Copper-silver porous and nano-grass array composite material as well as preparation method and application thereof

Abstract

The embodiment of the invention relates to a copper-silver porous and nano-grass array composite material and a preparation method and application thereof.The preparation method comprises the steps that metal Cu, metal Ag and metal Gd are mixed and subjected to electric arc melting treatment, and a Cu-Ag-Gd alloy ingot is obtained; metal Mg and the Cu-Ag-Gd alloy ingot are mixed, and an Mg-Cu-Ag-Gd alloy ingot is obtained through induction melting treatment; the Mg-Cu-Ag-Gd alloy ingot is subjected to melt spinning treatment, and an Mg-Cu-Ag-Gd amorphous alloy strip is obtained; the Mg-Cu-Ag-Gd amorphous alloy strip is subjected to dealloying treatment, and a Cu-Ag amorphous alloy strip is obtained; the Cu-Ag amorphous alloy strip is cleaned, dried and annealed, and a copper-silver substrate of a three-dimensional nano-porous structure is obtained; growing a copper hydroxide nano-grass array on the copper-silver substrate in situ to obtain a copper-silver porous and nano-grass array composite material; and the copper hydroxide nano-grass array grows on the surface or in a pore channel of the three-dimensional nano-porous structure in situ.

Description

Technical Field

[0001] This invention relates to the field of biochemical sensor technology, and in particular to a copper-silver porous composite material with nanograss arrays, its preparation method, and its application. Background Technology

[0002] In recent years, people's dietary structure and lifestyle have undergone significant changes. Influenced by unhealthy habits such as excessive calorie intake, lack of exercise, and frequent night shifts, more and more people are suffering from diabetes. With the increasing public awareness of health, the demand for accurate monitoring and control of blood glucose levels is becoming increasingly urgent, making the development of highly sensitive glucose sensors particularly important.

[0003] There are various methods for glucose detection, such as colorimetry, fluorescence spectroscopy, mass spectrometry, and electrochemical methods. Among them, electrochemical methods have attracted much attention due to their low cost and ease of use, and are currently the focus of glucose sensor research. Electrochemical glucose sensors are divided into enzyme-modified sensors and non-enzyme-modified sensors. Enzyme-modified sensors are unstable and easily affected by environmental factors such as temperature and pH, which limits their practical application. Therefore, developing non-enzyme-modified electrochemical glucose sensors that are simple to manufacture, highly stable, and highly sensitive is of great significance.

[0004] Most existing glucose sensor catalysts use conductive substrates or noble metals (Pt, Au) as support materials. However, when using conductive substrates, the catalyst material is prone to detaching from the substrate, and the resulting composite electrode exhibits poor conductivity. When using noble metals as support materials, the high cost and complexity of the composite electrode structure hinder mass production. All these factors impede the widespread application of electrochemical glucose sensors. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a copper-silver porous composite material with nano-grass arrays, its preparation method, and its applications.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a copper-silver porous composite material with a nano-grass array, the method comprising:

[0007] Metals Cu, Ag, and Gd are mixed and then subjected to electric arc melting to obtain Cu-Ag-Gd alloy ingots;

[0008] Metallic Mg is mixed with the Cu-Ag-Gd alloy ingot and then subjected to induction melting to obtain Mg-Cu-Ag-Gd alloy ingot;

[0009] The Mg-Cu-Ag-Gd alloy ingot was subjected to a strip spinning process to obtain Mg-Cu-Ag-Gd amorphous alloy strips;

[0010] The Mg-Cu-Ag-Gd amorphous alloy strip was subjected to a dealloying process to obtain a Cu-Ag amorphous alloy strip.

[0011] After cleaning and drying, the Cu-Ag amorphous alloy strip is annealed to obtain a copper-silver substrate with a three-dimensional nanoporous structure.

[0012] A copper hydroxide nano-grass array is grown in situ on the copper-silver substrate to obtain a copper-silver porous composite material with a nano-grass array; the copper hydroxide nano-grass array is grown in situ on the surface or within the pores of the three-dimensional nanoporous structure.

[0013] Preferably, the specific surface area of ​​the copper-silver porous composite material with nano-grass array is 21 m². 2 / g-24m 2 / g; the pore size of the three-dimensional nanoporous structure is 150nm-200nm.

[0014] Preferably, the copper hydroxide nanoparticle array within the pores of the three-dimensional nanoporous structure has a diameter of 45nm-55nm and a length of 120nm-180nm, while the copper hydroxide nanoparticle array on the surface of the three-dimensional nanoporous structure has a diameter of 150nm-250nm and a length of 1500nm-2500nm.

[0015] Preferably, the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot is (21.5-26.5):(9.4-11):(7.2-8.5); and the mass ratio of Mg to Cu-Ag-Gd alloy ingot is (23.78-28.33):(71.69-76.22).

[0016] Preferably, the arc melting process is carried out in an inert atmosphere with a vacuum degree of 4.5 × 10⁻⁶. 4 pa-5.5×10 4 pa, current is 200A-240A;

[0017] The induction melting process is specifically carried out in an induction melting furnace, with a current of 14A-16A and a time of 80-100 seconds;

[0018] The belt spinning process is specifically carried out in an inert atmosphere with a vacuum level of 7.5 × 10⁻⁶. 4 pa-8.5×10 4 The current is 14A-15A, and the rotation speed of the copper roller of the belt spinning machine is 1700-1900 rpm.

[0019] Preferably, the dealloying treatment specifically involves immersing the Mg-Cu-Ag-Gd amorphous alloy strip in sulfuric acid to react with the sulfuric acid and detach the Mg and Gd from the Mg-Cu-Ag-Gd amorphous alloy strip, thereby obtaining the Cu-Ag amorphous alloy strip.

[0020] Preferably, the cleaning process specifically involves rinsing with deionized water 3-5 times, followed by rinsing with anhydrous ethanol 3-5 times; the drying process specifically involves vacuum drying at room temperature for 1-2 hours.

[0021] The annealing conditions are: vacuum degree 1.5 × 10⁻⁶. -4 pa-2.5×10 -4 Pa, temperature 230℃-260℃, time 1.5-2.5 hours.

[0022] Preferably, the in-situ grown copper hydroxide nano-grass array specifically includes:

[0023] Using the copper-silver substrate as the working electrode, a platinum sheet as the counter electrode, Ag / AgCl as the reference electrode, and KOH as the electrolyte, electrochemical oxidation was carried out at a certain current density, resulting in the in-situ growth of copper hydroxide nano-grass arrays on a portion of the copper-silver substrate.

[0024] The copper-silver substrate with in-situ grown copper hydroxide nanograss arrays was immersed in ammonium persulfate and sodium hydroxide solution for further chemical oxidation to generate a copper-silver porous composite material with nanograss arrays.

[0025] In a second aspect, the present invention provides a copper-silver porous and nano-grass array composite material, characterized in that the copper-silver porous and nano-grass array composite material is prepared by any of the preparation methods described in the first aspect above.

[0026] Thirdly, the present invention provides an application of the copper-silver porous and nanograss array composite material described in the second aspect above, characterized in that the copper-silver porous and nanograss array composite material is applied in a glucose sensor.

[0027] The present invention provides a method for preparing a copper-silver porous composite material with a nano-grass array. This method involves two steps: melting, spinning, and dealloying, to obtain a copper-silver substrate with a three-dimensional nanoporous structure. Then, using the copper-silver substrate as a self-supporting body for the composite material, smaller copper hydroxide nano-grass is grown in situ within the pores of the three-dimensional nanoporous structure via electrochemical oxidation. Larger copper hydroxide nano-grass is then grown in situ on the surface of the three-dimensional nanoporous structure via chemical oxidation, thus forming a hierarchical nano-grass array on the copper-silver substrate. The three-dimensional nanoporous structure of the copper-silver substrate gives the composite material good electrical conductivity, and the three-dimensional nanoporous structure can support a large number of copper hydroxide nano-grass arrays, increasing the number of active sites and improving the catalytic activity of the composite material.

[0028] In summary, the preparation method is simple and easy to operate, with a short cycle and high yield. The prepared composite material has a high specific surface area and a large number of catalytic active sites, and exhibits excellent glucose detection sensitivity as a catalytic material for glucose sensors. Attached Figure Description

[0029] Figure 1 A flowchart illustrating the preparation method of the copper-silver porous and nano-grass array composite material provided in this embodiment of the invention;

[0030] Figure 2 The XRD patterns of Mg-Cu-Ag-Gd amorphous alloy strips before and after dealloying provided in the embodiments of the present invention;

[0031] Figure 3 This is a SEM image of the Mg-Cu-Ag-Gd amorphous alloy strip after dealloying, provided in an embodiment of the present invention.

[0032] Figure 4 This is a SEM image of a Cu-Ag amorphous alloy strip after annealing, provided in an embodiment of the present invention.

[0033] Figure 5 This is a SEM image of the copper-silver porous and nano-grass array composite material after dispersion, provided in an embodiment of the present invention.

[0034] Figure 6 TEM image of the copper-silver porous and nano-grass array composite material after dispersion provided in the embodiments of the present invention;

[0035] Figure 7 The surface morphology diagram of the copper-silver porous and nano-grass array composite material provided in Embodiment 1 of the present invention is shown.

[0036] Figure 8 This is a cross-sectional morphology diagram of the copper-silver porous and nano-grass array composite material provided in Example 1 of the present invention;

[0037] Figure 9 This is a surface morphology diagram of the copper-silver porous and nano-grass array composite material provided in Comparative Example 1 of the present invention;

[0038] Figure 10 This is a cross-sectional morphology diagram of the copper-silver porous and nano-grass array composite material provided in Comparative Example 1 of the present invention;

[0039] Figure 11 This is a surface morphology diagram of the copper-silver porous and nano-grass array composite material provided in Comparative Example 2 of the present invention;

[0040] Figure 12 This is a cross-sectional morphology diagram of the copper-silver porous and nano-grass array composite material provided in Comparative Example 2 of the present invention;

[0041] Figure 13 The specific surface area diagram of the copper-silver porous and nano-grass array composite material provided in Example 1 of the present invention;

[0042] Figure 14 The specific surface area diagram of the copper-silver porous and nano-grass array composite material provided in Comparative Example 1 of the present invention;

[0043] Figure 15 The test curves for the glucose oxidation performance of the copper-silver porous and nano-grass array composite material provided in Example 1 of the present invention are shown.

[0044] Figure 16 The graph shows the linear fit of the test results of the copper-silver porous and nano-grass array composite material provided in Example 1 of the present invention on the glucose oxidation performance.

[0045] Figure 17 The test curve of the anti-interference ability of the copper-silver porous and nano-grass array composite material provided in Example 1 of the present invention against glucose oxidation;

[0046] Figure 18 This is a comparison chart of the electrocatalytic sensitivity of the copper-silver porous and nanograss array composite materials provided in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0048] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0049] This invention provides a method for preparing a copper-silver porous composite material with nano-grass arrays. The method specifically includes the following steps: Figure 1 The steps shown are as follows:

[0050] Step 101: Mix metals Cu, Ag and Gd, and then perform electric arc melting to obtain Cu-Ag-Gd alloy ingots;

[0051] Specifically, the purity of the metals Cu, Ag, and Gd is 99.9 wt%. The atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot is (21.5-26.5):(9.4-11):(7.2-8.5), preferably 26.5:11:8.5.

[0052] Metallic Cu, Ag, and Gd are mixed to obtain an alloy precursor. The alloy precursor is then repeatedly melted several times in an electric arc melting furnace under an inert atmosphere to obtain a Cu-Ag-Gd alloy ingot. The inert atmosphere can be argon. The vacuum degree of the electric arc melting can be 4.5 × 10⁻⁶. 4 -5.5×10 4 pa, preferably 5×10 4 Pa; the current can be 210-230A, preferably 220A. The number of cycles can be 3-5. After cooling, remove the oxide layer from the surface and weigh.

[0053] As a preferred embodiment, before arc melting, the alloy precursor is placed in the arc melting furnace, and then the furnace is evacuated to a high vacuum, with a vacuum level of 4.5 × 10⁻⁶. -3 pa-5×10 -3 This ensures that the alloy precursor is not oxidized before arc melting.

[0054] Step 102: Mix Mg metal with Cu-Ag-Gd alloy ingots and perform induction melting to obtain Mg-Cu-Ag-Gd alloy ingots;

[0055] Specifically, the mass ratio of Mg to Cu-Ag-Gd alloy ingots can be (23.78-28.33):(71.69-76.22), preferably 23.78:76.22. That is, the target atomic ratio of the Mg-Cu-Ag-Gd alloy ingots is (54-60):(21.5-26.5):(9.4-11):(7.2-8.5), preferably 60:26.5:11:8.5.

[0056] First, place metallic Mg in a quartz tube, then add a Cu-Ag-Gd alloy ingot to the quartz tube. Evacuate the quartz tube until the vacuum level reaches 6 × 10⁻⁶. -5 -2×10 -4 pa, preferably 8×10-5 At pa, a sealing machine is used to seal the quartz tube before placing it into an induction melting furnace for melting. Since Mg has a lower boiling point than the other three metallic elements, sealing the tube before induction melting in the furnace is necessary to minimize Mg volatilization during the melting process. Even so, Mg will still volatilize during induction melting; therefore, as a preferred method, the amount of magnesium added in this step can be 2%-5% excess. The induction melting current can be 14A-16A, preferably 15A; the melting time can be 80-100 seconds, preferably 90 seconds.

[0057] Step 103: The Mg-Cu-Ag-Gd alloy ingot is subjected to a strip spinning process to obtain Mg-Cu-Ag-Gd amorphous alloy strips;

[0058] Specifically, the oxide layer of the cooled Mg-Cu-Ag-Gd alloy ingot is removed, and a certain amount is subjected to a strip spinning process. Under an inert atmosphere, the molten Mg-Cu-Ag-Gd alloy ingot is rapidly blown out, and the molten alloy ingot quickly solidifies on a high-speed rotating copper roller to form an amorphous alloy strip. The inert atmosphere can be argon. The vacuum degree of the strip spinning process can be 7.5 × 10⁻⁶. 4 -8.5×10 4 pa, preferably 8×10 4 The current can be 14A-15A, preferably 14.5A, and the copper roller speed can be 1700 rpm-1900 rpm, preferably 1800 rpm.

[0059] As a preferred method, before the strip spinning process, the Mg-Cu-Ag-Gd alloy ingot is placed into the strip spinning machine, and then the machine is evacuated to a vacuum level of 4.5 × 10⁻⁶. -4 pa-5×10 -4 The pa ensures that the Mg-Cu-Ag-Gd alloy ingot will not be oxidized before the strip spinning process.

[0060] Step 104: The Mg-Cu-Ag-Gd amorphous alloy strip is subjected to dealloying treatment to obtain Cu-Ag amorphous alloy strip;

[0061] Specifically, the Mg-Cu-Ag-Gd amorphous alloy strip is divided into small segments and then immersed in sulfuric acid for a certain period of time. The concentration of sulfuric acid can be 0.08 mol / L-0.2 mol / L, preferably 0.1 mol / L, and the immersion time is 4.5-5.5 hours, preferably 5 hours. The purpose of dealloying is to allow the Mg and Gd in the Mg-Cu-Ag-Gd amorphous alloy strip to react with the sulfuric acid and detach from the Mg-Cu-Ag-Gd amorphous alloy strip, obtaining Cu-Ag amorphous alloy strips. Figure 2It can be seen that the material is amorphous before dealloying and consists of two phases of copper and silver after dealloying. The specific ligament size and pore size of the Cu-Ag amorphous alloy strips formed in this step are 35nm-45nm.

[0062] It should be noted that the formation of amorphous alloys requires certain conditions and has relatively fixed compositional requirements. Dealloying also has certain requirements, necessitating a sacrificial element atomic ratio greater than 55%. This application chose Mg and Gd as the main sacrificial elements because metallic Mg and Gd have strong amorphous alloying capabilities, are easy to prepare, and the dealloying conditions are simple; dealloying can be completed simply by adding a low concentration of sulfuric acid to a glass container, making the operation very safe.

[0063] Step 105: After cleaning and drying the Cu-Ag amorphous alloy strip, it is annealed to obtain a copper-silver substrate with a three-dimensional nanoporous structure.

[0064] The cleaning process specifically involves rinsing with deionized water 3-5 times, preferably 3 times, followed by rinsing with anhydrous ethanol 3-5 times, preferably 3 times. The drying process involves vacuum drying at room temperature for 1-2 hours, preferably 1 hour. The annealing treatment involves a vacuum degree of 1.5 × 10⁻⁶. -4 pa-2.5×10 -4 pa, preferably 2×10 -4 Pa; temperature 230℃-260℃, preferably 250℃; time 1.5 hours-2.5 hours, preferably 2 hours. The purpose of annealing is to further increase the pore size of the three-dimensional nanoporous structure and make the channels of the three-dimensional nanoporous structure more uniform. (Comparison) Figure 3 and Figure 4 It can be seen that the Cu-Ag amorphous alloy strips after annealing have larger and more uniform pores. The copper-silver substrate ligaments formed in this step have a specific size of 150nm-200nm and a specific pore size of 150nm-200nm.

[0065] Annealing increases the pore size of the three-dimensional nanoporous structure of the copper-silver substrate, providing favorable conditions for the growth of nanograss arrays. It exhibits excellent mass transfer and charge transfer capabilities, as well as good electrical conductivity. Annealing also increases the toughness of the copper-silver substrate, mitigating its tendency to fracture and providing conditions for self-support. When this composite material is applied in a glucose sensor, it facilitates the transport of glucose molecules and the electrolyte.

[0066] Step 106: In situ growth of copper hydroxide nanograss array on copper-silver substrate to obtain copper-silver porous composite material with nanograss array.

[0067] Specifically, firstly, a copper-silver substrate was immersed in a KOH electrolyte as the working electrode, while a platinum sheet was used as the counter electrode, and a saturated Ag / AgCl solution was used as the reference electrode (wherein the concentration of the saturated KCl solution was 3 mol / L). A continuous current was applied using an electrochemical workstation to perform electrochemical oxidation, resulting in the growth of small nano-grass-like structures on the surface and within the pores of the three-dimensional nanoporous structure of the copper-silver substrate. The concentration of KOH was 0.45 mol / L-0.55 mol / L, preferably 0.5 mol / L. The current density was 14 mA / cm². 2 -16mA / cm 2 15mA / cm is preferred 2 The reaction time is 250-350 seconds, preferably 300 seconds. The reaction equation is as follows:

[0068] Cu + 2OH - →Cu(OH)2+2e - .

[0069] Next, the copper-silver substrate with the in-situ grown copper hydroxide nano-grass array is cleaned and dried. Specifically, it can be cleaned 3-5 times with deionized water, followed by 1-3 times with anhydrous ethanol. Afterward, it is vacuum dried at room temperature for 0.5-2.5 hours, preferably 1 hour.

[0070] Finally, the dried copper-silver substrate with the in-situ grown copper hydroxide nanograss array was immersed in a mixed solution of ammonium persulfate and sodium hydroxide for further chemical oxidation, allowing larger nanograss to grow on the surface of the three-dimensional nanoporous structure. Afterward, it underwent washing and drying. Specifically, it was washed 3-5 times with deionized water, followed by 1-3 times with anhydrous ethanol. Then, it was vacuum dried at room temperature for 0.5-2.5 hours, preferably 1 hour. The concentration of ammonium persulfate was 0.15 mol / L-0.25 mol / L, preferably 0.2 mol / L. The concentration of sodium hydroxide was 1.5 mol / L-2.5 mol / L, preferably 2 mol / L. The drying time was 30-90 seconds, preferably 60 seconds. The reaction equation is as follows:

[0071] Cu+4NaOH+(NH4)2S2O8→Cu(OH)2+2Na2SO4+2NH3+2H2O.

[0072] In this study, copper hydroxide nano-grass arrays are grown in situ on the surface or within the pores of a three-dimensional nanoporous structure. The copper hydroxide nano-grass within the pores is smaller, while the copper hydroxide nano-grass on the surface of the three-dimensional nanoporous structure is larger, thus forming a rich hierarchical nano-grass array. This increases the number of active sites in the composite material, and the unique tip effect of the nano-grass enhances the catalytic activity of the composite material.

[0073] The copper hydroxide nanofiber array within the pores of the three-dimensional nanoporous structure of this application has a diameter of 45-55 nm and a length of 120 nm-180 nm. The copper hydroxide nanofiber array on the surface of the three-dimensional nanoporous structure has a diameter of 150 nm-250 nm and a length of 1500 nm-2500 nm. The specific surface area of ​​this composite material is 21 m². 2 / g-24m 2 / g. For example... Figure 5 and Figure 6 Both sizes of nanograss can be observed to exhibit characteristics.

[0074] The present invention provides a method for preparing a copper-silver porous composite material with a nano-grass array. This method involves two steps: melting, spinning, and dealloying, to obtain a copper-silver substrate with a three-dimensional nanoporous structure. Then, using the copper-silver substrate as a self-supporting body for the composite material, smaller copper hydroxide nano-grass is grown in situ within the pores of the three-dimensional nanoporous structure via electrochemical oxidation. Larger copper hydroxide nano-grass is then grown in situ on the surface of the three-dimensional nanoporous structure via chemical oxidation, thus forming a hierarchical nano-grass array on the copper-silver substrate. The three-dimensional nanoporous structure of the copper-silver substrate gives the composite material good electrical conductivity, and the three-dimensional nanoporous structure can support a large number of copper hydroxide nano-grass arrays, increasing the number of active sites and improving the catalytic activity of the composite material.

[0075] In summary, the preparation method is simple and easy to operate, with a short cycle and high yield. The prepared composite material has a high specific surface area and a large number of catalytic active sites, and exhibits excellent glucose detection sensitivity as a catalytic material for glucose sensors.

[0076] The copper-silver porous and nano-grass array composite material provided by this invention can be applied to glucose sensors.

[0077] To better understand the technical solution provided by the present invention, the following uses several specific examples to illustrate the specific process of preparing copper-silver porous and nano-grass array composite materials using the method provided in the above embodiments of the present invention, as well as the characteristics of the prepared copper-silver porous and nano-grass array composite materials.

[0078] Example 1

[0079] The first step is to weigh out a total of 30g of Cu metal blocks, Ag metal blocks, and Gd metal blocks according to the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot of 26.5:11:8.5, to obtain the alloy precursor.

[0080] The second step involves placing the alloy precursor in an electric arc melting furnace with Ag metal blocks at the bottom, Cu metal blocks in the middle, and Gd metal blocks at the top. The furnace is then evacuated to a vacuum level of 5 × 10⁻⁶. -3 Then, argon gas is introduced into the electric arc melting furnace until the vacuum degree is 5×10⁻⁶. 4 The alloy precursor was repeatedly melted five times at an arc starting current of 220A. After cooling, the alloy was removed to obtain a Cu-Ag-Gd alloy ingot.

[0081] The third step is to remove the oxide layer on the surface of the Cu-Ag-Gd alloy ingot and weigh it to obtain a 29.5g Cu-Ag-Gd alloy ingot. Then, according to the mass ratio of Mg metal block to Cu-Ag-Gd alloy ingot of 23.78:76.22, 9.39g of excess Mg metal block (2%) is weighed.

[0082] Place the Mg metal block at the bottom of the quartz tube, then add the Cu-Ag-Gd alloy ingot on top of the Mg metal block, and evacuate the quartz tube to 8×10⁻⁶. -5 After pa, the tube is sealed using a sealing machine. Then, the quartz tube is placed in an induction melting furnace and melted for 90 seconds at a current of 15A. After cooling, Mg-Cu-Ag-Gd alloy ingots are obtained.

[0083] The fourth step is to remove the oxide layer on the surface of the Mg-Cu-Ag-Gd alloy ingot. Take 3g of the Mg-Cu-Ag-Gd alloy ingot and place it in a strip spinning machine. Evacuate the strip spinning machine to a vacuum degree of 5×10⁻⁶. -4 pa, then argon gas is introduced into the belt spinning machine until the vacuum degree is 8×10 4 The Mg-Cu-Ag-Gd amorphous alloy strip was obtained by spinning the strip under the conditions of a current of 14.5A and a copper roller speed of 1800 rpm.

[0084] The fifth step involves cutting the Mg-Cu-Ag-Gd amorphous alloy strip into small segments and immersing them in 0.1 mol / L sulfuric acid for 5 hours to undergo a dealloying treatment, thereby obtaining Cu-Ag amorphous alloy strips.

[0085] Step 6: Clean the Cu-Ag amorphous alloy strip three times with deionized water, then three times with anhydrous ethanol. Dry under vacuum for 1 hour at room temperature. (The process is repeated in the original text.) -4 Under the conditions of 250℃ and annealing for 2 hours, a copper-silver substrate with a three-dimensional nanoporous structure was obtained.

[0086] Step 7: First, the copper-silver substrate was used as the working electrode and immersed in a 0.5 mol / L KOH electrolyte. A platinum sheet was used as the counter electrode, and Ag / AgCl was used as the reference electrode. A current density of 15 mA / cm² was applied using an electrochemical workstation.2 Electrochemical oxidation was performed for 300 seconds to obtain samples with small-sized nanograss growing on the surface or inside the pores of a three-dimensional nanoporous structure on a copper-silver substrate.

[0087] Step 8: Wash the sample three times with deionized water, then twice with anhydrous ethanol. After that, vacuum dry at room temperature for 1 hour.

[0088] In the ninth step, the dried sample was immersed in a mixed solution of 0.2 mol / L ammonium persulfate and 2 mol / L sodium hydroxide for further chemical oxidation for 60 seconds. Then, it was washed three times with deionized water and twice with anhydrous ethanol, followed by vacuum drying for one hour to finally obtain the copper-silver porous composite material with nano-grass array.

[0089] Subsequently, the properties of the prepared copper-silver porous and nano-grass array composite materials were tested.

[0090] 1. The specific surface area of ​​the copper-silver porous and nano-grass array composite material was measured and calculated using a BET specific surface area analyzer.

[0091] 2. A three-electrode chemical system was constructed using a copper-silver porous composite material with a nano-grass array as the working electrode, a platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode. The electrolyte was a 0.5 mol / L NaOH solution. An electrochemical workstation was used to continuously apply a working voltage of 0.6 V, and the electrolyte was continuously stirred with a magnetic stirrer. After activating the working electrode for 3000 seconds, glucose solutions of different concentrations were added to the electrolyte every 40 seconds, as shown in Table 1. The added glucose solutions mixed in the electrolyte, gradually increasing the glucose concentration, and the glucose oxidation performance of the composite material was tested.

[0092] Table 1 shows the number of drops, the increase in glucose concentration with each drop, and the glucose concentration in the electrolyte. M represents mol / L.

[0093] Number of drops Concentration increase per time Concentration of glucose in the electrolyte 1 100nM 100nM 2 100nM 200nM 3 100nM 300nM 4 200nM 500nM 5 200nM 700nM 6 200nM 900nM 7 500nM 1.4uM 8 500nM 1.9uM 9 1uM 2.9uM 10 10uM 12.9uM 11 10uM 22.9uM 12 20uM 42.9uM 13 50uM 92.9uM 14 50uM 142.9uM 15 0.1mM 242.9uM 16 0.2mM 442.9uM 17 0.5mM 942.9uM 18 1mM 1.942mM 19 1mM 2.942mM 20 1mM 3.942mM 21 1mM 4.942mM 22 1mM 5.942mM 23 1mM 6.942mM 24 1mM 7.942mM 25 1mM 8.942mM 26 1mM 9.942mM

[0094] Table 1

[0095] 3. A three-electrode chemical system was constructed using a copper-silver porous composite material with a nano-grass array as the working electrode, a platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode. The electrolyte was a 0.5 mol / L NaOH solution. An electrochemical workstation was used to continuously apply a working voltage of 0.6 V, and the mixture was continuously stirred with a magnetic stirrer. After activating the working electrode for 3000 seconds, glucose, lactose, sucrose, fructose, maltose, uric acid (UA), and ascorbic acid (AA) were added sequentially to the electrolyte. Finally, glucose was added again to test the composite material's resistance to glucose oxidation.

[0096] Comparative Example 1

[0097] The first step is to weigh out a total of 30g of Cu metal blocks, Ag metal blocks, and Gd metal blocks according to the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot of 26.5:11:8.5, to obtain the alloy precursor.

[0098] The second step involves placing the alloy precursor in an electric arc melting furnace with Ag metal blocks at the bottom, Cu metal blocks in the middle, and Gd metal blocks at the top. The furnace is then evacuated to a vacuum level of 5 × 10⁻⁶. -3 Then, argon gas is introduced into the electric arc melting furnace until the vacuum degree is 5×10⁻⁶. 4 The alloy precursor was repeatedly melted five times at an arc starting current of 220A. After cooling, the alloy was removed to obtain a Cu-Ag-Gd alloy ingot.

[0099] The third step is to remove the oxide layer on the surface of the Cu-Ag-Gd alloy ingot and weigh it to obtain a 29.5g Cu-Ag-Gd alloy ingot. Then, according to the mass ratio of Mg metal block to Cu-Ag-Gd alloy ingot of 23.78:76.22, 9.39g of excess Mg metal block (2%) is weighed.

[0100] Place the Mg metal block at the bottom of the quartz tube, then add the Cu-Ag-Gd alloy ingot on top of the Mg metal block, and evacuate the quartz tube to 8×10⁻⁶. -5 After pa, the tube is sealed using a sealing machine. Then, the quartz tube is placed in an induction melting furnace and melted for 90 seconds at a current of 15A. After cooling, Mg-Cu-Ag-Gd alloy ingots are obtained.

[0101] The fourth step is to remove the oxide layer on the surface of the Mg-Cu-Ag-Gd alloy ingot. Take 3g of the Mg-Cu-Ag-Gd alloy ingot and place it in a strip spinning machine. Evacuate the strip spinning machine to a vacuum degree of 5×10⁻⁶. -4pa, then argon gas is introduced into the belt spinning machine until the vacuum degree is 8×10 4 The Mg-Cu-Ag-Gd amorphous alloy strip was obtained by spinning the strip under the conditions of a current of 14.5A and a copper roller speed of 1800 rpm.

[0102] The fifth step involves cutting the Mg-Cu-Ag-Gd amorphous alloy strip into small segments and immersing them in 0.1 mol / L sulfuric acid for 5 hours to undergo a dealloying treatment, thereby obtaining Cu-Ag amorphous alloy strips.

[0103] Step 6: Clean the Cu-Ag amorphous alloy strip three times with deionized water, then three times with anhydrous ethanol. Dry under vacuum for 1 hour at room temperature. (The process is repeated in the original text.) -4 Under the conditions of 250℃ and annealing for 2 hours, a copper-silver substrate with a three-dimensional nanoporous structure was obtained.

[0104] In the seventh step, the copper-silver substrate was chemically oxidized by immersing it in a mixed solution of 0.2 mol / L ammonium persulfate and 2 mol / L sodium hydroxide for 60 seconds, resulting in a sample with a nano-grass array.

[0105] Step 8: Wash the sample three times with deionized water, twice with anhydrous ethanol, and vacuum dry for 1 hour to finally obtain the copper-silver porous and nano-grass array composite material.

[0106] The testing process is the same as in Example 1.

[0107] Comparative Example 2

[0108] The first step is to weigh out a total of 30g of Cu metal blocks, Ag metal blocks, and Gd metal blocks according to the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot of 26.5:11:8.5, to obtain the alloy precursor.

[0109] The second step involves placing the alloy precursor in an electric arc melting furnace with Ag metal blocks at the bottom, Cu metal blocks in the middle, and Gd metal blocks at the top. The furnace is then evacuated to a vacuum level of 5 × 10⁻⁶. -3 Then, argon gas is introduced into the electric arc melting furnace until the vacuum degree is 5×10⁻⁶. 4 The alloy precursor was repeatedly melted five times at an arc starting current of 220A. After cooling, the alloy was removed to obtain a Cu-Ag-Gd alloy ingot.

[0110] The third step is to remove the oxide layer on the surface of the Cu-Ag-Gd alloy ingot and weigh it to obtain a 29.5g Cu-Ag-Gd alloy ingot. Then, according to the mass ratio of Mg metal block to Cu-Ag-Gd alloy ingot of 23.78:76.22, 9.39g of excess Mg metal block (2%) is weighed.

[0111] Place the Mg metal block at the bottom of the quartz tube, then add the Cu-Ag-Gd alloy ingot on top of the Mg metal block, and evacuate the quartz tube to 8×10⁻⁶. -5 After pa, the tube is sealed using a sealing machine. Then, the quartz tube is placed in an induction melting furnace and melted for 90 seconds at a current of 15A. After cooling, Mg-Cu-Ag-Gd alloy ingots are obtained.

[0112] The fourth step is to remove the oxide layer on the surface of the Mg-Cu-Ag-Gd alloy ingot. Take 3g of the Mg-Cu-Ag-Gd alloy ingot and place it in a strip spinning machine. Evacuate the strip spinning machine to a vacuum degree of 5×10⁻⁶. -4 pa, then argon gas is introduced into the belt spinning machine until the vacuum degree is 8×10 4 The Mg-Cu-Ag-Gd amorphous alloy strip was obtained by spinning the strip under the conditions of a current of 14.5A and a copper roller speed of 1800 rpm.

[0113] The fifth step involves cutting the Mg-Cu-Ag-Gd amorphous alloy strip into small segments and immersing them in 0.1 mol / L sulfuric acid for 5 hours to undergo a dealloying treatment, thereby obtaining Cu-Ag amorphous alloy strips.

[0114] Step 6: Clean the Cu-Ag amorphous alloy strip three times with deionized water, then three times with anhydrous ethanol. Dry under vacuum for 1 hour at room temperature. (The process is repeated in the original text.) -4 Under the conditions of 250℃ and annealing for 2 hours, a copper-silver substrate with a three-dimensional nanoporous structure was obtained.

[0115] Step 7: The copper-silver substrate is used as the working electrode and immersed in a 0.5 mol / L KOH electrolyte. A platinum sheet is used as the counter electrode, and Ag / AgCl is used as the reference electrode. A current density of 15 mA / cm² is applied using an electrochemical workstation. 2 Electrochemical oxidation was performed for 300 seconds to obtain samples with small-sized nanograss growing on the surface or inside the pores of a three-dimensional nanoporous structure on a copper-silver substrate.

[0116] Step 8: The sample was washed three times with deionized water and then twice with anhydrous ethanol. After that, it was vacuum dried at room temperature for 1 hour to finally obtain the copper-silver porous and nano-grass array composite material.

[0117] The testing process is the same as in Example 1.

[0118] SEM image of the copper-silver porous composite material with nanograss array prepared in Example 1 of this invention, as shown below. Figure 7 , 8 As shown in the figure, the copper hydroxide nanograss array is distributed on the surface and in the pores of the three-dimensional nanoporous structure. This is because Example 1 (steps 7 and 9) used both electrochemical oxidation and chemical oxidation methods to grow the nanograss array.

[0119] SEM images of the copper-silver porous composite material with nanograss array prepared in Comparative Example 1 are shown below. Figure 9 , 10 As shown in the figure, the copper hydroxide nanograss array is mainly concentrated on the surface of the three-dimensional nanoporous structure, and is not obvious inside the pores. This is because Comparative Example 1 only used the chemical oxidation method in the seventh step, that is, mainly through the chemical reaction in the solution to grow the nanograss array in situ. The size of the obtained nanograss is large and limited by the diameter of the pores, and is mainly distributed on the surface of the three-dimensional nanoporous structure.

[0120] SEM images of the copper-silver porous composite material with nanograss array prepared in Comparative Example 2 are shown below. Figure 11 , 12 As shown in the figure, the copper hydroxide nanograss array exists on the surface and in the pores of the three-dimensional nanoporous structure. However, the nanograss on the surface is relatively sparse. This is because in Comparative Example 2, only the electrochemical oxidation method was used in the seventh step, that is, the growth process of the nanograss was mainly controlled by applying an external voltage. The growth of the nanograss array was carried out in the working electrode, and the resulting nanograss was small in size and could be distributed on the surface and in the pores of the three-dimensional nanoporous structure.

[0121] contrast Figure 13 and 14 Based on the specific surface area calculation results, the specific surface area of ​​the copper-silver porous composite material prepared in Example 1 of this invention is increased by approximately 27% compared to the copper-silver porous composite material prepared in Comparative Example 1. This is because the copper-silver porous composite material prepared in Example 1 of this invention has a relatively abundant nano-grass array growing on the surface and within the pores of its three-dimensional nanoporous structure, which increases its specific surface area.

[0122] Figure 15To vary the glucose concentration during dropwise addition, the oxidation performance of the copper-silver porous composite material with nano-grass array was tested. It should be noted that only a few glucose concentrations are shown in the figures. The smaller figures are magnified views within the 0-200s test range. As can be seen from the figures, the minimum detectable concentration for the catalytic oxidation of glucose by the copper-silver porous composite material with nano-grass array prepared using the method in Example 1 of this application is very low, reaching 100 nmol / L, while the minimum detectable concentration for the catalytic oxidation of glucose by existing non-enzymatic modified sensors is 10 nmol / L. 4 nmo l / L. Because the three-dimensional nanoporous structure of the copper-silver porous and nanograss array composite material of this application has a large pore size, the copper-silver substrate has excellent mass transfer and charge transfer capabilities, good conductivity, and is beneficial for the transport of glucose molecules and electrolyte.

[0123] By performing linear fitting on the current density of glucose at different concentrations, the following results were obtained: Figure 16 The x-axis represents glucose concentration and the y-axis represents current density. The results show that the copper-silver porous and nano-grass array composite material prepared by the method in Example 1 of this application has a relatively high detection range and sensitivity. The detection range is 0 mmol / L-7 mmol / L and the sensitivity is 5.16 mA / mM, where M represents mol / L.

[0124] Figure 17 The test results were obtained by adding organic matter after the current stabilized using the copper-silver porous and nano-grass array composite material prepared in Example 1 of this invention as an electrode. It can be seen that only the addition of glucose to the electrolyte can produce a significant electrical signal, indicating that the copper-silver porous and nano-grass array composite material can only catalyze the oxidation of glucose and has a good anti-interference ability against other organic matter.

[0125] Figure 18 This section compares the electrocatalytic sensitivity of Examples 1, 1, and 2. In Example 1, TSO represents a combination of electrochemical and chemical oxidation; in Example 2, CO represents chemical oxidation; and in Example 3, ECO represents electrochemical oxidation. It can be seen that the copper-silver porous composite material with nano-grass array prepared in Example 1 has an electrocatalytic sensitivity of 5.16 mA / mM for glucose, compared to 3.39 mA / mM in Comparative Example 1 and 3.79 mA / mM in Comparative Example 2. Therefore, the copper-silver porous composite material with nano-grass array prepared in Example 1 of this invention exhibits higher catalytic activity because it has a larger specific surface area and abundant nano-grass arrays, resulting in more catalytic active sites and increased catalytic capacity.

[0126] Example 2

[0127] The first step is to weigh out a total of 30g of Cu metal blocks, Ag metal blocks, and Gd metal blocks according to the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot of 21.5:9.4:7.2, to obtain the alloy precursor.

[0128] The second step involves placing the alloy precursor in an electric arc melting furnace with Ag metal blocks at the bottom, Cu metal blocks in the middle, and Gd metal blocks at the top. The furnace is then evacuated to a vacuum level of 4.5 × 10⁻⁶. -3 Then, argon gas is introduced into the electric arc melting furnace until the vacuum degree is 4.5 × 10⁻⁶. 4 The alloy precursor was repeatedly melted three times at an arc starting current of 210A. After cooling, it was removed to obtain a Cu-Ag-Gd alloy ingot.

[0129] The third step is to remove the oxide layer on the surface of the Cu-Ag-Gd alloy ingot and weigh it to obtain 29.6g of Cu-Ag-Gd alloy ingot. Then, according to the mass ratio of Mg metal block to Cu-Ag-Gd alloy ingot of 24.56:75.33, 9.84g of Mg metal block in excess of 2% is weighed.

[0130] Place the Mg metal block at the bottom of the quartz tube, then add the Cu-Ag-Gd alloy ingot on top of the Mg metal block, and evacuate the quartz tube to a vacuum of 6 × 10⁻⁶. -5 After the initial melting, the tube is sealed using a sealing machine. Then, the quartz tube is placed in an induction melting furnace and melted for 80 seconds at a current of 14A. After cooling, the Mg-Cu-Ag-Gd alloy ingot is obtained.

[0131] The fourth step is to remove the oxide layer on the surface of the Mg-Cu-Ag-Gd alloy ingot. Take 3g of the Mg-Cu-Ag-Gd alloy ingot and place it in a strip spinning machine. Evacuate the strip spinning machine to a vacuum degree of 4.5×10⁻⁶. -4 Then, argon gas is introduced into the belt spinning machine until the vacuum degree is 8.5 × 10⁻⁶. 4 The Mg-Cu-Ag-Gd amorphous alloy strip was obtained by spinning the strip under the conditions of a current of 14A and a copper roller speed of 1900 rpm.

[0132] The fifth step involves cutting the Mg-Cu-Ag-Gd amorphous alloy strip into small segments and immersing them in 0.12 mol / L sulfuric acid for 4.5 hours for dealloying treatment to obtain Cu-Ag amorphous alloy strips.

[0133] Step 6: Clean the Cu-Ag amorphous alloy strip five times with deionized water, then five times with anhydrous ethanol. Dry under vacuum for 2 hours at room temperature. (The process is repeated in the original text.) -4Under the conditions of 230℃ and annealing for 1.5 hours, a copper-silver substrate with a three-dimensional nanoporous structure was obtained.

[0134] Step 7: First, the copper-silver substrate was used as the working electrode and immersed in a 0.45 mol / L KOH electrolyte. A platinum sheet was used as the counter electrode, and Ag / AgCl was used as the reference electrode. A current density of 14 mA / cm² was applied using an electrochemical workstation. 2 Electrochemical oxidation was performed for 350 seconds to obtain samples with small-sized nano-grass growing on the surface or within the pores of a three-dimensional nanoporous structure on a copper-silver substrate.

[0135] Step 8: Wash the sample 5 times with deionized water, then 3 times with anhydrous ethanol. After that, vacuum dry at room temperature for 0.5 hours.

[0136] In the ninth step, the dried sample was immersed in a mixed solution of 0.15 mol / L ammonium persulfate and 1.5 mol / L sodium hydroxide for further chemical oxidation for 80 seconds. Then, it was washed five times with deionized water, three times with anhydrous ethanol, and vacuum dried for 0.5 hours to finally obtain the copper-silver porous composite material with nano-grass array.

[0137] Example 3

[0138] The first step is to weigh out a total of 30g of Cu metal blocks, Ag metal blocks, and Gd metal blocks according to the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot of 22.8:10:7.8, to obtain the alloy precursor.

[0139] The second step involves placing the alloy precursor in an electric arc melting furnace with Ag metal blocks at the bottom, Cu metal blocks in the middle, and Gd metal blocks at the top. The furnace is then evacuated to a vacuum level of 4.8 × 10⁻⁶. -3 Then, argon gas is introduced into the electric arc melting furnace until the vacuum degree is 5.5 × 10⁻⁶. 4 The alloy precursor was repeatedly melted four times at an arc starting current of 230A. After cooling, the alloy was removed to obtain a Cu-Ag-Gd alloy ingot.

[0140] The third step is to remove the oxide layer on the surface of the Cu-Ag-Gd alloy ingot and weigh it to obtain a 29.5g Cu-Ag-Gd alloy ingot. Then, according to the mass ratio of Mg metal block to Cu-Ag-Gd alloy ingot of 28.33:71.69, 12g of excess Mg metal block (3%) is weighed.

[0141] Place the Mg metal block at the bottom of the quartz tube, then add the Cu-Ag-Gd alloy ingot on top of the Mg metal block, and evacuate the quartz tube to 2×10⁻⁶. -4After the initial melting, the tube is sealed using a sealing machine. Then, the quartz tube is placed in an induction melting furnace and melted for 100 seconds at a current of 16A. After cooling, the Mg-Cu-Ag-Gd alloy ingot is obtained.

[0142] The fourth step is to remove the oxide layer on the surface of the Mg-Cu-Ag-Gd alloy ingot. Take 3g of the Mg-Cu-Ag-Gd alloy ingot and place it in a strip spinning machine. Evacuate the strip spinning machine to a vacuum degree of 4.8×10⁻⁶. -4 Then, argon gas is introduced into the belt spinning machine until the vacuum degree reaches 7.5 × 10⁻⁶. 4 The Mg-Cu-Ag-Gd amorphous alloy strip was obtained by spinning the strip under the conditions of a current of 15A and a copper roller speed of 1700 rpm.

[0143] The fifth step involves cutting the Mg-Cu-Ag-Gd amorphous alloy strip into small segments and immersing them in 0.08 mol / L sulfuric acid for 5.5 hours for dealloying treatment to obtain Cu-Ag amorphous alloy strips.

[0144] Step 6: Clean the Cu-Ag amorphous alloy strip four times with deionized water, then four times with anhydrous ethanol. Dry under vacuum for 1.5 hours at room temperature. (The process is repeated in the original text.) -4 Under the conditions of Pa and a temperature of 260℃, an annealing treatment was performed for 2.5 hours to obtain a copper-silver substrate with a three-dimensional nanoporous structure.

[0145] Step 7: First, the copper-silver substrate was used as the working electrode and immersed in a 0.55 mol / L KOH electrolyte. A platinum sheet was used as the counter electrode, and Ag / AgCl was used as the reference electrode. A current density of 16 mA / cm² was applied using an electrochemical workstation. 2 Electrochemical oxidation was performed for 250 seconds to obtain samples with small-sized nanograss growing on the surface or in the pores of a three-dimensional nanoporous structure on a copper-silver substrate.

[0146] Step 8: Wash the sample four times with deionized water, then once with anhydrous ethanol. After that, vacuum dry at room temperature for 2.5 hours.

[0147] In the ninth step, the dried sample was immersed in a mixed solution of 0.25 mol / L ammonium persulfate and 2.5 mol / L sodium hydroxide for further chemical oxidation for 30 seconds. It was then washed four times with deionized water, once with anhydrous ethanol, and vacuum dried for 2.5 hours to finally obtain the copper-silver porous composite material with nano-grass array.

[0148] Example 4

[0149] The first step is to weigh out a total of 30g of Cu metal blocks, Ag metal blocks, and Gd metal blocks according to the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot of 23.58:10.6:8.2, to obtain the alloy precursor.

[0150] The second step involves placing the alloy precursor in an electric arc melting furnace with Ag metal blocks at the bottom, Cu metal blocks in the middle, and Gd metal blocks at the top. The furnace is then evacuated to a vacuum level of 4.8 × 10⁻⁶. -3 Then, argon gas is introduced into the electric arc melting furnace until the vacuum degree is 4.8 × 10⁻⁶. 4 The alloy precursor was repeatedly melted five times at an arc starting current of 225A. After cooling, the alloy was removed to obtain a Cu-Ag-Gd alloy ingot.

[0151] The third step is to remove the oxide layer on the surface of the Cu-Ag-Gd alloy ingot and weigh it to obtain a 29.8g Cu-Ag-Gd alloy ingot. Then, according to the mass ratio of Mg metal block to Cu-Ag-Gd alloy ingot of 27.56:73.25, 11.66g of excess Mg metal block (4%) is weighed.

[0152] A Mg metal block was placed at the bottom of the quartz tube, and then a Cu-Ag-Gd alloy ingot was placed on top of the Mg metal block. The quartz tube was then evacuated to a vacuum level of 1.8 × 10⁻⁶. -4 After the initial melting point (pa), the tube is sealed using a sealing machine. Then, the quartz tube is placed in an induction melting furnace and melted for 95 seconds at a current of 14.5A. After cooling, a Mg-Cu-Ag-Gd alloy ingot is obtained.

[0153] The fourth step is to remove the oxide layer on the surface of the Mg-Cu-Ag-Gd alloy ingot. Take 3g of the Mg-Cu-Ag-Gd alloy ingot and place it in a strip spinning machine. Evacuate the strip spinning machine to a vacuum degree of 4.8×10⁻⁶. -4 Then, argon gas is introduced into the belt spinning machine until the vacuum degree is 7.8 × 10⁻⁶. 4 The Mg-Cu-Ag-Gd amorphous alloy strip was obtained by spinning the strip under the conditions of a current of 15A and a copper roller speed of 1700 rpm.

[0154] The fifth step involves cutting the Mg-Cu-Ag-Gd amorphous alloy strip into small segments and immersing them in 0.09 mol / L sulfuric acid for 5 hours to undergo a dealloying treatment, thereby obtaining Cu-Ag amorphous alloy strips.

[0155] Step 6: Clean the Cu-Ag amorphous alloy strip three times with deionized water, then four times with anhydrous ethanol. Dry under vacuum for 1 hour at room temperature. (The process is repeated in the original text.) -4Under the conditions of Pa and a temperature of 250℃, an annealing treatment was performed for 1.8 hours to obtain a copper-silver substrate with a three-dimensional nanoporous structure.

[0156] Step 7: First, the copper-silver substrate was used as the working electrode and immersed in a 0.53 mol / L KOH electrolyte. A platinum sheet was used as the counter electrode, and Ag / AgCl was used as the reference electrode. A current density of 14.5 mA / cm² was applied using an electrochemical workstation. 2 Electrochemical oxidation was performed for 280 seconds to obtain samples with small-sized nanograss growing on the surface or in the pores of a three-dimensional nanoporous structure on a copper-silver substrate.

[0157] Step 8: Wash the sample 5 times with deionized water, then 2 times with anhydrous ethanol. After that, vacuum dry at room temperature for 1.5 hours.

[0158] In the ninth step, the dried sample was immersed in a mixed solution of 0.2 mol / L ammonium persulfate and 2 mol / L sodium hydroxide for further chemical oxidation for 40 seconds. Then, it was washed five times with deionized water and twice with anhydrous ethanol, followed by vacuum drying for 2.5 hours to finally obtain the copper-silver porous composite material with nano-grass array.

[0159] Example 5

[0160] The first step is to weigh out a total of 30g of Cu metal blocks, Ag metal blocks, and Gd metal blocks according to the atomic ratio of Cu, Ag, and Gd in the Cu-Ag-Gd alloy ingot of 25.86:11:8.5, to obtain the alloy precursor.

[0161] The second step involves placing the alloy precursor in an electric arc melting furnace with Ag metal blocks at the bottom, Cu metal blocks in the middle, and Gd metal blocks at the top. The furnace is then evacuated to a vacuum level of 5 × 10⁻⁶. -3 Then, argon gas is introduced into the electric arc melting furnace until the vacuum degree is 4.5 × 10⁻⁶. 4 The alloy precursor was repeatedly melted four times at an arc starting current of 215A. After cooling, the alloy was removed to obtain a Cu-Ag-Gd alloy ingot.

[0162] The third step is to remove the oxide layer on the surface of the Cu-Ag-Gd alloy ingot and weigh it to obtain a Cu-Ag-Gd alloy ingot of 29.4g. Then, according to the mass ratio of Mg metal block to Cu-Ag-Gd alloy ingot of 25.56:74.82, weigh out 10.55g of Mg metal block with an excess of 5%.

[0163] Place the Mg metal block at the bottom of the quartz tube, then add the Cu-Ag-Gd alloy ingot on top of the Mg metal block, and evacuate the quartz tube to 7×10⁻⁶. -5After the initial melting, the tube is sealed using a sealing machine. Then, the quartz tube is placed in an induction melting furnace and melted for 85 seconds at a current of 14A. After cooling, a Mg-Cu-Ag-Gd alloy ingot is obtained.

[0164] The fourth step is to remove the oxide layer on the surface of the Mg-Cu-Ag-Gd alloy ingot. Take 3g of the Mg-Cu-Ag-Gd alloy ingot and place it in a strip spinning machine. Evacuate the strip spinning machine to a vacuum degree of 5×10⁻⁶. -4 Then, argon gas is introduced into the belt spinning machine until the vacuum degree is 8.5 × 10⁻⁶. 4 The Mg-Cu-Ag-Gd amorphous alloy strip was obtained by spinning the strip under the conditions of a current of 15A and a copper roller speed of 1900 rpm.

[0165] The fifth step involves cutting the Mg-Cu-Ag-Gd amorphous alloy strip into small segments and immersing them in 0.2 mol / L sulfuric acid for 5.5 hours for dealloying treatment to obtain Cu-Ag amorphous alloy strips.

[0166] Step 6: Clean the Cu-Ag amorphous alloy strip five times with deionized water, then three times with anhydrous ethanol. Dry under vacuum for 2 hours at room temperature. (The process is repeated in the original text.) -4 Under the conditions of Pa and a temperature of 240℃, an annealing treatment was performed for 1.6 hours to obtain a copper-silver substrate with a three-dimensional nanoporous structure.

[0167] Step 7: First, the copper-silver substrate was used as the working electrode and immersed in a 0.5 mol / L KOH electrolyte. A platinum sheet was used as the counter electrode, and Ag / AgCl was used as the reference electrode. A current density of 15 mA / cm² was applied using an electrochemical workstation. 2 Electrochemical oxidation was performed for 330 seconds to obtain samples with small-sized nanograss growing on the surface or in the pores of a three-dimensional nanoporous structure on a copper-silver substrate.

[0168] Step 8: Wash the sample four times with deionized water, then three times with anhydrous ethanol. After that, vacuum dry at room temperature for 1.5 hours.

[0169] In the ninth step, the dried sample was immersed in a mixed solution of 0.25 mol / L ammonium persulfate and 2.5 mol / L sodium hydroxide for further chemical oxidation for 90 seconds. Then, it was washed four times with deionized water and twice with anhydrous ethanol, followed by vacuum drying for 2 hours to finally obtain the copper-silver porous composite material with nano-grass array.

[0170] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a copper-silver porous and nanograss array composite material, characterized in that, The preparation method comprises: mixing metals Cu, Ag and Gd, and performing electric arc smelting treatment to obtain a Cu-Ag-Gd alloy ingot; mixing metal Mg with the Cu-Ag-Gd alloy ingot, and performing induction smelting treatment to obtain a Mg-Cu-Ag-Gd alloy ingot; performing ribbon casting treatment on the Mg-Cu-Ag-Gd alloy ingot to obtain a Mg-Cu-Ag-Gd amorphous alloy strip; performing dealloying treatment on the Mg-Cu-Ag-Gd amorphous alloy strip to obtain a Cu-Ag amorphous alloy strip; after cleaning and drying the Cu-Ag amorphous alloy strip, performing annealing treatment to obtain a copper-silver substrate with a three-dimensional nano-porous structure; in-situ growing a cupric hydroxide nano-grass array on the copper-silver substrate to obtain a copper-silver porous and nano-grass array composite material; the cupric hydroxide nano-grass array is in-situ grown on the surface or in the pores of the three-dimensional nano-porous structure.

2. The production method according to claim 1, characterized by, The atomic ratio of Cu, Ag and Gd in the Cu-Ag-Gd alloy ingot is (21.5-26.5):(9.4-11):(7.2-8.5); the mass ratio of the metal Mg to the Cu-Ag-Gd alloy ingot is (23.78-28.33):(71.69-76.22).

3. The preparation method according to claim 1, characterized in that, The specific surface area of the copper-silver porous and nano grass array composite material is 21 m 2 / g-24 m 2 / g; and the pore size of the three-dimensional nano porous structure is 150 nm-200 nm.

4. The method of claim 1, wherein, The cupric hydroxide nano-grass array in the pores of the three-dimensional nano-porous structure has a diameter of 45nm-55nm and a length of 120nm-180nm; the cupric hydroxide nano-grass array on the surface of the three-dimensional nano-porous structure has a diameter of 150nm-250nm and a length of 1500nm-2500nm.

5. The preparation method according to claim 1, characterized in that, The arc melting process is carried out in particular in an inert atmosphere, at a vacuum of 4.5 x 10 4 pa-5.5 x 10 4 pa, at a current of 200 A - 240 A; The induction smelting treatment is specifically performed in an induction smelting furnace, and the current is 14A-16A and the time is 80-100 seconds; Said spinning process is carried out in an inert atmosphere, at a vacuum degree of 7.5 x 10 4 pa-8.5 x 10 4 pa, at a current of 14 A - 15 A, at a copper roller rotation speed of the spinning machine of 1700 rpm - 1900 rpm.

6. The method of claim 1, wherein, The dealloying treatment specifically comprises: immersing the Mg-Cu-Ag-Gd amorphous alloy strip in sulfuric acid to make Mg and Gd in the Mg-Cu-Ag-Gd amorphous alloy strip react with the sulfuric acid and separate from the Mg-Cu-Ag-Gd amorphous alloy strip, so as to obtain the Cu-Ag amorphous alloy strip.

7. The preparation method according to claim 1, characterized in that, The cleaning specifically comprises: cleaning 3-5 times with deionized water and then cleaning 3-5 times with anhydrous ethanol; and the drying specifically comprises: vacuum drying at room temperature for 1-2 hours. The conditions of the annealing treatment are: vacuum degree 1.5 x 10 -4 pa-2.5 x 10 -4 pa, temperature 230°C-260°C, time 1.5-2.5 hours.

8. The method of claim 1, wherein, The in-situ growth of the cupric hydroxide nano-grass array specifically comprises: using the copper-silver substrate as a working electrode, a platinum sheet as a counter electrode, Ag / AgCl as a reference electrode and KOH as an electrolyte, and performing electrochemical oxidation at a certain current density to in-situ grow the cupric hydroxide nano-grass array on part of the copper-silver substrate; immersing the copper-silver substrate in which the cupric hydroxide nano-grass array is in-situ grown in ammonium persulfate and sodium hydroxide solution to continue chemical oxidation, so as to obtain the copper-silver porous and nano-grass array composite material.

9. A copper-silver porous and nanograss array composite material, characterized in that, The copper-silver porous and nano-grass array composite material is prepared by the preparation method in any one of claims 1-8.

10. Use of the copper-silver porous and nanograss array composite material according to claim 9, characterized in that, The copper-silver porous and nano-grass array composite material is applied to a glucose sensor.

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