Hydrogen sensitive element, preparation method thereof, and hydrogen sensor

Abstract

This application relates to the field of hydrogen sensor technology, providing a hydrogen-sensitive element, its fabrication method, and a hydrogen sensor. The hydrogen-sensitive element includes a carrier, a heating layer, a thermistor layer, and a hydrogen-sensitive layer. The carrier contains a first cavity and a second cavity; the heating layer is sealed within the first cavity; the thermistor layer is sealed within the second cavity; and the hydrogen-sensitive layer is disposed on the carrier. The hydrogen-sensitive element of this application features good thermal stability, high heating efficiency, and fast response speed.

Description

Technical Field

[0001] This application relates to the field of hydrogen sensor technology, and in particular to a hydrogen-sensitive element, its preparation method, and a hydrogen sensor. Background Technology

[0002] In the field of process control, monitoring, and analysis of hydrogen energy systems, hydrogen sensors are indispensable sensitive elements. Among them, palladium alloy hydrogen sensors have attracted widespread attention in the industry due to their specific selectivity, high sensitivity, stability, and good chemical and thermal stability for hydrogen.

[0003] Specifically, palladium alloy hydrogen sensors utilize the specific selectivity of palladium for hydrogen, enabling accurate measurement of hydrogen concentration in complex gas environments. This characteristic is particularly important in fields requiring precise hydrogen measurement and control under complex operating conditions. However, palladium alloys have a large temperature coefficient of resistance, thus palladium alloy hydrogen sensors require extremely high stability at operating temperatures. The solubility of hydrogen in the palladium alloy film varies at different temperatures. For example, low temperatures slow down the dissolution rate of hydrogen in palladium alloys, causing a decrease in sensor sensitivity; excessively high temperatures cause palladium alloy lattice expansion, reducing hydrogen solubility. Temperature fluctuations can lead to enthalpy fluctuations during hydrogen dissolution, causing sensor measurement data to deviate, resulting in decreased accuracy and stability. Therefore, improving the heating stability and reliability of hydrogen sensors is crucial for the accuracy of hydrogen concentration detection under dynamic environmental temperatures. Summary of the Invention

[0004] Therefore, it is necessary to provide a hydrogen-sensitive element that is stable in heating and has a fast temperature response, as well as its preparation method and a hydrogen sensor.

[0005] In a first aspect, this application provides a hydrogen-sensitive element, the hydrogen-sensitive element comprising:

[0006] A carrier, wherein a first cavity and a second cavity are provided within the carrier;

[0007] A heating layer is sealed within the first cavity;

[0008] A heat-sensitive layer, wherein the heat-sensitive layer is sealed within the second cavity; and,

[0009] A hydrogen-sensitive layer is disposed on the carrier.

[0010] In some embodiments, the carrier includes a carrier layer and a sealing layer stacked together, the sealing layer being disposed on the side of the carrier layer away from the hydrogen-sensitive layer.

[0011] Optionally, the second cavity is formed between the sealing layer and the carrier layer.

[0012] Optionally, the first cavity is formed within the carrier layer.

[0013] In some embodiments, the material of the sealing layer includes at least one of glass glaze and silicon nitride.

[0014] In some embodiments, the thickness of the sealing layer is 1 μm to 5 μm.

[0015] In some embodiments, the material of the carrier layer includes at least one selected from alumina, aluminum nitride, silicon carbide, beryllium oxide, boron nitride, and zirconium oxide.

[0016] In some embodiments, the thickness of the carrier layer is 0.5 mm to 2 mm.

[0017] In some embodiments, the material of the hydrogen-sensitive layer includes at least one of palladium-based binary alloys and palladium-based ternary alloys.

[0018] In some embodiments, the thickness of the hydrogen-sensitive layer is 30 nm to 350 nm.

[0019] In some embodiments, the heating layer is made of at least one of ruthenium dioxide, nickel-chromium alloy, and tungsten.

[0020] In some embodiments, the thickness of the heating layer is 1 μm to 5 μm.

[0021] In some embodiments, the material of the thermosensitive layer includes at least one of platinum, cobalt oxides, and manganese oxides.

[0022] In some embodiments, the thickness of the thermal layer is 1 μm to 3 μm.

[0023] In some embodiments, the hydrogen-sensitive element further includes an activation layer disposed on the surface of the hydrogen-sensitive layer away from the support, the activation layer being used to promote the catalytic rate and hydrogen dissolution rate of the hydrogen-sensitive layer.

[0024] In some embodiments, the hydrogen-sensitive element further includes a transition layer disposed between the hydrogen-sensitive layer and the carrier.

[0025] In some embodiments, the material of the activation layer includes at least one of platinum and ZIF-8 metal framework material.

[0026] In some embodiments, the thickness of the activation layer is 30 nm to 80 nm.

[0027] In some embodiments, the material of the transition layer includes at least one of tantalum oxide, molybdenum oxide, and titanium.

[0028] In some embodiments, the thickness of the transition layer is 60 nm to 300 nm.

[0029] Secondly, this application provides a method for preparing a hydrogen-sensitive element as described in the first aspect, the method comprising:

[0030] The first cavity and the second cavity are formed in the material used to prepare the carrier, and the heating layer is sealed in the first cavity and the thermosensitive layer is sealed in the second cavity. After sintering, the carrier with the heating layer and the thermosensitive layer sealed inside is formed.

[0031] The hydrogen-sensitive layer is formed on the carrier to prepare the hydrogen-sensitive element.

[0032] In some embodiments, the carrier includes a carrier layer and a sealing layer, and the method for preparing the carrier includes: disposing the heating layer in the material for preparing the carrier layer, and sintering to form the carrier layer with the heating layer sealed inside;

[0033] The thermosensitive layer is disposed on one side surface of the carrier layer, and the thermosensitive layer is sealed using the material used to prepare the sealing layer. After sintering, the sealing layer is formed, and the thermosensitive layer is sealed between the sealing layer and the carrier layer.

[0034] In some embodiments, the hydrogen-sensitive element further includes an activation layer, which is formed on the side of the hydrogen-sensitive layer away from the carrier by at least one of magnetron sputtering, ion beam sputtering, and evaporation coating.

[0035] In some embodiments, the hydrogen-sensitive element further includes a transition layer, which is formed on the surface of the carrier near the hydrogen-sensitive layer by at least one of magnetron sputtering, ion beam sputtering, and evaporation deposition.

[0036] Thirdly, this application provides a hydrogen sensor, which includes a hydrogen-sensitive element as described in the first aspect.

[0037] Compared with traditional technologies, this application has at least the following beneficial effects:

[0038] This application places the heating layer and the thermistor layer inside the carrier. The heating layer's placement inside the carrier allows for more direct and efficient heat transfer, significantly improving heating efficiency and resulting in better temperature uniformity and faster response speed. The thermistor layer, also inside the carrier, enables in-situ monitoring of the carrier temperature, effectively avoiding the influence of external ambient temperature and ensuring the accuracy of heating layer temperature regulation, thus synergistically improving the carrier's temperature stability. Furthermore, sealing the heating and thermistor layers within the carrier prevents contact and reaction between ambient gases and the heating and thermistor layers, improving heating and detection stability. Therefore, the hydrogen sensor of this application effectively improves heating efficiency and response speed, enabling rapid response to changes in hydrogen concentration. Moreover, under dynamic temperature environments, the hydrogen sensor of this application exhibits rapid temperature equilibrium and minimal temperature drift, allowing for stable operation under complex and variable temperature conditions, greatly enhancing the overall performance and applicability of the hydrogen sensor. Attached Figure Description

[0039] Figure 1 This is a cross-sectional schematic diagram of a hydrogen-sensitive element provided in one embodiment of this application;

[0040] Figure 2 This is a schematic diagram of the structure of one side of the hydrogen-sensitive layer in a hydrogen-sensitive element provided in one embodiment of this application;

[0041] Figure 3 This is a schematic diagram of the internal structure of a hydrogen sensor provided in one embodiment of this application;

[0042] Figure 4 This is a schematic diagram of the top surface structure of a hydrogen sensor provided in one embodiment of this application;

[0043] Figure 5 This is a side view of the hydrogen sensor provided in one embodiment of this application;

[0044] Figure 6 This is a schematic diagram of the structure of a hydrogen sensor testing system provided in one embodiment of this application;

[0045] Figure 7 The graph shows the performance test results of the hydrogen sensor provided in Example 1 of this application at different concentrations under normal temperature and pressure (25°C, 1 atm);

[0046] Figure 8 The graph shows the repeatability test results of the hydrogen sensor provided in Embodiment 1 of this application;

[0047] Figure 9 The graph shows the response time test results of the hydrogen sensor provided in Embodiment 1 of this application in a 1% nitrogen-hydrogen mixture.

[0048] Figure 10The graph shows the response time test results of the hydrogen sensor provided in Embodiment 1 of this application in a 3% nitrogen-hydrogen mixture.

[0049] Figure 11 The graph shows the response time test results of the hydrogen sensor provided in Embodiment 1 of this application in a 5% nitrogen-hydrogen mixture.

[0050] Figure 12 This is a graph showing the performance test results of the hydrogen sensor provided in Embodiment 1 of this application under different gas pressures;

[0051] Figure 13 This is a graph showing the performance test results of the hydrogen sensor provided in Embodiment 1 of this application under the influence of carbon monoxide gas;

[0052] Figure 14 The graph shows the performance test results of the hydrogen sensor provided in Embodiment 1 of this application under the influence of methane gas.

[0053] Among them, 100-hydrogen-sensitive element; 110-carrier; 111-carrier layer; 112-sealing layer; 120-heating layer; 121-heating electrode; 130-thermosensitive layer; 131-thermosensitive electrode; 140-hydrogen-sensitive layer; 141-hydrogen-sensitive electrode; 150-transition layer; 160-activation layer; 200-shell; 210-base; 211-base electrode; 220-cover plate; 221-vent hole; 1-hydrogen cylinder; 2-nitrogen cylinder; 3-gas flow meter; 4-float flow meter; 5-hydrogen sensor; 6-data acquisition unit. Detailed Implementation

[0054] The present application will be further described in detail below with reference to the embodiments and examples. These embodiments and examples are only for illustrating the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. In addition, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0056] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0057] In this application, the terms "first aspect," "second aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first aspect," "second aspect," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0058] In this application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0059] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0060] All references to this application are incorporated herein by reference as if each document were individually incorporated herein by reference. Unless they conflict with the purpose and / or technical solution of this application, all cited references are incorporated herein by reference in their entirety and for all purposes. When references are cited in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. Examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.

[0061] In traditional technologies, the heating layer and the hydrogen-sensitive layer in a hydrogen-sensitive element are located on the same side or opposite side of the carrier. To ensure the accuracy of the temperature at the hydrogen-sensitive layer, the thermistor layer and the hydrogen-sensitive layer are located on the same surface of the carrier. However, during detection, the heating layer is affected by ambient temperature, and direct contact with the environment causes heat loss, reducing heating efficiency and slowing response. Furthermore, the thermistor layer and heating layer are mostly made of metallic materials, which are prone to reacting with ambient gases, affecting their resistance and thus impacting the measurement accuracy of the thermistor layer and the heating accuracy of the heating layer. This can lead to temperature drift in the hydrogen-sensitive element, affecting the stability of the sensor.

[0062] The first aspect of this application provides a hydrogen-sensitive element, such as... Figure 1 As shown, the hydrogen-sensitive element 100 includes a carrier 110, a heating layer 120, a thermistor layer 130, and a hydrogen-sensitive layer 140.

[0063] The carrier 110 is provided with a first cavity and a second cavity; the heating layer 120 is sealed in the first cavity; the thermistor layer 130 is sealed in the second cavity; and the hydrogen-sensitive layer 140 is disposed on the carrier 110.

[0064] This application places the heating layer 120 and the thermistor layer 130 inside the carrier 110. The heating layer 120, located inside the carrier 110, allows for more direct and efficient heat transfer, significantly improving heating efficiency and resulting in good temperature uniformity and a fast response speed for the carrier 110. The thermistor layer 130, located inside the carrier 110, enables in-situ monitoring of the carrier 110 temperature, effectively avoiding the influence of external ambient temperature and ensuring the accuracy of temperature regulation of the heating layer 120, thereby synergistically improving the temperature stability of the carrier 110. Furthermore, sealing the heating layer 120 and the thermistor layer 130 within the carrier 110 prevents contact and reaction between ambient gases and the heating layer 120 and the thermistor layer 130, improving heating and detection stability. Therefore, the hydrogen sensor of this application effectively improves heating efficiency and response speed, enabling rapid response to changes in hydrogen concentration. Moreover, under dynamic temperature environments, the hydrogen sensor 100 of this application exhibits rapid temperature equilibrium and minimal temperature drift, enabling stable operation under complex and variable temperature conditions, greatly enhancing the overall performance and applicability of the hydrogen sensor.

[0065] It is understandable that if Figure 2 As shown, the carrier 110 of this application is provided with a heating electrode 121, a thermistor 131 and a hydrogen-sensitive electrode 141, wherein the heating electrode 121 is electrically connected to the heating layer 120, the thermistor 131 is electrically connected to the thermistor layer 130, and the hydrogen-sensitive electrode 141 is electrically connected to the hydrogen-sensitive layer 140.

[0066] It is understood that in this application, the heating layer 120 can realize the heating function; the thermistor layer 130 can realize the temperature detection function; and the hydrogen-sensitive layer 140 can realize the hydrogen concentration detection function. In some embodiments, the heating layer 120 is fitted and filled in the first cavity, and the thermistor layer 130 is fitted and filled in the second cavity.

[0067] In some embodiments, such as Figure 1 As shown, the carrier 110 includes a carrier layer 111 and a sealing layer 112 stacked together. The sealing layer 112 is disposed on the surface of the carrier layer 111 away from the hydrogen-sensitive layer 140. By providing the sealing layer 112, this application can further improve the airtightness of the carrier 110, suppress the entry of ambient gas into the carrier 110 and its reaction with the heating layer 120 and the thermistor layer 130, avoid temperature drift of the hydrogen-sensitive element 100 due to chemical reactions, and improve the temperature stability of the sensor.

[0068] Alternatively, the sealing layer 112 may be an insulating sealing layer 112.

[0069] It is understood that the heating layer 120 and the thermistor layer 130 are spaced apart in this application to avoid direct contact between the heating layer 120 and the thermistor layer 130.

[0070] Optionally, the second cavity is formed between the sealing layer 112 and the carrier layer 111, that is, the heat-sensitive layer 130 is sealed between the sealing layer 112 and the carrier layer 111.

[0071] Optionally, the first cavity is formed within the carrier layer 111, that is, the heating layer 120 is sealed within the carrier layer 111. Further optionally, the heating layer 120 and the thermistor layer 130 are disposed in the middle region of the carrier layer 111 in the thickness direction. Even further optionally, the heating layer 120 is centrally disposed within the carrier layer 111.

[0072] In some embodiments, the material of the sealing layer 112 includes at least one of glass glaze and silicon nitride.

[0073] In some embodiments, the thickness of the sealing layer 112 is 1μm to 5μm, for example, it can be 1.0μm, 1.5μm, 2.0μm, 2.5μm, 3.0μm, 3.5μm, 4.0μm, 4.5μm or 5.0μm.

[0074] In some embodiments, the material of the carrier layer 111 includes at least one selected from aluminum oxide, aluminum nitride, silicon carbide, beryllium oxide, boron nitride, and zirconium oxide.

[0075] In some embodiments, the thickness of the carrier layer 111 is 0.5mm to 2.0mm, for example, it can be 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm or 2.0mm.

[0076] In some embodiments, the material of the hydrogen-sensitive layer 140 includes at least one of a palladium-based binary alloy and a palladium-based ternary alloy. For example, the material of the hydrogen-sensitive layer 140 may be a palladium-based ternary alloy, which, by mass percentage, comprises: Pd (palladium), 83%~94.9%; Y (yttrium), 5%~12%; and Ru (ruthenium), 0.1%~5%.

[0077] In some embodiments, the thickness of the hydrogen-sensitive layer 140 is 30nm to 350nm, for example, it can be 30nm, 60nm, 90nm, 120nm, 150nm, 180nm, 210nm, 240nm, 270nm, 300nm, 330nm or 350nm.

[0078] In some embodiments, the material of the heating layer 120 includes at least one of ruthenium dioxide, nickel-chromium alloy, and tungsten.

[0079] In some embodiments, the thickness of the heating layer 120 is 1μm to 5μm, for example, it can be 1μm, 2μm, 3μm, 4μm or 5μm.

[0080] In some embodiments, the material of the thermosensitive layer 130 includes at least one of platinum, cobalt oxide, and manganese oxide.

[0081] In some embodiments, the thickness of the thermal layer 130 is 1μm to 3μm, for example, it can be 1.0μm, 1.5μm, 2.0μm, 2.5μm or 3.0μm.

[0082] In some embodiments, such as Figure 1 As shown, the hydrogen-sensitive element 100 further includes an activation layer 160, which is disposed on the surface of the hydrogen-sensitive layer 140 away from the support 110. The activation layer 160 is used to promote the catalytic rate and hydrogen dissolution rate of the hydrogen-sensitive layer 140. By providing the activation layer 160 on the surface of the hydrogen-sensitive layer 140, this application can promote the catalytic rate and hydrogen dissolution rate of hydrogen on the surface of the hydrogen-sensitive layer 140, thereby improving the response speed of the hydrogen-sensitive element.

[0083] In some embodiments, the hydrogen-sensitive element 100 further includes a transition layer 150 disposed between the hydrogen-sensitive layer 140 and the carrier 110. This application utilizes the transition layer 150 between the carrier 110 and the hydrogen-sensitive layer 140 to effectively repair the surface flatness of the carrier 110, improve the surface dielectric constant of the carrier 110, and also provides a sealing effect and improves the bonding stability of the hydrogen-sensitive layer 140, further preventing gas from entering the carrier 110 and contacting the thermistor layer 130 and the heating layer 120.

[0084] In some embodiments, the material of the activation layer 160 includes at least one of platinum and ZIF-8 metal framework material.

[0085] In some embodiments, the thickness of the activation layer 160 is 30nm to 80nm, for example, it can be 30nm, 40nm, 50nm, 60nm, 70nm or 80nm.

[0086] In some embodiments, the material of the transition layer 150 includes at least one of tantalum oxide, molybdenum oxide, and titanium.

[0087] In some embodiments, the thickness of the transition layer 150 is 60nm to 300nm, for example, it can be 60nm, 80nm, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 260nm, 280nm or 300nm.

[0088] It should be noted that the heating layer 120, the thermistor layer 130, and the hydrogen-sensitive layer 140 in the hydrogen-sensitive element 100 of this application can be graphically represented as needed. For example... Figure 2 As shown, the hydrogen-sensitive layer 140 can be a reciprocating zigzag structure.

[0089] In some embodiments, the hydrogen-sensitive element 100 includes a carrier 110, on one side surface of the carrier 110, a transition layer 150, a hydrogen-sensitive layer 140, and an activation layer 160 are sequentially disposed along a direction away from the carrier 110. A heating layer 120 and a thermistor layer 130 are sealed within the carrier 110. The carrier 110 includes a carrier layer 111 and a sealing layer 112 sequentially stacked, wherein the carrier layer 111 is in contact with the transition layer 150, and the sealing layer 112 is disposed on the side surface of the carrier layer 111 away from the transition layer 150. Optionally, the heating layer 120 is sealed within the carrier layer 111, and the thermistor layer 130 is sealed between the sealing layer 112 and the carrier layer 111.

[0090] A second aspect of this application provides a method for preparing a hydrogen-sensitive element as described in the first aspect, the method comprising:

[0091] The first cavity and the second cavity are formed in the material used to prepare the carrier 110, and the heating layer 120 is sealed in the first cavity and the thermosensitive layer 130 is sealed in the second cavity. After sintering, the carrier 110 with the heating layer 120 and the thermosensitive layer 130 sealed inside is formed.

[0092] A hydrogen-sensitive layer 140 is formed on the carrier 110 to prepare the hydrogen-sensitive element 100.

[0093] In some embodiments, the carrier 110 includes a carrier layer 111 and a sealing layer 112. The method for preparing the carrier 110 includes: disposing the heating layer 120 in the material for preparing the carrier layer 111, and sintering to form the carrier layer 111 with the heating layer 120 internally sealed.

[0094] The thermosensitive layer 130 is disposed on one side surface of the carrier layer 111, and the thermosensitive layer 130 is sealed with the material used to prepare the sealing layer 112. After sintering, the sealing layer 112 is formed, and the thermosensitive layer 130 is sealed between the sealing layer 112 and the carrier layer 111.

[0095] This application employs a co-sintering method to seal the heating layer 120 and the thermistor layer 130 within the carrier 110. This method is simple and has good structural stability, effectively improving heating efficiency and temperature detection accuracy, thereby enhancing the stability of the hydrogen-sensitive element.

[0096] It is understandable that a flow port for connecting the heating layer 120 and the thermistor layer 130 is reserved before sintering, so that the electrodes of the heating layer 120 and the thermistor layer 130 can be led out by gold paste pouring.

[0097] Optionally, the sintering method can be low-temperature co-fired ceramic (LTCC) with a sintering temperature of 800℃~950℃, or high-temperature co-fired ceramic (HTCC) with a sintering temperature of 1600℃~1800℃.

[0098] In some embodiments, the hydrogen-sensitive element further includes an activation layer 160, which is formed on the side of the hydrogen-sensitive layer 140 away from the carrier 110 by at least one of magnetron sputtering, ion beam sputtering, and evaporation coating.

[0099] In some embodiments, the hydrogen-sensitive element further includes a transition layer 150, which is formed on the side surface of the carrier 110 near the hydrogen-sensitive layer 140 by at least one of magnetron sputtering, ion beam sputtering, and evaporation coating.

[0100] A third aspect of this application provides a hydrogen sensor, such as... Figure 3 , Figure 4 and Figure 5 As shown, the hydrogen sensor includes the hydrogen-sensitive element 100 as described in the first aspect, and further includes:

[0101] A housing 200, wherein the hydrogen-sensitive element 100 is disposed within the housing 200; and,

[0102] Multiple leads are provided, including at least a first lead, a second lead, and a third lead. The first lead is electrically connected to the heating layer 120 and is used to conduct the circuit. The second lead is electrically connected to the thermistor layer 130 and is used for the detection signal of the thermistor layer 130. The third lead is connected to the hydrogen-sensitive layer 140 and is used to conduct the detection signal of the hydrogen-sensitive layer 140.

[0103] In some embodiments, such as Figure 3 and Figure 4 As shown, the housing 200 includes a cover plate 220 and a base 210 that interlock. Optionally, the cover plate 220 has multiple vent holes 221, and the side of the hydrogen-sensitive element 100 with the hydrogen-sensitive layer 140 is close to the cover plate 220. The base 210 is provided with a heat insulation plate and multiple base electrodes 211. The base electrodes 211 are electrically connected to the heating layer 120, the thermistor layer 130, and the hydrogen-sensitive layer 140 in the hydrogen-sensitive element 100 through leads, thereby realizing circuit conduction and signal transmission.

[0104] In some embodiments, the lead wire may be a gold wire with a diameter of not less than 25 μm.

[0105] The embodiments of this application will be described in detail below with reference to examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0106] Example 1

[0107] This embodiment provides a method for preparing a hydrogen-sensitive element, including the following steps:

[0108] S1. The heating layer 120 is placed in the alumina ceramic material (carrier layer 111 raw material) and the electrode is reserved along the flow port. The co-sintering is carried out at 1500℃~1600℃ for 12h to prepare the carrier layer 111 with the heating layer 120 inside. The thickness of the heating layer 120 is 3μm and the thickness of the carrier layer 111 is 2mm.

[0109] S2. After grinding both sides of the carrier layer 111 prepared in step S1, a thermosensitive layer 130 is set on one side of the carrier layer 111. The layer is sealed with glass glaze material (the raw material of the sealing layer 112) and an electrode outlet is reserved. The layer is co-sintered at 650°C for 15 minutes to obtain the sealing layer 112. The thermosensitive layer 130 is sealed between the sealing layer 112 and the carrier layer 111. The thickness of the sealing layer 112 is 3μm, the thickness of the thermosensitive layer is 1μm, and the material of the thermosensitive layer is platinum.

[0110] S3. In step S2, a transition layer 150 with a thickness of 55 nm is formed by physical vapor deposition on the side of the carrier layer 111 away from the sealing layer 112. The material of the transition layer 150 is tantalum pentoxide.

[0111] S4. A hydrogen-sensitive layer 140 with a thickness of 200 nm is formed on the transition layer 150 obtained in step S3 by magnetron sputtering. The material of the hydrogen-sensitive layer 140 is the same as the hydrogen-sensitive thin film material in Example 1 of CN111118330A.

[0112] S5. An activation layer 160 with a thickness of 55 nm is formed on the hydrogen-sensitive layer 140 obtained in step S4 using a physical vapor deposition method. The material of the activation layer 160 is platinum.

[0113] S6. Using a gold paste casting method, the electrodes of the heating layer 120 and the thermistor layer 130 are brought to the surface of the hydrogen-sensitive element.

[0114] Example 2

[0115] The hydrogen-sensitive element is prepared according to the method of Example 1, except that in step S1, the thermistor layer 130 and the heating layer 120 are directly disposed alternately in the alumina ceramic material and co-sintered to form a carrier layer 111 containing the thermistor layer 130 and the heating layer 120. In step S2, a sealing layer 112 is directly sintered on the carrier layer 111.

[0116] Example 3

[0117] The hydrogen-sensitive element was prepared according to the method of Example 2, except that in step S1, the thermistor layer 130 and the heating layer 120 were directly disposed alternately in the alumina ceramic material and co-sintered to form a carrier layer 111 containing the thermistor layer 130 and the heating layer 120. Step S2 was not performed.

[0118] Example 4

[0119] The hydrogen-sensitive element was prepared according to the method of Example 1, except that step S5 was not performed and the activation layer 160 was not formed on the surface of the hydrogen-sensitive layer 140.

[0120] Comparative Example 1

[0121] This comparative example provides a method for preparing a hydrogen-sensitive element, including:

[0122] S1. Alumina ceramic material (carrier layer 111 raw material) is sintered at 1500℃~1600℃ for 12h to prepare carrier layer 111.

[0123] S2. After grinding both sides of the carrier layer 111 prepared in step S1, a heating layer 120 is set on one side of the carrier layer 111.

[0124] S3. In step S2, a transition layer 150 with a thickness of 55 nm is formed by physical vapor deposition on the side of the carrier layer 111 away from the heating layer 120.

[0125] S4. A hydrogen-sensitive layer 140 with a thickness of 200 nm is formed on the transition layer 150 obtained in step S3 by physical vapor deposition, and a thermosensitive layer 130 is formed on the transition layer 150. The hydrogen-sensitive layer 140 and the thermosensitive layer 130 are spaced apart.

[0126] S5. An activation layer 160 with a thickness of 55 nm is formed on the hydrogen-sensitive layer 140 obtained in step S4 by magnetron sputtering.

[0127] Comparative Example 2

[0128] The hydrogen-sensitive element is prepared according to the method of Example 1, except that the thermistor layer 130 is formed on the transition layer 150 and is disposed in the same layer as the hydrogen-sensitive layer 140.

[0129] The hydrogen-sensitive elements prepared in the above embodiments and comparative examples are assembled into a hydrogen sensor. The assembly method includes:

[0130] The hydrogen-sensitive element is installed on the base 210. The electrodes of the heating layer 120, the thermistor layer 130, and the hydrogen-sensitive layer 140 in the hydrogen-sensitive element are respectively connected to the base electrode 211. Then, the cover plate 220 with the vent hole 221 is fastened to the base 210 and sealed with gold-tin fusion welding.

[0131] The above-mentioned hydrogen sensor is installed in such a way as Figure 6 Performance testing was conducted on the test system shown. The test system includes hydrogen cylinder 1, nitrogen cylinder 2, gas flow meter 3, float flow meter 4, hydrogen sensor 5, and data acquisition unit 6. The test methods include:

[0132] After preheating for 30 minutes, start the vacuum pump to purge the air from the test container until the internal pressure reaches 10 kPa. Then, inject a 1% standard nitrogen-hydrogen mixture (volume content 1% H2 / 99% N2) to 101 kPa (atmospheric pressure) and close the standard gas valve. During this process, the hydrogen sensor reading rises and the sensor resistance stabilizes. Record the measured data; at this point, the test data corresponds to an H2 volume concentration of 1%.

[0133] Start the vacuum pump to extract the standard hydrogen gas from the container, and then inject a second hydrogen concentration for testing and calibration. Continue this process, using 1% hydrogen concentration increments until the desired hydrogen concentration value is reached. After obtaining the sensor's unit concentration resistance value, establish a mathematical model and fit and input it into the secondary acquisition system.

[0134] In the testing system, nitrogen-hydrogen mixed gas was used, and standard hydrogen gas was sequentially introduced at concentrations of 1%, 3%, 5%, 7%, 10%, 15%, and 20% for testing, yielding the following results: Figure 7 The results shown in the figure indicate that the gradients in each interval are clear, the resistance changes are sufficiently large, and the performance meets the design specifications. Table 1 shows the T90 response time and measurement accuracy at a hydrogen concentration of 3%. Measurement accuracy refers to the measurement time over 10 minutes at a hydrogen concentration of 3%, calculated as (maximum concentration detected - minimum concentration detected) / average hydrogen concentration.

[0135] refer to Figure 8 The repeatability of the sensor was tested under nitrogen-hydrogen mixtures with concentrations of 1%, 3%, and 5%, and the repeatability of the test results was within 1.5% FS.

[0136] refer to Figure 9 The response time of the sensor, tested using a 1% nitrogen-hydrogen mixture, is 24 seconds.

[0137] refer to Figure 10 The response time of the sensor, tested using a 3% nitrogen-hydrogen mixture, is 32 seconds.

[0138] refer to Figure 11 The response time of the sensor, tested using a 5% nitrogen-hydrogen mixture, is 32 seconds.

[0139] refer to Figure 12 The sensor exhibits good linearity for hydrogen concentrations of 0–25 vol.% under pressures ranging from 10 kPa to 800 kPa, with measurement accuracy within the range of +2% FS.

[0140] refer to Figure 13 The experiment on the hydrogen sensor under normal temperature and pressure, involving carbon monoxide (CO) gas, showed that the effect was negligible. (Reference) Figure 14As shown, under normal temperature and pressure, the effect of methane gas on the hydrogen sensor is negligible.

[0141] Table 1

[0142]

[0143] As can be seen from the table above:

[0144] (1) Compared with Example 1, it can be seen that by setting the sealing layer 112, this application can achieve a stable substrate working temperature (±0.01℃) in a hydrogen atmosphere for a long time, thereby ensuring measurement accuracy.

[0145] (2) Compared with Example 1 and Example 4, it can be seen that this application has advantages such as fast sensor response speed, high sensitivity and fast dehydrogenation by setting the activation layer 160.

[0146] (3) Compared with Comparative Examples 1-2, Example 1 shows that the present application places the heating layer 120 and the thermistor layer 130 inside the carrier 110. The heating layer 120 inside the carrier 110 makes heat transfer more direct and effective, greatly improving heating efficiency, resulting in good temperature uniformity and fast response speed of the carrier 110. The thermistor layer 130 inside the carrier 110 can monitor the temperature of the carrier 110 in situ, effectively avoiding the influence of the external ambient temperature, ensuring the accuracy of the temperature regulation of the heating layer 120, and thus working together to improve the temperature stability of the carrier 110. In addition, sealing the heating layer 120 and the thermistor layer 130 inside the carrier 110 can prevent the ambient gas from contacting and reacting with the heating layer 120 and the thermistor layer 130, improving heating stability and detection stability. Therefore, the sensitive element of the present application effectively improves heating efficiency and response speed, and can quickly respond to changes in hydrogen concentration; moreover, in dynamic temperature environments, the hydrogen sensitive element of the present application has a fast operating temperature balance speed and small temperature drift, and can work stably under complex and changing temperature conditions, greatly improving the overall performance and applicability of the hydrogen sensor.

[0147] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0148] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A hydrogen-sensitive element, characterized in that, The hydrogen-sensitive element includes: A carrier, wherein a first cavity and a second cavity are provided within the carrier; A heating layer is sealed within the first cavity; A heat-sensitive layer, wherein the heat-sensitive layer is sealed within the second cavity; and, A hydrogen-sensitive layer, wherein the hydrogen-sensitive layer is disposed on the carrier; The carrier includes a carrier layer and a sealing layer stacked together. The sealing layer is disposed on the side surface of the carrier layer away from the hydrogen-sensitive layer. The first cavity is formed in the carrier layer, and the second cavity is formed between the sealing layer and the carrier layer. The method for preparing the carrier includes: placing the heating layer in the material for preparing the carrier layer, and sintering it to form the carrier layer with the heating layer sealed inside; The thermosensitive layer is disposed on one side surface of the carrier layer, and the thermosensitive layer is sealed using the material used to prepare the sealing layer. After sintering, the sealing layer is formed, and the thermosensitive layer is sealed between the sealing layer and the carrier layer.

2. The hydrogen-sensitive element as described in claim 1, characterized in that, The carrier satisfies at least one of the following conditions: (1) The material of the sealing layer includes at least one of glass glaze and silicon nitride; (2) The thickness of the sealing layer is 1μm~5μm; (3) The material of the carrier layer includes at least one of alumina, aluminum nitride, silicon carbide, beryllium oxide, boron nitride and zirconium oxide; (4) The thickness of the carrier layer is 0.5mm~2.0mm.

3. The hydrogen-sensitive element as described in claim 1, characterized in that, The hydrogen-sensitive element satisfies at least one of the following conditions: (1) The material of the hydrogen-sensitive layer includes at least one of palladium-based binary alloy and palladium-based ternary alloy; (2) The thickness of the hydrogen-sensitive layer is 30nm~350nm; (3) The material of the heating layer includes at least one of ruthenium dioxide, nickel-chromium alloy and tungsten; (4) The thickness of the heating layer is 1μm~5μm; (5) The material of the thermosensitive layer includes at least one of platinum, cobalt oxide and manganese oxide; (6) The thickness of the thermal layer is 1μm~3μm.

4. The hydrogen-sensitive element according to any one of claims 1-3, characterized in that, The hydrogen-sensitive element also satisfies at least one of the following conditions: (1) The hydrogen-sensitive element further includes an activation layer, which is disposed on the surface of the hydrogen-sensitive layer away from the support. The activation layer is used to promote the catalytic rate and hydrogen dissolution rate of the hydrogen-sensitive layer. (2) The hydrogen-sensitive element further includes a transition layer, which is disposed between the hydrogen-sensitive layer and the carrier.

5. The hydrogen-sensitive element as described in claim 4, characterized in that, The activation layer satisfies at least one of the following conditions: (1) The material of the activation layer includes at least one of platinum and ZIF-8 metal framework material; (2) The thickness of the activation layer is 30nm~80nm.

6. The hydrogen-sensitive element as described in claim 4, characterized in that, The transition layer satisfies at least one of the following conditions: (1) The material of the transition layer includes at least one of tantalum oxide, molybdenum oxide and titanium; (2) The thickness of the transition layer is 60nm~300nm.

7. A method for preparing a hydrogen-sensitive element according to any one of claims 1-6, characterized in that, The preparation method includes: The heating layer is disposed in the material for preparing the carrier layer, and after sintering, the carrier layer with the heating layer sealed inside is formed. The thermosensitive layer is disposed on one side surface of the carrier layer, and the thermosensitive layer is sealed using the material used to prepare the sealing layer. After sintering, the sealing layer is formed, and the thermosensitive layer is sealed between the sealing layer and the carrier layer. The hydrogen-sensitive layer is formed on the carrier to prepare the hydrogen-sensitive element.

8. The method for preparing a hydrogen-sensitive element as described in claim 7, characterized in that, The preparation method also satisfies at least one of the following conditions: (1) The hydrogen-sensitive element further includes an activation layer, which is formed on the side of the hydrogen-sensitive layer away from the carrier by at least one of magnetron sputtering, ion beam sputtering and evaporation coating; (2) The hydrogen-sensitive element further includes a transition layer, which is formed on the side surface of the carrier near the hydrogen-sensitive layer by at least one of magnetron sputtering, ion beam sputtering and evaporation coating.

9. A hydrogen sensor, characterized in that, The hydrogen sensor includes the hydrogen-sensitive element as described in any one of claims 1-6.

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