Two-dimensional copper oxysulfide nanosheet material, preparation method and application

Abstract

The invention discloses a two-dimensional copper oxysulfide nanosheet material, a preparation method and application, and the preparation method comprises the following steps: mixing copper nitrate with deionized water to prepare a solution I; stirring and mixing thiourea and ethanol to prepare a solution II; mixing the solution I and the solution II, centrifuging, pouring into a reaction kettle, and heating to obtain a solution III; the third solution is subjected to centrifugal operation, supernate is extracted, and copper sulfide is prepared; copper sulfide is subjected to calcination treatment; mixing the calcined copper sulfide with ethanol, and performing ultrasonic crushing to obtain a solution IV; and carrying out centrifugal operation on the solution IV to prepare the two-dimensional copper oxysulfide material. Through the steps, the two-dimensional copper oxysulfide material with a large surface area and good normal-temperature gas molecule physical adsorption characteristics is successfully prepared, is suitable for a high-density fork type electrode sensor, and shows strong response sensitivity, rapid recovery, high selectivity and long-term stability to low-concentration hydrogen sulfide.

Description

Technical Field

[0001] The invention relates to the technical field of copper oxysulfide preparation, and in particular to a two-dimensional copper oxysulfide nanosheet material, a preparation method and an application thereof. Background Art

[0002] Hydrogen sulfide is a toxic, corrosive and foul-smelling gas that is widely found in industries such as petroleum refining, natural gas processing, chemical production, and sewage treatment. High concentrations of hydrogen sulfide not only pose a serious threat to human health, but also cause corrosion to equipment and infrastructure, so accurate monitoring of its concentration is particularly important. Currently, most common hydrogen sulfide sensors detect gas based on resistance changes caused by chemical reaction mechanisms, and usually require additional excitation methods, such as increasing the operating temperature of the sensor or irradiating it with light of a specific wavelength. However, this brings additional power consumption and cost to the sensor, and its chemical reaction mechanism also poses great challenges to the life and long-term stability of the sensor.

[0003] Two-dimensional nanomaterials have great potential for enhancing hydrogen sulfide detection when combined with high-density forked electrode sensors due to their unique physical properties. This sensor usually consists of two sets of interlaced tiny comb electrodes to form a high-density forked finger structure, which significantly increases the contact area between the electrode and the two-dimensional nanomaterial. A layer of two-dimensional copper oxysulfide sensitive material is deposited between the forked finger electrodes. When hydrogen sulfide gas molecules are adsorbed onto the surface of copper oxysulfide, the carrier concentration on the surface of the material changes, thereby changing its resistance value. This process is dominated by physical adsorption, making it possible for the sensor to sense at room temperature without an additional excitation source. In order to improve the sensor response sensitivity, recovery, selectivity and long-term stability, it is necessary to optimize the preparation process of the sensitive layer material two-dimensional copper oxysulfide. Summary of the invention

[0004] Therefore, in order to solve the above problems, the object of the present invention is to provide a method for preparing a two-dimensional copper oxysulfide nanosheet material, comprising the following steps:

[0005] S1: Mix copper nitrate and deionized water in a ratio of 1 g: 1000 ml to prepare solution 1;

[0006] S2: Mix thiourea and ethanol in a ratio of 1 g: 100 ml to prepare solution 2;

[0007] S3: After mixing solution 1 and solution 2, pour into a reaction kettle and heat at 140 degrees Celsius for 9-11 hours to obtain solution 3;

[0008] S4: centrifuging solution 3 for 15 minutes, and then extracting the supernatant to obtain supernatant 1;

[0009] S5: mixing the supernatant 1 with deionized water and centrifuging for 15 minutes to obtain copper sulfide;

[0010] S6: calcining the copper sulfide at a set temperature of 400-600 degrees Celsius for 4-6 hours;

[0011] S7: Mix the calcined copper sulfide with ethanol in a ratio of 5 mg:25 ml to prepare solution 4;

[0012] S8: Centrifuging solution 4 for 10 minutes to obtain copper oxysulfide material.

[0013] Preferably, in step S3, the mixture is stirred and mixed at room temperature, with a stirring speed of 100 RPM and a stirring time of 30 minutes.

[0014] Preferably, in step S4, the centrifugal speed is 4000RPM.

[0015] Preferably, in step S5, the centrifugal speed is 10000 RPM.

[0016] Preferably, in step S5, after the first centrifugation operation, the supernatant is extracted to obtain a second supernatant, the second supernatant is mixed with deionized water, and the mixture is centrifuged for 15 minutes to obtain a copper sulfide solution.

[0017] Preferably, in step S6, copper sulfide is calcined in an amount of 45-55 mg.

[0018] Preferably, in step S7, solution 29 is subjected to ultrasonic grinding for 30-35 minutes.

[0019] A two-dimensional copper oxysulfide nanosheet material prepared by the above preparation method.

[0020] An application of the above two-dimensional copper oxysulfide nanosheet material in a high-density fork electrode sensor, wherein the high-density fork electrode sensor is used to detect the concentration of hydrogen sulfide.

[0021] The beneficial effects of the present invention are:

[0022] The two-dimensional copper oxysulfide nanosheet material layer formed by the present invention has a large surface area and good physical adsorption characteristics of gas molecules at room temperature, does not require an additional excitation source, can be applied to high-density fork electrode sensors, and exhibits strong response sensitivity, recovery, selectivity and long-term stability for low-concentration hydrogen sulfide (0.25ppm). BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a transmission electron micrograph of copper oxysulfide;

[0025] Figure 2 This is an atomic force microscope image of copper oxysulfide;

[0026] Figure 3 This is the X-ray transmission photoelectron spectrum of copper oxysulfide Cu2p;

[0027] Figure 4 is the X-ray transmission photoelectron spectrum S2p of copper oxysulfide;

[0028] Figure 5 is the UV-visible absorption spectrum of copper oxysulfide;

[0029] Figure 6 is the energy band gap of copper oxysulfide;

[0030] Figure 7 The sensor responds to low concentrations of 0.25ppm and 0.5ppm of hydrogen sulfide; DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0032] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] Embodiment 1:

[0035] A two-dimensional copper oxysulfide nanosheet material, a preparation method and an application thereof, comprising the following steps:

[0036] Mix copper nitrate and deionized water in a ratio of 1g:1000ml to prepare solution 1;

[0037] Thiourea and ethanol were stirred and mixed at room temperature at a speed of 100 RPM for 30 minutes in a ratio of 1 g: 100 ml to prepare solution 2;

[0038] Solution 1 and solution 2 were mixed and centrifuged at a centrifugal speed of 4000 RPM, poured into a reactor and heated at 140 degrees Celsius for 10 hours to obtain solution 3;

[0039] Solution 3 was centrifuged for 15 minutes, and then the supernatant was extracted to obtain supernatant 1;

[0040] The supernatant 1 was mixed with deionized water, and centrifuged for 15 minutes, and the supernatant was extracted to obtain supernatant 2. The supernatant 2 was mixed with deionized water, and centrifuged for 15 minutes, and the centrifugal speed was set to 10000 RPM to obtain copper sulfide;

[0041] 50 mg of copper sulfide was calcined at a set temperature of 400 degrees Celsius for 4 hours;

[0042] The calcined copper sulfide was mixed with ethanol at a ratio of 5 mg:25 ml to prepare solution 4, and solution 4 was subjected to ultrasonic grinding for 35 minutes;

[0043] Solution 4 was centrifuged for 10 minutes to obtain a two-dimensional copper oxysulfide material.

[0044] Figure 1 This is the result of the projection electron microscope (TEM) image of the two-dimensional copper oxysulfide material finally synthesized. It can be seen from the figure that the synthesized two-dimensional copper oxysulfide material is in the form of translucent nanosheets with an average sheet width of about 50-200nm.

[0045] Figure 2This is a characterization image of the two-dimensional copper oxysulfide material under an atomic force microscope (AFM). It can be seen from the image that the sampled copper oxysulfide material is about 5nm thick and about 200nm wide.

[0046] Figure 3 X-ray transmission photoelectric spectrum XPS analysis was performed on the two-dimensional copper oxysulfide material. From the analysis in the figure, it can be seen that the material shows a characteristic peak of divalent copper (Cu2+) in the copper spectrum (Cu 2p) test results. Figure 4 From the S2p spectrum analysis, it can be seen that the material presents the chemical bond energy of sulfur-oxygen in the sulfur energy spectrum (S2p).

[0047] Figure 5 The ultraviolet absorption spectrum of the two-dimensional copper oxysulfide material obtained by the present invention is shown in FIG. It can be seen from the figure that the copper oxysulfide material exhibits an absorption peak in the visible light band. Figure 6 As shown, further Tauc plot calculation and deduction show that the energy band gap of the material is about 2.4 electron volts. It can be seen that the two-dimensional copper oxysulfide material is a semiconductor material. After contacting with external gas, the surface carrier concentration is easily changed by physical adsorption of specific gases, so it can be used as a medium for gas sensing at room temperature.

[0048] Figure 7 Dynamic gas reaction tests of two-dimensional copper oxysulfide materials on high-density fork-electrode substrates, such as Figure 7 The Y-axis in the figure uses the response factor to express the response degree of the sensor, and its calculation formula is (R H2S –R Air ) / R Air × 100%, where R H2S represents the saturation resistance value when the sensor is exposed to hydrogen sulfide, and R Air It represents the saturated resistance value under pure air. The test environment is at room temperature and one atmosphere. 0.25ppm and 0.5ppm of hydrogen sulfide are injected into the test chamber in sequence, during which the sensor resistance value rises. During the recovery phase, the injection of hydrogen sulfide is stopped and pure air is injected, and the sensor resistance recovers.

[0049] Embodiment 2:

[0050] Mix copper nitrate and deionized water in a ratio of 1g:1000ml to prepare solution 1;

[0051] Thiourea and ethanol were stirred and mixed at room temperature at a speed of 100 RPM for 30 minutes in a ratio of 1 g: 100 ml to prepare solution 2;

[0052] Solution 1 and solution 2 were mixed and centrifuged at a centrifugal speed of 4000 RPM, poured into a reactor and heated at 140 degrees Celsius for 9 hours to obtain solution 3;

[0053] Solution 3 was centrifuged for 15 minutes, and then the supernatant was extracted to obtain supernatant 1;

[0054] The supernatant 1 was mixed with deionized water, and centrifuged for 15 minutes, and the supernatant was extracted to obtain supernatant 2. The supernatant 2 was mixed with deionized water, and centrifuged for 15 minutes, and the centrifugal speed was set to 10000 RPM to obtain copper sulfide;

[0055] 45 mg of copper sulfide was calcined at a set temperature of 500 degrees Celsius for 5 hours;

[0056] The calcined copper sulfide was mixed with ethanol at a ratio of 5 mg:25 ml to prepare solution 4, and solution 4 was subjected to ultrasonic grinding for 30 minutes;

[0057] Solution 4 was centrifuged for 10 minutes to obtain a two-dimensional copper oxysulfide material.

[0058] The properties of the two-dimensional copper oxysulfide material prepared by the above method are similar to those of the two-dimensional copper oxysulfide material prepared in Example 1 in terms of response sensitivity, recovery, and selectivity.

[0059] Embodiment 3:

[0060] Mix copper nitrate and deionized water in a ratio of 1g:1000ml to prepare solution 1;

[0061] Thiourea and ethanol were stirred and mixed at room temperature at a speed of 100 RPM for 30 minutes in a ratio of 1 g: 100 ml to prepare solution 2;

[0062] Solution 1 and solution 2 were mixed and centrifuged at a centrifugal speed of 4000 RPM, poured into a reactor and heated at 140 degrees Celsius for 11 hours to obtain solution 3;

[0063] Solution 3 was centrifuged for 15 minutes, and then the supernatant was extracted to obtain supernatant 1;

[0064] The supernatant 1 was mixed with deionized water, and centrifuged for 15 minutes, and the supernatant was extracted to obtain supernatant 2. The supernatant 2 was mixed with deionized water, and centrifuged for 15 minutes, and the centrifugal speed was set to 10000 RPM to obtain copper sulfide;

[0065] 55 mg of copper sulfide was calcined at a set temperature of 400 degrees Celsius for 6 hours;

[0066] The calcined copper sulfide was mixed with ethanol at a ratio of 5 mg:25 ml to prepare solution 4, and solution 4 was subjected to ultrasonic grinding for 35 minutes;

[0067] Solution 4 was centrifuged for 10 minutes to obtain a two-dimensional copper oxysulfide material.

[0068] The properties of the two-dimensional copper oxysulfide material prepared by the above method are similar to those of the two-dimensional copper oxysulfide material prepared in Example 1 in terms of response sensitivity, recovery, and selectivity.

[0069] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a two-dimensional copper oxysulfide nanosheet material, characterized in that: The following steps are involved: S1: Mix copper nitrate and deionized water in a ratio of 1 g: 1000 ml to prepare solution 1; S2: Mix thiourea and ethanol in a ratio of 1 g: 100 ml to prepare solution 2; S3: After mixing solution 1 and solution 2, pour into a reaction kettle and heat at 140 degrees Celsius for 9-11 hours to obtain solution 3; S4: centrifuging solution 3 for 15 minutes, and then extracting the supernatant to obtain supernatant 1; S5: mixing the supernatant 1 with deionized water and centrifuging for 15 minutes to obtain copper sulfide; S6: calcining the copper sulfide at a set temperature of 400-600 degrees Celsius for 4-6 hours; S7: Mix the calcined copper sulfide with ethanol in a ratio of 5 mg:25 ml to prepare solution 4; S8: Centrifuging solution 4 for 10 minutes to obtain copper oxysulfide material.

2. The method for preparing the two-dimensional copper oxysulfide nanosheet material according to claim 1, characterized in that: In step S3, the mixture is stirred at room temperature with a stirring speed of 100 RPM and a stirring time of 30 minutes.

3. The method for preparing the two-dimensional copper oxysulfide nanosheet material according to claim 1, characterized in that: In step S4, the centrifugal speed is 4000RPM.

4. The method for preparing the two-dimensional copper oxysulfide nanosheet material according to claim 1, characterized in that: In step S5, the centrifugal speed is 10000 RPM.

5. The method for preparing the two-dimensional copper oxysulfide nanosheet material according to claim 1, characterized in that: In step S5, after the first centrifugation operation, the supernatant is extracted to obtain a second supernatant, and the second supernatant is mixed with deionized water and centrifuged for 15 minutes to obtain a copper sulfide solution.

6. The method for preparing the two-dimensional copper oxysulfide nanosheet material according to claim 1, characterized in that: In step S6, copper sulfide is calcined in an amount of 45-55 mg.

7. The method for preparing the two-dimensional copper oxysulfide nanosheet material according to claim 1, characterized in that: In step S7, solution 29 is subjected to ultrasonic grinding for 30-35 minutes.

8. A two-dimensional copper oxysulfide nanosheet material obtained by the preparation method according to any one of claims 1 to 7.

9. Use of the two-dimensional copper oxysulfide nanosheet material according to claim 8 in a high-density fork electrode sensor.

10. The use of the two-dimensional copper oxysulfide nanosheet material in a high-density fork electrode sensor according to claim 9, characterized in that: The high-density forked electrode sensor is used to detect the concentration of hydrogen sulfide.

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