Hydrogen-sensitive material for hydrogen sensor and preparation method of hydrogen-sensitive material
By depositing Pd thin films using a small-angle flotation technique combined with annealing and Au filling, the problems of slow response speed, high measurement limit, and poor long-term stability of optical hydrogen sensors were solved, achieving rapid, sensitive, and stable hydrogen detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-16
- Publication Date
- 2026-04-10
AI Technical Summary
Existing optical hydrogen sensors suffer from slow response speed, insufficient measurement lower limit, poor long-term stability, and structural relaxation issues leading to inaccurate detection.
A nanoscale porous hydrogen-sensitive material was formed by depositing a Pd thin film using a small-angle sweep technique, combined with in-situ annealing and aging and Au metal compound solution filling treatment.
The response speed and sensitivity of the hydrogen sensor have been improved, enabling accurate measurements at the ppm level, enhancing long-term stability, and extending service life.
Smart Images
Figure CN121830822A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of hydrogen sensors, more particularly, it relates to a hydrogen-sensitive material for hydrogen sensors and a preparation method thereof. BACKGROUND
[0002] Hydrogen, as a clean, renewable and efficient energy, has played an important role in industrial production, energy storage and other fields, and is considered as one of the important choices of future energy. However, hydrogen molecules are small and prone to leakage during production, storage, transportation and use. Since hydrogen is not conducive to breathing, colorless and odorless, it cannot be detected by the human nose, and the ignition point is only 585℃. When the content in the air is in the range of 4-75%, it will explode when encountering fire. Therefore, in the use of hydrogen, hydrogen sensors must be used to detect the content of hydrogen in the environment and monitor its leakage.
[0003] At present, common hydrogen sensors include catalytic hydrogen sensors, thermal conductivity hydrogen sensors, optical hydrogen sensors and resistance hydrogen sensors, etc. Among them, the optical hydrogen sensor has inherent EMI immunity, and also has the ability of distributed and multiplexing detection, so it has stronger competitiveness in practical application. In the existing optical hydrogen sensor, a palladium-nickel alloy film is often used as a hydrogen-sensitive material, and the resistance of the hydrogen-sensitive material changes with the change of hydrogen concentration.
[0004] However, the prior art has the following problems: 1. Slow response speed, the diffusion speed of hydrogen molecules in the palladium-nickel alloy film is slow, which leads to a long response time of the sensor to the change of hydrogen concentration, and cannot meet the demand of rapid detection; 2. The lower limit of measurement is not enough, the detection sensitivity for low concentration hydrogen is not enough, and it is difficult to realize accurate measurement of ppm level or even lower concentration; 3. Poor long-term stability, the performance of the sensor will gradually decrease during long-term use, and the zero point is easy to drift, which affects the accuracy of the detection result; 4. Structural relaxation problem, the hydrogen-sensitive material will occur structural relaxation such as creep relaxation and mechanical relaxation during use, which leads to unstable performance of the sensor. SUMMARY
[0005] In order to solve the above technical problems, the present application provides a hydrogen-sensitive material for hydrogen sensors and a preparation method thereof.
[0006] In a first aspect, the present application provides a preparation method of a hydrogen-sensitive material for hydrogen sensors, comprising the following steps: S1, providing a pretreated substrate; S2, depositing a Pd film on the surface of the substrate by small-angle technology; S3, performing in-situ annealing aging treatment on the product obtained in step S2; S4, filling treatment is performed on the material obtained in step S3 by using an Au metal compound solution.
[0007] Preferably, in S1, the pretreatment specifically comprises: soaking the substrate in acetone and performing ultrasonic cleaning for 30-40 min.
[0008] Preferably, in S2, the deposition process specifically comprises: after heating the substrate under vacuum, electrically conducting the substrate under the protection of inert gas and depositing Pd on the surface of the substrate at a deposition angle of 10-85°, the deposition time being 5-10 min and the deposition rate being 10-20 nm / min, to obtain a Pd film with a thickness of 50-200 nm.
[0009] By using the above technical solution, the substrate is first immersed in acetone for pretreatment to remove the small inorganic particles and organic impurities on the surface of the substrate, thereby improving the subsequent treatment effect, and then a Pd film is deposited on the pretreated substrate, the structure of the Pd film is controlled by adjusting the deposition angle and the deposition time, so that the Pd film forms a porous columnar or spiral structure. The present application uses small-angle deposition technology, at this time the Pd particles will impact the substrate surface at a small angle, resulting in tilted particle accumulation, thereby forming a high-porosity film.
[0010] Subsequently, the substrate on which the Pd film has been deposited is subjected to annealing aging treatment, thereby releasing the stress in the growth of the Pd film, adjusting the surface structure of the Pd film, optimizing the alloy chemical proportion coefficient, improving the long-term stability of the Pd film, and enhancing the response speed and sensitivity of the hydrogen sensor. Finally, the material subjected to the annealing treatment is immersed in an Au metal compound solution for filling treatment, at this time the Au metal compound solution reacts with the active sites in the Pd film to generate Au particles and deposit them in the pores of the Pd film, thereby filling part of the pores, enhancing the structural stability of the Pd film, and improving its hydrogen sensing performance.
[0011] The surface of the hydrogen-sensitive material has a Pd film with a nano-scale porous structure, so the contact area with hydrogen gas is effectively improved, making it easier for hydrogen gas to diffuse into the structure of the hydrogen-sensitive material, improving the response speed of the hydrogen sensor to changes in hydrogen gas concentration, and the nano-scale porous structure also improves the detection sensitivity of the hydrogen sensor to low-concentration hydrogen gas, enabling accurate measurement at the ppm level or even lower levels. The annealing treatment releases the stress in the growth of the Pd film, the filling treatment prevents long-term structural relaxation (such as creep relaxation and mechanical relaxation), and suppresses the zero-point drift, thereby greatly improving the long-term stability of the hydrogen-sensitive material and the service life and reliability of the hydrogen sensor. Overall, the present application sequentially performs deposition, annealing and filling treatment on the pretreated substrate, thereby obtaining a hydrogen-sensitive material for hydrogen sensors with high response speed, high detection sensitivity and good long-term stability.
[0012] The preparation method of the present application is suitable for various substrate materials, including but not limited to quartz glass and ceramic sheets, and in the specific embodiments of the present application, single-side polished quartz glass is taken as an example for illustration, and those skilled in the art can make reasonable changes according to actual conditions, and the protection scope of the present application cannot be limited in sequence.
[0013] Preferably, in S2, the substrate is rotated at a constant speed when depositing Pd on the surface of the substrate.
[0014] By adopting the above technical solution, the substrate is rotated at a constant speed when depositing Pd on the surface of the substrate, so that the Pd particles can be more uniformly distributed on the surface of the substrate during the deposition process, thereby making the Pd thin film formed more uniform.
[0015] Preferably, in S2, a transition layer is deposited before depositing the Pd thin film on the surface of the substrate, and the thickness of the transition layer is 3-20 nm.
[0016] Preferably, the transition layer is a Cr layer or a Ti layer.
[0017] Optionally, the transition layer is prepared by direct current magnetron sputtering, and the deposition parameters are as follows: Ar flow rate 10-50 sccm, working gas pressure 0.2-1.0 Pa, target power 50-200 W, and deposition time 1-5 min.
[0018] By adopting the above technical solution, a transition layer is deposited before depositing the Pd thin film on the surface of the substrate, Cr and Ti can form stable chemical bonds with the substrate, and at the same time, the diffusion effect caused by ion bombardment promotes the mixing of interface atoms, which helps to increase the bonding force between Pd and the substrate and improve the film quality, so that the structure of the hydrogen-sensitive material is more stable, and the comprehensive performance of the hydrogen sensor is improved.
[0019] Preferably, in S3, the in-situ annealing aging treatment is specifically as follows: the product obtained in step S2 is heated to 330-370℃, and in-situ annealing is performed for 1.8-2.2 h.
[0020] By adopting the above technical solution, the product obtained in step S2 is heated to 330-370℃, and in-situ annealing is performed for 1.8-2.2 h, so as to remove the stress not completely released during film growth, making the Pd thin film obtained by deposition more dense and significantly improving the film quality.
[0021] Preferably, in S4, the mass concentration of the Au metal compound solution is 1-5%.
[0022] Preferably, in the S4, the Au metal compound solution is any one of AuCl3 solution, AuBr3 solution, AuI3 solution, Au(acac)3 solution, Au(PPh3)Cl solution or Au(en)2Cl3 solution.
[0023] By adopting the technical solution, the Au metal compound solution is used to fill the Pd thin film, and substantial metal filling is caused in the pores of the Pd thin film, thereby effectively preventing long-term structural relaxation (such as creep relaxation and mechanical relaxation) and improving long-term stability of the Pd thin film.
[0024] In a second aspect, the application provides a hydrogen-sensitive material for a hydrogen sensor, which is prepared by the above method for preparing a hydrogen-sensitive material for a hydrogen sensor.
[0025] By adopting the technical solution, the hydrogen-sensitive material for a hydrogen sensor has a nanoscale microstructure, has a large contact area with hydrogen, and makes hydrogen molecules more easily diffuse, thereby improving the response speed of the hydrogen sensor to hydrogen concentration changes; the nanoscale porous structure of the hydrogen-sensitive material makes the sensor more sensitive to low-concentration hydrogen, and accurate measurement of ppm-level or even lower concentration can be achieved; after annealing and aging treatment, stress of the Pd thin film is released, the structure is more stable, long-term structural relaxation is prevented by the void filling treatment, long-term stability of the Pd film layer is improved, and zero-point drift is inhibited, thereby improving the service life and reliability of the sensor.
[0026] In summary, the application has the following beneficial technical effects: Improved response speed: the application deposits a Pd thin film by small-angle technology, manufactures a hydrogen-sensitive material with a nanoscale microstructure, increases the contact area of the Pd thin film with H2, and makes hydrogen molecules more easily diffuse into the structure, thereby improving the response speed of the hydrogen sensor to hydrogen concentration changes; Lower measurement limit: the nanoscale porous structure of the Pd thin film makes the hydrogen sensor more sensitive to the detection of low-concentration hydrogen, and accurate measurement of ppm-level or even lower concentration can be achieved; Improved long-term stability: in-situ annealing and aging treatment releases stress during growth of the Pd thin film, and the Au metal compound solution filling treatment prevents long-term structural relaxation, thereby comprehensively improving long-term stability of the Pd thin film, inhibiting zero-point drift, and improving the service life and reliability of the hydrogen sensor. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 The figure is a schematic diagram of the small-angle technology deposition process in S2 of the application; Figure 2 The figure is a schematic diagram of the metal filling process in S4 of the application; Figure 3A Pd film TEM image obtained in S2 of the present application; Figure 4 A response spectrum of a hydrogen sensor to be tested obtained in Example 4.1 of the present application; Figure 5 A response spectrum of a hydrogen sensor to be tested obtained in Example 3 and Comparative Example 1 of the present application; Figure 6 A comparison chart of aging effects of hydrogen-sensitive materials for hydrogen sensors obtained in Example 3 and Comparative Example 2 of the present application. DETAILED DESCRIPTION
[0028] The following combines examples, comparative examples and Figures 1-6 The present application is further described in detail.
[0029] Example 1 A method for preparing a hydrogen-sensitive material for a hydrogen sensor, comprising the following steps: S1, providing a pretreated substrate: immerse the single-side polished quartz glass in acetone according to a solid-liquid ratio of 1:10, and ultrasonically clean at 68 kHz for 40 min; S2, depositing a Pd film on the surface of the substrate by small-angle technology: load the pretreated substrate obtained in S1 and a Pd target into a double-target magnetron sputtering instrument, use a direct current power source to deposit the Pd target, vacuumize the chamber before deposition, heat the substrate to 300℃ after the air pressure is extracted to 10 -6 Pa, keep warm for 30 min, then start deposition, set the deposition time to 10 min, the deposition rate to 20 nm / min, the deposition angle to 85°, the direct current power source voltage to 380 V, the current to 0.05 A, the argon flow into the chamber to 4 sccm, keep the substrate table rotating at a constant speed according to a rotation speed of 5 rpm during deposition, to obtain a substrate with a Pd film of a thickness of 200 nm deposited on the surface; S3, in-situ annealing aging treatment of the product obtained in step S2: after deposition, turn off the power source of the double-target magnetron sputtering instrument, and control the temperature setting of the heating module of the equipment to 370℃, to perform in-situ annealing treatment on the substrate with the Pd film deposited on the surface obtained in S2, for a treatment time of 1.8 h; S4, filling treatment of the product obtained in step S3 by using an Au metal compound solution: take out the in-situ annealed material, naturally cool, then immerse in an AuCl3 solution with a mass concentration of 5% according to a solid-liquid ratio of 1:10, reduce, perform metal filling treatment on the in-situ annealed material, for a treatment time of 5 min, to obtain a hydrogen-sensitive material for a hydrogen sensor.
[0030] Example 2 A method for preparing a hydrogen-sensitive material for a hydrogen sensor, comprising the following steps: S1, providing a pretreated substrate: immersing the single-side polished quartz glass in acetone and ultrasonic cleaning for 30 min; S2, depositing a Pd film on the surface of the substrate by small-angle technique: loading the pretreated substrate and a Pd target obtained in S1 into a double-target magnetron sputtering instrument, depositing the Pd target by using a direct current power source, vacuumizing the chamber before deposition, heating the substrate to 300℃ after the pressure is extracted to 10 -6 Pa, then depositing after 30 min of heat preservation, setting the deposition time to 5 min, the deposition rate to 10 nm / min, the deposition angle to 10°, the direct current power source voltage to 380 V, the current to 0.05 A, the argon flow into the chamber to 4 sccm, and keeping the substrate table rotating at a constant speed during deposition, to obtain a substrate with a Pd film of 50 nm in thickness deposited on the surface; S3, in-situ annealing and aging treatment of the product obtained in step S2: after deposition, turning off the power source of the double-target magnetron sputtering instrument, setting the temperature of the heating module of the equipment to 330℃, and performing in-situ annealing treatment on the substrate with a Pd film deposited on the surface obtained in S2, for 2.2 h; S4, filling treatment of the product obtained in step S3 by using an Au metal compound solution: taking out the in-situ annealed material, naturally cooling, then immersing in a 1% Au(acac)3 solution for reduction, and performing metal filling treatment on the in-situ annealed material, to obtain a hydrogen-sensitive material for hydrogen sensor.
[0031] Example 3 A method for preparing a hydrogen-sensitive material for hydrogen sensor, comprising the following steps: S1, providing a pretreated substrate: immersing the single-side polished quartz glass in acetone and ultrasonic cleaning for 35 min; S2, depositing a Pd film on the surface of the substrate by small-angle technique: loading the pretreated substrate and a Pd target obtained in S1 into a double-target magnetron sputtering instrument, depositing the Pd target by using a direct current power source, vacuumizing the chamber before deposition, heating the substrate to 300℃ after the pressure is extracted to 10 -6 Pa, then depositing after 30 min of heat preservation, setting the deposition time to 8 min, the deposition rate to 15 nm / min, the deposition angle to 50°, the direct current power source voltage to 380 V, the current to 0.05 A, the argon flow into the chamber to 4 sccm, and keeping the substrate table rotating at a constant speed during deposition, to obtain a substrate with a Pd film of 120 nm in thickness deposited on the surface; S3, in-situ annealing treatment of the material obtained in step S2: after the deposition, the power supply of the dual-target magnetron sputtering instrument is turned off, the temperature of the heating module of the instrument is set to 350℃, and the material obtained in step S2 is subjected to in-situ annealing treatment, and the treatment time is 2h; S4, filling treatment of the material obtained in step S3 by using an Au metal compound solution: the material subjected to in-situ annealing is taken out and naturally cooled, and then immersed in a Au(PPh3)Cl solution with a mass concentration of 3% for reduction, so that the material subjected to in-situ annealing is subjected to metal filling treatment, thereby obtaining a hydrogen-sensitive material for a hydrogen sensor.
[0032] Example 4.1 A method for preparing a hydrogen-sensitive material for a hydrogen sensor, which is different from example 3 in that, in step S2, before the Pd target is loaded into the dual-target magnetron sputtering instrument, a transition layer Cr layer is first deposited on the surface of the pretreated substrate obtained in step S1, and the specific steps are as follows: direct current magnetron sputtering is used, the Ar flow rate is set to 10sccm, the working pressure is set to 1.0Pa, the target power is set to 50watts, the final Cr film thickness is set to 20nm, the film deposition termination time is set to 5min according to the real-time film deposition rate, and the rest is the same as example 3.
[0033] Example 4.2 A method for preparing a hydrogen-sensitive material for a hydrogen sensor, which is different from example 3 in that, in step S2, before the Pd target is loaded into the dual-target magnetron sputtering instrument, a transition layer Cr layer is first deposited on the surface of the pretreated substrate obtained in step S1, and the specific steps are as follows: direct current magnetron sputtering is used, the Ar flow rate is set to 50sccm, the working pressure is set to 0.2Pa, the target power is set to 200watts, the final Cr film thickness is set to 3nm, the film deposition termination time is set to 1min according to the real-time film deposition rate, and the rest is the same as example 3.
[0034] Example 5.1 A method for preparing a hydrogen-sensitive material for a hydrogen sensor, which is different from example 3 in that, in step S2, before the Pd target is loaded into the dual-target magnetron sputtering instrument, a transition layer Ti layer is first deposited on the surface of the pretreated substrate obtained in step S1, and the specific steps are as follows: direct current magnetron sputtering is used, and when the vacuum degree is ≤1×10 -5 Pa, plasma cleaning of the substrate is started, the Ar flow rate is set to 10sccm, the working pressure is set to 1.0Pa, the target power is set to 50watts, the final Ti film thickness is set to 20nm, the film deposition termination time is set to 5min according to the real-time film deposition rate, and the rest is the same as example 3.
[0035] Example 5.2 A preparation method of a hydrogen-sensitive material for a hydrogen sensor, which is different from example 3 in that: in S2, before the Pd target is loaded into the double-target magnetron sputtering instrument, a transition layer Ti layer is first deposited on the surface of the pretreated substrate obtained in S1, and the specific steps are as follows: using direct current magnetron sputtering, plasma cleaning of the substrate is started at a vacuum degree of ≤1×10 -5 Pa, and the time lasts for 2 minutes, the Ar flow rate is set to 50 sccm, the working gas pressure is set to 0.2 Pa, the target power is set to 200 W, the final Ti film thickness is set to 3 nm, the deposition termination time is set to 1 min according to the real-time deposition rate, and the rest are the same as in example 3.
[0036] Comparative example 1 The difference from example 3 is that: in S2, the Pd thin film is not deposited by small-angle technology, but is deposited by electron beam evaporation (E-beam evaporation) technology, and the specific steps are as follows: after the Pd target is loaded, vacuum pumping is performed to ≤5×10⁻ 6 Torr, low-power pre-evaporation degassing is performed, the deposition rate is controlled at 0.6 Å / s, the thickness is 100 nm, the substrate can be at room temperature to 100°C, the rotation of the turntable ensures uniformity, after deposition, the power is reduced, the gun is turned off, and the gas is sampled, and the rest are the same as in example 3.
[0037] Comparative example 2 The difference from example 3 is that: S3 and S4 are removed, and the rest are the same as in example 3.
[0038] Performance detection
[0039] 1. The hydrogen-sensitive material for a hydrogen sensor obtained in example 4.1 is added with conductive silver paste at both ends, and after cooling and solidification, it is connected with the probe in the hydrogen sensor to obtain a sample to be tested, and the following detection is performed: In 90 minutes, the response of the sample to be tested at hydrogen concentrations of 100 ppm, 200 ppm and 400 ppm is recorded respectively. Figure 4 .
[0040] 2. The hydrogen-sensitive material for a hydrogen sensor obtained in example 3 and comparative example 2 is added with conductive silver paste at both ends, and after cooling and solidification, it is connected with the probe in the hydrogen sensor to obtain a sample to be tested, and the following detection is performed: In 90 minutes, the response of the sample to be tested at hydrogen concentrations of 2 ppm, 10 ppm and 20 ppm is recorded respectively. Figure 5 .
[0041] 3. The hydrogen-sensitive material for a hydrogen sensor obtained in example 3 and comparative example 2 is subjected to an aging experiment, and the comparison chart of the aging effect is as shown in Figure 6 .
[0042] Data analysis: According to Figure 1 , Figures 3-5 It can be known that, by depositing Pd film through small-angle technology, the hydrogen-sensitive material with nanoscale microstructure is manufactured, the contact area between the Pd film and H2 is increased, the hydrogen molecules are more easily diffused into the structure, thereby the response speed of the hydrogen sensor to the change of hydrogen concentration is improved, the nanoscale porous structure of the Pd film makes the hydrogen sensor more sensitive to the detection of low-concentration hydrogen, and accurate measurement of ppm level or even lower concentration can be realized.
[0043] According to Figure 2 and Figure 6 It can be known that, by in-situ annealing aging treatment and Au metal filling, the stress in the growth of the Pd film is released, the long-term structural relaxation is prevented by the Au metal compound solution filling treatment, the long-term stability of the Pd film is comprehensively enhanced, the zero-point drift is inhibited, and thereby the service life and reliability of the hydrogen sensor are improved.
[0044] The embodiments of the specific implementation are the preferred embodiments of the present application, and are not limited to the protection scope of the present application, so that: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.
Claims
1. A method for producing a hydrogen-sensitive material for a hydrogen sensor, characterized by, The method comprises the following steps: S1, providing a pretreated substrate; S2, depositing a Pd film on the surface of the substrate by small-angle deposition technology; S3, performing in-situ annealing aging treatment on the product of step S2; S4, performing filling treatment on the product of step S3 by using an Au metal compound solution.
2. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 1, characterized by, In the step S1, the pretreatment is specifically as follows: the substrate is immersed in acetone and ultrasonically cleaned for 30-40 min.
3. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 1, characterized in that, In the step S2, the deposition process is specifically as follows: after the substrate is heated under vacuum, Pd is deposited on the surface of the substrate at a deposition angle of 10-85° under the protection of inert gas, the deposition time is 5-10 min, and a Pd film with a thickness of 50-200 nm is obtained.
4. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 3, characterized in that, In the step S2, the substrate is rotated at a constant speed when the Pd is deposited on the surface of the substrate.
5. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 3, characterized in that, In the step S2, a transition layer is deposited before the Pd film is deposited on the surface of the substrate, and the thickness of the transition layer is 3-20 nm.
6. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 5, wherein The transition layer is a Cr layer or a Ti layer.
7. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 1, wherein In the step S3, the in-situ annealing aging treatment is specifically as follows: the product of step S2 is heated to 330-370℃, and in-situ annealing is performed for 1.8-2.2 h.
8. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 1, characterized by, In the step S4, the mass concentration of the Au metal compound solution is 1-5%.
9. The method for producing a hydrogen-sensitive material for a hydrogen sensor according to claim 8, wherein In the step S4, the Au metal compound solution is any one of AuCl3 solution, AuBr3 solution, AuI3 solution, Au(acac)3 solution, Au(PPh3)Cl solution or Au(en)2Cl3 solution.
10. A hydrogen sensor hydrogen-sensitive material prepared by the method for preparing the hydrogen sensor hydrogen-sensitive material according to any one of claims 1-9.