Hydrogen sensor of monatomic doped sensitive material prepared based on two-step calcination method and preparation method of hydrogen sensor
The preparation of Ir single-atom doped SnO2 material through two-step calcination method has solved the problems of insufficient sensitivity and long response time of existing hydrogen sensors, and achieved a hydrogen sensor with high sensitivity, fast response and wide detection range, which is suitable for large-scale production.
Patent Information
- Application Number
- CN202510442408.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-08
AI Technical Summary
Existing semiconductor metal oxide hydrogen sensors have problems such as insufficient sensitivity, poor selectivity, and long response and recovery time. The size and agglomeration of precious metal particles limit the catalytic efficiency. The application of single-atom catalysts in the field of gas sensing is rarely reported.
The Ir single-atom-doped SnO2 material was prepared by two-step calcination method. The Ir single-atom-modified SnO2 nanorods were used to achieve good dispersion of Ir single atoms on the SnO2 surface by using strong metal-support interactions, and Ir1-SnO2 composite gas-sensitive material was prepared.
It realizes a hydrogen sensor with high sensitivity, fast response recovery time and a wide detection range, with good long-term stability and specific recognition functions, suitable for large-scale production.
Smart Images
Figure CN120271037A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of gas-sensitive materials and sensor preparation, and specifically relates to a hydrogen sensor based on an Ir single-atom doped sensitive material prepared by a two-step calcination method and a preparation method thereof. Background Art
[0002] Hydrogen energy (H2) has been widely used in industries such as industrial manufacturing, transportation, and aerospace due to its high efficiency, sustainability, and environmental friendliness. As a fuel, hydrogen can release a huge amount of energy during combustion, and its only emission is water, which is environmentally friendly. Promoting hydrogen energy helps reduce carbon emissions and combat environmental problems caused by the greenhouse effect. However, hydrogen is colorless, odorless, and highly flammable, and its flammable concentration range is wide (4% - 75%), which requires us to closely monitor the storage and use of hydrogen to prevent safety accidents.
[0003] Semiconductor metal oxide materials have been widely used in hydrogen sensing technology due to their diverse types, low cost, simple preparation process, high sensitivity, and wide detection range. These sensors still face problems such as insufficient sensitivity, poor selectivity, and too long response and recovery times. Optimizing their performance is the key to improving their practicality and reliability. Using noble metal-loaded semiconductor metal oxide materials is an effective method to improve the gas-sensing performance of sensors. However, the size and agglomeration of noble metal particles limit their catalytic efficiency. Therefore, developing metal catalysts with high dispersibility and high specific surface area to improve metal utilization and reduce costs is a key technical bottleneck.
[0004] Single-atom catalysts (SACs) have shown significant advantages in the catalytic field due to their unique structure and properties. Each metal atom serves as an independent active site, not only maximizing the use of metal atoms in catalytic reactions but also improving the utilization rate of active sites. Moreover, compared with traditional nanoparticle catalysts, single-atom catalysts exhibit higher catalytic activity and selectivity. Their good stability benefits from the strong interaction between metal atoms and the support, reducing the shedding and sintering of metal atoms and extending the service life of the catalyst. At the same time, single-atom catalysts significantly reduce the metal consumption, thereby reducing costs, and are easy to regulate the catalytic performance by changing the type of metal atoms, the nature of the support, or the interaction between the metal and the support. However, there are few reports on the application of single-atom catalysts in the field of gas sensing. Summary of the Invention
[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing a hydrogen sensor with a single-atom doped sensitive material based on a two-step calcination method. Taking the hydrogen gas sensor as an example, through the two-step calcination method, the present invention synthesizes an Ir single-atom modified SnO2 material. The sensor based on the Ir1-SnO2 composite gas-sensitive material has good sensitivity characteristics to hydrogen, can maintain good long-term stability under complex working environmental conditions, and the sensor has the advantages of high response value, fast response and recovery time, and wide detection range.
[0006] To achieve the above object, the present invention adopts the following technical solutions:
[0007] A hydrogen sensor with a single-atom doped sensitive material prepared by a two-step calcination method and its preparation method, wherein the sensitive material is a single-atom Ir-loaded SnO2 sensitive material, and the sensitive material is prepared by the following steps:
[0008] (1) Dissolve 0.6 g of SnCl2·2H2O in a mixed solution of 4.8 ml of N,N-dimethylformamide and 1.2 ml of ethanol. After stirring for 2 h, add 0.8 g of PVP (K90), and continuously stir for 18 h until the solution becomes clear.
[0009] (2) Transfer the solution obtained in step (1) into a 10 mL micro syringe. Control the environmental humidity at 45%, the temperature at 25 °C, set the voltage of the electrospinning machine at 16 - 18 kV, the injection rate at 0.5 ml - 0.7 ml / h, and the distance between the positive and negative electrodes at 15 - 16 cm to obtain white nanofibers.
[0010] (3) Calcinate in an air atmosphere at 550 °C for 2.5 h, wash by centrifugation with deionized water and ethanol for multiple times, and dry at 80 °C for 24 h to obtain SnO2 nanorods composed of nanoparticles.
[0011] (4) Dissolve 9 - 10 mg of Ir(acac)3 in the solution, heat and stir for 20 min until it is completely dissolved, then add 15 - 20 mg of KNO3, heat and stir for 20 min until it is completely dissolved, add the SnO2 nanorods obtained in step (3), heat and stir until the solvent completely evaporates, calcinate in an air atmosphere, wash with deionized water and ethanol for multiple times, and dry at 80 °C for 24 h to obtain an Ir-modified SnO2 sample, labeled as Ir1-SnO2.
[0012] As a preferred embodiment, the calcination temperature in step (3) is 300 °C, the heating rate is 5 - 10 °C / min, and the calcination time is 2.5 h.
[0013] As a preferred embodiment, the solution in which Ir(acac)3 is dissolved in step (4) is ethanol:deionized water at a ratio of 6:1.
[0014] As a preferred embodiment, the Ir1-SnO2 obtained in step (4) is nanorods modified with Ir single atoms, with a diameter of about 150 - 200 nm, and the modification amount of the Ir single atoms is 1 wt%.
[0015] As a preferred embodiment, the thickness of the sensitive material thin film of the hydrogen sensor with the SnO2 sensitive material is 15 - 25 μm.
[0016] As a preferred embodiment, the preparation method of the hydrogen sensor based on the SnO2 sensitive material specifically includes the following steps:
[0017] 1) Mix 1 g of the Ir1-SnO2 gas-sensitive material with 0.1 ml of ethanol and grind it in an agate mortar to form a homogeneous mixture.
[0018] 2) Coat the mixture on the central area of the MEMS chip using a spin coater, evenly covering the interdigital electrodes of the MEMS chip to form a uniform sensitive thin film. Subsequently, dry it in a vacuum oven at 50 °C for 24 h, and then age the sensor at a voltage of 1.9 V for 72 h to stabilize its performance.
[0019] The technical principle of the present invention: Taking hydrogen gas detection as an example, the present invention designs a two-step calcination method to prepare Ir single-atom modified tin dioxide materials. Ir has good dispersion on the surface of SnO2 nanorods. Due to the strong metal-support interaction, Ir single atoms are stably anchored on the SnO2 substrate. The Ir single-atom catalyst has high catalytic activity and good stability under high-temperature conditions. The developed Ir1-SnO2 gas sensor has the advantages of high sensitivity, fast response and recovery time, and good long-term stability, and has good application value in practical applications.
[0020] Compared with the prior art, the present invention has achieved the following beneficial effects:
[0021] (a) The present invention proposes a new idea for the development of high-performance hydrogen sensors by using a two-step calcination-synthesized Ir single-atom gas-sensitive material.
[0022] (b) The present invention relates to a preparation technology using Ir single atoms to modify SnO2 as a sensing material. This technology is characterized by simple operation, high cost-effectiveness, and is suitable for large-scale production.
[0023] (c) The present invention uses Ir single-atom modified SnO2 as the sensitive material to prepare a hydrogen MEMS sensor with specific recognition function. Compared with the traditional gas sensors sensitized by metal particles, the Ir1-SnO2 sensor proposed by the present invention has high sensitivity to hydrogen, fast response and recovery time, wide detection range (1 ppm - 4%), and excellent long-term stability. Description of the Drawings
[0024] The attached drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.
[0025] Figure 1 XRD patterns of the SnO2, Ir nps -SnO2, Ir1-SnO2 materials prepared in Examples 1, 2, and 3 of the present invention.
[0026] Figure 2 In a and b, the SnO2 prepared in Examples 1 and 2 of the present invention, r nps HRTEM images of the r
[0027] Figure 3 In a, the response values of the Ir1-SnO2 gas sensor prepared in Example 3 of the present invention to hydrogen gas at different operating temperatures, Figure 3 In b, the resistance changes of the Ir1-SnO2 gas sensor prepared in Example 3 of the present invention at different operating temperatures.
[0028] Figure 4 In the test of Example 3 of the present invention, the response values of the prepared Ir1-SnO2 gas sensor to hydrogen gas at different concentrations at 260 °C.
[0029] Figure 5 In a, the linear fitting curve of the response values of the Ir1-SnO2 gas sensor prepared in Example 3 of the present invention to hydrogen gas at different concentrations at 260 °C, Figure 5 In b, the cyclic stability of the Ir1-SnO2 gas sensor prepared in Example 3 of the present invention. Detailed Description of the Invention
[0030] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.
[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. For example, as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0032] Example 1:
[0033] A hydrogen gas sensor with a single SnO2 sensitive material, and its specific manufacturing process is as follows:
[0034] (1) Dissolve 0.6 g of SnCl2·2H2O in a mixed solution of 4.8 ml of N,N-dimethylformamide and 1.2 ml of ethanol. After stirring for 10 min, add 0.8 g of PVP (K90) and continuously stir for 12 h until the solution becomes clear.
[0035] (2) Transfer the solution obtained in step (1) into a 10 mL micro syringe. Control the environmental humidity to 45% and the temperature to 25 °C. Set the voltage of the electrospinning machine to 16 - 18 kV, the injection rate to 0.5 ml - 0.7 ml / h, and the distance between the positive and negative electrodes to 15 - 16 cm to obtain white nanofibers.
[0036] (3) Calcinate in an air atmosphere at 550 °C for 2.5 h, wash by centrifugation with deionized water and ethanol multiple times, and dry at 80 °C for 24 h to obtain a white solid powder, labeled as SnO2.
[0037] (4) Construction of a hydrogen MEMS gas sensor:
[0038] Mix 1 g of SnO2 gas-sensitive material with 0.1 ml of ethanol and grind in an agate mortar to form a homogeneous mixture.
[0039] Coat the mixture on the central area of the MEMS chip using a spin coater, evenly covering the interdigital electrodes of the MEMS chip to form a uniform sensitive film. Then, dry in a vacuum oven at 50 °C for 24 h, and then age the sensor at a voltage of 1.9 V for 72 h to stabilize its performance.
[0040] As Figure 1 shown, the diffraction peaks in the X-ray diffraction (XRD) pattern of the prepared SnO2 are in complete agreement with the peak positions of the standard card (JCPDS#41-1445), confirming that it is tetragonal SnO2. No impurity peaks of other metal oxides were observed in the pattern, indicating that the obtained sample is a pure SnO2 phase.
[0041] As Figure 2 shown in a of, the lattice spacing of SnO2 in the composite material is 0.338 nm, corresponding to the (110) crystal plane of SnO2, further proving that the synthesized material is SnO2.
[0042] Example 2:
[0043] A hydrogen gas sensor based on Ir nanoparticle-modified SnO2 sensitive material was fabricated as follows:
[0044] (1) Dissolve 0.6 g of SnCl2·2H2O in a mixed solution of 4.8 ml of N,N-dimethylformamide and 1.2 ml of ethanol. After stirring for 10 min, add 0.8 g of PVP (K90) and continuously stir for 12 h until the solution becomes clear.
[0045] (2) Transfer the solution obtained in step (1) into a 10 mL microsyringe. Control the environmental humidity at 45% and the temperature at 25 °C. Set the voltage of the electrospinning machine to 16 - 18 kV, the injection rate to 0.5 ml - 0.7 ml / h, and the distance between the positive and negative electrodes to 15 - 16 cm to obtain white nanofibers.
[0046] (3) Calcinate in an air atmosphere at 550 °C for 2.5 h, wash by centrifugation with deionized water and ethanol several times, and dry at 80 °C for 24 h to obtain a white solid powder, labeled as SnO2.
[0047] (4) Dissolve 9 - 10 mg of Ir(acac)3 in the solution, heat and stir for 20 min to completely dissolve it. Add the SnO2 nanorods obtained in step (3), heat and stir until the solvent completely evaporates, calcinate in an air atmosphere, wash with deionized water and ethanol several times, and dry at 80 °C for 24 h to obtain an Ir nanoparticle-modified SnO2 sample, labeled as Ir nps -SnO2.
[0048] (5) Fabrication of a hydrogen MEMS gas sensor:
[0049] Mix 1 g of the SnO2 gas-sensitive material with 0.1 ml of ethanol and grind in an agate mortar to form a homogeneous mixture.
[0050] The mixture was coated on the central area of the MEMS chip using a spin coater, evenly covering the interdigital electrodes of the MEMS chip to form a uniform sensitive film. Subsequently, after drying in a vacuum oven at 50 °C for 24 h, the sensor was aged at a voltage of 1.9 V for 72 h to stabilize its performance.
[0051] As Figure 1 shown, the diffraction peaks in the X-ray diffraction (XRD) pattern of the prepared Ir nps -SnO2 are in complete agreement with the peak positions of the standard card (JCPDS#41-1445), confirming that it is tetragonal SnO2. No impurity peaks of other metal oxides were observed in the pattern, indicating that the obtained sample is a pure SnO2 phase.
[0052] As Figure 2 shown in b of nps , it can be seen from the HRTEM image of the synthesized Ir
[0053] Example 3:
[0054] (1) Dissolve 0.6 g of SnCl2·2H2O in a mixed solution of 4.8 ml of N,N-dimethylformamide and 1.2 ml of ethanol. After stirring for 2 h, add 0.8 g of PVP (K90) and continuously stir for 18 h until the solution becomes clear.
[0055] (2) Transfer the solution obtained in step (1) into a 10 mL microsyringe. Control the environmental humidity at 45%, the temperature at 25 °C, set the voltage of the electrospinning machine at 16 - 18 kV, the injection rate at 0.5 ml - 0.7 / h, and the distance between the positive and negative electrodes at 15 - 16 cm to obtain white nanofibers.
[0056] (3) Calcinate in an air atmosphere at 550 °C for 2.5 h, wash it by centrifugation with deionized water and ethanol multiple times, and dry it at 80 °C for 24 h to obtain SnO2 nanorods composed of nanoparticles.
[0057] (4) Dissolve 9 - 10 mg of Ir(acac)3 in the solution, heat and stir for 20 min to completely dissolve it, then add 15 - 20 mg of KNO3, heat and stir for 20 min until it is completely dissolved. Add the SnO2 nanorods obtained in step (3), heat and stir until the solvent completely evaporates, calcinate in an air atmosphere, wash it with deionized water and ethanol multiple times, and dry it at 80 °C for 24 h to obtain an Ir-modified SnO2 sample, labeled as Ir1-SnO2.
[0058] (4) Construction of a hydrogen MEMS gas sensor:
[0059] Mix 1 g of SnO2 gas-sensitive material with 0.1 ml of ethanol and grind it in an agate mortar to form a homogeneous mixture.
[0060] Coat the mixture on the central area of the MEMS chip using a spin coater, evenly covering the interdigital electrodes of the MEMS chip to form a uniform sensitive film. Subsequently, dry it in a vacuum oven at 50 °C for 24 h, and then age the sensor at a voltage of 1.9 V for 72 h to stabilize its performance.
[0061] As Figure 1 shown, the diffraction peaks in the X-ray diffraction (XRD) pattern of the prepared Ir nps -SnO2 are completely consistent with the peak positions of the standard card (JCPDS#41-1445), confirming that it is tetragonal SnO2. No impurity peaks of other metal oxides are observed in the pattern, indicating that the obtained sample is a pure SnO2 phase.
[0062] As Figure 3 a in shows the response values of the synthesized Ir1-SnO2 MEMS sensor at corresponding temperatures from 1.2 V to 2.2 V. The response values show a trend of first increasing and then decreasing. The response value to 4000 ppm of hydrogen at 260 °C is 46.1, indicating that 260 °C is its optimal operating temperature. Figure 3 b in shows the resistance change values of the Ir1-SnO2 MEMS sensor at corresponding temperatures from 1.2 V to 2.2 V. As the temperature increases, the resistance of the sensor gradually decreases, conforming to the basic trend of the resistance of semiconductor materials changing with temperature.
[0063] As Figure 4 shows the change in the response values of the MEMS sensor to hydrogen gas in the concentration range of 1000 - 5000 ppm H2. As the concentration of injected hydrogen increases, the response of the sensor gradually increases, and as the concentration of injected hydrogen decreases, the response of the sensor gradually decreases, indicating that the Ir1-SnO2 MEMS sensor has good qualitative and quantitative capabilities for hydrogen.
[0064] Figure 5 a in shows the linear fitting curve between the response values and concentrations of the Ir1-SnO2 MEMS sensor to 10 - 60 ppm H2, demonstrating that the change in the response values of the Ir1-SnO2 MEMS sensor has a good linear relationship. Figure 5 b in shows the cyclic stability diagram of the Ir1-SnO2 MEMS sensor to 4000 ppm H2, indicating that the Ir1-SnO2 MEMS sensor has good stability.
[0065] In summary, the Ir1-SnO2 of the Ir-modified gas-sensitive material prepared by the two-step calcination method can be used for hydrogen sensing to achieve efficient detection of hydrogen gas. In the above embodiments, Ir is loaded on the surface of SnO2 in the form of single atoms by the impregnation method and the salt-assisted method to obtain the Ir1-SnO2 composite material. The MEMS sensor based on this material exhibits excellent gas-sensing performance towards hydrogen gas, which is mainly due to the well-dispersed single atoms and the optimized carrier interaction, which promote the efficient electron transfer between the gas reactants and the sensing material. The Ir1-SnO2 composite material is combined with the MEMS chip to obtain a MEMS gas sensor for detecting hydrogen gas. The single-atom Ir-loaded tin dioxide sensor prepared in the above embodiments exhibits very excellent hydrogen-sensitive performance, which is superior to most of the reported hydrogen gas sensors, can meet the requirements of actual hydrogen detection, and has the advantages of fast response speed, wide detection range and good stability.
[0066] The above are only the preferred embodiments of the present invention and do not limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A hydrogen sensor based on a single-atom doped sensitive material prepared by a two-step calcination method and a preparation method thereof, characterized in that, The sensitive material is a single-atom Ir-loaded SnO₂ sensitive material, and the sensitive material is prepared by the following steps: (1) Dissolve 0.6 g of SnCl₂·2H₂O in a mixed solution of 4.8 ml of N,N-dimethylformamide and 1.2 ml of ethanol. After stirring for 2 h, add 0.8 g of PVP (K90) and continuously stir for 18 h until the solution becomes clear. (2) Transfer the solution obtained in step (1) into a 10 mL microsyringe. Control the environmental humidity at 45% and the temperature at 25 °C. Set the voltage of the electrospinning machine to 16 - 18 kV, the injection rate to 0.5 ml - 0.7 ml / h, and the distance between the positive and negative electrodes to 15 - 16 cm to obtain white nanofibers. (3) Calcinate in an air atmosphere at 550 °C for 2.5 h, wash by centrifugation with deionized water and ethanol multiple times, and dry at 80 °C for 24 h to obtain SnO₂ nanorods composed of nanoparticles. (4) Dissolve 9 - 10 mg of Ir(acac)₃ in the solution. After heating and stirring for 20 min to completely dissolve it, then add 15 - 20 mg of KNO₃ and heat and stir for 20 min until it is completely dissolved. Add the SnO₂ nanorods obtained in step (3), heat and stir until the solvent completely evaporates, calcinate in an air atmosphere, wash with deionized water and ethanol multiple times, and dry at 80 °C for 24 h to obtain an Ir-modified SnO₂ sample, denoted as Ir1-SnO₂.
2. The hydrogen sensor of a single-atom doped sensitive material prepared by a two-step calcination method according to claim 1 and its preparation method, characterized in that, The calcination temperature in step (3) is 300 °C, the heating rate is 5 - 10 °C / min, and the calcination time is 2.5 h.
3. The hydrogen sensor of a single-atom doped sensitive material prepared based on a two-step calcination method according to claim 1 and its preparation method, characterized in that, The solution in which Ir(acac)₃ is dissolved in step (4) is ethanol:deionized water at a ratio of 6:
1.
4. A hydrogen sensor based on a single-atom doped sensitive material prepared by a two-step calcination method and a preparation method thereof according to claim 1, characterized in that, The Ir1-SnO₂ obtained in step (4) is a nanorod modified with single-atom Ir, with a diameter of about 150 - 200 nm, and the modification amount of the single-atom Ir is 1 wt%.
5. The hydrogen sensor of a single-atom doped sensitive material prepared by a two-step calcination method according to claim 1 and its preparation method, characterized in that, The thickness of the sensitive material film of the hydrogen sensor using the SnO₂ sensitive material is 15 - 25 μm.
6. The hydrogen sensor of a single-atom doped sensitive material prepared by a two-step calcination method according to claim 1 and its preparation method, characterized in that, A preparation method of a hydrogen sensor based on the SnO₂ sensitive material specifically includes the following steps: 1) Mix 1 g of the Ir1-SnO₂ gas-sensitive material with 0.1 ml of ethanol and grind it in an agate mortar to form a homogeneous mixture. 2) Coating the mixture on the central area of the MEMS chip using a spin coater, evenly covering it on the interdigital electrodes of the MEMS chip to form a uniform sensitive film. Subsequently, dry it in a vacuum oven at 50 °C for 24 h, and then age the sensor at a voltage of 1.9 V for 72 h to stabilize the performance.