Cu3(hhtp)2-w03.h2o gas sensitive sensing material, and preparation method and application thereof

Abstract

The application discloses a Cu3(HHTP)2-WO3.H2O gas sensitive sensing material and a preparation method and application thereof. The gas sensitive sensing material is composed of WO3.H2O and metal organic framework material dispersed on the surface of the WO3.H2O, and the metal organic framework material is Cu3(HHTP)2. The application further 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 can realize sensing of 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] This invention relates to the field of semiconductor metal oxide-organic two-dimensional material heterojunction technology. More specifically, it relates to a Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material, its preparation method, and its applications. Background Technology

[0002] Chemical agents are a class of highly toxic compounds capable of causing mass casualties to humans and animals, and are a major component of military chemical weapons. Mustard gas is a typical blistering agent; skin contact causes severe blisters and damages the eyes and respiratory tract, even leading to death. Since its large-scale use in World War I, mustard gas has not only caused massive casualties—accounting for over 80% of all poison gas-related deaths and earning it the title of "King of Poison Gases"—but has also had a profound impact on human health and the environment. 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 sensors, chemical impedance spectroscopy (CIS) is one of the most commonly used. It offers advantages such as simple structure, compatibility with traditional DC circuits, low cost, predictable chemical properties, and ease of high-precision measurement, making it ideal for studying the chemical sensing properties of materials. Currently, resistive sensing of mustard gas simulants is mainly based on semiconductor metal oxide gas-sensitive materials such as ZnO and WO3, but it suffers from drawbacks such as high operating temperature (generally at least above 200℃), poor selectivity, and long response time.

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

[0005] The first objective of this 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 this invention can sense 2-chlorodiethyl sulfide (2-CEES) at room temperature and exhibits good response recovery, stability, high response, and selectivity.

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

[0007] The third objective of this invention is to provide an application of Cu3(HHTP)2-WO3·H2O gas-sensitive material in the preparation of mustard gas simulants, particularly 2-chlorodiethyl sulfide (2-CEES) gas sensors.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[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 its surface, wherein the metal-organic framework material is Cu3(HHTP)2.

[0010] While WO3·H2O itself exhibits a response to 2-CEES, its response temperature is relatively high. To improve its sensing performance, a heterojunction is formed using a composite two-dimensional metal-organic framework (MOF) Cu3(HHTP)2, enabling 2-CEES sensing at room temperature. Firstly, the porous nature of MOF Cu3(HHTP)2 facilitates the adsorption of 2-CEES gas. Secondly, a heterojunction with good contact is formed between the p-type semiconductor Cu3(HHTP)2 and the n-type semiconductor WO3·H2O. Charge transfer from 2-CEES to Cu3(HHTP)2 occurs on the Cu3(HHTP)2 surface, altering the width of the depletion layer in the Cu3(HHTP)2-WO3·H2O heterojunction, thus changing the resistance and demonstrating a gas-sensitive response. Furthermore, the good conductivity of MOF Cu3(HHTP)2 further enhances the gas-sensitive sensing response.

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

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

[0013] S1. Preparation of WO3·H2O

[0014] Dissolve Na2WO4·2H2O in distilled water, add hydrochloric acid, stir for a certain time to obtain a mixed solution; transfer the mixed solution to an oven for heating, and after the reaction is complete, allow it to cool naturally to room temperature, 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 was dispersed in distilled water and ultrasonically dispersed to obtain a WO3·H2O suspension. CuSO4·5H2O and hexahydroxytriphenylene (HHTP) were added to distilled water and ultrasonically dispersed to ensure uniform dispersion. Then, they were added to the dispersed WO3·H2O suspension and sealed. The mixture was heated in an oil bath under magnetic stirring. After the reaction was completed, the mixture was naturally cooled to room temperature. The supernatant was removed by centrifugation, and the mixture was washed with distilled water and ethanol and then dried to obtain the Cu3(HHTP)2-WO3·H2O gas-sensitive material.

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

[0018] Further, in step S1, the product is washed with distilled water at least three times and then vacuum dried 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] Furthermore, 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℃, and the heating time is 12-36h.

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

[0023] Thirdly, the present invention provides an application of the above-mentioned Cu3(HHTP)2-WO3·H2O gas-sensitive 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 involves drop-coating Cu3(HHTP)2-WO3·H2O gas-sensitive material onto a SiO2 / Si substrate with gold interdigitated electrodes to obtain a mustard gas simulant 2-chlorodiethyl sulfide gas sensor.

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

[0027] 1. This invention prepares MOF-modified WO3·H2O sensing material. WO3·H2O is prepared under organic solvent-free conditions. The obtained WO3·H2O is then reacted with hexahydroxytriphenylene and CuSO4·5H2O under hydrothermal conditions. Finally, after vacuum drying, Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material is obtained. The preparation method has few steps, is simple to operate, and is green and pollution-free.

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

[0029] 3. The Cu3(HHTP)2-WO3·H2O gas-sensitive sensing material prepared by this invention can achieve the sensing of 2-CEES at room temperature, and has good response recovery, stability, high response and selectivity. Attached Figure Description

[0030] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

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

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

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

[0034] Figure 4 The gas-sensing response of a 1% Cu3(HHTP)2-WO3·H2O gas sensor to 2-CEES is shown in the figure.

[0035] Figure 5 The graph shows the gas sensitivity test results of a 1% Cu3(HHTP)2-WO3·H2O gas sensor on 2-CEES at room temperature.

[0036] Figure 6 The figure shows the stability test results of the 1% Cu3(HHTP)2-WO3·H2O gas sensor.

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

[0038] Figure 8 The X-ray diffraction patterns of the prepared WO3·H2O composite materials with 1% Cu3(HHTP)2-WO3·H2O and 3% Cu3(HHTP)2-WO3·H2O are shown.

[0039] Figure 9 The results of the response performance test of 2-CEES for 2%-5% Cu3(HHTP)2-WO3·H2O composite materials. Detailed Implementation

[0040] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further clarifies the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0041] Example 1

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

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

[0044] 233 mg WO3·H2O was added to 5 ml of distilled water and sonicated for 30 min to ensure full dispersion of WO3·H2O. 4.1 mg CuSO4·5H2O and 2.3 mg HHTP were dispersed in 7.2 mL of distilled water and sonicated for 5-10 min. Then, the mixture was added to the dispersed WO3·H2O suspension and sealed. The mixture was heated in an oil bath to 80 °C for 24 h under magnetic stirring. Afterward, it was naturally cooled to room temperature, the supernatant was removed by centrifugation, and the mixture was washed three times with distilled water and ethanol, respectively. The mixture was then vacuum dried at 40 °C for 12 h to obtain a 1% Cu3(HHTP)2-WO3·H2O composite material.

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

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

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

[0048] Example 2

[0049] The specific process for preparing a 2% Cu3(HHTP)2-WO3·H2O composite material and fabricating a 2-CEES gas sensor is as follows:

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

[0051] Example 3

[0052] The specific process for preparing a 3% Cu3(HHTP)2-WO3·H2O composite material and fabricating a 2-CEES gas sensor is as follows:

[0053] 233 mg of WO3·H2O prepared in Example 1 was added to 5 ml of distilled water and sonicated for 30 min to fully disperse the WO3·H2O. 12.3 mg of CuSO4·5H2O and 6.9 mg of HHTP were dispersed in 7.2 mL of distilled water and sonicated for 5 min. Then, the mixture was added to the dispersed WO3·H2O suspension and sealed. The mixture was heated in an oil bath to 80 °C for 24 h under magnetic stirring. After that, it was naturally cooled to room temperature. The supernatant was removed by centrifugation. The mixture was washed three times with distilled water and ethanol and then vacuum dried at 40 °C for 12 h to obtain the 3% Cu3(HHTP)2-WO3·H2O composite material.

[0054] Example 4

[0055] The preparation of a 4% Cu3(HHTP)2-WO3·H2O composite material and the fabrication of a 2-CEES gas sensor are detailed below:

[0056] 233 mg of WO3·H2O prepared in Example 1 was added to 5 ml of distilled water and sonicated for 30 min to fully disperse the WO3·H2O. 16.4 mg of CuSO4·5H2O and 9.2 mg of HHTP were dispersed in 7.2 mL of distilled water and sonicated for 5 min. Then, the mixture was added to the dispersed WO3·H2O suspension and sealed. The mixture was heated in an oil bath to 80 °C for 24 h under magnetic stirring and then allowed to cool naturally to room temperature. The supernatant was removed by centrifugation, and the mixture was washed three times with distilled water and ethanol. The mixture was then vacuum dried at 40 °C for 12 h to obtain a 4% Cu3(HHTP)2-WO3·H2O composite material.

[0057] Example 5

[0058] The specific process for preparing a 5% Cu3(HHTP)2-WO3·H2O composite material and fabricating a 2-CEES gas sensor is as follows:

[0059] 233 mg of WO3·H2O prepared in Example 1 was added to 5 ml of distilled water and sonicated for 30 min to fully disperse the WO3·H2O. 20.5 mg of CuSO4·5H2O and 11.7 mg of HHTP were dispersed in 7.2 mL of distilled water and sonicated for 5 min. Then, the mixture was added to the dispersed WO3·H2O suspension and sealed. The mixture was heated in an oil bath to 80 °C for 24 h under magnetic stirring and then allowed to cool naturally to room temperature. The supernatant was removed by centrifugation, and the mixture was washed three times with distilled water and ethanol. The mixture was then vacuum dried at 40 °C for 12 h to obtain a 5% Cu3(HHTP)2-WO3·H2O composite material.

[0060] Application Example 1

[0061] 10 mg of the prepared 1% Cu3(HHTP)2-WO3·H2O composite material was added to 5 mL of ethanol and ultrasonically dispersed. The mixture was then uniformly drop-coated onto a SiO2 / Si substrate with gold interdigitated electrodes. After the ethanol evaporated, a gas sensor with 1% Cu3(HHTP)2-WO3·H2O as the gas-sensitive sensing material was obtained.

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

[0063] The gas-sensing response test results of the 1% Cu3(HHTP)2-WO3·H2O gas sensor to 2-CEES are as follows: Figure 4 As shown, under normal temperature conditions, the 1% Cu3(HHTP)2-WO3·H2O gas sensor has a fast response recovery time of 2.48 min and 10.83 min for 20 ppm concentration of 2-CEES, respectively, with a response value of 9.6%.

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

[0065] Stability tests were conducted on a 1% Cu3(HHTP)2-WO3·H2O gas sensor. Figure 6 As can be seen, the sensor still has high sensing performance after being placed in air for 30 days, indicating that the prepared Cu3(HHTP)2-WO3·H2O gas sensor has good stability.

[0066] A 1% Cu3(HHTP)2-WO3·H2O gas sensor was used to selectively react with 20 ppm of different target gases (ethanol, DMMP, 2-CEES, acetone, acetonitrile, and dichloromethane) at room temperature. Figure 7 As can be seen, the 1% Cu3(HHTP)2-WO3·H2O gas sensor has very high selectivity for 2-CEES.

[0067] Application Example 2

[0068] 10 mg of the prepared 2% Cu3(HHTP)2-WO3·H2O composite material was added to 5 mL of ethanol and ultrasonically dispersed. The mixture was then uniformly drop-coated onto a SiO2 / Si substrate with gold interdigitated electrodes. After the ethanol evaporated, a gas sensor with 2% Cu3(HHTP)2-WO3·H2O as the gas-sensitive sensing material was obtained.

[0069] Application Example 3

[0070] 10 mg of the prepared 3% Cu3(HHTP)2-WO3·H2O composite material was added to 5 mL of ethanol and ultrasonically dispersed. The mixture was then uniformly drop-coated onto a SiO2 / Si substrate with gold interdigitated electrodes. After the ethanol evaporated, a gas sensor with 3% Cu3(HHTP)2-WO3·H2O as the gas-sensitive sensing material was obtained.

[0071] Application Example 4

[0072] 10 mg of the prepared 4% Cu3(HHTP)2-WO3·H2O composite material was added to 5 mL of ethanol and ultrasonically dispersed. The mixture was then uniformly drop-coated onto a SiO2 / Si substrate with gold interdigitated electrodes. After the ethanol evaporated, a gas sensor with 4% Cu3(HHTP)2-WO3·H2O as the gas-sensitive sensing material was obtained.

[0073] Application Example 5

[0074] 10 mg of the prepared 5% Cu3(HHTP)2-WO3·H2O composite material was added to 5 mL of ethanol and ultrasonically dispersed. The mixture was then uniformly drop-coated onto a SiO2 / Si substrate with gold interdigitated electrodes. After the ethanol evaporated, a gas sensor with 5% Cu3(HHTP)2-WO3·H2O as the gas-sensitive sensing material was obtained.

[0075] from Figure 8 The X-ray diffraction patterns show that the prepared WO3·H2O composites with 1% Cu3(HHTP)2-WO3·H2O and 3% Cu3(HHTP)2-WO3·H2O have an orthorhombic crystal system. The crystal structure of the WO3·H2O nanosheets did not change after loading Cu3(HHTP)2, and there were 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 application examples 2-5 was tested and compared with the gas-sensitive performance of 1% Cu3(HHTP)2-WO3·H2O in application example 1. Figure 9 As shown, Cu3(HHTP)2 still exhibits excellent response performance at a concentration of 5%.

[0077] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions 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 is composed of WO3·H2O and a metal-organic framework material dispersed on its surface, wherein 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 has an orthorhombic crystal structure, and the Cu3(HHTP)2 has a two-dimensional layered structure with 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 1-2, characterized in that, The preparation method includes the following steps: S1. Preparation of WO3·H2O Dissolve Na2WO4·2H2O in distilled water, add hydrochloric acid, stir for a certain time to obtain a mixed solution; transfer the mixed solution to an oven and heat it. After the reaction is complete, cool it naturally to room temperature, 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 was dispersed in distilled water and ultrasonically dispersed to obtain a WO3·H2O suspension. CuSO4·5H2O and hexahydroxytriphenylbenzene were added to distilled water and ultrasonically dispersed to ensure uniform dispersion. Then, they were added to the dispersed WO3·H2O suspension and sealed. The mixture was heated in an oil bath under magnetic stirring. After the reaction was completed, it was naturally cooled to room temperature. The supernatant was removed by centrifugation, and the mixture was washed with distilled water and ethanol and then dried to obtain the Cu3(HHTP)2-WO3·H2O gas-sensitive 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℃; and the reaction time is 24-96 h.

5. The preparation method according to claim 3, characterized in that, In step S1, the product is washed with distilled water at least three times and then vacuum dried at 80°C for 6-18 hours to obtain WO3·H2O.

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

7. The preparation method according to claim 3, characterized in that, In step S2, the molar ratio of CuSO4·5H2O to hexahydroxytriphenylene is 3:2; the ultrasonic dispersion time is 5-15 min. The oil bath heating temperature is 60-80℃, 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 at least three times with distilled water and ethanol, and then vacuum dried at 40°C for 6-18 hours to obtain Cu3(HHTP)2-WO3·H2O gas-sensitive material.

9. The application of the Cu3(HHTP)2-WO3·H2O gas-sensitive material according to any one of claims 1-2 or the Cu3(HHTP)2-WO3·H2O gas-sensitive material obtained by the preparation method according to any one of claims 3-8 in the preparation of mustard gas simulant gas sensors.

10. The application according to claim 9, characterized in that, The mustard gas simulant is 2-chlorodiethyl sulfide.

11. The application according to claim 9, characterized in that, The application involves drop-coating Cu3(HHTP)2-WO3·H2O gas-sensitive material onto a SiO2 / Si substrate with gold interdigitated electrodes to obtain a mustard gas simulant 2-chlorodiethyl sulfide gas sensor.

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