Preparation method and application of uniform mesoporous copper oxide material

Abstract

The invention discloses a preparation method and application of mesoporous copper oxide. The preparation method comprises the following steps: S1, preparing a hydroxyl copper nitrate micron plate by taking calcium carbonate paper as a substrate and copper nitrate as a solvent; s2, an ordered copper hydroxide nanowire assembly is synthesized through an alkali liquor reaction; and S3, performing annealing treatment in a muffle furnace to obtain the mesoporous copper oxide micron plate. Under the conditions of no hard template, soft template and strong acid treatment, a mesoporous copper oxide micron plate material with a uniform pore structure is synthesized on carbonic acid paper by adopting copper nitrate hydrolysis, alkali etching and annealing methods, and the mesoporous structure synthesis method has the advantages of simplicity in operation, good controllability and low cost. The invention also relates to application of the mesoporous copper oxide as an electrocatalyst material in the field of glucose electrochemical sensing.

Description

Technical Field

[0001] The invention relates to the technical field of nanomaterials and electrochemical technology, and in particular to a preparation method of a mesoporous transition metal oxide and application thereof. Background Art

[0002] Excessive glucose levels in the human body can cause diabetes and its complications, which in turn can lead to symptoms such as brain hypoxia and myocardial ischemia, making the detection of glucose content crucial for monitoring human health levels. To date, a series of methods for detecting glucose have been developed, including fluorescence, colorimetry, chromatography, surface plasmon resonance, and electrochemical techniques. Among them, electrochemical methods have attracted widespread attention due to their simple operation and fast response speed. Compared with enzyme-based sensors, non-enzymatic electrochemical glucose sensors no longer use enzymes that are sensitive to environmental conditions, but instead use precious metals, transition metal compounds, carbon materials, and conductive polymers as sensing materials. This greatly improves the stability of the sensor and reduces the overall cost.

[0003] Numerous studies have shown that sensing performance and mass transfer capacity can be improved by constructing favorable adsorption sites in electrocatalysts. Among them, porosity engineering has been shown to be particularly effective. Micropores have a large specific surface area, but the small pore size hinders the passage of some macromolecules, which limits the application of micropores. According to the Fick-diffusion empirical formula, macropores significantly improve the mass transfer efficiency, but it is difficult to maintain structural stability during the synthesis of macroporous materials, which may affect their overall performance. In contrast, mesoporous materials are widely used due to their superior molecular diffusivity, adjustable pore size and enhanced structural stability. Common mesoporous structured materials need to be prepared by hard template method or soft template method. Unfortunately, their synthesis involves complex steps to create templates, which usually need to be removed using acidic, alkaline solutions and high temperatures later, which not only leads to increased costs, but also may destroy the pore structure and surface chemical properties of the material. Therefore, it is urgent to develop an economical and simple method to prepare mesoporous metal oxide materials. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for preparing a mesoporous copper oxide material, aiming to provide an effective method with simple process, low cost and no template. The prepared copper oxide has mutually interpenetrating mesoporous channels, connected to form a micron plate with a stable structure, and has excellent electrochemical glucose sensing performance.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for preparing a mesoporous copper oxide material, comprising the following steps:

[0007] S1: Using calcium carbonate paper as the substrate, immersing it in a copper nitrate solution to prepare a hydroxy copper nitrate microplate / calcium carbonate paper;

[0008] S2: soaking the hydroxy copper nitrate microplate-calcium carbonate paper with an alkaline solution to obtain a copper hydroxide nanowire assembly / calcium carbonate paper; before soaking the hydroxy copper nitrate microplate-calcium carbonate paper with an alkaline solution, removing the copper nitrate solution remaining on the surface of the hydroxy copper nitrate microplate-calcium carbonate paper;

[0009] S3: Perform annealing to obtain a mesoporous copper oxide microplate material. As a preferred embodiment,

[0010] Before the annealing treatment, the potassium hydroxide solution remaining on the surface of the ordered copper hydroxide nanowire assembly-calcium carbonate paper is removed; the copper hydroxide nanowire assembly-calcium carbonate paper is treated by ultrasonic method to obtain the copper hydroxide nanowire assembly;

[0011] Furthermore, in the optimized technical solution:

[0012] In the step S1, the concentration of the copper nitrate solution is 0.09-0.26 g / mL. In some specific implementation methods, the solution concentration is 0.09, 0.13, 0.17, 0.21, 0.26 g / mL, or any value therebetween. The soaking time of the calcium carbonate paper in the copper nitrate solution is 4-20 hours. In some specific implementation methods, the soaking time is 4, 8, 12, 16, 20 hours, or any value therebetween.

[0013] In step S2, the alkaline solution is potassium hydroxide or sodium hydroxide, and the concentration of the solution is 0.03-0.08 g / mL. In some specific implementation methods, the concentration of the solution is 0.03, 0.05, 0.07, 0.08 g / mL, or any value therebetween; the immersion time of the hydroxy copper nitrate microplate-calcium carbonate paper in the potassium hydroxide solution is 1-24 hours. In some specific implementation methods, the immersion time is 1, 4, 8, 12, 18, 24 hours, or any value therebetween.

[0014] In the step S3, the ordered copper hydroxide nanowire assembly is separated from the calcium carbonate paper by ultrasound, the ultrasound time is 30 minutes to 3 hours, and then the assembly is collected by centrifugation, the rotation speed is 3000-6000r / min, the centrifugation time is 3-15 minutes, the drying temperature is 40-60°C, and the drying time is 12-24 hours.

[0015] In the step S3, the annealing temperature is 250-500° C., and in some specific implementation methods, the annealing temperature is 250, 300, 350, 400, 450, or 500° C.; the annealing time is 1-4 hours, and in some specific implementation methods, the annealing time is 1, 2, 3, or 4 hours or any value therebetween.

[0016] The core of the present invention is to propose a novel synthesis path for mesoporous copper oxide materials, which does not rely on traditional hard templates, soft templates or strong acid treatment methods, but cleverly utilizes the uniform shrinkage of ordered copper hydroxide nanowires during annealing treatment, thereby forming a uniformly distributed and uniformly sized mesoporous structure in the assembly (microplate) composed of nanowires, and the ordered copper hydroxide nanowires can be prepared by a mild chemical synthesis method using calcium carbonate paper as a substrate.

[0017] The present invention mainly relates to a method for preparing mesoporous copper oxide materials and their application in the field of electrochemical sensing. Specifically, the method is implemented by the following steps:

[0018] S1. Preparation of hydroxy copper nitrate microplate: Calcium carbonate paper is used as the substrate and soaked in a copper nitrate solution to form a hydroxy copper nitrate microplate. This process uses the hydrogen ions produced by the hydrolysis of copper nitrate to react with calcium carbonate. As the reaction proceeds, the hydrolysis of copper nitrate is promoted, thereby synthesizing a hydroxy copper nitrate microplate, which lays the foundation for subsequent reactions.

[0019] S2. Synthesis of ordered copper hydroxide nanowire assemblies: The copper hydroxynitrate microplates were soaked in an alkaline solution to promote the orderly assembly of copper hydroxide nanowires. The key to this step is the concentration of the alkaline solution and the soaking time, which regulates the orderliness of the nanowire assembly and achieves structural transformation.

[0020] S3, annealing treatment: annealing the ordered copper hydroxide nanowire assembly to finally obtain a mesoporous copper oxide material. The annealing process is the key to achieving uniform shrinkage of the nanowires and producing a uniformly distributed and uniformly sized mesoporous structure, which is conducive to exhibiting good electrochemical performance.

[0021] In a second aspect, the present invention provides a mesoporous copper oxide microplate material obtained by the above-mentioned preparation method. In a preferred embodiment, the thickness of the obtained mesoporous copper oxide microplate material is 300-800nm, and the internal pore size is concentrated in 10-20nm. The structure has strong controllability: the mesopore size is uniform, which is conducive to improving the electrochemical reaction rate.

[0022] In the third aspect, the present invention provides an application of the above-mentioned mesoporous copper oxide material in electrochemical sensing, which is used to construct an enzyme-free electrochemical sensor for detecting glucose content. Application example: Glucose electrochemical sensor; High-performance electrocatalyst: Mesoporous copper oxide exhibits excellent glucose redox activity and is suitable for blood glucose monitoring devices. High sensitivity: It shows excellent detection sensitivity in a wide range of glucose concentrations. Stable and durable: Even after multiple cycle tests, it can still maintain a high response speed and stability.

[0023] The mesoporous copper oxide material obtained by the preparation method of the present invention has a promising application value in the field of electrochemical glucose sensing: it is mainly reflected in its performance as an electrocatalyst material. Mesoporous copper oxide can be used to prepare a high-performance enzyme-free glucose sensor. The preparation method of this sensor includes using a mesoporous copper oxide microplate as an electrode material, and analyzing the morphology and structure of the sample by characterization instruments such as a scanning electron microscope, an X-ray diffraction and a nitrogen adsorption-desorption instrument. In practical applications, the mesoporous copper oxide material exhibits good catalytic activity and sensitivity. Studies have shown that the mesoporous copper oxide microplate shows the required linear response for glucose detection in the concentration range of 0.003 to 1.8501mM, and shows a reasonable detection limit of 0.054μM and a high sensitivity of 1499.2μA mM^-1cm^-2 in the alkaline pH range. The mesoporous copper oxide material of the present invention has potential application value in the field of electrochemical glucose sensing, and its performance is mainly further improved by optimizing factors such as pore structure, and these performance improvements are achieved through the preparation method of the present invention.

[0024] In summary, the present invention not only opens up a new way to construct mesoporous structures in copper oxide materials, but also demonstrates its great potential in the field of electrochemical sensing, especially in glucose detection, and is expected to become an important component of future diabetes management tools.

[0025] The advantages and beneficial effects of the present invention are as follows:

[0026] 1. Simple process and low cost: The preparation method adopted by the present invention does not require the use of complex hard templates or soft templates, avoids the extremely high temperature and acid-base treatment steps in the traditional method, and reduces the production cost and operation difficulty.

[0027] 2. Uniform pore structure: The prepared mesoporous copper oxide material has good porosity and uniform pore size (10-20nm), which makes it have excellent molecular diffusion and mass transfer capabilities in electrochemical reactions, facilitates the rapid adsorption of glucose on the active sites on the material surface, and improves the catalytic performance.

[0028] 3. Excellent electrochemical performance: The application of mesoporous copper oxide materials in glucose electrochemical sensors shows good catalytic activity and sensitivity, and can effectively detect glucose in a wide concentration range (0.003 to 1.8501mM), with a sensitivity of 1499.2μA mM^-1cm^-2.

[0029] 4. Environmental friendliness: The preparation process of the present invention avoids the use of chemical reagents that are harmful to the environment, conforms to the concept of sustainable development, and has good environmental friendliness.

[0030] 5. Broad application prospects: In addition to its application in glucose detection, mesoporous copper oxide materials can also be extended to other electrochemical sensing fields, with great market potential and application value.

[0031] In summary, the present invention is not only innovative in technology, but also shows significant advantages in economy and environmental protection, and provides new ideas and methods for the development of electrochemical sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a SEM image of the mesoporous copper oxide microplate material of Example 1 of the present invention;

[0033] Figure 2 This is a TEM image of the mesoporous copper oxide microplate material of Example 1 of the present invention;

[0034] Figure 3 This is a BET diagram of the mesoporous copper oxide microplate material of Example 1 of the present invention;

[0035] Figure 4 This is the XRD pattern of the mesoporous copper oxide microplate material of Example 1 of the present invention;

[0036] Figure 5 The cyclic voltammetry curves of the mesoporous copper oxide microplate obtained in Example 1 modified on the surface of indium tin oxide glass to construct a sensing electrode in response to the oxidation reaction of glucose at different concentrations;

[0037] Figure 6 After the mesoporous copper oxide microplate obtained in Example 1 was modified on the surface of indium tin oxide glass to construct a sensing electrode, the cyclic voltammetry curve of the electrochemical active area was measured in a potassium ferrocyanide solution system;

[0038] Figure 7 The current response curves to glucose at different detection voltages after the mesoporous copper oxide microplate obtained in Example 1 was modified on the surface of indium tin oxide glass to construct a sensing electrode;

[0039] Figure 8After the sensing electrode was constructed by modifying the non-porous copper oxide and the mesoporous copper oxide microplate obtained in Example 1 on the surface of indium tin oxide glass, the current response curve to the addition of glucose and the linear relationship curve between current density and glucose concentration were compared;

[0040] Fig. 9 The effects of various test agents on the glucose oxidation current signal after the mesoporous copper oxide microplate obtained in Example 1 was modified on the surface of indium tin oxide glass to construct a sensing electrode.

[0041] Fig.10 This is a SEM image of the porous copper oxide material of the comparative example of the present invention;

[0042] Fig.11 TEM image of the porous copper oxide material of the comparative example of the present invention;

[0043] Fig.12 This is a BET diagram of the porous copper oxide material of the comparative example of the present invention;

[0044] Fig.13 This is the XRD diagram of the porous copper oxide material of the comparative example of the present invention;

[0045] Fig.14 After the porous copper oxide obtained in the comparative example was modified on the surface of indium tin oxide glass to construct a sensing electrode, the current response curve of dripping glucose and the linear relationship curve of current density-glucose concentration were compared. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation to the present invention.

[0047] Example 1

[0048] 1) Weigh 2.416 g of copper nitrate solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, soak a 2.5 cm×2.5 cm calcium carbonate paper for 6 hours, take it out and rinse its surface with deionized water to remove residual liquid, thereby obtaining a hydroxy copper nitrate microplate / calcium carbonate paper;

[0049] 2) Weigh 1.12 g of potassium hydroxide solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, immerse the hydroxy copper nitrate microplate / calcium carbonate paper prepared in step 1) therein, react for 4 hours, take it out and rinse its surface with deionized water to remove residual liquid, and obtain an ordered copper hydroxide nanowire assembly / calcium carbonate paper;

[0050] 3) placing the ordered copper hydroxide nanowire assembly / calcium carbonate paper obtained in step 2) in deionized water, ultrasonicating for 30 minutes, then centrifuging for 5 minutes at a speed of 5000 r / min, removing the supernatant, and drying in an oven at 50° C. for 12 hours to obtain an ordered copper hydroxide nanowire assembly;

[0051] 4) The ordered copper hydroxide nanowire assembly obtained in step 3) is placed in a porcelain boat, the muffle furnace is set at 350°C, annealed for 2 hours, and mesoporous copper oxide microplate powder is obtained after natural cooling. Scanning electron microscope (SEM) images are shown in FIG. Figure 1 As shown, it shows that the prepared sample has mesoporous pores, and the microplate has not collapsed and the structure is stable; the transmission electron microscope (TEM) picture is as follows Figure 2 As shown, it further shows that the prepared sample is mesoporous; the specific surface area detection (BET) picture is as follows Figure 3 As shown, the average size of the prepared mesoporous sample is 13.48nm, the BET specific surface area is 30.13m^2g^-1, and the pore volume is 0.14m^3g^-1; the X-ray diffraction (XRD) image is shown Figure 4 As shown, it indicates that the prepared sample is pure phase copper oxide crystal.

[0052] Example 2

[0053] 1) Weigh 2.416 g of copper nitrate solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, soak a 2.5 cm×2.5 cm calcium carbonate paper for 4 hours, take it out and rinse its surface with deionized water to remove residual liquid, and obtain a hydroxy copper nitrate microplate / calcium carbonate paper;

[0054] 2) Weigh 1.12 g of potassium hydroxide solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, immerse the hydroxy copper nitrate microplate / calcium carbonate paper prepared in step 1) in the solution, react for 2 hours, take it out and rinse its surface with deionized water to remove residual liquid, and obtain an ordered copper hydroxide nanowire assembly / calcium carbonate paper;

[0055] 3) placing the ordered copper hydroxide nanowire assembly / calcium carbonate paper obtained in step 2) in deionized water, ultrasonicating for 60 minutes, then centrifuging for 3 minutes at a speed of 6000 r / min, removing the supernatant, and drying in an oven at 50° C. for 12 hours to obtain an ordered copper hydroxide nanowire assembly;

[0056] 4) placing the ordered copper hydroxide nanowire assembly obtained in step 3) in a porcelain boat, setting the muffle furnace at 350° C., annealing for 1 h, and obtaining mesoporous copper oxide microplate powder after natural cooling.

[0057] Example 3

[0058] 1) Weigh 3.866 g of copper nitrate solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, soak a 2.5 cm×2.5 cm calcium carbonate paper for 6 hours, take it out and rinse its surface with deionized water to remove residual liquid, and obtain a hydroxy copper nitrate microplate / calcium carbonate paper;

[0059] 2) Weigh 1.12 g of potassium hydroxide solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, immerse the hydroxy copper nitrate microplate / calcium carbonate paper prepared in step 1) therein, react for 4 hours, take it out and rinse its surface with deionized water to remove residual liquid, and obtain an ordered copper hydroxide nanowire assembly / calcium carbonate paper;

[0060] 3) placing the ordered copper hydroxide nanowire assembly / calcium carbonate paper obtained in step 2) in deionized water, ultrasonicating for 30 minutes, and then centrifuging for 5 minutes at a speed of 5000 r / min, removing the supernatant, and drying in an oven at 50° C. for 18 hours to obtain an ordered copper hydroxide nanowire assembly;

[0061] 4) placing the ordered copper hydroxide nanowire assembly obtained in step 3) in a porcelain boat, setting the muffle furnace at 400° C., annealing for 2 h, and obtaining mesoporous copper oxide microplate powder after natural cooling.

[0062] Example 4

[0063] 1) Weigh 4.832 g of copper nitrate solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, soak a 2.5 cm×2.5 cm calcium carbonate paper for 12 hours, take it out and rinse its surface with deionized water to remove residual liquid, thereby obtaining a hydroxy copper nitrate microplate / calcium carbonate paper;

[0064] 2) Weigh 1.344 g of potassium hydroxide solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, immerse the hydroxy copper nitrate microplate / calcium carbonate paper prepared in step 1) in the solution, react for 6 hours, take it out and rinse its surface with deionized water to remove residual liquid, and obtain an ordered copper hydroxide nanowire assembly / calcium carbonate paper;

[0065] 3) placing the ordered copper hydroxide nanowire assembly / calcium carbonate paper obtained in step 2) in deionized water, ultrasonicating for 60 minutes, and then centrifuging for 10 minutes at a speed of 5000 r / min, removing the supernatant, and drying in an oven at 50° C. for 15 hours to obtain an ordered copper hydroxide nanowire assembly;

[0066] 4) placing the ordered copper hydroxide nanowire assembly obtained in step 3) in a porcelain boat, setting the muffle furnace at 500° C., annealing for 2 h, and obtaining mesoporous copper oxide powder after natural cooling.

[0067] Test Case

[0068] The mesoporous copper oxide material obtained in Example 1 was used as an electrocatalyst for the electrochemical oxidation reaction of glucose. 3 mg of copper oxide material was weighed on an analytical balance, 500 μL of ultrapure water, 400 μL of ethanol solution and 100 μL of 0.5 wt% nafion solution were added, and the mixed solution was placed in an ultrasonic machine for 1 hour until the electrocatalyst in the solution was evenly dispersed without agglomeration. Before using the drop coating method to prepare the sensing electrode, the indium tin oxide conductive glass was placed in acetone, ethanol, and deionized water for 5 minutes, and then the nitrogen was taken out and blown dry. 10 μL of the above sample solution was dropped onto the treated conductive surface of the indium tin oxide glass to obtain an electrode film of uniform thickness. During the entire electrochemical test process, the mesoporous copper oxide / indium tin oxide glass was the working electrode, silver / silver chloride was the reference electrode, the platinum wire was the auxiliary electrode, and the 0.1M sodium hydroxide solution was the electrolyte.

[0069] The cyclic method (CV) test selected a voltage test interval of 0-0.8V and was tested at a scan rate of 50mV / s in a sodium hydroxide solution containing 0-2M glucose. The data are summarized in Figure 5 ,The results show that mesoporous copper oxide can be used for the electrocatalytic oxidation of glucose, and as the glucose concentration increases, the peak current of glucose oxidation increases, indicating its good catalytic activity;

[0070] The CV test was conducted in a voltage range of 0-0.8 V in a 0.1 M potassium chloride solution containing 5 mM potassium ferrocyanide / potassium ferrocyanide at a scan rate of 10-140 mV / s. The results are summarized in Figure 6 By fitting the linear relationship between the scan rate and the redox peak current, the electrochemical area of ​​the sensing electrode was calculated to be 0.4313 cm 2 , which is much higher than the drop coating area of ​​0.1256cm on the surface of ITO glass. 2 ;

[0071] Using the time-current test technique, the electrocatalytic oxidation reaction of glucose was carried out at a voltage of 0.40V to 0.60V vs. Ag|AgCl. The data are summarized in Figure 7 ,The results show that as the detection voltage increases, the oxidation current response of glucose increases, and when the detection voltage reaches 0.5V and 0.55V, the current response is not much different, so 0.55V is preferred for performance testing;

[0072] Using the time-current test technology, at 0.55Vvs.Ag|AgCl, different concentrations of glucose solution were added dropwise to obtain the time-current step curve and the concentration-current density linear relationship line ( Figure 8), the results showed that the sensitivity of the glucose electrochemical sensor constructed with mesoporous copper oxide reached 1499.2μA mM^-1cm^-2, and the linear range was 0.003 to 1.8501mM.

[0073] Using the time-current test technology, at 0.55Vvs.Ag|AgCl, 0.5mM glucose, 0.05mM potassium chloride, 0.05mM lactic acid, 0.05mM uric acid, 0.05mM ascorbic acid, 0.05mM fructose, 0.05mM acetaminophen, 0.05mM cysteine, 0.05mM dopamine, and 0.5mM glucose were added to the test solution. Fig. 9 The detection results show that the sensor has excellent selectivity.

[0074] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

[0075] Comparative Example

[0076] 1) Weigh 2.416 g of copper nitrate solid, dissolve it in 20 mL of ultrapure water to prepare a copper nitrate solution, soak a 2.5 cm×2.5 cm calcium carbonate paper for 6 hours, take it out and rinse its surface with deionized water to remove residual liquid, thereby obtaining a hydroxy copper nitrate microplate / calcium carbonate paper;

[0077] 2) placing the ordered copper hydroxide nanowire assembly / calcium carbonate paper obtained in step 1) in deionized water, ultrasonicating for 60 minutes, and then centrifuging for 10 minutes at a speed of 5000 r / min, removing the supernatant, and drying in an oven at 50° C. for 15 hours to obtain copper hydroxynitrate microplate powder;

[0078] 3) The hydroxy copper nitrate microplate powder obtained in step 2) is placed in a porcelain boat, the muffle furnace is set at 350°C, annealed for 2 hours, and porous copper oxide powder is obtained after natural cooling. Scanning electron microscope (SEM) images are shown in FIG. Fig.10 As shown in Figure 2, it indicates that the surface of the prepared sample does not generate a uniform mesoporous structure; the transmission electron microscopy (TEM) image is shown in Figure 2 Fig.11 As shown, it further shows that the surface of the prepared sample has only a small amount of pore structure; the specific surface area detection (BET) picture is shown Fig.12 As shown in the figure, the pore sizes of the prepared copper oxide sample are mainly concentrated at 1.8nm, 3.83nm and 11.7nm, with mesopores and micropores. The BET specific surface area is 2.98m^2g^-1 and the pore volume is 0.01m^3g^-1; the X-ray diffraction (XRD) image is shown in the figure Fig.13 As shown, it indicates that the prepared sample is a pure phase copper oxide crystal;

[0079] 4) The porous copper oxide material obtained in the comparative example is used as an electrocatalyst for the electrochemical oxidation reaction of glucose. Weigh 3 mg of copper oxide material on an analytical balance, add 500 μL of ultrapure water, 400 μL of ethanol solution and 100 μL of 0.5wt% nafion solution, and place the mixed solution in an ultrasonic machine for 1 hour until the electrocatalyst in the solution is evenly dispersed without agglomeration. Take 10 μL of the above sample solution and drop it on the treated indium tin oxide glass conductive surface to obtain an electrode film of uniform thickness as a comparison electrode. Using the time-current test technology, at 0.55 V vs. Ag|AgCl, glucose solutions of different concentrations were added to obtain a time-current step curve and a concentration-current density linear relationship line ( Fig.14 ), the results showed that the sensitivity of the comparison electrode was only 281.7μA mM^-1cm^-2, and the linear range was 0.0030~0.5108mM, which fully demonstrated that the mesoporous structure with uniform pore distribution and uniform pore size is crucial to improving its sensing performance in the process of glucose electrochemical sensing.

Claims

1. A method for preparing a mesoporous copper oxide material, characterized in that: The steps include: S1: Using calcium carbonate paper as the substrate, immersing it in a copper nitrate solution to prepare a hydroxy copper nitrate microplate-calcium carbonate paper; S2: soaking the copper hydroxynitrate microplate-calcium carbonate paper in an alkaline solution to obtain an ordered copper hydroxide nanowire assembly / calcium carbonate paper; S3: performing annealing treatment to obtain a mesoporous copper oxide microplate material.

2. The preparation method according to claim 1, characterized in that: in, In step S2, before soaking the copper nitrate hydroxyl nitrate microplate / calcium carbonate paper in an alkaline solution, the copper nitrate solution remaining on the surface of the copper nitrate hydroxyl nitrate microplate / calcium carbonate paper is removed.

3. The preparation method according to claim 2, characterized in that: in, In step S3, before the annealing treatment, the potassium hydroxide solution remaining on the surface of the ordered copper hydroxide nanowire assembly-calcium carbonate paper is removed; The ordered copper hydroxide nanowire assembly / calcium carbonate paper is treated by ultrasonic method to obtain the copper hydroxide nanowire assembly.

4. The preparation method according to claim 3, characterized in that: In the step S1, the concentration of the copper nitrate solution is 0.09-0.26 g / mL; and the soaking time of the calcium carbonate paper in the copper nitrate solution is 4-20 hours.

5. The preparation method according to claim 4, characterized in that: In the step S2, the alkaline solution is a potassium hydroxide solution or a sodium hydroxide solution, and the concentration of the solution is 0.03-0.08 g / mL; the soaking time of the hydroxy copper nitrate microplate / calcium carbonate paper in the alkaline solution is 1-24 hours.

6. The preparation method according to claim 5, characterized in that: In the step S3, when the ordered copper hydroxide nanowire assembly / calcium carbonate paper is treated by ultrasonic method, the solvent is deionized water, the ultrasonic time is 30 minutes to 3 hours, and then the assembly is collected by centrifugation at a speed of 3000-6000 r / min and a centrifugal time of 3-15 minutes, and then dried at 40-60° C. for 12-24 hours.

7. The preparation method according to claim 6, characterized in that: In the step S3, the annealing temperature is 250-500° C., and the annealing time is 1-4 hours.

8. A mesoporous copper oxide microplate material obtained by the preparation method according to any one of claims 1 to 7.

9. The mesoporous copper oxide material according to claim 8, characterized in that: The thickness of the mesoporous copper oxide microplate material is 300-800 nm, and the pore size is concentrated in 10-20 nm.

10. An application of the mesoporous copper oxide material according to claim 8 or 9 in electrochemical sensing, characterized in that: Used to construct an enzyme-free electrochemical sensor to detect glucose content.

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