layer comprise one or both of TiO2 and Ti4O7.

7. The anode material according to claim 1 or 6, characterized in that The total oxygen content of the transition layer is 30 at% to 45 at%.

8. The anode material of claim 1, wherein The thickness of the second layer is 500 nm to 1000 nm.

9. The anode material of claim 1, wherein The thickness of the third layer is 50 nm to 100 nm.

10. The anode material of claim 1, wherein, The catalytic material in the third layer comprises a noble metal or a noble metal alloy, the noble metal being selected from one or more of Pt, Ir, Au, and Ru.

11. The anode material according to claim 1 or 10, characterized in that, The porosity of the third layer is 25% to 50%.

12. A method of producing the anode material according to any one of claims 1 to 11, characterized in that, The method comprises: Step 1: pretreating the surface of the substrate; Step 2: preparing the first layer on the surface of the substrate by magnetron sputtering in an atmosphere of a mixture of argon and oxygen at a pressure of 0.5-1.5 Pa, and gradually reducing the proportion of oxygen in the mixture during the magnetron sputtering process; Step 3: preparing the transition layer on the surface of the first layer by magnetron sputtering in an atmosphere of a mixture of argon, oxygen, and nitrogen at a pressure of 0.5-1.5 Pa, and gradually reducing the proportion of oxygen and gradually increasing the proportion of nitrogen in the mixture during the magnetron sputtering process; Step 4: preparing the second layer on the surface of the transition layer by magnetron sputtering in an atmosphere of a mixture of argon and nitrogen at a pressure of 0.5-1.0 Pa; Step 5: preparing the third layer on the surface of the second layer by magnetron sputtering in an atmosphere of argon at a pressure of 0.6-1.0 Pa.

13. The method of claim 12, wherein, The surface roughness of the pretreated substrate is 0.5 μm to 2.0 μm.

14. The method of claim 12, wherein, In the process of preparing the first layer, the substrate temperature is 200-300℃, the power is 100-200W, the deposition rate is 0.2-0.35nm / s, the oxygen flow rate is 15-20sccm and the argon flow rate is 20-30sccm in the initial stage; and the oxygen flow rate is 7-15sccm and the argon flow rate is 30-40sccm in the end stage.

15. The method of claim 12, wherein, In the process of preparing the transition layer, the substrate temperature is 250-350℃, the power is 200-300W, the deposition rate is 0.25-0.45nm / s, the oxygen flow rate is 15-25sccm, the nitrogen flow rate is 5-10sccm and the argon flow rate is 30-40sccm in the initial stage; and the oxygen flow rate is 2-5sccm, the nitrogen flow rate is 20-30sccm and the argon flow rate is 30-40sccm in the end stage.

16. The method of claim 12, wherein, In the process of preparing the second layer, the substrate temperature is 300-400℃, the power is 300-400W, the deposition rate is 0.3-0.55nm / s, the nitrogen flow rate is 1-5sccm and the argon flow rate is 2-10sccm, and the total pressure is 0.5-1.0Pa.

17. The method of claim 12, wherein, In the process of preparing the third layer, the substrate temperature is room temperature, the power is 100-150W, the deposition rate is 0.2-0.3nm / s, and the argon flow rate is 20-40sccm.

18. The method according to any one of claims 12 to 17, characterized in that, After the preparation of any one of the first layer, the transition layer or the second layer is completed, the oxygen and / or nitrogen source is closed, the argon flow rate is adjusted to 20-40sccm, the plasma is turned on and the power is maintained at 200-300W for 2-6min, and then the next layer is prepared.

19. The method of claim 12, wherein, After the preparation of the third layer is completed, the anode material is further subjected to an annealing treatment in an argon atmosphere, the annealing temperature is 300-450℃, and the holding time is 1-3h.

20. A proton exchange membrane electrolyzer characterized by, The anode material according to any one of claims 1-11.

21. A method for hydrogen production by water electrolysis using a proton exchange membrane, characterized in that, The anode material according to any one of claims 1-11 is used as an anode.

22. A method for hydrogen production by water electrolysis using a proton exchange membrane, characterized in that, The proton exchange membrane electrolyzer according to claim 20.

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