Cu3 (HHTP) 2-WO3.H2O gas-sensitive sensing material as well as preparation method and application thereof

Abstract

The invention discloses a Cu3 (HHTP) 2-WO3.H2O gas-sensitive sensing material as well as a preparation method and an application of the Cu3 (HHTP) 2-WO3.H2O gas-sensitive sensing material. The gas-sensitive sensing material is composed of WO3.H2O and a metal organic framework material dispersed on the surface of the WO3.H2O, wherein the metal organic framework material is Cu3 (HHTP) 2. The invention also discloses a preparation method of the Cu3 (HHTP) < 2 >-WO3.H2O gas sensitive sensing material. The Cu3 (HHTP) 2-WO3.H2O gas-sensitive sensing material disclosed by the invention can be used for sensing a mustard gas simulation agent 2-chlorodiethyl sulfide (2-CEES) at normal temperature, and has good response recovery, stability, high response and selectivity.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor metal oxide-organic two-dimensional material heterojunction preparation, and more specifically, to a Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material and a preparation method and application thereof. Background Art

[0002] Chemical agents are a class of highly toxic compounds that can cause mass casualties to humans and animals, and are the main components of military chemical weapons. Mustard gas is a typical corrosive agent, which can cause severe blisters through skin contact, damage the eyes and respiratory tract, and even cause death. Since its large-scale use in World War I, mustard gas has not only caused a large number of casualties, with its mortality rate accounting for more than 80% of the total number of casualties caused by poisonous agents, and has the title of "King of Poison Gas", but also has a profound impact on human health and the ecological environment. In order to achieve rapid and effective early warning of chemical agent threats, chemical agent gas sensing technology is one of the key technologies for building a real-time, distributed chemical threat sensing network.

[0003] Among the many types of sensor devices, chemical impedance sensing is the most commonly used type of device. It has the advantages of simple structure, compatibility with traditional DC circuits, low cost, predictable chemical properties and easy high-precision measurement, making it very suitable for studying the chemical sensing properties of materials. At present, the resistive sensing of mustard gas simulants is mainly based on semiconductor metal oxide gas-sensitive materials such as ZnO and WO3, but it has disadvantages such as high operating temperature (generally at least above 200°C), poor selectivity and long response time.

[0004] Therefore, it is necessary to provide a Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material to solve the problem of room temperature and high selectivity detection of mustard gas and its simulants. Summary of the invention

[0005] The first object of the present invention is to provide a Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material. The Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material of the present invention can sense 2-chlorodiethyl sulfide (2-CEES) at room temperature and has good response recovery, stability, high response and selectivity.

[0006] The second object of the present invention is to provide a method for preparing Cu3(HHTP)2-WO3·H2O gas sensitive sensing material.

[0007] The third object of the present invention is to provide a Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material for use in preparing a mustard gas simulant, in particular a 2-chlorodiethyl sulfide (2-CEES) gas sensor.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material, wherein the gas-sensitive sensing material is composed of WO3·H2O and a metal organic framework material dispersed on the surface thereof, wherein the metal organic framework material is Cu3(HHTP)2.

[0010] WO3·H2O itself has a response to 2-CEES, but the response temperature is relatively high. By compounding the two-dimensional metal-organic framework material (MOF, Metal-Organic Framework) Cu3(HHTP)2 to form a heterojunction, its sensing performance is improved, and the sensing of 2-CEES at room temperature is realized. On the one hand, MOF Cu3(HHTP)2 is a porous material, which is conducive to the adsorption of 2-CEES gas; on the other hand, a heterojunction with good contact is formed between the P-type semiconductor Cu3(HHTP)2 and the N-type semiconductor WO3·H2O. There will be charge transfer from 2-CEES to Cu3(HHTP)2 on the surface of Cu3(HHTP)2, which changes the width of the Cu3(HHTP)2-WO3·H2O heterojunction depletion layer, thereby changing the resistance and showing a response to gas; in addition, MOF Cu3(HHTP)2 has good conductivity, which can further improve the gas-sensitive sensing response.

[0011] Furthermore, in the gas-sensitive sensing material, WO3·H2O is an orthorhombic crystal structure, and Cu3(HHTP)2 is a two-dimensional layered structure of a hexagonal crystal phase.

[0012] In a second aspect, the present invention provides a method for preparing a Cu3(HHTP)2-WO3·H2O gas sensitive sensor material, the preparation method comprising the following steps:

[0013] S1. Preparation of WO3·H2O

[0014] Take Na2WO4·2H2O and dissolve it in distilled water, add hydrochloric acid, stir for a certain period of time to obtain a mixed solution; transfer the mixed solution to an oven for heating, cool it naturally to room temperature after the reaction is completed, centrifuge the solution, wash the obtained solid with distilled water, and dry it to obtain WO3·H2O.

[0015] S2. Preparation of Cu3(HHTP)2-WO3·H2O gas sensitive sensing material

[0016] The WO3·H2O obtained in step S1 is dispersed in distilled water and ultrasonically dispersed to obtain a WO3·H2O suspension; CuSO4·5H2O and hexahydroxytriphenylbenzene (HHTP) are added to distilled water, ultrasonically dispersed to make them uniform, and then added to the dispersed WO3·H2O suspension and sealed, heated in an oil bath under magnetic stirring conditions, cooled naturally to room temperature after the reaction is completed, centrifuged to remove the supernatant, washed with distilled water and ethanol, and then dried to obtain the Cu3(HHTP)2-WO3·H2O gas sensitive sensing material.

[0017] Furthermore, in step S1, the stirring time is 5-15 min; the reaction temperature is 30-50° C., and the reaction time is 24-96 h.

[0018] Furthermore, in step S1, washing with distilled water is performed at least 3 times, and vacuum drying is performed at 80° C. for 6-18 hours to obtain WO3·H2O.

[0019] Furthermore, in step S2, the ultrasonic dispersion time of WO3·H2O is 30-40 min.

[0020] Further, in step S2, the molar ratio of CuSO4·5H2O to HHTP is 3:2; the ultrasonic dispersion time is 5-15 min;

[0021] Furthermore, the oil bath heating temperature is 60-80°C and the heating time is 12-36h.

[0022] Furthermore, in step S2, the material is washed with distilled water and ethanol at least three times respectively, and vacuum dried at 40°C for 6-18 hours to obtain the Cu3(HHTP)2-WO3·H2O gas sensitive sensing material.

[0023] In a third aspect, the present invention provides a use of the above-mentioned Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material in the preparation of a mustard gas simulant gas sensor.

[0024] Furthermore, the mustard gas simulant is 2-chlorodiethyl sulfide (2-CEES).

[0025] Furthermore, the application is to drop-coat the Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material onto a SiO2 / Si substrate deposited with gold interdigital electrodes to obtain a mustard gas simulant 2-chlorodiethyl sulfide gas sensor.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. The present invention prepares a MOF-modified WO3·H2O sensing material, prepares WO3·H2O under organic solvent-free conditions, reacts the obtained WO3·H2O with hexahydroxytriphenylenebenzene and CuSO4·5H2O under hydrothermal conditions, and finally obtains a Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material through vacuum drying. The preparation method has few steps, simple operation, and is green and pollution-free.

[0028] 2. The Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material prepared by the present invention has the following structural characteristics: the synthesized WO3·H2O has an orthorhombic phase crystal structure, and the Cu3(HHTP)2 has a hexagonal two-dimensional layered structure. The heterojunction formed by the two can realize gas-sensitive response to 2-CEES.

[0029] 3. The Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material prepared by the present invention can sense 2-CEES at room temperature and has good response recovery, stability, high response and selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0031] Figure 1 Schematic diagram of the chemical structure of the supported 2D MOF Cu3(HHTP)2.

[0032] Figure 2 The SEM images of the prepared WO3·H2O and the 1% Cu3(HHTP)2-WO3·H2O gas-sensitive material in Example 1 are shown.

[0033] Figure 3 This is the TEM image of 1% Cu3(HHTP)2-WO3·H2O gas sensitive material.

[0034] Figure 4 This is a diagram showing the gas-sensitive response effect of 1% Cu3(HHTP)2-WO3·H2O gas sensor to 2-CEES.

[0035] Figure 5 This is the gas sensitivity test result of 1% Cu3(HHTP)2-WO3·H2O gas sensor to 2-CEES at room temperature.

[0036] Figure 6 This is the stability test result diagram of 1%Cu3(HHTP)2-WO3·H2O gas sensor.

[0037] Figure 7This is the selectivity test result of 1%Cu3(HHTP)2-WO3·H2O gas sensor for 20ppm different target gases (ethanol, DMMP, 2-CEES, acetone, acetonitrile, dichloromethane) at room temperature.

[0038] Figure 8 This is the X-ray diffraction pattern of the prepared WO3·H2O and 1%Cu3(HHTP)2-WO3·H2O and 3%Cu3(HHTP)2-WO3·H2O composite materials.

[0039] Fig. 9 These are the test results of the response performance of 2%-5% Cu3(HHTP)2-WO3·H2O composite materials to 2-CEES. DETAILED DESCRIPTION

[0040] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0041] Example 1

[0042] A 1% Cu3(HHTP)2-WO3·H2O (1% is the mass ratio of Cu3(HHTP)2 to WO3·H2O, wherein the mass of Cu3(HHTP)2 is calculated by the mass of CuSO4·5H2O and HHTP added during preparation, and the mass of WO3·H2O is the mass used in step S2) composite material is prepared and a 2-CEES gas sensor is made. The specific process is as follows:

[0043] Take 2.97g Na2WO4·2H2O and dissolve it in 20ml distilled water, then add 30ml 2M hydrochloric acid dropwise, and after further stirring for 5min, transfer the mixed solution to an oven and react at 40℃ for 72h, then cool naturally to room temperature, centrifuge the solution, wash the obtained solid with distilled water 3 times, and vacuum dry at 80℃ for 12h to obtain WO3·H2O.

[0044] Take 233 mg WO3·H2O and add it to 5 ml distilled water, and ultrasonicate for 30 minutes to fully disperse the WO3·H2O; disperse 4.1 mg CuSO4·5H2O and 2.3 mg HHTP in 7.2 mL distilled water, ultrasonicate for 5-10 minutes, and then add them to the dispersed WO3·H2O suspension and seal it. Heat it to 80°C in an oil bath under magnetic stirring conditions for 24 hours, then cool it naturally to room temperature, remove the supernatant by centrifugation, wash it with distilled water and ethanol for 3 times respectively, and vacuum dry it at 40°C for 12 hours to obtain a 1% Cu3(HHTP)2-WO3·H2O composite material.

[0045] Figure 1 Schematic diagram of the chemical structure of the supported 2D MOF Cu3(HHTP)2, composed of Cu 2+ It forms a two-dimensional porous structure through coordination with HHTP.

[0046] Figure 2 The SEM images of the prepared WO3·H2O and the 1% Cu3(HHTP)2-WO3·H2O gas-sensitive material in Example 1, wherein the WO3·H2O has a uniform morphology and a lateral size of about 500nm-1um.

[0047] Figure 3 This is the TEM image of 1% Cu3(HHTP)2-WO3·H2O gas-sensitive material. The morphology of WO3·H2O is similar to the SEM image. High-resolution TEM shows the lattice fringe structure of WO3·H2O and Cu3(HHTP)2.

[0048] Example 2

[0049] Preparation of 2% Cu3(HHTP)2-WO3·H2O composite material and fabrication of 2-CEES gas sensor, the specific process is as follows:

[0050] Take 233 mg of WO3·H2O prepared in Example 1 and add it to 5 ml of distilled water, and ultrasonicate for 30 min to fully disperse the WO3·H2O; disperse 8.2 mg CuSO4·5H2O and 4.6 mg HHTP in 7.2 mL of distilled water, ultrasonicate for 5 min, and then add them to the dispersed WO3·H2O suspension and seal it. Heat it to 80°C in an oil bath under magnetic stirring conditions for 24 h, then cool it naturally to room temperature, remove the supernatant by centrifugation, wash it with distilled water and ethanol for 3 times, and vacuum dry it at 40°C for 12 h to obtain a 2% Cu3(HHTP)2-WO3·H2O composite material.

[0051] Example 3

[0052] Preparation of 3% Cu3(HHTP)2-WO3·H2O composite material and fabrication of 2-CEES gas sensor, the specific process is as follows:

[0053] Take 233 mg of WO3·H2O prepared in Example 1 and add it to 5 ml of distilled water, and ultrasonicate for 30 min to fully disperse the WO3·H2O; disperse 12.3 mg of CuSO4·5H2O and 6.9 mg of HHTP in 7.2 mL of distilled water, ultrasonicate for 5 min, and then add them to the dispersed WO3·H2O suspension and seal it. Heat it to 80°C in an oil bath under magnetic stirring conditions and react for 24 h. Then cool it naturally to room temperature, remove the supernatant by centrifugation, wash it with distilled water and ethanol for 3 times, and vacuum dry it at 40°C for 12 h to obtain a 3% Cu3(HHTP)2-WO3·H2O composite material.

[0054] Example 4

[0055] Preparation of 4% Cu3(HHTP)2-WO3·H2O composite material and fabrication of 2-CEES gas sensor, the specific process is as follows:

[0056] Take 233 mg of WO3·H2O prepared in Example 1 and add it to 5 ml of distilled water, and ultrasonicate for 30 min to fully disperse the WO3·H2O; disperse 16.4 mg CuSO4·5H2O and 9.2 mg HHTP in 7.2 mL of distilled water, ultrasonicate for 5 min, and then add them to the dispersed WO3·H2O suspension and seal it. Heat it to 80°C in an oil bath under magnetic stirring for 24 h, then cool it naturally to room temperature, remove the supernatant by centrifugation, wash it with distilled water and ethanol for 3 times, and vacuum dry it at 40°C for 12 h to obtain a 4% Cu3(HHTP)2-WO3·H2O composite material.

[0057] Example 5

[0058] Preparation of 5% Cu3(HHTP)2-WO3·H2O composite material and fabrication of 2-CEES gas sensor, the specific process is as follows:

[0059] Take 233 mg of WO3·H2O prepared in Example 1 and add it to 5 ml of distilled water, and ultrasonicate for 30 min to fully disperse the WO3·H2O; disperse 20.5 mg CuSO4·5H2O and 11.7 mg HHTP in 7.2 mL of distilled water, ultrasonicate for 5 min, and then add them to the dispersed WO3·H2O suspension and seal it. Heat it to 80°C in an oil bath under magnetic stirring conditions for 24 h, then cool it naturally to room temperature, remove the supernatant by centrifugation, wash it with distilled water and ethanol for 3 times, and vacuum dry it at 40°C for 12 h to obtain a 5% Cu3(HHTP)2-WO3·H2O composite material.

[0060] Application Example 1

[0061] Take 10 mg of the prepared 1% Cu3(HHTP)2-WO3·H2O composite material, add it to 5 mL of ethanol for ultrasonic dispersion, and evenly drop it on a SiO2 / Si substrate deposited with gold interdigital electrodes. After the ethanol evaporates, a gas sensor with 1% Cu3(HHTP)2-WO3·H2O as the gas sensitive sensing material is obtained.

[0062] The response value, detection line, response time and selectivity of Cu3(HHTP)2-WO3·H2O gas sensor to 2-CEES were tested at room temperature.

[0063] The gas-sensitive response test results of 1% Cu3(HHTP)2-WO3·H2O gas sensor to 2-CEES are shown in Figure 4 As shown, under room temperature conditions, the 1% Cu3(HHTP)2-WO3·H2O gas sensor has a faster response recovery time to 20ppm concentration of 2-CEES, which are 2.48min and 10.83min respectively, and the response value is 9.6%.

[0064] The gas sensitivity test results of 1% Cu3(HHTP)2-WO3·H2O gas sensor to different concentrations of 2-CEES at room temperature are as follows Figure 5 As shown, the 1% Cu3(HHTP)2-WO3·H2O based gas sensor has a good linear relationship with 0.129 14.81ppm 2-CEES. The lowest practical detection limit of 1% Cu3(HHTP)2-WO3·H2O at room temperature is 129ppb, and the response value is 1.4%.

[0065] The stability test of 1% Cu3(HHTP)2-WO3·H2O gas sensor was carried out. Figure 6 It can be seen that the sensor still has high sensing performance after being placed in the air for 30 days, indicating that the prepared Cu3(HHTP)2-WO3·H2O gas sensor has good stability.

[0066] The selectivity test of 1% Cu3(HHTP)2-WO3·H2O gas sensor for 20ppm different target gases (ethanol, DMMP, 2-CEES, acetone, acetonitrile, dichloromethane) at room temperature is as follows: Figure 7 It can be seen that the 1% Cu3(HHTP)2-WO3·H2O gas sensor has a very high selectivity for 2-CEES.

[0067] Application Example 2

[0068] Take 10 mg of the prepared 2% Cu3(HHTP)2-WO3·H2O composite material, add it to 5 mL of ethanol for ultrasonic dispersion, and evenly drop it on a SiO2 / Si substrate deposited with gold interdigital electrodes. After the ethanol evaporates, a gas sensor with 2% Cu3(HHTP)2-WO3·H2O as the gas sensitive sensing material is obtained.

[0069] Application Example 3

[0070] Take 10 mg of the prepared 3% Cu3(HHTP)2-WO3·H2O composite material, add it to 5 mL of ethanol for ultrasonic dispersion, and evenly drop it on a SiO2 / Si substrate deposited with gold interdigital electrodes. After the ethanol evaporates, a gas sensor with 3% Cu3(HHTP)2-WO3·H2O as the gas sensitive sensing material is obtained.

[0071] Application Example 4

[0072] Take 10 mg of the prepared 4% Cu3(HHTP)2-WO3·H2O composite material, add it to 5 mL of ethanol for ultrasonic dispersion, and evenly drop it on a SiO2 / Si substrate deposited with gold interdigital electrodes. After the ethanol evaporates, a gas sensor with 4% Cu3(HHTP)2-WO3·H2O as the gas sensitive sensing material is obtained.

[0073] Application Example 5

[0074] Take 10 mg of the prepared 5% Cu3(HHTP)2-WO3·H2O composite material, add it to 5 mL of ethanol for ultrasonic dispersion, and evenly drop it on a SiO2 / Si substrate deposited with gold interdigital electrodes. After the ethanol evaporates, a gas sensor with 5% Cu3(HHTP)2-WO3·H2O as the gas sensitive sensing material is obtained.

[0075] from Figure 8 It can be seen from the X-ray diffraction patterns that the prepared WO3·H2O and 1% Cu3(HHTP)2-WO3·H2O and 3% Cu3(HHTP)2-WO3·H2O composite materials X-ray diffraction patterns show that WO3·H2O is an orthorhombic crystal system, the crystal structure of WO3·H2O nanosheets does not change after loading Cu3(HHTP)2, and there are no diffraction peaks of other impurities.

[0076] The response performance of the 2%-5% Cu3(HHTP)2-WO3·H2O composite material to 2-CEES in Example 2-5 was tested and compared with the gas sensing performance of 1% Cu3(HHTP)2-WO3·H2O in Example 1. Fig. 9 As shown, it can be seen that Cu3(HHTP)2 still has good response performance when it is 5%.

[0077] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A Cu3(HHTP)2-WO3·H2O gas sensitive sensing material, characterized in that: The gas-sensitive sensing material consists of WO3·H2O and a metal organic framework material dispersed on the surface thereof, and the metal organic framework material is Cu3(HHTP)2.

2. The Cu3(HHTP)2-WO3·H2O gas sensitive sensing material according to claim 1, characterized in that: The WO3·H2O is an orthorhombic crystal structure, and the Cu3(HHTP)2 is a two-dimensional layered structure of a hexagonal crystal phase.

3. A method for preparing the Cu3(HHTP)2-WO3·H2O gas sensitive sensing material according to any one of claims 1 to 2, characterized in that: The preparation method comprises the following steps: S1. Preparation of WO3·H2O Take Na2WO4·2H2O and dissolve it in distilled water, add hydrochloric acid, stir for a certain period of time to obtain a mixed solution; transfer the mixed solution to an oven for heating, cool it naturally to room temperature after the reaction is completed, centrifuge the solution, wash the obtained solid with distilled water, and dry it to obtain WO3·H2O. S2. Preparation of Cu3(HHTP)2-WO3·H2O gas sensitive sensing material The WO3·H2O obtained in step S1 is dispersed in distilled water and ultrasonically dispersed to obtain a WO3·H2O suspension; CuSO4·5H2O and hexahydroxytriphenylenebenzene are added to distilled water, ultrasonically dispersed to make them uniform, and then added to the dispersed WO3·H2O suspension and sealed, heated in an oil bath under magnetic stirring conditions, cooled naturally to room temperature after the reaction is completed, centrifuged to remove the supernatant, washed with distilled water and ethanol and then dried to obtain the Cu3(HHTP)2-WO3·H2O gas sensitive sensing material.

4. The preparation method according to claim 3, characterized in that: In step S1, the stirring time is 5-15 min; the reaction temperature is 30-50° C., and the reaction time is 24-96 h.

5. The preparation method according to claim 3, characterized in that: In step S1, washing with distilled water for at least 3 times, and vacuum drying at 80° C. for 6-18 h to obtain WO3·H2O.

6. The preparation method according to claim 3, characterized in that: In step S2, the WO3·H2O ultrasonic dispersion time is 30-40 minutes.

7. The preparation method according to claim 3, characterized in that: In step S2, the molar ratio of CuSO4·5H2O to hexahydroxytriphenylenebenzene is 3:2; the ultrasonic dispersion time is 5-15 min; Preferably, the oil bath heating temperature is 60-80°C and the heating time is 12-36h.

8. The preparation method according to claim 3, characterized in that: In step S2, the material is washed with distilled water and ethanol at least three times respectively, and vacuum dried at 40° C. for 6-18 h to obtain the Cu3(HHTP)2-WO3·H2O gas sensitive sensing material.

9. Use of the Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material according to any one of claims 1 to 2 or the Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material obtained by the preparation method according to any one of claims 3 to 8 in the preparation of a mustard gas simulant gas sensor; Preferably, the mustard gas simulant is 2-chlorodiethyl sulfide.

10. The use according to claim 9, characterized in that: The application is to drop-coat the Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material on a SiO2 / Si substrate deposited with gold interdigital electrodes to obtain a mustard gas simulant 2-chlorodiethyl sulfide gas sensor.

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