Preparation method and application of gas sensor based on FeSe2 nanowires

Abstract

The invention discloses a preparation method and application of a gas-sensitive sensor based on FeSe2 nanowires, and the preparation method comprises the following steps: adding ferric trichloride hexahydrate into H2O to prepare a solution, adding sodium hydroxide into H2O to prepare a solution, mixing the ferric trichloride solution and the sodium hydroxide solution, then carrying out water bath, respectively filling the pasty solutions into a hydrothermal reaction kettle for hydrothermal reaction, washing with water, and drying to obtain the gas-sensitive sensor based on the FeSe2 nanowires. And alternately washing the obtained product with water and ethanol for three times, and then transferring the product into a vacuum drying oven to be placed, so as to prepare the FeO (OH) nanowire. Se powder and FeO (OH) are put into a closed porcelain boat, and the FeSe2 nanowire is prepared through high-temperature calcination in the H2 / Ar flow atmosphere. According to the present invention, the gas sensitive adsorption capacity is excellent, and the detection temperature and the detection lower limit are excellent.

Description

Technical Field

[0001] The present invention belongs to the field of novel nanomaterials and gas-sensitive sensor technology, and specifically relates to a preparation method and application of a FeSe2 nanowire gas-sensitive sensor. Background Art

[0002] Power transmission and transformation equipment is a key node in the current power system, including enclosed switchgear (GIS) with SF6 / N2 as gas insulation medium, transformers with insulating oil as liquid insulation medium, and high-voltage cables with cross-linked polyethylene (XLPE) as solid insulation medium. However, these devices may fail during actual operation. If these failures cannot be promptly checked, more serious consequences will occur. The discharge or overheating energy generated by the failure will cause the insulating medium to decompose into a variety of gas components, some of which are important parameters for characterizing the safe and stable operation of power transmission and transformation equipment, and are also important references for monitoring its operating status.

[0003] Studies have shown that there is a corresponding relationship between the types of SF6 / N2 decomposition component gases and the operating status and insulation defect characteristics of gas-insulated equipment, as shown in Table 1. By detecting these gases, the types and severity of insulation defects inside SF6 / N2 insulation equipment, equipment operating status, fault information, etc. can be monitored and diagnosed, providing important data for determining the source and cause of equipment insulation defects, reducing the incidence of secondary equipment failures through timely early warning and preventive maintenance, improving the efficiency of electrical equipment operating status assessment, and ensuring that the equipment is safe and reliable. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a gas sensor based on FeSe2 nanowires.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for preparing a FeSe2 nanowire gas sensor, characterized in that: it comprises:

[0008] The hexahydrate ferric chloride solution and the sodium hydroxide solution are mixed and then treated in a water bath to obtain a slurry solution;

[0009] The obtained slurry solution is subjected to a hydrothermal reaction to obtain a product, and then the sample is washed alternately with water and ethanol and then vacuum dried to obtain FeO(OH) nanowires;

[0010] The FeO(OH) nanowires and Se powder were mixed in a closed environment and calcined at high temperature in a H2 / Ar gas atmosphere to obtain FeSe2 nanowires.

[0011] The FeSe2 nanowires are dissolved in an ethylene glycol solution, ultrasonically dispersed at room temperature, coated on interdigital electrodes by silk-screen printing technology, and vacuum-baked to obtain the FeSe2 nanowire gas sensor.

[0012] As a preferred embodiment of the preparation method of the present invention, in the mixture of the hexahydrate ferric chloride solution and the sodium hydroxide solution, the concentration of the hexahydrate ferric chloride solution is 30-50%, and the concentration of the sodium hydroxide solution is 10-30%.

[0013] As a preferred embodiment of the preparation method of the present invention, the mass ratio of the hexahydrate ferric chloride solution to the sodium hydroxide solution is 1:1.

[0014] As a preferred embodiment of the preparation method of the present invention, the hydrothermal reaction temperature is 100.0-120.0°C and the reaction time is 5.0-6.0 days.

[0015] As a preferred embodiment of the preparation method of the present invention, the vacuum drying temperature is 60.0-80.0°C and the drying time is 24.0-30.0h.

[0016] As a preferred embodiment of the preparation method of the present invention, the FeO(OH) nanowires and Se powder are mixed in a closed environment, and calcined at high temperature under inert gas to obtain FeSe2 nanowires, wherein the mass ratio of FeO(OH) nanowires to Se powder is 1:2; and the closed environment is a closed porcelain boat.

[0017] As a preferred embodiment of the preparation method of the present invention, the ultrasonic dispersion time is 45.0 to 50.0 min; the vacuum baking temperature is 60.0 to 80.0° C., and the insulation time is 8.0 to 12.0 h.

[0018] Another object of the present invention is to overcome the deficiencies in the prior art and provide a FeSe2 nanowire gas sensor prepared based on the preparation method of the FeSe2 nanowire gas sensor.

[0019] Another object of the present invention is to overcome the deficiencies in the prior art and provide an application of a FeSe2 nanowire gas sensor in SF6 / N2 decomposition component detection material.

[0020] As a preferred embodiment of the preparation method of the present invention, the SF6 / N2 decomposition component detection is gas-sensitive detection of SO2F2, SO2, and C2H6 under the conditions of a test temperature of 200.0°C and a gas concentration of 200.0 ppm.

[0021] Beneficial effects of the present invention:

[0022] Compared with the existing detection technology, the FeSe2 nanowire gas sensor prepared by the present invention has the following advantages: at 200.0°C, the gas sensitive response ratio to 200.0ppm SO2F2 can reach 2.66, the gas sensitive response ratio to 200.0ppm SO2 can reach 2.9, and the gas sensitive response ratio to 200.0ppm C2H6 can reach 1.4. The prepared FeSe2 nanowire is used for SF6 / N2 decomposition component detection material, which not only shows excellent gas sensitive adsorption ability, but also has excellent detection temperature and detection lower limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative labor. Among them:

[0024] Figure 1 This is the SEM image of FeSe2 nanowires prepared in Example 1 of the present invention.

[0025] Figure 2 This is the SEM image of FeSe2 nanowires prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0029] Unless otherwise specified, all raw materials used in the examples of the present invention are commercially available, as shown in Table 1 for details.

[0030] Table 1

[0031] name Commercial channels Part Number Hexahydrate ferric chloride solution Taobao 7705-08-0 Sodium hydroxide solution Taobao 1310-73-2 Se powder Taobao 7782-49-2 Ethylene glycol solution Taobao 107-21-1

[0032] Example 1

[0033] The present invention provides a method for preparing a FeSe2 nanowire gas sensor:

[0034] (1) Add hexahydrated ferric chloride to H2O to prepare solution 1, and add sodium hydroxide to H2O to prepare solution 2 ， The H2O content is 50.0 ml, the mass of ferric chloride hexahydrate is 27.0 g, and the mass of sodium hydroxide is 10.0 g.

[0035] (2) mixing the solutions 1 and 2 obtained in step (1) in a ratio of 1:1, and subjecting the mixed solution to a water bath treatment at a temperature of 75.0° C. for 30.0 min to obtain a slurry solution;

[0036] (2) respectively charging the above slurry solutions into a hydrothermal reaction kettle, and performing a hydrothermal reaction in the reaction kettle to obtain a product; the temperature is 100.0° C., and the time is 5.0 days;

[0037] (3) The obtained product was washed with water and ethanol alternately three times and then transferred to a vacuum drying oven to prepare FeO(OH) nanowires; the temperature was 60.0°C and the time was 24 hours;

[0038] (4) The obtained FeO(OH) nanowires and Se powder were placed in a sealed porcelain boat at a mass ratio of 1:2, and FeSe2 nanowires were prepared by high-temperature calcination in a H2 / Ar gas atmosphere. The calcination temperature was 500.0°C, the time was 2.0 h, and the heating rate was 20.0°C / min. The morphology was characterized by scanning electron microscopy (SEM). Figure 1 shown), from Figure 1 It is clearly seen that FeSe2 has a nanowire-like structure;

[0039] (5) FeSe2 nanowires were dissolved in ethylene glycol solution and ultrasonically dispersed in an ultrasonic cleaner at room temperature. The solution was then coated on the interdigital electrodes for 45.0 min.

[0040] (6) Place the platinum interdigital electrode coated with FeSe2 nanowires into a vacuum oven and bake it under vacuum conditions until the ethylene glycol is completely volatilized and FeSe2 forms a stable film covering the interdigital electrode sensing area to obtain a FeSe2 nanowire gas sensor. The oven temperature is 60.0°C and the insulation time is 8.0 h.

[0041] Example 2

[0042] The present invention provides a method for preparing a FeSe2 nanowire gas sensor:

[0043] (3) Add hexahydrated ferric chloride to H2O to prepare solution 1, and add sodium hydroxide to H2O to prepare solution 2 ， The H2O content is 60.0 ml, the mass of ferric chloride hexahydrate is 28.0 g, and the mass of sodium hydroxide is 11.0 g.

[0044] (4) mixing the solutions 1 and 2 obtained in step (1) in a ratio of 1:1, and subjecting the mixed solution to a water bath treatment at a temperature of 80.0° C. for 40.0 min to obtain a slurry solution;

[0045] (2) respectively charging the above slurry solutions into a hydrothermal reaction kettle, and subjecting the reaction kettle to a hydrothermal reaction to obtain a product; the temperature is 120.0° C., and the time is 6 days;

[0046] (3) The obtained product was washed with water and ethanol alternately three times and then transferred to a vacuum drying oven to prepare FeO(OH) nanowires; the temperature was 80.0°C and the time was 30 hours;

[0047] (4) The obtained FeO(OH) nanowires and Se powder were placed in a sealed porcelain boat at a mass ratio of 1:2, and FeSe2 nanowires were prepared by high-temperature calcination in a H2 / Ar gas atmosphere. The calcination temperature was 600.0°C, the time was 3.0 h, and the heating rate was 25.0°C / min. The morphology was characterized by scanning electron microscopy (SEM). Figure 2 shown), from Figure 2 The structure of FeSe2 can be clearly seen in the figure;

[0048] (5) FeSe2 nanowires were dissolved in ethylene glycol solution and ultrasonically dispersed in an ultrasonic cleaner at room temperature. The solution was then coated on the interdigital electrodes for 50.0 min.

[0049] (6) Place the platinum interdigital electrode coated with FeSe2 nanowires into a vacuum oven and bake it under vacuum conditions until the ethylene glycol is completely volatilized and FeSe2 forms a stable film covering the interdigital electrode sensing area to obtain a FeSe2 nanowire gas sensor. The oven temperature is 80.0°C and the insulation time is 12 h.

[0050] Example 3

[0051] Gas-sensitive detection of SO2F2, SO2, and C2H6 was performed under the conditions of a test temperature of 200°C and a gas concentration of 200ppm. The sensor terminals were connected to a resistance meter to measure their resistance values. The first measurement was made before the gas was introduced to obtain the initial resistance R0. After 50s of the gas introduction, the second resistance was measured to obtain the reaction resistance R1. Then, pure N2 was introduced. After 350s of pure N2 introduction, the resistance was measured for the third time to obtain the recovery resistance R2.

[0052] The values ​​obtained from the detection are shown in Table 2. The FeSe2 nanowire gas-sensitive material has a strong response to SO2F2, with a response ratio S1 of up to 2.66 and a recovery ratio S2 of up to 1.36, indicating that the gas-sensitive material has good recovery characteristics after detecting SO2F2 and can almost recover to its initial state after the test.

[0053] The FeSe2 nanowire gas-sensitive material has a strong response to SO2, with a response ratio S1 of up to 2.98 and a recovery ratio S2 of up to 1.4, indicating that the gas-sensitive material has good recovery properties after detecting SO2 and can almost recover to its initial state after testing.

[0054] The FeSe2 nanowire gas-sensitive material has a strong response to C2H6, with a response ratio S1 of 1.24 and a recovery ratio S2 of 1.28, indicating that the gas-sensitive material has good recovery characteristics after detecting C2H6 and can almost recover to its initial state after testing.

[0055] Table 2

[0056]

[0057]

[0058] Comparative Example 1

[0059] The difference between this embodiment and embodiment 1 is that the mixed solution is subjected to water bath treatment to obtain a slurry solution, the temperature is 90.0° C., and the time is 40 minutes.

[0060] Comparative Example 2

[0061] The present embodiment is different from the embodiment 1 in that high temperature calcination in H2 / Ar gas atmosphere is not performed, but the reaction kettle is directly subjected to hydrothermal reaction to obtain the product, which is then dried and the process is continued according to step (5).

[0062] Table 3

[0063]

[0064]

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A method for preparing a FeSe2 nanowire gas sensor, characterized in that: include, The hexahydrate ferric chloride solution and the sodium hydroxide solution are mixed and then treated in a water bath to obtain a slurry solution; The obtained slurry solution is subjected to a hydrothermal reaction to obtain a product, and then the sample is washed alternately with water and ethanol and then vacuum dried to obtain FeO(OH) nanowires; The FeO(OH) nanowires and Se powder were mixed in a closed environment and calcined at high temperature in a H2 / Ar gas atmosphere to obtain FeSe2 nanowires. The FeSe2 nanowires are dissolved in an ethylene glycol solution, ultrasonically dispersed at room temperature, coated on interdigital electrodes by silk-screen printing technology, and vacuum-baked to obtain the FeSe2 nanowire gas sensor.

2. The preparation method according to claim 1, characterized in that: In the mixing of the hexahydrate ferric chloride solution and the sodium hydroxide solution, the concentration of the hexahydrate ferric chloride solution is 30-50%, and the concentration of the sodium hydroxide solution is 10-30%.

3. The preparation method according to claim 2, characterized in that: The mass ratio of the hexahydrate ferric chloride solution to the sodium hydroxide solution is 1:

1.

4. The preparation method according to claim 1, characterized in that: The hydrothermal reaction temperature is 100.0-120.0° C. and the reaction time is 5.0-6.0 days.

5. The preparation method according to claim 1, characterized in that: The vacuum drying temperature is 60.0-80.0°C and the time is 24.0-30.0h.

6. The preparation method according to claim 1, characterized in that: The FeO(OH) nanowires and Se powder are mixed in a closed environment and calcined at high temperature under an inert gas to obtain FeSe2 nanowires, wherein the mass ratio of FeO(OH) nanowires to Se powder is 1:2; the closed environment is a closed porcelain boat.

7. The preparation method according to claim 1, characterized in that: The ultrasonic dispersion time is 45.0-50.0 min; the vacuum baking temperature is 60.0-80.0° C., and the heat preservation time is 8.0-12.0 h.

8. The FeSe2 nanowire gas sensor prepared by the preparation method according to claims 1 to 7.

9. Use of the FeSe2 nanowire gas sensor as claimed in claim 8 in SF6 / N2 decomposition component detection materials.

10. The use according to claim 9, characterized in that: The SF6 / N2 decomposition component detection is to test SO2F2, SO2, C under the conditions of test temperature 200.0℃ and gas concentration 200.0ppm. 2H6 Perform gas sensitive testing.

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