Composite material based on WO3 and Ti3C2Tx as well as preparation method and application of composite material

Abstract

The invention relates to the field of composite materials and sensors, and discloses a composite material based on WO3 and Ti < 3 > C < 2 > T < x > and a preparation method and application of the composite material based on WO3 and Ti < 3 > C < 2 > T < x >, and the composite material based on WO3 and Ti < 3 > C < 2 > T < x > comprises Ti < 3 > C < 2 > T < x > and a WO3 nano material loaded on Ti < 3 > C < 2 > T < x >. The composite material based on WO3 and Ti3C2Tx has a relatively large specific surface area and excellent catalytic activity, can work under a room temperature condition when being applied to a sensor, is high in response speed to H2S, wide in detectable H2S volume concentration range and low in detection lower limit, and is simple in preparation process operation and easy to industrialize.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite materials and sensors, in particular to a composite material based on WO3 and Ti3C2T x and a preparation method and application thereof. BACKGROUND

[0002] Hydrogen sulfide (H2S) is a highly toxic and flammable gas, widely used in petroleum, chemical, metallurgical, pharmaceutical and other fields. However, hydrogen sulfide leakage can pose a serious threat to the production environment, and may cause fires, explosions and other accidents. It can cause serious harm to human health. Low concentration of hydrogen sulfide can cause headache, dizziness, nausea and other symptoms, while high concentration of hydrogen sulfide can cause suffocation and death. Realizing high-performance detection of hydrogen sulfide can detect leakage early and take appropriate measures to ensure the safe operation of industrial production, and also protect people in the work and living environment from the threat of hydrogen sulfide poisoning.

[0003] Therefore, it is crucial to realize quantitative detection of hydrogen sulfide by reliable gas sensors. Traditional chemical resistance type gas sensors are usually made of low-cost, small-volume metal oxide semiconductors (MOSs), which play an important role in the field of hydrogen sulfide detection. Among them, WO3 as a typical resistance type gas sensitive material, shows sensitive sensing ability to a variety of gases (such as NO2, H2S, O3, H2 and NH3). However, single-component WO3 has the problems of low response and high working temperature in hydrogen sulfide detection, which limits its commercial use in the field of gas sensing. Currently, Ti3C2T x as a high-performance room-temperature conductive two-dimensional material has attracted more attention. Ti3C2T x combined with WO3 effectively reduces the resistance to achieve the goal of room-temperature detection. SUMMARY

[0004] The purpose of the present application is to overcome the problems of low sensitivity, poor selectivity and high working temperature of H2S sensors in the prior art, and to provide a composite material based on WO3 and Ti3C2T x The composite material based on WO3 and Ti3C2T x (WO3@Ti3C2T x ) has a large specific surface area and excellent catalytic activity, and when applied in sensors, it can work at room temperature, has a fast response speed to H2S, a wide range of detectable H2S volume concentration and a low detection lower limit, the preparation process is simple and easy to industrialize.

[0005] In order to achieve the above purpose, one aspect of the present application provides a composite material based on WO3 and Ti3C2T x The composite material based on WO3 and Ti3C2Tx The composite material based on WO3 and Ti3C2T x xene and WO3 nanomaterials loaded on Ti3C2T x xene.

[0006] Preferably, the content of the WO3 nanomaterial is 5-35wt% based on the total weight of the composite material based on WO3 and Ti3C2T x xene.

[0007] Preferably, the specific surface area of the composite material based on WO3 and Ti3C2T x xene is 100-1000m 2 / g.

[0008] Preferably, the WO3 nanomaterial is selected from one or more of WO3 nanoparticles, WO3 nanocubes, WO3 nanosheets and WO3 nanowires.

[0009] Preferably, the size of the WO3 nanoparticles is 5-500nm.

[0010] Preferably, the edge length of the WO3 nanocubes is 5-50nm.

[0011] Preferably, the thickness of the WO3 nanosheets is 10-100nm.

[0012] Preferably, the length of the WO3 nanowires is 100-500nm and the width is 2-10nm.

[0013] The second aspect of the present application provides a method for preparing a composite material based on WO3 and Ti3C2T x xene, which comprises the following steps:

[0014] (1) mixing WO3 nanomaterials, Ti3C2T x xene and a first solvent;

[0015] (2) performing solid-liquid separation on the material obtained in step (1) and then performing freeze-drying on the obtained solid-phase material.

[0016] Preferably, in step (1), the weight ratio of the amount of Ti3C2T x xene to the amount of WO3 nanomaterials is 1:0.1-0.5.

[0017] Preferably, in step (1), the weight ratio of the amount of Ti3C2T x xene to the amount of the first solvent is 1:100-400.

[0018] Preferably, in step (1), the mixing conditions include a temperature of 0-100℃ and a time of 2-36h.

[0019] Preferably, in step (1), the Ti3C2T x The preparation method of the Ti3AlC2 includes: mixing Ti3AlC2 with a solution containing fluoride ions and hydrogen ions, and then performing a first reaction.

[0020] Preferably, the conditions of the first reaction include: a temperature of 10-70℃ and a time of 10-48h.

[0021] Preferably, in step (1), the WO3 nanomaterial is selected from one or more than two of WO3 nanoparticles, WO3 nanocubes, WO3 nanosheets and WO3 nanowires.

[0022] Preferably, the preparation method of the WO3 nanoparticles includes: performing a first hydrothermal reaction and a first calcination on a W precursor solution, a sulfate and a first acidic substance.

[0023] Preferably, the conditions of the first hydrothermal reaction include: a temperature of 100-180℃ and a time of 5-30h.

[0024] Preferably, the conditions of the first calcination include: a temperature of 400-600℃ and a time of 5-20h.

[0025] Preferably, the preparation method of the WO3 nanocubes includes: performing a second hydrothermal reaction and a second calcination on a W precursor solution, tartaric acid and a second acidic substance.

[0026] Preferably, the conditions of the second hydrothermal reaction include: a temperature of 100-160℃ and a time of 5-35h.

[0027] Preferably, the conditions of the second calcination include: a temperature of 400-600℃ and a time of 5-30h.

[0028] Preferably, the preparation method of the WO3 nanosheets includes: performing a third hydrothermal reaction and a third calcination on a W precursor solution, citric acid and a third acidic substance.

[0029] Preferably, the conditions of the third hydrothermal reaction include: a temperature of 100-180℃ and a time of 10-30h.

[0030] Preferably, the conditions of the third calcination include: a temperature of 400-600℃ and a time of 5-15h.

[0031] Preferably, the preparation method of the WO3 nanowires includes: performing a fourth hydrothermal reaction and a fourth calcination on a W precursor and ethanol.

[0032] Preferably, the conditions of the fourth hydrothermal reaction include: a temperature of 100-170℃ and a time of 10-40h.

[0033] Preferably, the fourth calcination condition comprises 400-600℃ for 5-20h.

[0034] Preferably, the first solvent is selected from one or more of water, ethanol, methanol, chloroform and acetone.

[0035] Preferably, in step (2), the freeze-drying condition comprises -70- -40℃ for 2-36h.

[0036] The third aspect of the present application provides a composite material based on WO3 and Ti3C2T x prepared by the above method.

[0037] The fourth aspect of the present application provides an application of the above composite material based on WO3 and Ti3C2T x in hydrogen sulfide detection.

[0038] The fifth aspect of the present application provides a hydrogen sulfide sensor comprising the above composite material based on WO3 and Ti3C2T x .

[0039] The sixth aspect of the present application provides a method for preparing the above hydrogen sulfide sensor, comprising the following steps: mixing and grinding the above composite material based on WO3 and Ti3C2T x and an organic solvent, then coating the mixture on the surface of a ceramic tube with electrodes to form a sensing film, and then vacuum drying.

[0040] Preferably, the weight ratio of the composite material based on WO3 and Ti3C2T x and the organic solvent is 1:1-10.

[0041] Preferably, the thickness of the sensing film is 200-1000μm.

[0042] The seventh aspect of the present application provides a method for hydrogen sulfide detection, comprising contacting the above hydrogen sulfide sensor with a mixed gas containing hydrogen sulfide.

[0043] Compared with the prior art, the technical scheme of the present application has the following advantages:

[0044] (1) The composite material based on WO3 and Ti3C2T x of the present application can work at room temperature when applied in a sensor, has a fast response speed to H2S, a wide detection range of H2S concentration and a low detection lower limit, can respond to 50ppb H2S within 10s, and the detection range is 50ppb-100ppb, which is mainly due to the fact that the WO3 nanomaterial can quickly adsorb and dissociate H2S as an active site, and secondly, the composite material based on WO3 and Ti3C2Tx The composite material is hierarchical, provides an ideal diffusion channel for rapid diffusion of H2S, and the WO3 nanomaterial is embedded in Ti3C2T x The hierarchy avoids aggregation of the WO3 nanomaterial and inhibits collapse of Ti3C2T x , which is beneficial to the improvement of charge migration, transmission and sensing performance;

[0045] (2) The method for preparing the composite material based on WO3 and Ti3C2T x The process operation of the method is simple, easy to industrialize, and beneficial to large-scale production and application of the sensor. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a scanning electron microscope image of Ti3C2T x prepared in Example 1;

[0047] Figure 2 is a scanning electron microscope image of WO3 nanoparticles prepared in Example 1;

[0048] Figure 3 is a scanning electron microscope image of WO3@Ti3C2T x prepared in Example 1;

[0049] Figure 4 is a curve graph of the change in response intensity of the hydrogen sulfide sensor prepared in Example 1, Comparative Example 1 and Comparative Example 2 in different concentrations of hydrogen sulfide. DETAILED DESCRIPTION

[0050] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0051] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and the values are approximate values and should be understood to include values approximately the same as the stated values. For ranges, the endpoints are included in the ranges, and the ranges are inclusive of the single values therein. For values, the value includes approximately the same value.

[0052] In one aspect, the present application provides a composite material based on WO3 and Ti3C2T x The composite material based on WO3 and Ti3C2T x includes Ti3C2T x and a WO3 nanomaterial loaded on Ti3C2T x .

[0053] In a preferred embodiment, in order to improve the stability and sensitivity to hydrogen sulfide gas of the composite material based on WO3 and Ti3C2T x , the content of the WO3 nanomaterial is 5-35wt% based on the total weight of the composite material based on WO3 and Ti3C2T x ; specifically, the content of the WO3 nanomaterial can be 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt% or 35wt%.

[0054] In a preferred embodiment, in order to improve the adsorption of the composite material based on WO3 and Ti3C2T x to hydrogen sulfide gas, the specific surface area of the composite material based on WO3 and Ti3C2T x is 100-1000m 2 / g.

[0055] In a preferred embodiment, the WO3 nanomaterial is selected from one or more of WO3 nanoparticles, WO3 nanocubes, WO3 nanosheets and WO3 nanowires, based on which the WO3 nanomaterial can better embed into the interior of Ti3C2T x , improve the problem of Ti3C2T x collapse and thus improve its stability.

[0056] In a preferred embodiment, the size of the WO3 nanoparticles is 5-100nm.

[0057] In a preferred embodiment, the edge length of the WO3 nanocubes is 5-50nm.

[0058] In a preferred embodiment, the thickness of the WO3 nanosheets is 10-100nm.

[0059] In a preferred embodiment, the length of the WO3 nanowires is 100-500nm and the width is 2-10nm.

[0060] The composite material based on WO3 and Ti3C2T x has good electrical conductivity and stability, and good sensitivity and response performance to hydrogen sulfide, which is mainly due to the large specific surface area of the WO3 nanomaterial, which can quickly adsorb and dissociate H2S as an active site, secondly, the hierarchical structure of the composite material based on WO3 and Ti3C2T x provides an ideal channel for the diffusion of H2S, and the WO3 nanomaterial is embedded in the hierarchical interior of Ti3C2T x , which avoids the aggregation of WO3 nanomaterial and inhibits the collapse of Ti3C2T xThe collapse of the material is conducive to the improvement of charge migration, transmission and sensing performance.

[0061] The second aspect of the application provides a method for preparing a composite material based on WO3 and Ti3C2T x The method comprises the following steps:

[0062] (1) mixing WO3 nanomaterial, Ti3C2T x and a first solvent;

[0063] (2) performing solid-liquid separation on the material obtained in step (1), and then performing freeze-drying on the obtained solid-phase material.

[0064] In a preferred embodiment, in order to improve the stability of the composite material based on WO3 and Ti3C2T x and the sensitivity to hydrogen sulfide gas, in step (1), the weight ratio of the amount of Ti3C2T x to the amount of WO3 nanomaterial is 1:0.1-0.5; specifically, the weight ratio of the amount of Ti3C2T x to the amount of WO3 nanomaterial can be 1:0.1, 1:0.2, 1:0.3, 1:0.4 or 1:0.5.

[0065] In a preferred embodiment, in order to better disperse Ti3C2T x , in step (1), the weight ratio of the amount of Ti3C2T x to the amount of the first solvent is 1:100-400; specifically, the weight ratio of the amount of Ti3C2T x to the amount of the first solvent can be 1:100, 1:150, 1:200, 1:250, 1:300, 1:350 or 1:400.

[0066] In the present application, there is no special requirement for the first solvent, and any commonly used in the art can be used. In a preferred embodiment, the first solvent is selected from one or more than two of water, ethanol, methanol, chloroform and acetone.

[0067] In a preferred embodiment, in order to further improve the stability of the composite material based on WO3 and Ti3C2T x and the sensitivity to hydrogen sulfide gas, in step (1), the mixing conditions include a temperature of 0-100℃ and a time of 2-36h; specifically, the temperature can be 20℃, 40℃, 60℃, 80℃ or 100℃, and the time can be 6h, 12h, 18h, 24h, 30h or 36h.

[0068] In a preferred embodiment, in step (1), the Ti3C2T xThe preparation method of the Ti3C2T

[0069] In a preferred embodiment, the conditions of the first reaction include: temperature of 10-70℃, time of 10-48h; specifically, the temperature can be 10℃, 20℃, 30℃, 35℃, 40℃, 50℃, 60℃ or 70℃; the time can be 10h, 12h, 24h, 36h or 48h.

[0070] In a preferred embodiment, the Ti3C2T x The preparation method of the Ti3C2T

[0071] In a specific embodiment, the vacuum filtration of the washed material is performed by using a polytetrafluoroethylene membrane with a pore size of 0.22μm.

[0072] In a specific embodiment, the Ti3C2T x The preparation method of the Ti3C2T

[0073] In the present application, there is no special requirement for the solution containing fluoride ions and hydrogen ions, as long as the fluoride ions and hydrogen ions contained in the solution can remove the Al atoms in Ti3AlC2, for example, it can be a mixed solution of hydrofluoric acid or inorganic acid and fluoride salt.

[0074] The Ti3C2T x The micro-morphology of the Ti3C2T x The hierarchical structure is conducive to the embedding of the WO3 nanomaterials into the Ti3C2T x The hierarchical structure is conducive to the embedding of the WO3 nanomaterials into the Ti3C2T x The hierarchical structure is conducive to the embedding of the WO3 nanomaterials into the Ti3C2T x The hierarchical structure is conducive to the embedding of the WO3 nanomaterials into the Ti3C2T x

[0075] In a preferred embodiment, in step (1), the WO3 nanomaterials are selected from one or two or more of WO3 nanoparticles, WO3 nanocubes, WO3 nanosheets and WO3 nanowires, based on which the WO3 nanomaterials can be better embedded into the Ti3C2T xthe interior of Ti3C2T x and improve its stability.

[0076] In a preferred embodiment, the preparation method of the WO3nanoparticles comprises: performing a first hydrothermal reaction and a first calcination on a W precursor solution, a sulfate and a first acidic substance.

[0077] In a preferred embodiment, the weight ratio of the amount of the W precursor to the amount of the sulfate is 1:1-1.5, wherein the W precursor is calculated by W element and the sulfate is calculated by sulfate radical; specifically, it can be 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1:1.5.

[0078] In a preferred embodiment, the conditions of the first hydrothermal reaction comprise: a temperature of 100-180℃ and a time of 5-30h; specifically, the temperature can be 100℃, 120℃, 130℃, 150℃, 160℃ or 180℃; and the time can be 5h, 7h, 10h, 12h, 15h, 20h, 25h or 30h.

[0079] In a preferred embodiment, the conditions of the first calcination comprise: a temperature of 400-600℃ and a time of 5-20h; specifically, the temperature can be 400℃, 450℃, 500℃, 550℃ or 600℃; and the time can be 5h, 7h, 10h, 12h, 15h or 20h.

[0080] In a preferred embodiment, the preparation method of the WO3nanoparticles further comprises washing and drying the intermediate material before the first calcination after the first hydrothermal reaction, and the washing and drying are both in a conventional manner in the art.

[0081] In a specific embodiment, the preparation method of the WO3nanoparticles specifically comprises: mixing the W precursor and water, stirring, adding ethylene glycol and ultrasonic, then adding the sulfate and hydrochloric acid, placing in a hydrothermal kettle for the first hydrothermal reaction, then washing with ethanol and water and placing in a vacuum drying oven for drying, and finally placing in a muffle furnace for the first calcination.

[0082] In the preparation method of the WO3nanoparticles, there is no special requirement for the sulfate, and any conventional sulfate used in the art can be used, for example, the sulfate can be Na2SO4·10H2O.

[0083] In the preparation method of the WO3nanoparticles, the W precursor solution is obtained by mixing a W precursor and a second solvent, and the second solvent is selected from water and / or ethylene glycol.

[0084] In the present application, there is no special requirement for the amount of the W precursor and the second solvent, as long as the second solvent can dissolve the W precursor.

[0085] In a preferred embodiment, the preparation method of the WO3nanocube comprises: subjecting the W precursor solution, tartaric acid and a second acidic substance to a second hydrothermal reaction and a second calcination.

[0086] In a preferred embodiment, the weight ratio of the amount of the W precursor and the tartaric acid is 1:1-3, wherein the W precursor is calculated based on the element W; specifically, it can be 1:1, 1:1.5, 1:2, 1:2.5 or 1:3.

[0087] In a preferred embodiment, the conditions of the second hydrothermal reaction comprise: a temperature of 100-160°C and a time of 5-35h; specifically, the temperature can be 100°C, 120°C, 130°C, 150°C or 160°C; and the time can be 5h, 10h, 15h, 18h, 20h, 25h or 35h.

[0088] In a preferred embodiment, the conditions of the second calcination comprise: a temperature of 400-600°C and a time of 5-30h; specifically, the temperature can be 400°C, 450°C, 500°C, 550°C or 600°C; and the time can be 5h, 7h, 10h, 12h, 15h, 20h, 25h or 30h.

[0089] In a preferred embodiment, the preparation method of the WO3nanoparticle further comprises washing and drying the intermediate material after the second hydrothermal reaction and before the second calcination, which are both in a conventional manner in the art.

[0090] In a specific embodiment, the preparation method of the WO3nanocube specifically comprises: mixing the W precursor and water, stirring, adding isopropyl alcohol and ultrasonicating, then adding tartaric acid and hydrochloric acid, subjecting to a second hydrothermal reaction in a hydrothermal kettle, then washing with ethanol and water and placing in a vacuum drying oven for drying, and finally placing in a muffle furnace for a second calcination.

[0091] In the preparation method of the WO3nanocube, the W precursor solution is obtained by mixing a W precursor and a third solvent, and the third solvent is selected from water and / or isopropyl alcohol.

[0092] In the present application, there is no special requirement for the amount of the W precursor and the third solvent, as long as the third solvent can dissolve the W precursor.

[0093] In a preferred embodiment, the preparation method of the WO3nanosheet comprises: subjecting a W precursor solution, citric acid and a third acidic substance to a third hydrothermal reaction and a third calcination.

[0094] In preferred embodiments, the weight ratio of the amount of W precursor and citric acid is 1:2-4, wherein the W precursor is in terms of W element; specifically, it can be 1:2, 1:2.5, 1:3, 1:3.5 or 1:4.

[0095] In preferred embodiments, the third hydrothermal reaction is performed at a temperature of 100-180°C for 10-30h; specifically, the temperature can be 100°C, 120°C, 130°C, 150°C, 160°C or 180°C; and the time can be 10h, 12h, 15h, 20h, 25h or 30h.

[0096] In preferred embodiments, the third calcination is performed at a temperature of 400-600°C for 5-15h; specifically, the temperature can be 400°C, 450°C, 500°C, 550°C or 600°C; and the time can be 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h or 15h.

[0097] In preferred embodiments, the method for preparing WO3 nanosheets further comprises washing and drying the intermediate material after the third hydrothermal reaction and before the third calcination, which are both in a conventional manner in the art.

[0098] In specific embodiments, the method for preparing WO3 nanosheets specifically comprises mixing W precursor and water, stirring, adding citric acid and hydrochloric acid, performing third hydrothermal reaction in a hydrothermal kettle, washing with ethanol and water, drying in a vacuum drying oven, and finally performing third calcination in a muffle furnace.

[0099] In preferred embodiments, the method for preparing WO3 nanowires comprises performing fourth hydrothermal reaction and fourth calcination on W precursor and ethanol.

[0100] In preferred embodiments, the weight ratio of W precursor to ethanol is 1:30-120g / ml, wherein the W precursor is in terms of W element; specifically, it can be 1:30g / ml, 1:50g / ml, 1:60g / ml, 1:80g / ml, 1:100g / ml or 1:120g / ml.

[0101] In preferred embodiments, the fourth hydrothermal reaction is performed at a temperature of 100-170°C for 10-40h; specifically, the temperature can be 100°C, 120°C, 130°C, 150°C, 160°C or 170°C; and the time can be 10h, 15h, 20h, 25h, 30h, 35h or 40h.

[0102] In a preferred embodiment, the fourth calcination is performed at a temperature of 400-600℃, specifically, 400℃, 450℃, 500℃, 550℃, or 600℃, for 5-20h, specifically, 5h, 10h, 15h, or 20h.

[0103] In a preferred embodiment, the method for preparing the WO3 nanowires further comprises washing and drying the intermediate material before the fourth calcination after the fourth hydrothermal reaction, which are both in a conventional manner in the art.

[0104] In a specific embodiment, the method for preparing the WO3 nanowires specifically comprises: placing the W precursor and ethanol in a hydrothermal kettle for the fourth hydrothermal reaction, then washing with ethanol and water and drying in a vacuum drying oven, and finally placing in a muffle furnace for the fourth calcination.

[0105] In the present application, the W precursor is not particularly required, and any W precursor conventionally used in the art can be used, for example, the W precursor can be Na2WO4·2H2O.

[0106] In the present application, the first, second, and third acidic substances are not particularly required, and any acidic substance conventionally used in the art can be used, for example, the acidic substance can be hydrochloric acid, sulfuric acid, nitric acid, etc.

[0107] In the present application, the amount of the first, second, and third acidic substances is not particularly required, as long as the system solution can be adjusted to be acidic.

[0108] In a preferred embodiment, in step (2), the solid-liquid separation is performed by centrifugation at a speed of 8000-10000r / min.

[0109] In a preferred embodiment, in step (2), the freeze-drying is performed at a temperature of -70--40℃ for 2-36h, specifically, the temperature can be -70℃, -65℃, -60℃, -55℃, -50℃, -45℃, or -40℃, and the time can be 6h, 12h, 18h, 24h, 30h, or 36h.

[0110] The third aspect of the present application provides a composite material based on WO3 and Ti3C2T x of the above method.

[0111] The fourth aspect of the present application provides an application of the composite material based on WO3 and Ti3C2T x of the above method in hydrogen sulfide detection.

[0112] The fifth aspect of the present application provides a hydrogen sulfide sensor based on the composite material of WO3 and Ti3C2T x .

[0113] The composite material of WO3 and Ti3C2T x of the present application has high sensitivity to hydrogen sulfide, and can be directly used for monitoring and detecting the leakage of hydrogen sulfide in the atmospheric environment, rapidly and selectively detecting the leaked hydrogen sulfide in the environment at room temperature, reducing the harm caused by the leakage of hydrogen sulfide, and thus ensuring the safety of personnel, environment and equipment.

[0114] The sixth aspect of the present application provides a method for preparing the hydrogen sulfide sensor, which comprises the following steps: mixing and grinding the composite material of WO3 and Ti3C2T x and an organic solvent, then coating the mixture on the surface of a ceramic tube with an electrode to form a sensing film, and then vacuum drying.

[0115] In a preferred embodiment, in order to improve the sensitivity of the hydrogen sulfide sensor, the weight ratio of the composite material of WO3 and Ti3C2T x to the organic solvent is 1:1-10; specifically, the weight ratio of the composite material of WO3 and Ti3C2T x to the organic solvent can be 1:2, 1:4, 1:6, 1:8 or 1:10.

[0116] In the present application, there is no special requirement for the organic solvent, and the commonly used ones in the art can be used, for example, the organic solvent can be terpineol.

[0117] In the present application, there is no special requirement for the conditions of vacuum drying, and the commonly used conditions in the art can be used.

[0118] In a preferred embodiment, in order to further improve the sensitivity of the hydrogen sulfide sensor, the thickness of the sensing film is 200-1000 μm; specifically, the thickness of the sensing film can be 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1000 μm.

[0119] The seventh aspect of the present application provides a method for detecting hydrogen sulfide, which comprises contacting the hydrogen sulfide sensor with a mixed gas containing hydrogen sulfide.

[0120] The following examples further illustrate the composite material of WO3 and Ti3C2T xComposite material and preparation method and application thereof. The examples are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following examples.

[0121] The experimental methods in the following examples are all conventional methods in the art, unless otherwise specified. The experimental materials and experimental instruments used in the following examples are all commercially available, unless otherwise specified, wherein the scanning electron microscope is Hitachi SU3800, and the energy spectrometer is Hitachi SU3800.

[0122] Example 1

[0123] Preparation of Ti3C2T x (S1):

[0124] A1: 1g of Ti3AlC2 was added to 50ml of hydrofluoric acid with a mass concentration of 30%, stirred at 30°C for 48h, then centrifuged by a centrifuge, washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0125] A2: The precipitate collected in step A1 was washed with deionized water again, then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22μm, and then dried in a vacuum drying oven at 60°C for 8h;

[0126] A3: The intermediate material obtained in step A2 was dispersed in deionized water, ultrasonicated at 4°C for 30min, then separated by a centrifuge to obtain Ti3C2T x (S1);

[0127] Preparation of WO3 nanoparticles (M1):

[0128] 0.4g of Na2WO4·2H2O was dissolved in 10mL of ultrapure water and stirred vigorously for 10min, then 5mL of ethylene glycol was added, stirred for 20min, then ultrasonicated for 5min, then 0.9g of Na2SO4·10H2O and 4mL of HCl (12M) were added, the above mixed solution was placed in a 50mL polytetrafluoroethylene-lined hydrothermal kettle, reacted at a temperature of 140°C for 8h, after the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times respectively, then placed in a vacuum drying oven at 80°C for 15h, and finally placed in a 550°C muffle furnace for calcination for 6h to obtain WO3 nanoparticles (M1);

[0129] Preparation of WO3@Ti3C2T x (K1):

[0130] (1) 0.1g of Ti3C2T x(S1) and 20 g of the first solvent (V(acetone):V(water) = 5:1) were mixed and subjected to ultrasonic treatment at a power of 600 W and a temperature of 25°C for 60 min, and then 0.03 g of WO3 nanoparticles (M1) was added, stirred for 2 h in the dark, and then refluxed at 60°C for 6 h;

[0131] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 10000 r / min, washed with deionized water, and freeze-dried at a temperature of -50°C for 8 h to obtain WO3@Ti3C2T x (K1) (the microstructure of which is shown in Figure 3

[0132] Example 2

[0133] Ti3C2T x (S2):

[0134] A1: 2 g of Ti3AlC2 was added to 3 g of LiF in 40 mL of 9 mol / L HCl aqueous solution, stirred at 50°C for 36 h, then centrifuged by a centrifuge, washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0135] A2: The precipitate collected in step A1 was washed with deionized water, then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60°C for 8 h;

[0136] A3: The intermediate material obtained in step A2 was dispersed in deionized water, ultrasonicated at 4°C for 30 min, and then separated by a centrifuge to obtain Ti3C2T x (S2);

[0137] The WO3 nanoparticles (M1) were prepared in the manner of Example 1;

[0138] WO3@Ti3C2T x (K2):

[0139] (1) 0.1 g of Ti3C2T x (S2) and 30 g of the first solvent (V(ethanol):V(water) = 4:1) were mixed and subjected to ultrasonic treatment at a power of 800 W and a temperature of 25°C for 30 min, and then 0.03 g of WO3 nanoparticles (M1) was added, stirred for 3 h in the dark, and then refluxed at 60°C for 6 h;

[0140] ​(2) centrifuging the intermediate product at a speed of 10,000 r / min, then washing with deionized water, and freeze-drying at a temperature of -50°C for 8 h to obtain WO3@Ti3C2T x (K2).

[0141] Example 3

[0142] Preparation of Ti3C2T x (S3):

[0143] A1: 2 g of Ti3AlC2 was added to 40 mL of 9 mol / L aqueous HCl solution containing 3 g of LiF, and stirred at 50°C for 28 h, then centrifuged by a centrifuge, washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0144] A2: The precipitate collected in step A1 was washed with deionized water, then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 70°C for 12 h;

[0145] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and ultrasonicated at 10°C for 30 min, then separated by a centrifuge to obtain Ti3C2T x (S3);

[0146] Preparation of WO3 nanoparticles (M3):

[0147] 0.4 g of Na2WO4·2H2O was dissolved in 10 mL of ultrapure water and stirred vigorously for 10 min, then 5 mL of ethylene glycol was added, and after stirring for 20 min, ultrasonic treatment was performed for 5 min, then 0.9 g of Na2SO4·10H2O and 4 mL of HCl (12M) were added, and the above mixture was placed in a 50 mL polytetrafluoroethylene-lined hydrothermal kettle, and reacted at a temperature of 130°C for 5 h. After the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, then placed in a vacuum drying oven at 80°C for 10 h, and finally placed in a 500°C muffle furnace for calcination for 8 h to obtain WO3 nanoparticles (M3);

[0148] Preparation of WO3@Ti3C2T x (K3):

[0149] (1) 0.1 g of Ti3C2T x(S3) and 20 g of the first solvent (V(acetone):V(water) = 3:1) were mixed and then subjected to ultrasonic treatment at a power of 600 W and a temperature of 25°C for 40 min, and then 0.02 g of WO3 nanoparticles (M3) was added, stirred for 3 h in the dark, and then refluxed at 60°C for 6 h;

[0150] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 8000 r / min, washed with deionized water, and freeze-dried at a temperature of -70°C for 8 h to obtain WO3@Ti3C2T x (K3).

[0151] Example 4

[0152] Preparation of Ti3C2T x (S4):

[0153] A1: 1 g of Ti3AlC2 was added to 50 ml of hydrofluoric acid with a mass concentration of 20%, stirred at 30°C for 36 h, and then centrifuged by a centrifuge, washed with deionized water until the pH value of the upper clear liquid was 6, and the precipitate was collected;

[0154] A2: The precipitate collected in step A1 was washed with deionized water, and then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60°C for 8 h;

[0155] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and ultrasonic treatment was performed at 0°C for 30 min, and then separated by a centrifuge to obtain Ti3C2T x (S4);

[0156] The WO3 nanoparticles (M1) were prepared in the manner of Example 1;

[0157] Preparation of WO3@Ti3C2T x (K4):

[0158] (1) 0.1 g of Ti3C2T x (S4) and 40 g of the first solvent (V(acetone):V(water) = 4:1) were mixed and then subjected to ultrasonic treatment at a power of 800 W and a temperature of 25°C for 50 min, and then 0.04 g of WO3 nanoparticles (M1) was added, stirred for 2 h in the dark, and then refluxed at 60°C for 6 h;

[0159] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 10000 r / min, washed with deionized water, and freeze-dried at a temperature of -60°C for 8 h to obtain WO3@Ti3C2Tx (K4).

[0160] Example 5

[0161] Preparation of Ti3C2T x (S5):

[0162] A1: Add 1g Ti3AlC2 to 40mL 9mol / L HCl aqueous solution containing 3g LiF, stir at 35℃ for 40h, then centrifuge and wash with deionized water until the pH value of the supernatant reaches 6, and collect the precipitate;

[0163] A2: The precipitate collected in step A1 was re-washed with deionized water, then vacuum filtered through a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 80°C for 6 h;

[0164] A3: The intermediate material obtained in step A2 was dispersed in deionized water, ultrasonicated at 4°C for 30 min, and then separated by centrifuge to obtain Ti3C2T x (S5);

[0165] Preparation of WO3 nanocube (M5):

[0166] 0.5 g of Na2WO4·2H2O was dissolved in 15 mL of ultrapure water and stirred vigorously for 10 min. Then, 5 mL of isopropanol was added, stirred for 10 min, and ultrasonicated for 5 min. Then, 0.8 g of tartaric acid and 2 mL of HCl (12 M) were added. The mixed solution was placed in a 50 mL polytetrafluoroethylene-lined hydrothermal autoclave and reacted at 140 ° C for 14 h. After the reaction, the solid intermediate product was centrifuged and washed three times with ultrapure water and ethanol respectively, then placed in a vacuum drying oven at 80 ° C for 16 h, and finally calcined in a muffle furnace at 550 ° C for 7 h to obtain WO3 nanocubes (M5);

[0167] Preparation of WO3@Ti3C2T x (K5):

[0168] (1) 0.1g Ti3C2T x (S5) and 35 g of the first solvent (V(ethanol):V(water) is 3:

[0169] 1) After mixing, ultrasonic treatment was performed at a power of 500 W, a temperature of 25° C., and a time of 50 min. Then, 0.03 g of WO3 nanocubes (M5) was added, stirred for 2 h in the dark, and then refluxed at 50° C. for 6 h.

[0170] (2) centrifugation was used to separate the solid and liquid of the intermediate product above, the centrifugation speed was 8000 r / min, then deionized water was used for washing, freeze-drying was carried out at a temperature of -70°C for 8h, and WO3@Ti3C2T x (K5).

[0171] Example 6

[0172] Ti3C2T x (S1);

[0173] Preparation of WO3 nanocubes (M6):

[0174] 0.5g of Na2WO4·2H2O was dissolved in 15mL of ultrapure water and stirred vigorously for 10min, then 5mL of isopropanol was added, after stirring for 10min, ultrasonic treatment was carried out for 5min, then 0.7g of tartaric acid and 2mL of HCl (12M) were added, the above mixed solution was placed in a 50mL polytetrafluoroethylene lined autoclave, and reacted at a temperature of 140°C for 14h, after the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times respectively, then placed in a vacuum drying oven at 80°C for 16h, and finally placed in a 550°C muffle furnace for calcination for 6h, WO3 nanocubes (M6) were obtained;

[0175] Preparation of WO3@Ti3C2T x (K6):

[0176] (1) 0.1g of Ti3C2T x (S1) and 15g of the first solvent (acetone:water = 4:1 (V / V) were mixed:

[0177] 1) After mixing, ultrasonic treatment was carried out, the power of ultrasonic treatment was 500W, the temperature was 25°C, and the time was 50min, then 0.04g of WO3 nanocubes (M6) was added, stirred for 2h in the dark, and then refluxed at a temperature of 50°C for 6h;

[0178] (2) centrifugation was used to separate the solid and liquid of the intermediate product above, the centrifugation speed was 8000 r / min, then deionized water was used for washing, freeze-drying was carried out at a temperature of -70°C for 8h, and WO3@Ti3C2T x (K6).

[0179] Example 7

[0180] Preparation of Ti3C2T x (S7):

[0181] A1 : 2 g of Ti3AlC2 was added into 40 mL of 9 mol / L HCl aqueous solution containing 3 g of LiF, stirred at 25 °C for 20 h, then centrifuged by a centrifuge, washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0182] A2: The precipitate collected in step A1 was washed with deionized water again, then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60 °C for 8 h;

[0183] A3: The intermediate material obtained in step A2 was dispersed in deionized water, ultrasonicated at 10 °C for 30 min, then separated by a centrifuge to obtain Ti3C2T x (S7);

[0184] WO3 nanocubes (M5) were prepared in the same manner as in Example 5;

[0185] WO3@Ti3C2T x (K7) was prepared:

[0186] (1) 0.1 g of Ti3C2T x (S7) and 30 g of the first solvent (V(acetone):V(water) was 3:1) were mixed and ultrasonicated at a power of 700 W and a temperature of 25 °C for 60 min, then 0.1 g of WO3 nanocubes (M5) was added, stirred in the dark for 2 h, and then refluxed at 50 °C for 6 h;

[0187] (2) The above intermediate product was separated by centrifugation at a speed of 8000 r / min, then washed with deionized water, and freeze-dried at a temperature of -70 °C for 8 h to obtain WO3@Ti3C2T x (K7).

[0188] Example 8

[0189] Ti3C2T x (S8) was prepared:

[0190] A1 : 1 g of Ti3AlC2 was added into 50 mL of 20% hydrofluoric acid, stirred at 30 °C for 48 h, then centrifuged by a centrifuge, washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0191] A2: The precipitate collected in step A1 was washed with deionized water again, then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 70 °C for 8 h;

[0192] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and ultrasonic treatment was performed at 0°C for 30 min, and then centrifugation was performed to obtain Ti3C2T x (S8) ;

[0193] Preparation of WO3 nanocubes (M8) :

[0194] 0.5 g of Na2WO4·2H2O was dissolved in 15 mL of ultrapure water and stirred vigorously for 10 min, then 5 mL of isopropanol was added, and after stirring for 10 min, ultrasonic treatment was performed for 5 min, then 0.6 g of tartaric acid and 2 mL of HCl (12 M) were added, and the above mixed solution was placed in a 50 mL polytetrafluoroethylene-lined hydrothermal kettle, and reacted at a temperature of 130°C for 13 h, after the reaction was completed, the solid-phase intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, and then placed in a vacuum drying oven at 80°C for 16 h and finally placed in a 550°C muffle furnace for calcination for 5 h, to obtain WO3 nanocubes (M8) ;

[0195] Preparation of WO3@Ti3C2T x (K8) :

[0196] (1) 0.1 g of Ti3C2T x (S8) and 20 g of the first solvent (V(acetone):V(water) is 2:

[0197] 1) After mixing, ultrasonic treatment was performed at a power of 600 W and a temperature of 25°C for 40 min, then 0.005 g of WO3 nanocubes (M8) was added, and stirring was performed in the dark for 2 h, and then reflux was performed at a temperature of 50°C for 6 h;

[0198] (2) The above intermediate product was separated by centrifugation at a speed of 8000 r / min, then washed with deionized water, and freeze-dried at a temperature of -70°C for 10 h to obtain WO3@Ti3C2T x (K8).

[0199] Example 9

[0200] Preparation of Ti3C2T x (S8) ;

[0201] Preparation of WO3 nanosheets (M9) :

[0202] 0.1 g of Na2WO4·2H2O was dissolved in 15 mL of ultrapure water and stirred vigorously for 10 min, then 0.2 g of citric acid and 2 mL of HCl (12 M) were added, and the above mixed solution was placed in a 50 mL polytetrafluoroethylene-lined hydrothermal kettle, and reacted at a temperature of 130°C for 15 h. After the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, and then placed in a vacuum drying oven at 80°C for 16 h and finally calcined in a 400°C muffle furnace for 10 h to obtain WO3nanosheets (M9);

[0203] Preparation of WO3@Ti3C2T x (K9):

[0204] (1) 0.1 g of Ti3C2T x (S8) and 30 g of the first solvent (V(acetone):V(water) is 2:1) were mixed and ultrasonically treated, the power of ultrasonic treatment was 600 W, the temperature was 25°C, and the time was 40 min, then 0.03 g of WO3nanosheets (M9) was added, stirred for 2 h in the dark, and then refluxed at 50°C for 6 h;

[0205] (2) The above intermediate product was separated by centrifugation, the speed of centrifugation was 8000 r / min, then washed with deionized water, and freeze-dried at a temperature of -70°C for 10 h to obtain WO3@Ti3C2T x (K9).

[0206] Example 10

[0207] Preparation of Ti3C2T x (S10):

[0208] A1: 2 g of Ti3AlC2 was added to 40 mL of 9 mol / L HCl aqueous solution containing 3 g of LiF, stirred at 25°C for 20 h, then centrifuged by a centrifuge, washed with deionized water until the pH value of the upper clear liquid was 6, and the precipitate was collected;

[0209] A2: The precipitate collected in step A1 was washed with deionized water, then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60°C for 8 h;

[0210] A3: The intermediate material obtained in step A2 was dispersed in deionized water, ultrasonicated at 10°C for 30 min, and then separated by a centrifuge to obtain Ti3C2T x (S10);

[0211] Preparation of WO3nanosheets (M10):

[0212] 0.5 g of Na2WO4·2H2O was dissolved in 15 mL of ultrapure water and stirred vigorously for 10 min, then 0.8 g of citric acid and 4 mL of HCl (12 M) were added, and the above mixed solution was placed in a 50 mL polytetrafluoroethylene-lined autoclave, and reacted at a temperature of 140°C for 15 h. After the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, and then placed in a vacuum drying oven at 80°C for 16 h and finally calcined in a 550°C muffle furnace for 5 h to obtain WO3 nanosheets (M10);

[0213] Preparation of WO3@Ti3C2T x (K10):

[0214] (1) 0.1 g of Ti3C2T x (S10) was mixed with 20 g of the first solvent (V(ethanol):V(water) was 3:1) and ultrasonically treated, the power of ultrasonic treatment was 700 W, the temperature was 25°C, and the time was 60 min, then 0.04 g of WO3 nanosheets (M10) was added, stirred for 3 h in the dark, and then refluxed at 50°C for 6 h;

[0215] (2) The above intermediate product was separated by centrifugation at a speed of 8000 r / min, then washed with deionized water, and freeze-dried at a temperature of -70°C for 8 h to obtain WO3@Ti3C2T x (K10).

[0216] Example 11

[0217] Preparation of Ti3C2T x (S11):

[0218] A1: 1 g of Ti3AlC2 was added to 50 ml of hydrofluoric acid with a mass concentration of 25%, stirred at 30°C for 48 h, then centrifuged by a centrifuge, washed with deionized water until the pH value of the upper clear liquid was 6, and the precipitate was collected;

[0219] A2: The precipitate collected in step A1 was washed with deionized water, then vacuum filtered through a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60°C for 7 h;

[0220] A3: The intermediate material obtained in step A2 was dispersed in deionized water, ultrasonicated at 4°C for 30 min, and then separated by a centrifuge to obtain Ti3C2T x (S11);

[0221] Preparation of WO3 nanosheets (M11):

[0222] 0.5 g of Na2WO4·2H2O was dissolved in 15 mL of ultrapure water and stirred vigorously for 10 min, then 0.8 g of citric acid and 3 mL of HCl (12 M) were added, and the above mixed solution was placed in a 50 mL polytetrafluoroethylene-lined autoclave, and reacted at a temperature of 140°C for 14 h. After the reaction was completed, the solid-phase intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, and then placed in a vacuum drying box at 80°C for 16 h and finally placed in a 550°C muffle furnace for calcination for 6 h, to obtain WO3nanosheets (M11);

[0223] Preparation of WO3@Ti3C2T x (K11):

[0224] (1) 0.1 g of Ti3C2T x (S11) and 25 g of the first solvent (V(acetone):V(water) is 4:1) were mixed and ultrasonically treated, the power of ultrasonic treatment was 500 W, the temperature was 25°C, and the time was 50 min, then 0.1 g of WO3nanosheets (M11) was added, stirred for 2 h in the dark, and then refluxed at 50°C for 6 h;

[0225] (2) The above intermediate product was separated by centrifugation, the speed of centrifugation was 8000 r / min, then washed with deionized water, and freeze-dried at a temperature of -70°C for 8 h, to obtain WO3@Ti3C2T x (K11).

[0226] Example 12

[0227] Ti3C2T x (S5) was prepared in the manner of Example 5:

[0228] Preparation of WO3nanosheets (M12):

[0229] 0.5 g of Na2WO4·2H2O was dissolved in 15 mL of ultrapure water and stirred vigorously for 10 min, then 0.8 g of citric acid and 3 mL of HCl (12 M) were added, and the above mixed solution was placed in a 50 mL polytetrafluoroethylene-lined autoclave, and reacted at a temperature of 140°C for 14 h. After the reaction was completed, the solid-phase intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, and then placed in a vacuum drying box at 80°C for 16 h and finally placed in a 550°C muffle furnace for calcination for 6 h, to obtain WO3nanosheets (M11);

[0230] Preparation of WO3@Ti3C2T x (K12)

[0231] (1) 0.1 g of Ti3C2T x(S5) and 25 g of the first solvent (V(ethanol):V(water) = 2:1) were mixed and then subjected to ultrasonic treatment at a power of 500 W and a temperature of 25°C for 50 min, and then 0.005 g of WO3nanosheets (M12) was added, and stirred for 2 h in the dark, and then refluxed at 50°C for 6 h;

[0232] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 8000 r / min, and then washed with deionized water, and freeze-dried at a temperature of -70°C for 8 h to obtain WO3@Ti3C2T x (K12).

[0233] Example 13

[0234] Preparation of Ti3C2T x (S13):

[0235] A1: 2 g of Ti3AlC2 was added to 50 ml of hydrofluoric acid with a mass concentration of 30%, and stirred at 30°C for 45 h, and then centrifuged by a centrifuge, and washed with deionized water until the pH value of the upper clear liquid was 6, and the precipitate was collected;

[0236] A2: The precipitate collected in step A1 was washed with deionized water, and then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 70°C for 8 h;

[0237] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and ultrasonically treated at 0°C for 40 min, and then separated by a centrifuge to obtain Ti3C2T x (S13);

[0238] Preparation of WO3nanowires (M13):

[0239] 0.5 g of Na2WO4·2H2O was dissolved in 20 mL of anhydrous ethanol, and the mixed solution was placed in a 50 mL polytetrafluoroethylene-lined hydrothermal kettle, and reacted at a temperature of 140°C for 10 h. After the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, and then placed in a vacuum drying oven at 80°C for 16 h, and finally placed in a 500°C muffle furnace for calcination for 7 h to obtain WO3nanowires (M13);

[0240] Preparation of WO3@Ti3C2T x (K13):

[0241] (1) 0.1 g of Ti3C2T x(S13) and 30 g of the first solvent (V(ethanol):V(water) = 2:1) were mixed and then subjected to ultrasonic treatment at a power of 600 W and a temperature of 25°C for 40 min, and then 0.03 g of WO3 nanowires (M13) was added and stirred for 2 h in the dark, and then refluxed at 50°C for 6 h;

[0242] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 8000 r / min, and then washed with deionized water, and freeze-dried at a temperature of -70°C for 10 h to obtain WO3@Ti3C2T x (K13).

[0243] Example 14

[0244] Preparation of Ti3C2T x (S14):

[0245] A1: 2 g of Ti3AlC2 was added to 50 mL of 9 mol / L HCl aqueous solution containing 3 g of LiF, and stirred at 25°C for 15 h, and then centrifuged by a centrifuge, and washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0246] A2: The precipitate collected in step A1 was washed with deionized water, and then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60°C for 8 h;

[0247] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and ultrasonicated at 10°C for 30 min, and then separated by a centrifuge to obtain Ti3C2T x (S14);

[0248] Preparation of WO3 nanowires (M14):

[0249] 0.5 g of Na2WO4·2H2O was dissolved in 15 mL of anhydrous ethanol, and the mixed solution was placed in a 50 mL polytetrafluoroethylene-lined autoclave, and reacted at a temperature of 140°C for 15 h. After the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times, respectively, and then placed in a vacuum drying oven at 80°C for 16 h, and finally placed in a muffle furnace at 550°C for calcination for 5 h to obtain WO3 nanowires (M14);

[0250] Preparation of WO3@Ti3C2T x (K14):

[0251] (1) 0.1 g of Ti3C2T x(S14) and 30 g of the first solvent (V(ethanol):V(water) = 4:1) were mixed and then subjected to ultrasonic treatment at a power of 700 W and a temperature of 25°C for 60 min, and then 0.04 g of WO3 nanowires (M14) was added and stirred for 3 h in the dark, and then refluxed at 50°C for 6 h;

[0252] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 8000 r / min, and then washed with deionized water, and freeze-dried at a temperature of -70°C for 8 h to obtain WO3@Ti3C2T x (K14).

[0253] Example 15

[0254] Preparation of Ti3C2T x (S15):

[0255] A1: 1 g of Ti3AlC2 was added to 50 ml of hydrofluoric acid with a mass concentration of 35%, and stirred at 40°C for 48 h, and then centrifuged by a centrifuge, and washed with deionized water until the pH value of the upper clear liquid was 6, and the precipitate was collected;

[0256] A2: The precipitate collected in step A1 was washed with deionized water, and then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60°C for 7 h;

[0257] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and ultrasonically treated at 4°C for 30 min, and then separated by a centrifuge to obtain Ti3C2T x (S15);

[0258] Preparation of WO3 nanosheets (M15):

[0259] 0.5 g of Na2WO4·2H2O was dissolved in 25 mL of anhydrous ethanol, and the mixed solution was placed in a 50 mL polytetrafluoroethylene-lined autoclave, and reacted at a temperature of 140°C for 14 h. After the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times, and then placed in a vacuum drying oven at 80°C for 16 h, and finally placed in a muffle furnace at 550°C for calcination for 7 h to obtain WO3 nanowires (M15);

[0260] Preparation of WO3@Ti3C2T x (K15):

[0261] (1) 0.1 g of Ti3C2T x(S15) and 25 g of the first solvent (V(acetone) : V(water) = 4:1) were mixed and ultrasonically treated at a power of 500 W and a temperature of 25°C for 50 min, and then 0.1 g of WO3 nanowires (M15) was added and stirred for 2 h in the dark, and then refluxed at 50°C for 6 h;

[0262] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 8000 r / min, and then washed with deionized water, and freeze-dried at a temperature of -70°C for 8 h to obtain WO3@Ti3C2T x (K15).

[0263] Example 16

[0264] Preparation of Ti3C2T x (S16):

[0265] A1: 1 g of Ti3AlC2 was added to 40 mL of 9 mol / L HCl aqueous solution containing 3 g of LiF, and stirred at 35°C for 40 h, and then centrifuged by a centrifuge, and washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0266] A2: The precipitate collected in step A1 was washed with deionized water, and then vacuum filtered by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 80°C for 6 h;

[0267] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and ultrasonically treated at 4°C for 30 min, and then separated by a centrifuge to obtain Ti3C2T x (S16);

[0268] Preparation of WO3 nanosheet (M16):

[0269] 0.5 g of Na2WO4·2H2O was dissolved in 15 mL of anhydrous ethanol, and the mixed solution was placed in a 50 mL polytetrafluoroethylene-lined autoclave, and reacted at a temperature of 140°C for 14 h, after the reaction, the solid intermediate product was washed with ultrapure water and ethanol three times, and then placed in a vacuum drying oven at 80°C for 16 h, and finally placed in a muffle furnace at 550°C for calcination for 8 h to obtain WO3 nanowires (M16);

[0270] Preparation of WO3@Ti3C2T x (K16):

[0271] (1) 0.1 g of Ti3C2T x(S16) and 30 g of the first solvent (V(acetone) : V(water) = 2 : 1) were mixed and subjected to ultrasonic treatment at a power of 500 W and a temperature of 25°C for 50 min, and then 0.005 g of WO3nanowires (M16) was added and stirred for 2 h in the dark, followed by refluxing at 50°C for 6 h;

[0272] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 8000 r / min, and then washed with deionized water and freeze-dried at a temperature of -70°C for 8 h to obtain WO3@Ti3C2T x (K16).

[0273] Example 17

[0274] Ti3C2T x (S1);

[0275] WO3nanoparticles (M1) were prepared in the same manner as in Example 1.

[0276] WO3@Ti3C2T x (K17):

[0277] (1) 0.1 g of Ti3C2T x (S1) and 20 g of the first solvent (V(acetone) : V(water) = 5 : 1) were mixed and subjected to ultrasonic treatment at a power of 600 W and a temperature of 25°C for 60 min, and then 0.1 g of WO3nanoparticles (M1) was added and stirred for 2 h in the dark, followed by refluxing at 60°C for 6 h.

[0278] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 10000 r / min, and then washed with deionized water and freeze-dried at a temperature of -50°C for 8 h to obtain WO3@Ti3C2T x (K17).

[0279] Example 18

[0280] Ti3C2T x (S1);

[0281] WO3nanoparticles (M1) were prepared in the same manner as in Example 1.

[0282] WO3@Ti3C2T x (K18):

[0283] (1) 0.1 g of Ti3C2T x(S1) and 20 g of the first solvent (V(acetone):V(water) = 5:1) were mixed and then subjected to ultrasonic treatment at a power of 600 W and a temperature of 25°C for 60 min, and then 0.005 g of WO3 nanoparticles (M18) was added, and stirred for 2 h in the dark, and then refluxed at 60°C for 6 h;

[0284] (2) The intermediate product was subjected to solid-liquid separation by centrifugation at a speed of 10000 r / min, and then washed with deionized water, and freeze-dried at a temperature of -50°C for 8 h to obtain WO3@Ti3C2T x (K18).

[0285] Comparative Example 1

[0286] Preparation of Ti3C2T x (S1):

[0287] A1: 1 g of Ti3AlC2 was added to 50 ml of hydrofluoric acid with a mass concentration of 30%, and stirred at 30°C for 48 h, and then subjected to centrifugation by a centrifuge, and washed with deionized water until the pH value of the supernatant was 6, and the precipitate was collected;

[0288] A2: The precipitate collected in step A1 was washed with deionized water, and then subjected to vacuum filtration by a polytetrafluoroethylene membrane with a pore size of 0.22 μm, and then dried in a vacuum drying oven at 60°C for 8 h;

[0289] A3: The intermediate material obtained in step A2 was dispersed in deionized water, and subjected to ultrasonic treatment at 4°C for 30 min, and then subjected to separation by a centrifuge to obtain Ti3C2T x (S1) (the microstructure of which is shown in Figure 1 ).

[0290] Comparative Example 2

[0291] Preparation of WO3 nanoparticles (M1)

[0292] 0.4 g of Na2WO4·2H2O was dissolved in 10 mL of ultrapure water and stirred vigorously for 10 min, and then 5 mL of ethylene glycol was added, and after stirring for 20 min, ultrasonic treatment was performed for 5 min, and then 0.9 g of Na2SO4·10H2O and 4 mL of HCl (12M) were added, and the mixed solution was placed in a 50 mL polytetrafluoroethylene-lined hydrothermal kettle, and reacted at a temperature of 140°C for 8 h, and after the reaction was completed, the solid intermediate product was washed by centrifugation with ultrapure water and ethanol three times, and then placed in a vacuum drying oven at 80°C for 15 h, and finally placed in a 550°C muffle furnace for calcination for 2 h to obtain WO3 nanoparticles (M1) (the microstructure of which is shown in Figure 2 ).

[0293] Test Case

[0294] (1) The Ti3C2T prepared in Examples 1-18 was observed using a scanning electron microscope. x , WO3 nanomaterials and WO3@Ti3C2T x Composite material and Ti3C2T prepared in Comparative Example 1 x The morphology of the WO3 nanomaterials prepared in the comparative example was characterized. Figure 1 The Ti3C2T prepared in Comparative Example 1 x Scanning electron microscope images of Figure 2 This is a scanning electron microscope image of WO3 nanoparticles prepared in comparative example 2. Figure 3 WO3@Ti3C2T prepared in Example 1 x SEM images of Ti3C2T x The test results of the thickness and size of WO3 nanomaterials are shown in Table 1;

[0295] Depend on Figure 1 It can be seen that Ti3C2T x It is a layered nanosheet with a thickness of about 100nm; Figure 2 It can be seen that WO3 nanoparticles are spherical and have a size of about 5 to 20 nm. Figure 3 It can be seen that WO3 nanoparticles are loaded onto Ti3C2T x WO3@Ti3C2T is formed on x ;

[0296] (2) The products prepared in Examples 1-18 and Comparative Examples 1-2 were subjected to semi-quantitative EDS spectrum analysis using an energy dispersive spectrometer to calculate the loading amount of the WO3 nanomaterial. The results are shown in Table 1.

[0297] (3) The sensing performance of the products prepared in the examples and comparative examples was tested by the following method: 2 mg of terpineol was placed in a mortar, 1 mg of the product was added, and the mixture was ground for 3 min. The above material was then applied to a ceramic tube with an interdigitated gold electrode using a brush to form a sensing film. The film was then dried under vacuum to obtain a hydrogen sulfide sensor. The thickness of the sensing film and the original resistance of the sensor were measured. The sensor was then placed in a 50 ppb concentration of hydrogen sulfide and its resistance change was measured. The results are shown in Table 2, where: Figure 4 1 is a graph showing the change in resistance of the sensors prepared in Example 1, Comparative Example 1 and Comparative Example 2 in different concentrations of hydrogen sulfide;

[0298] (4) Test of WO3@Ti3C2T prepared in Example 1 x The response of the prepared sensor to interfering gases, including ammonia, methane, carbon monoxide, and nitric oxide;

[0299] WO3@Ti3C2T x The prepared sensor was placed in different volume concentrations of ammonia gas, and the results showed that the response intensity of ammonia was only 1% of that of hydrogen sulfide under the same volume concentration; WO3@Ti3C2T x The prepared sensor was placed in different volume concentrations of methane gas, and the results showed that the response intensity of methane was only 0.8% of that of hydrogen sulfide under the same volume concentration; WO3@Ti3C2T x The prepared sensor was placed in different volume concentrations of carbon monoxide gas, and the results showed that the response intensity of carbon monoxide was only 0.4% of that of hydrogen under the same volume concentration; WO3@Ti3C2T x The prepared sensor was placed in different volume concentrations of carbon monoxide gas, and the results showed that the response intensity of carbon monoxide was only 0.4% of that of hydrogen under the same volume concentration; WO3@Ti3C2T

[0300] The above results show that the WO3@Ti3C2T x The prepared sensor has selectivity to gases, and only when the detected gas is hydrogen sulfide does it have high sensitivity and fast response.

[0301] Table 1

[0302]

[0303]

[0304] Table 2

[0305]

[0306]

[0307] As can be seen from the results in Table 1, the Ti3C2T x prepared by the present application has a thickness of 50-100 nm, and the loading amount of WO3 nanomaterial is 5-35 wt%.

[0308] As can be seen from the results in Table 2, the WO3@Ti3C2T x prepared by the present application has high sensitivity to H2S, fast response speed, and low lower limit of detectable H2S volume concentration, and can respond to H2S with a volume concentration of 50 ppb within 10 s.

[0309] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A method based on WO3 and Ti3C2T x The composite material is characterized in that The WO3 and Ti3C2T x Composite materials include Ti3C2T x and loaded on Ti3C2T x WO3 nanomaterials on.

2. The method according to claim 1 based on WO3 and Ti3C2T x The composite material is characterized in that Based on WO3 and Ti3C2T x The total weight of the composite material is taken as a basis, and the content of the WO3 nanomaterial is 5 to 35 wt%.

3. The method based on WO3 and Ti3C2T according to claim 1 or 2 x The composite material is characterized in that The WO3 and Ti3C2T x The specific surface area of ​​the composite material is 100~1000m 2 / g.

4. The method according to any one of claims 1 to 3, wherein the method is based on WO3 and Ti3C2T x The composite material is characterized in that The WO3 nanomaterial is selected from one or more of WO3 nanoparticles, WO3 nanocubes, WO3 nanosheets and WO3 nanowires.

5. The method according to claim 4 based on WO3 and Ti3C2T x The composite material is characterized in that The WO3 nanoparticle size is 5 to 500 nm; Preferably, the side length of the WO3 nanocube is 5 to 50 nm; Preferably, the thickness of the WO3 nanosheet is 10 to 100 nm; Preferably, the length of the WO3 nanowire is 100-500 nm, and the width is 2-10 nm.

6. A method for preparing a WO3 and Ti3C2T x A method of making a composite material, characterized in that The method comprises the following steps: (1) WO3 nanomaterials, Ti3C2T x mixing with a first solvent; (2) The material obtained in step (1) is subjected to solid-liquid separation, and then the obtained solid phase material is freeze-dried.

7. The method according to claim 6, characterized in that In step (1), Ti3C2T x The weight ratio of the amount of WO3 nanomaterial is 1:0.1-0.

5.

8. The method according to claim 6 or 7, characterized in that In step (1), Ti3C2T x The weight ratio of the amount of the first solvent is 1:100-400.

9. The method according to any one of claims 6 to 8, characterized in that In step (1), the mixing conditions include: temperature of 0 to 100° C. and time of 2 to 36 hours.

10. The method according to claim 6, characterized in that In step (1), the Ti3C2T x The preparation method includes: mixing Ti3AlC2 with a solution containing fluoride ions and hydrogen ions and then performing a first reaction.

11. The method according to claim 10, characterized in that The conditions of the first reaction include: temperature of 10 to 70° C. and time of 10 to 48 hours.

12. The method according to claim 6, characterized in that In step (1), the WO3 nanomaterial is selected from one or more of WO3 nanoparticles, WO3 nanocubes, WO3 nanosheets and WO3 nanowires.

13. The method according to claim 12, characterized in that The preparation method of the WO3 nanoparticles comprises: subjecting a W precursor solution, sulfate and a first acidic substance to a first hydrothermal reaction and a first calcination.

14. The method according to claim 13, characterized in that The conditions of the first hydrothermal reaction include: temperature of 100 to 180° C. and time of 5 to 30 hours; Preferably, the first calcination conditions include: 400-600° C., and time of 5-20 h.

15. The method according to claim 12, characterized in that The preparation method of the WO3 nanocube comprises: subjecting a W precursor solution, tartaric acid, and a second acidic substance to a second hydrothermal reaction and a second calcination.

16. The method according to claim 15, characterized in that The conditions of the second hydrothermal reaction include: temperature of 100 to 160° C., time of 5 to 35 hours; Preferably, the second calcination conditions include: 400-600° C., and time of 5-30 hours.

17. The method according to claim 12, wherein: The preparation method of the WO3 nanosheets comprises: subjecting a W precursor solution, citric acid and a third acidic substance to a third hydrothermal reaction and a third calcination.

18. The method according to claim 17, characterized in that The conditions of the third hydrothermal reaction include: temperature of 100 to 180° C., time of 10 to 30 h; Preferably, the conditions for the third calcination include: 400-600° C., and time of 5-15 hours.

19. The method according to claim 12, wherein: The method for preparing the WO3 nanowires includes: subjecting a W precursor and ethanol to a fourth hydrothermal reaction and a fourth calcination.

20. The method according to claim 19, characterized in that The conditions of the fourth hydrothermal reaction include: temperature of 100 to 170° C., time of 10 to 40 hours; Preferably, the fourth calcination conditions include: 400-600° C., and time of 5-20 h.

21. The method according to claim 6, characterized in that The first solvent is selected from one or more of water, ethanol, methanol, chloroform and acetone.

22. The method according to any one of claims 6 to 21, characterized in that In step (2), the freeze-drying conditions include: a temperature of -70 to -40°C and a time of 2 to 36 hours.

23. The WO3 and Ti3C2T3 based quartz crystals prepared by the method according to any one of claims 6 to 22 x composite materials.

24. The WO3 and Ti3C2T based composite material according to any one of claims 1 to 6 or 23. x Application of composite materials in hydrogen sulfide detection.

25. A hydrogen sulfide sensor, characterized in that: The hydrogen sulfide sensor comprises the WO3 and Ti3C2T based sensor according to any one of claims 1 to 6 or 23. x composite materials.

26. A method for preparing the hydrogen sulfide sensor according to claim 25, characterized in that: The method comprises the following steps: x The composite material is mixed with an organic solvent and ground, then coated on the surface of a ceramic tube with electrodes to form a sensing film, and then vacuum dried.

27. The method according to claim 26, characterized in that Based on WO3 and Ti3C2T x The weight ratio of the composite material to the organic solvent is 1:1-10.

28. The method according to claim 26 or 27, characterized in that The thickness of the sensing film is 200-1000 μm.

29. A method for detecting hydrogen sulfide, characterized in that: The method comprises contacting the hydrogen sulfide sensor according to claim 25 with a mixed gas containing hydrogen sulfide.

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