Preparation method of nano-porous metal film based on low-temperature activation on surface of target material
By activating the target surface at low temperature and alloying it with Ga, the problems of inflexible composition and high energy consumption in the existing technology were solved, and the low-temperature preparation and structural uniformity of high melting point metal nanoporous films were realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-03-10
AI Technical Summary
Existing technologies rely on prefabricated alloy targets, resulting in inflexible composition, complex processes, and limited material systems, making it difficult to prepare nanoporous metal films of high-melting-point metals or metals that are difficult to immiscible.
Liquid Ga was used as the alloying medium, and the surface of the target material was activated at low temperature. Ga-based alloy films were deposited by magnetron sputtering and then dealloyed to achieve the low-temperature preparation of nanoporous metal films.
This technology enables flexible and adjustable composition, low-temperature preparation, reduced energy consumption, and the production of nanoporous metal films with narrow pore size distribution and uniform structure.
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Abstract
Description
TECHNICAL FIELD
[0001] The application relates to a nano-porous metal film preparation method based on low-temperature activation of a target surface and belongs to the technical field of nano-material preparation. BACKGROUND
[0002] The nano-porous metal film plays a key role in multiple frontier technology fields due to its high specific surface area and unique physical and chemical properties. Magnetron sputtering combined with dealloying is one of the mainstream technologies for preparing the nano-porous metal film at present. However, the technology seriously depends on a bulk alloy target prepared in advance through high-temperature smelting. Therefore, there are the following inherent limitations: first, it is extremely difficult or even impossible to prepare an alloy target with uniform composition for high-melting-point metals (such as Pt) or thermodynamically immiscible metal combinations (such as Ag-Fe); second, the process flow is long, and the energy consumption is high; and third, the target composition is fixed, and the flexibility is poor, so that rapid screening and gradient design of the film composition are difficult to realize.
[0003] Therefore, developing a nano-porous metal film preparation method capable of breaking away from the dependence on the pre-prepared alloy target and simultaneously having wide flexibility in composition and fine regulation and control capability in microstructure has become a technical bottleneck to be broken through in the field. SUMMARY
[0004] In view of the problems of inflexible composition, complex process and limited applicable material system caused by the dependence on the pre-prepared alloy target in the prior art, the application provides a nano-porous metal film preparation method based on low-temperature activation of a target surface. The target is modified in situ before sputtering, so that the nano-porous film preparation is realized at low temperature, energy saving and with flexible and adjustable composition. The application creatively converts the high-temperature and solid-phase bulk alloy preparation problem into the low-temperature and liquid-solid interface surface modification problem by introducing liquid Ga as a "universal alloying medium" and "structure precursor", so that the process is simplified, the energy consumption is reduced, and the material system and application range are greatly expanded at the source.
[0005] A nano-porous metal film preparation method based on low-temperature activation of a target surface has the following specific steps: (1) In a protective atmosphere or a vacuum environment, liquid metal gallium is coated on the surface of a target, and the metal gallium and the target metal are alloyed at the interface to obtain a continuous Ga-based pre-alloy activation layer on the surface of the target by heat preservation treatment at a temperature of 50-300 DEG C for 4-36 h; (2) A Ga-based alloy film is deposited on a substrate by magnetron sputtering with the target with the Ga-based pre-alloy activation layer on the surface as a sputtering source; the substrate temperature is 10-50 DEG C, the working gas pressure is 1x10 -3 ~1x10 -5 Pa, and the magnetron sputtering power is 120-200 W. (3) Ga-based alloy thin film is subjected to dealloying treatment to selectively remove Ga component in the Ga-based alloy thin film to obtain a nano-porous metal thin film; the dealloying treatment method is an electrochemical dealloying method or a step-by-step chemical dealloying method.
[0006] Preferably, the protective atmosphere in step (1) is nitrogen or inert gas.
[0007] Preferably, the target material in step (1) is a single metal target or an alloy target.
[0008] More preferably, the target material is composed of one or more of Au, Ag, Cu, Pt, Pd and Ni.
[0009] Preferably, the substrate in step (2) is a silicon wafer, glass, metal foil or flexible polymer substrate.
[0010] Preferably, the electrochemical dealloying method in step (3) specifically comprises: taking the Ga-based alloy thin film as a working electrode, a Pt sheet as a counter electrode, and a saturated calomel electrode as a reference electrode, and performing constant potential electrolysis in a room temperature electrolyte to selectively dissolve Ga.
[0011] More preferably, the electrolyte is a hydrochloric acid solution or a sulfuric acid solution, the electrolyte concentration is 0.5-1.0 mol / L, the voltage of the constant potential electrolysis is -0.5-0.5 V vs. SCE, and the electrolysis time is 0.5-4 h.
[0012] Preferably, the step-by-step chemical dealloying method specifically comprises: pre-etching the Ga-based alloy thin film in a low-concentration acid solution and then dealloying it in a high-concentration acid solution; the low-concentration acid solution is a hydrochloric acid solution, nitric acid solution or sulfuric acid solution with a concentration of 0.05-0.3 mol / L, and the high-concentration acid solution is a hydrochloric acid solution, nitric acid solution or sulfuric acid solution with a concentration of 0.5-2.0 mol / L.
[0013] More preferably, the pre-etching time is 0.5-4 h, and the dealloying time is 6-24 h.
[0014] The present application has the following advantages: (1) The present application realizes "on-line alloying" of a pure metal target or a refractory alloy target by taking advantage of the low-temperature alloying characteristics of Ga, thereby fundamentally eliminating the dependence on pre-prepared alloy target materials and making it possible to prepare nano-porous thin films of high-melting-point metals (such as Pt) or difficultly-miscible systems; (2) The entire alloying process is completed at low temperature (<300℃), thereby avoiding the thousands of degrees of smelting energy consumption in traditional processes, significantly reducing production costs, and meeting the requirements of green manufacturing; (3) The electrochemical dealloying method or the step-by-step chemical dealloying method is used for dealloying, the corrosion process can be accurately controlled, and a high-quality nano-porous structure with a narrower pore size distribution and a more uniform ligament structure can be obtained. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 SEM image of the nano-porous Cu thin film of Example 1; Figure 2 SEM image of the nano-porous Ag thin film of Example 2; Figure 3 SEM image of the nano-porous Pt thin film prepared on the flexible PI substrate of Example 3; Figure 4 SEM image of the nano-porous alloy thin film of Example 4. DETAILED DESCRIPTION
[0016] The application will be further described in conjunction with specific embodiments, but the protection scope of the application is not limited to the described content.
[0017] Example 1: A nano-porous metal thin film preparation method based on low-temperature activation of a target surface, and the specific steps are as follows: (1) Under an argon atmosphere, liquid gallium is coated on the surface of a target (high-purity copper with a purity greater than 99.99%), and the target is treated at a temperature of 180℃ for 24h to make the metal gallium and the target metal alloy at the interface to obtain a continuous Ga-based pre-alloyed activation layer (Ga-Cu pre-alloy) on the surface of the target; (2) The target with the Ga-based pre-alloyed activation layer (Ga-Cu pre-alloy) on the surface is used as a sputtering source to magnetron sputter deposit a Ga-based alloy thin film on a substrate (a single crystal silicon wafer); the substrate (a single crystal silicon wafer) has a temperature of 30℃, the working gas pressure is 0.5Pa, and the magnetron sputtering power is 100W; (3) The Ga-based alloy thin film is dealloyed to selectively remove the Ga component in the Ga-based alloy thin film, washed with deionized water, and vacuum dried to obtain a nano-porous metal thin film; the dealloying method is an electrochemical dealloying method, which specifically includes: using the Ga-based alloy thin film as a working electrode, a Pt sheet as a counter electrode, and a saturated calomel electrode as a reference electrode, and performing constant potential electrolysis in a room temperature electrolyte (0.5mol / L HCl solution) to selectively dissolve Ga; the voltage of the constant potential electrolysis is 0.1V vs. SCE, and the electrolysis time is 20min; The SEM image of the nano-porous Cu thin film of this example is shown in Figure 1 It can be seen from Figure 1 that the nano-porous Cu thin film has a uniform pore size, and the average pore size is about 400nm, and the highest temperature of the process is only 180℃.
[0018] Example 2: A method for preparing nanoporous metal thin films based on low-temperature activation of target surface, the specific steps of which are as follows: (1) Under an argon atmosphere, liquid gallium metal is coated on the surface of the target material (high purity Ag with a purity greater than 99.99%) and kept at 200℃ for 20h to allow the gallium metal and the target metal to undergo an alloying reaction at the interface to obtain a continuous Ga-based pre-alloy activation layer (Ga-Ag pre-alloy) on the surface of the target material. (2) Using a target with a Ga-based pre-alloyed activation layer (Ga-Ag pre-alloy) on its surface as a sputtering source, a Ga-based alloy thin film is deposited on a substrate (glass) by magnetron sputtering; the substrate (glass) temperature is 30°C and the working pressure is 1×10⁻⁶. -5 Pa, magnetron sputtering power is 150W; (3) The Ga-based alloy film is subjected to dealloying treatment to selectively remove the Ga component in the Ga-based alloy film, wash with deionized water, and vacuum dry to obtain a nanoporous metal film; the stepwise chemical dealloying method specifically includes: the Ga-Ag alloy film is placed in a low-concentration acid solution (0.1 mol / L nitric acid solution) for pre-etching for 30 min, and then placed in a high-concentration acid solution (1.0 mol / L nitric acid solution) for dealloying for 12 h; The SEM image of the nanoporous Ag film in this embodiment is shown below. Figure 2 ,from Figure 2 It is known that the nanoporous Ag film has a uniform pore size of about 400~600nm, and the highest temperature of this process is only 200℃.
[0019] Example 3: A method for preparing nanoporous metal thin films based on low-temperature activation of target surface, the specific steps of which are as follows: (1) Under a nitrogen atmosphere, liquid gallium metal is coated on the surface of the target material (high purity Pt with a purity greater than 99.99%) and kept at 250°C for 18 hours to allow the gallium metal and the target metal to undergo an alloying reaction at the interface to obtain a continuous Ga-based pre-alloy activation layer (Ga-Pt pre-alloy) on the surface of the target material. (2) Using a target with a Ga-based pre-alloyed activation layer (Ga-Pt pre-alloy) on its surface as a sputtering source, a Ga-based alloy thin film is deposited by magnetron sputtering on a substrate (polyimide); the substrate (polyimide) temperature is 15°C and the working pressure is 1×10⁻⁶. - 4 Pa, magnetron sputtering power is 120W; (3) The Ga-based alloy film is subjected to dealloying treatment to selectively remove the Ga component in the Ga-based alloy film, washed with deionized water, and vacuum dried to obtain a nanoporous metal film; the dealloying treatment method is electrochemical dealloying method, specifically including: using the Ga-based alloy film as the working electrode, the Pt sheet as the counter electrode, and the saturated calomel electrode as the reference electrode, constant potential electrolysis is performed in the room temperature electrolyte (0.15 mol / L nitric acid solution) to selectively dissolve Ga, the voltage of constant potential electrolysis is -0.2 V vs. SCE, and the electrolysis time is 1 h; The SEM image of the nanoporous Pt film in this embodiment is shown below. Figure 3 ,from Figure 3 It is known that the pore size of the nanoporous Pt film is uniform, with a pore size of about 100~200nm, and the highest temperature of this process is only 250℃.
[0020] Example 4: A method for preparing nanoporous metal thin films based on low-temperature activation of target surface, the specific steps of which are as follows: Method for preparing nanoporous Ag-Cu alloy thin films (1) In a vacuum environment, liquid gallium metal is coated on the surface of the target material (Cu-Ag alloy, in which Cu accounts for 50.% and Ag accounts for 50wt.%), and the surface is kept at 20℃ for 20h to allow the metal gallium and the target metal to undergo an alloying reaction at the interface to obtain a continuous Ga-based pre-alloy activation layer (Ga-Ag-Cu pre-alloy) on the surface of the target material. (2) Using a target with a Ga-based pre-alloyed activation layer (Ag-Cu pre-alloy) on its surface as a sputtering source, a Ga-based alloy thin film is deposited on a substrate (glass) by magnetron sputtering; the substrate (glass) temperature is 50°C and the working pressure is 5×10⁻⁶. -4 Pa, magnetron sputtering power is 120W; (3) The Ga-based alloy film is subjected to dealloying treatment to selectively remove the Ga component in the Ga-based alloy film, washed with deionized water, and vacuum dried to obtain a nanoporous metal film; the dealloying treatment method is electrochemical dealloying method, specifically including: using the Ga-based alloy film as the working electrode, the Pt sheet as the counter electrode, and the saturated calomel electrode as the reference electrode, constant potential electrolysis is carried out in room temperature electrolyte (H2SO4 solution with a concentration of 1 mol / L) to selectively dissolve Ga, the voltage of constant potential electrolysis is -0.5V vs. SCE, and the electrolysis time is 30 min; The SEM image of the nanoporous Ag-Cu alloy thin film in this embodiment is shown below. Figure 4 ,from Figure 4 It can be seen that the nanoporous Ag-Cu alloy film in this embodiment has a uniform pore size of about 200~300nm, and the highest temperature of this process is only 50℃.
[0021] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. A method for preparing a nano-porous metal thin film based on low-temperature activation of a target surface, characterized by, The specific steps are as follows: (1) under a protective atmosphere or a vacuum environment, liquid gallium is coated on the surface of a target material, and the metal gallium and the target material metal are allowed to react at the interface under heat preservation treatment at a temperature of 50-300 DEG C for 4-36 h to obtain a continuous Ga-based pre-alloyed activation layer on the surface of the target material; (2) the target material with the Ga-based pre-alloyed activation layer on the surface is used as a sputtering source to magnetron sputter deposit a Ga-based alloy thin film on a substrate; (3) the Ga-based alloy thin film is subjected to dealloying treatment to selectively remove the Ga component in the Ga-based alloy thin film to obtain a nano-porous metal thin film; the dealloying treatment method is an electrochemical dealloying method or a step-by-step chemical dealloying method.
2. The method of claim 1, wherein the method further comprises: In step (1), the protective atmosphere is nitrogen or an inert gas.
3. The method of claim 1, wherein the method further comprises: In step (1), the target material is a single metal target material or an alloy target material. 4. The method of claim 3, wherein the method further comprises the step of: The target material comprises one or more of Au, Ag, Cu, Pt, Pd and Ni. 5. The method of claim 1, wherein the method further comprises: In step (2), the substrate is a silicon wafer, glass, metal foil or flexible polymer substrate. 6. The method of claim 1, wherein the method further comprises: In step (3), the electrochemical dealloying method specifically comprises: using the Ga-based alloy thin film as a working electrode, a Pt sheet as a counter electrode, and a saturated calomel electrode as a reference electrode, and performing constant potential electrolysis in a room temperature electrolyte to selectively dissolve Ga.
7. The method of claim 6, wherein the method further comprises the step of: The electrolyte is a hydrochloric acid solution or a sulfuric acid solution, the electrolyte concentration is 0.5-1.0 mol / L, the constant potential electrolysis voltage is-0.5-0.5 V vs. SCE, and the electrolysis time is 0.5-4 h. 8. The method of claim 1, wherein the method further comprises: The step-by-step chemical dealloying method specifically comprises: pre-etching the Ga-based alloy thin film in a low-concentration acid solution and then dealloying it in a high-concentration acid solution; the low-concentration acid solution is a hydrochloric acid solution, nitric acid solution or sulfuric acid solution with a concentration of 0.05-0.3 mol / L, and the high-concentration acid solution is a hydrochloric acid solution, nitric acid solution or sulfuric acid solution with a concentration of 0.5-2.0 mol / L.
9. The method of claim 8, wherein the method further comprises the step of: The pre-etching time is 0.5-4 h, and the dealloying time is 6-24 h.