Preparation method and application of Se-doped O vacancy tungsten oxide porous material
Se-doped O-vacancy tungsten oxide porous materials were prepared by solution thermal method, which solved the agglomeration problem of nano-tungsten oxide materials during the preparation process, improved the active surface and active sites of the material, and realized the application of high-sensitivity H2S gas sensor.
Patent Information
- Application Number
- CN202510854215.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-24
- Publication Date
- 2025-09-16
AI Technical Summary
Nano-tungsten oxide materials agglomerate during the preparation process, resulting in a reduction in effective surface area and reduced functional properties. At the same time, the material structure limits its performance improvement.
Se-doped O-vacancy tungsten oxide porous material was prepared by solution thermal method. Tungsten hexachloride, selenium oxide and oleyl primary amine were used as raw materials to form a reaction solution, which was reacted under a specific temperature and atmosphere, precipitated and calcined to form Se-WO3-x material with a microspherical porous structure and a large number of O vacancy defects.
The active surface and active sites of the material are improved, and the performance of the material is enhanced, so that it exhibits excellent gas-sensing performance to H2S gas at room temperature, realizing the application of H2S sensor with high sensitivity and low detection limit.
Smart Images
Figure CN120646911A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a preparation method of a Se-doped O-vacancy tungsten oxide porous material and application thereof. Background Art
[0002] Tungsten oxide semiconductor materials possess excellent physical and chemical properties and are important functional materials, widely used in fields such as photoelectrocatalysis, gas sensing, and energy storage. Currently, nano-tungsten oxide materials with different morphologies, such as nanospheres, nanowires, nanoflowers, and nanofilms, are prepared through physical and chemical methods such as electrochemistry, magnetron sputtering, chemical vapor deposition, hydrothermal methods, and sol-gel methods. The performance of nano-tungsten oxide as a functional material can be significantly improved by morphological manipulation.
[0003] Currently, the preparation process of nano-tungsten oxide materials causes agglomeration, which reduces the effective surface area and degrades functional properties. Furthermore, the functional properties of tungsten oxide materials are limited by the material's own structure, which restricts further improvement of their functional properties. Summary of the Invention
[0004] In order to solve the above problems, the present invention provides a method for preparing a Se-doped O-vacancy tungsten oxide porous material and its application.
[0005] The preparation method of a Se-doped O-vacancy tungsten oxide porous material of the present invention is carried out by the following steps:
[0006] 1. Preparation of reaction solution: tungsten hexachloride and selenium oxide are sequentially added to oleyl primary amine to form a reaction solution; wherein the mass ratio of tungsten hexachloride, selenium oxide and oleyl primary amine is 346-446:190-250:11000-15000;
[0007] 2. Reaction: Transfer the reaction solution to a flask, seal it, heat it to 115-125°C and stir it magnetically, introduce nitrogen for 25-35 minutes, then heat it to 290-310°C and continue the reaction for 1-2 hours. After the reaction is complete, continue introducing nitrogen and cool it to room temperature to obtain a reacted solution.
[0008] 3. Precipitation: Add anhydrous ethanol to the reaction solution for precipitation, take the solid phase product after centrifugation, and then wash and dry it to obtain dry WSe2 material;
[0009] 4. Calcination: Place the dried WSe2 material in a ceramic crucible, heat it to 395-405°C, keep it warm for 1-2 hours, and then cool it to room temperature to obtain Se-doped O vacancy tungsten oxide porous material Se-WO 3-x .
[0010] The Se-doped O-vacancy tungsten oxide porous material prepared by the present invention is used as a gas-sensitive material for an H2S gas sensor.
[0011] The present invention prepares the WSe2 material with flower-shaped structure by solution thermal method, and calcines it in air environment to form Se-WO 3-x Materials, Se-WO 3-x The material has a microspherical porous structure and is rich in a large number of O vacancy defects. This structural feature can increase the active surface and active sites of the material, effectively improving the material performance, making the material have broad application prospects.
[0012] The present invention is to prepare Se-WO 3-x The material was coated on the Ag interdigital electrode to make a gas sensor. 3-x The sensor exhibits excellent gas-sensing performance to H2S at room temperature.
[0013] Beneficial effects of the present invention:
[0014] (1) The preparation method of the present invention is simple and can realize large-scale preparation of materials;
[0015] (2) Se-WO of the present invention 3-x Porous materials can effectively reduce material agglomeration and have a large specific surface area;
[0016] (3) Se-WO of the present invention 3-x Porous materials have a large number of O vacancy defects and many active sites;
[0017] (4) Se-WO of the present invention 3-x The porous material has excellent room temperature H2S sensitivity; the Se-WO 3-x The sensor can achieve (0.1~10)×10 -6 Volume fraction concentration H2S room temperature test, for 1×10 -6 The sensitivity of volume fraction concentration of H2S is 3.8, and the detection limit is 0.1×10 -6 Volume fraction concentration of H2S, combined with room temperature operation, based on Se-WO 3-x H2S gas sensors made of porous materials have the characteristics of high sensitivity, low detection limit and low power consumption, and have good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is the SEM image of the WSe2 material obtained in step 3 of Example 1;
[0019] Figure 2 Se-doped O vacancy Se-WO obtained by calcination 3-x SEM images of materials;
[0020] Figure 3 Se-doped O vacancy Se-WO obtained by calcination 3-xXPS spectrum of the material;
[0021] Figure 4 Se-doped O vacancy Se-WO obtained by calcination 3-x EPR spectrum of the material;
[0022] Figure 5 for Se-WO 3-x Dynamic test curve of H2S concentration of gas sensor at room temperature. DETAILED DESCRIPTION
[0023] Specific embodiment 1: In this embodiment, a method for preparing a Se-doped O-vacancy tungsten oxide porous material is carried out in the following steps:
[0024] 1. Preparation of reaction solution: tungsten hexachloride and selenium oxide are sequentially added to oleyl primary amine to form a reaction solution; wherein the mass ratio of tungsten hexachloride, selenium oxide and oleyl primary amine is 346-446:190-250:11000-15000;
[0025] 2. Reaction: Transfer the reaction solution to a flask, seal it, heat it to 115-125°C and stir it magnetically, introduce nitrogen for 25-35 minutes, then heat it to 290-310°C and continue the reaction for 1-2 hours. After the reaction is complete, continue introducing nitrogen and cool it to room temperature to obtain a reacted solution.
[0026] 3. Precipitation: Add anhydrous ethanol to the reaction solution for precipitation, take the solid phase product after centrifugation, and then wash and dry it to obtain dry WSe2 material;
[0027] 4. Calcination: Place the dried WSe2 material in a ceramic crucible, heat it to 395-405°C, keep it warm for 1-2 hours, and then cool it to room temperature with the furnace to obtain Se-doped O-vacancy tungsten oxide porous material.
[0028] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the mass ratio of tungsten hexachloride, selenium oxide and oleyl primary amine solution in step 1 is 396:220:13000. Other aspects are the same as specific embodiment 1.
[0029] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that the magnetic stirring is performed for 5 minutes in step 2. Other aspects are the same as specific embodiment 1 or 2.
[0030] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the volume ratio of the reaction solution to anhydrous ethanol in step 3 is 1-2:1-2. Other aspects are the same as specific embodiments 1 to 3.
[0031] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the centrifugation in step 3 is performed at 10,000 rpm for 15 minutes. Other aspects are the same as specific embodiments 1 to 4.
[0032] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the washing in step 3 refers to washing with cyclohexane and anhydrous ethanol in sequence, and the washing times are ≥ 2 times. Other aspects are the same as specific embodiments 1 to 5.
[0033] Specific embodiment 7: This embodiment differs from Specific embodiments 1 to 6 in that step 3 is vacuum drying in a vacuum drying oven at 65° C. for 10 hours. Other aspects are the same as Specific embodiments 1 to 6.
[0034] Specific embodiment 8: This embodiment differs from specific embodiments 1 to 7 in that step 4 is performed at a heating rate of 10°C / min. Other aspects are the same as specific embodiments 1 to 7.
[0035] Specific embodiment 9: In this embodiment, Se-doped O-vacancy tungsten oxide porous material is used as a gas-sensitive material for H2S gas sensor.
[0036] Specific embodiment 10: This embodiment differs from specific embodiment 9 in that the preparation method of Se-doped O-vacancy tungsten oxide porous material as the gas-sensitive material of H2S gas sensor is as follows:
[0037] 5 mg of Se-doped O-vacancy porous tungsten oxide material was placed in 5 mL of anhydrous ethanol and ultrasonically dispersed for 5 minutes. The material was then spin-coated onto an Al2O3 ceramic Ag interdigitated electrode and vacuum-dried to form a 6 μm thick gas-sensitive film layer. This yielded a H2S sensor based on Se-doped O-vacancy porous tungsten oxide material. The remaining steps were the same as those in Specific Embodiment 9.
[0038] The following experiments were conducted to verify the beneficial effects of the present invention:
[0039] Example 1: This example is a Se-doped O-vacancy Se-WO 3-x The porous material preparation method is carried out according to the following steps:
[0040] 1. Preparation of reaction solution: 396 mg of tungsten hexachloride and 220 mg of selenium oxide are sequentially added to 13 g of oleyl primary amine solution to form a reaction solution.
[0041] Reaction: Quickly transfer the reaction solution to a sealed flask. Using a thermostat, heat the reaction solution to 125°C and magnetically stir for 5 minutes. Continue flowing 99.99% nitrogen for 30 minutes, then rapidly heat the mixture to 290°C. Continue reacting under this atmosphere for 1 hour. After the reaction is complete, continue flowing 99.99% nitrogen. Turn off the heating plate and allow the mixture to cool naturally to room temperature to obtain a post-reaction solution.
[0042] 3. Precipitation: Add ethanol to the reaction solution for precipitation, use a high-speed centrifuge to separate the products, the centrifuge is set to 10,000 rpm, and centrifuge for 15 minutes to obtain the reaction product WSe2 material. The product is centrifuged and washed with cyclohexane and ethanol for ≥2 times in sequence. Finally, the WSe2 product is vacuum dried in a vacuum drying oven at 65°C for 10 hours to obtain a dry WSe2 material; the volume ratio of the reaction solution to anhydrous ethanol is 1:1.
[0043] 4. Calcination: Weigh 50 mg of dried WSe2 material and put it into an Al2O3 ceramic crucible. Push it into a high-temperature box furnace and heat it to 395℃ at 10℃ / min. Keep the temperature constant for 1 hour. The product is cooled naturally to room temperature along with the furnace body to obtain Se-doped O vacancy tungsten oxide porous material Se-WO 3-x .
[0044] The obtained WSe2 material was examined by scanning electron microscopy (SEM). Figure 1 It can be seen that WSe2 presents a spherical flower-like structural feature with a diameter of about 200 nm. It is well dispersed and forms a large void structure, which is conducive to material diffusion and adsorption.
[0045] Figure 2 Se-WO is formed after calcination of WSe2 material 3-x SEM image of the material, Se-WO 3-x The material has a spherical structure with a diameter of about 200nm. Pores are formed between the spheres. The pores accelerate the diffusion, adsorption and desorption of substances, thereby improving the material performance.
[0046] Figure 3 for Se-WO 3-x Se element XPS spectrum of the material, Se-WO 3-x There is a small amount of Se element in the material, which proves the doping of Se element.
[0047] Figure 4 for Se-WO 3-x The EPR spectrum of the material shows an obvious signal at g = 2.000, proving the existence of O vacancies in the material. Combined with the characterization structure, it is proved that Se-doped O vacancy Se-WO 3-x The porous material was successfully prepared.
[0048] Example 2: Se-WO synthesized in Example 1 3-x Porous materials are used as H2S gas-sensitive materials, as follows:
[0049] 5 mg of Se-WO 3-x The porous material was placed in 5 mL of anhydrous ethanol, ultrasonically dispersed for 5 minutes, spin-coated onto an Al2O3 ceramic Ag interdigital electrode, and vacuum-dried to form a 6 μm thick gas-sensitive film layer to obtain a H2S sensor.
[0050] The performance of the prepared H2S sensor was tested. Figure 5 As shown, the Se-WO 3-x The sensor can achieve (0.1~10)×10 -6 Volume fraction concentration H2S room temperature test, for 1×10 -6 The sensitivity of volume fraction concentration of H2S is 3.8, and the detection limit is 0.1×10 -6 Volume fraction concentration of H2S, combined with room temperature operation, based on Se-WO 3-x H2S gas sensors made of porous materials have the characteristics of high sensitivity, low detection limit and low power consumption, and have good application prospects.
Claims
1. A method for preparing a Se-doped O-vacancy tungsten oxide porous material, characterized in that The preparation method is carried out according to the following steps:
1. Preparation of reaction solution: tungsten hexachloride and selenium oxide are sequentially added to oleyl primary amine to form a reaction solution; wherein the mass ratio of tungsten hexachloride, selenium oxide and oleyl primary amine is 346-446:190-250:11000-15000; 2. Reaction: Transfer the reaction solution to a flask, seal it, heat it to 115-125°C and stir it magnetically, introduce nitrogen for 25-35 minutes, then heat it to 290-310°C and continue the reaction for 1-2 hours. After the reaction is complete, continue introducing nitrogen and cool it to room temperature to obtain a reacted solution.
3. Precipitation: Add anhydrous ethanol to the reaction solution for precipitation, take the solid phase product after centrifugation, and then wash and dry it to obtain dry WSe2 material; 4. Calcination: Place the dried WSe2 material in a ceramic crucible, heat it to 395-405°C, keep it warm for 1-2 hours, and then cool it to room temperature with the furnace to obtain Se-doped O-vacancy tungsten oxide porous material.
2. The method for preparing a Se-doped O-vacancy tungsten oxide porous material according to claim 1, characterized in that In step 1, the mass ratio of tungsten hexachloride, selenium oxide and oleyl primary amine solution is 396:220:13000.
3. The method for preparing a Se-doped O-vacancy tungsten oxide porous material according to claim 1, characterized in that In step 2, magnetic stirring was performed for 5 min.
4. The method for preparing a Se-doped O-vacancy tungsten oxide porous material according to claim 1, characterized in that In step 3, the volume ratio of the reaction solution to anhydrous ethanol is 1-2:1-2.
5. The method for preparing a Se-doped O-vacancy tungsten oxide porous material according to claim 1, characterized in that The centrifugation in step 3 is performed at 10,000 rpm for 15 min.
6. The method for preparing a Se-doped O-vacancy tungsten oxide porous material according to claim 1, characterized in that The cleaning in step 3 refers to cleaning with cyclohexane and anhydrous ethanol in sequence, and the number of cleaning times is ≥ 2 times.
7. The method for preparing a Se-doped O-vacancy tungsten oxide porous material according to claim 1, characterized in that Step three is vacuum drying in a vacuum drying oven at 65°C for 10 hours.
8. The method for preparing a Se-doped O-vacancy tungsten oxide porous material according to claim 1, characterized in that Step 4 is to increase the temperature at a heating rate of 10°C / min.
9. Use of the Se-doped O-vacancy tungsten oxide porous material prepared according to any one of claims 1 to 8 as a gas-sensitive material for an H2S gas sensor.
10. The use according to claim 9, characterized in that The preparation method of Se-doped O vacancy tungsten oxide porous material as a gas-sensitive material for H2S gas sensor is as follows: 5 mg of Se-doped O-vacancy tungsten oxide porous material was placed in 5 mL of anhydrous ethanol, ultrasonically dispersed for 5 minutes, spin-coated onto Al2O3 ceramic Ag interdigital electrodes, and vacuum-dried to form a 6 μm thick gas-sensitive film layer. A H2S sensor based on Se-doped O-vacancy tungsten oxide porous material was obtained.