A hydrogen sensor and a manufacturing method thereof

Abstract

The application provides a hydrogen sensor and a manufacturing method thereof, and relates to the technical field of gas sensors. The sensor electrode is manufactured based on a carrier, and at least one of microelectronic printing technology, screen printing technology, nanoimprint, spin coating or blade coating, and sputtering or evaporation in microelectronic technology is used to manufacture titanium dioxide and palladium nanoparticles on the sensor electrode, so as to manufacture a gas sensitive layer and form a hydrogen sensor, wherein the gas sensitive layer is connected with the sensor electrode. The hydrogen sensor and the manufacturing method thereof have the advantages of simple process, shortened response time of the hydrogen sensor, and improved sensitivity of the hydrogen sensor.

Description

Technical Field

[0001] This application relates to the field of gas sensor technology, and more specifically, to a hydrogen sensor and a method for manufacturing the same. Background Technology

[0002] Hydrogen, as an ideal clean energy source, is widely used in nuclear power plants, fuel cells, industry, and petroleum refining due to its advantages such as renewability, high efficiency, and cleanliness. However, because hydrogen is colorless, odorless, has a small molecular weight, and strong penetrability, leaks during its production and transportation are difficult to detect. When hydrogen occupies a large volume in the air, it is highly susceptible to explosion upon contact with an open flame. Therefore, rapid and accurate in-situ measurement of hydrogen in air and under specific environments, and the development of safe and sensitive hydrogen sensors, have broad research prospects and significant academic importance.

[0003] However, existing hydrogen sensors suffer from complex manufacturing processes and insufficient sensitivity. Summary of the Invention

[0004] The purpose of this application is to provide a hydrogen sensor and its manufacturing method, so as to solve the problems of complex manufacturing process and insufficient sensitivity of existing hydrogen sensors.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] On one hand, embodiments of this application provide a method for manufacturing a hydrogen sensor, the method comprising:

[0007] Sensor electrodes were fabricated based on a carrier.

[0008] Titanium dioxide and palladium nanoparticles are fabricated on the sensor electrode using at least one of the following processes: microelectronic printing technology, screen printing, nanoimprinting, spin coating or scraping coating, and sputtering or vapor deposition in microelectronic processes, to create a gas-sensitive layer and form a hydrogen sensor, wherein the gas-sensitive layer is connected to the sensor electrode.

[0009] Optionally, prior to the step of fabricating titanium dioxide and palladium nanoparticles on the sensor electrode using at least one of microelectronic printing technology, screen printing, nanoimprinting, spin coating or blade coating, and sputtering or vapor deposition in microelectronic processes, the method further includes:

[0010] Preparation of anatase titanium dioxide-palladium nanoparticle dispersion.

[0011] Optionally, the steps for preparing anatase-type titanium dioxide-palladium nanoparticle dispersions include:

[0012] A mixed solution is formed using palladium compounds and titanium compounds;

[0013] The mixed solution is placed and heated for a preset time;

[0014] The mixed solution was centrifuged to obtain titanium dioxide-palladium nanocomposite particles;

[0015] The titanium dioxide-palladium nanocomposite particles were washed and redispersed to obtain a titanium dioxide-palladium nanoparticle dispersion.

[0016] A viscosity modifier is added to adjust the viscosity of the titanium dioxide-palladium nanoparticle dispersion.

[0017] Optionally, the step of forming a mixed solution using palladium compounds and titanium compounds includes:

[0018] Palladium chloride and titanium sulfate are dissolved in an aqueous ethanol solution to form a mixed solution.

[0019] Optionally, the steps for fabricating sensor electrodes based on a carrier include:

[0020] Sensor electrodes are printed by applying adhesive to a plastic film using a microelectronic printer.

[0021] Optionally, after the step of fabricating titanium dioxide and palladium nanoparticles on the sensor electrode using at least one of microelectronic printing technology, screen printing, nanoimprinting, spin coating or blade coating, and sputtering or evaporation in microelectronic processes to create a gas-sensitive layer and form a hydrogen sensor, the method further includes:

[0022] Place the fabricated hydrogen sensor on a heating platform and heat it for a preset time.

[0023] The surface of the hydrogen sensor is cleaned.

[0024] Optionally, after the step of fabricating titanium dioxide and palladium nanoparticles on the sensor electrode using at least one of microelectronic printing technology, screen printing, nanoimprinting, spin coating or blade coating, and sputtering or evaporation in microelectronic processes to create a gas-sensitive layer and form a hydrogen sensor, the method further includes:

[0025] The electrodes of the hydrogen sensor are connected to an external circuit for conductivity measurement to measure the performance of the hydrogen sensor.

[0026] On the other hand, this application also provides a hydrogen sensor, which is manufactured by the above-described hydrogen sensor manufacturing method; the hydrogen sensor includes:

[0027] carrier;

[0028] Electrodes located on the carrier;

[0029] A gas-sensitive layer located on the carrier and connected to the electrode, wherein the gas-sensitive layer is composed of titanium dioxide and palladium nanoparticles, and the resistance of the gas-sensitive layer changes with the hydrogen concentration in the environment.

[0030] Optionally, the size of the titanium dioxide nanoparticles is 1 to 1000 nm; the size of the palladium nanoparticles is 1 to 1000 nm.

[0031] Optionally, the thickness of the gas-sensitive layer is 1 nm to 1000 μm.

[0032] Compared with the prior art, this application has the following advantages:

[0033] This application provides a hydrogen sensor and its fabrication method. First, a sensor electrode is fabricated on a carrier. Then, titanium dioxide and palladium nanoparticles are fabricated on the sensor electrode using microelectronic printing technology, screen printing, nanoimprinting, spin coating, or at least one of the microelectronic processes, including sputtering and vapor deposition, to create a gas-sensitive layer and form the hydrogen sensor. The gas-sensitive layer is connected to the sensor electrode. On one hand, this application directly uses microelectronic printing technology, screen printing, nanoimprinting, spin coating, or at least one of the microelectronic processes, including sputtering and vapor deposition, to fabricate the gas-sensitive layer on the sensor electrode, making its fabrication process relatively simple and promising for applications. On the other hand, palladium nanoparticles have excellent hydrogen absorption activity, enabling them to adsorb and dissociate more hydrogen and oxygen molecules, thereby shortening the response time and improving the sensitivity of the hydrogen sensor.

[0034] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is an exemplary flowchart of a method for manufacturing a hydrogen sensor provided in an embodiment of this application.

[0037] Figure 2 A physical image of the hydrogen sensor provided in the embodiments of this application.

[0038] Figure 3This is a schematic diagram of the structure of a hydrogen sensor provided in an embodiment of this application.

[0039] Figure 4 This is a schematic diagram of a first structure of a sensor electrode provided in an embodiment of this application.

[0040] Figure 5 This is a schematic diagram of a second structure of the sensor electrode provided in an embodiment of this application.

[0041] Figure 6 This is a schematic diagram of a third structure of the sensor electrode provided in an embodiment of this application.

[0042] Figure 7 This is another exemplary flowchart of a method for fabricating a hydrogen sensor provided in an embodiment of this application.

[0043] Figure 8 Provided for the embodiments of this application Figure 7 An exemplary flowchart of the sub-step S103.

[0044] Figure 9 SEM image of the hydrogen sensor provided in the embodiments of this application.

[0045] Figure 10 This is a schematic diagram illustrating the cyclic response of a hydrogen sensor at different concentrations provided in an embodiment of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0048] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0049] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0050] In the description of this application, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0051] In the description of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0052] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0053] As described in the background section, the use of hydrogen is becoming increasingly widespread, making the measurement of hydrogen concentration crucial.

[0054] Metal oxide semiconductor sensors have been widely researched and applied in gas detection due to their low cost, high stability, and simple structure. Titanium dioxide, as a common semiconductor gas-sensitive material, has been widely used in gas sensing due to its good physicochemical properties, stable mechanical properties, and good conductivity. Currently, the preparation of titanium dioxide-based gas-sensitive materials includes hydrolysis, solution gelation, and vapor deposition methods. However, single titanium dioxide gas-sensitive materials suffer from common technical problems such as poor selectivity, high operating temperature, and slow response recovery time, which limit their development in practical applications.

[0055] Existing research indicates that noble metals possess excellent hydrogen catalytic properties, and doping with noble metals can enhance the hydrogen sensitivity of titanium dioxide gas-sensitive materials. For example, palladium-titanium dioxide nanofilm electrode hydrogen-sensitive materials can be prepared using an electrodeless electrolysis method, thereby achieving a hydrogen response at room temperature. However, the palladium-titanium dioxide nanofilm gas-sensitive materials produced by this method have a small specific surface area, providing insufficient active sites for adequate contact with gas molecules. Furthermore, the preparation process also suffers from several drawbacks, such as the introduction of impurities, poor surface activity of the prepared powder material, and easy agglomeration of nanoparticles.

[0056] In terms of fabrication technology, traditional methods for preparing metal-oxide-semiconductor hydrogen sensors include magnetron sputtering plasma aggregation and photolithography. However, these processes are relatively complex and costly, making them unsuitable for large-scale hydrogen sensor applications. Furthermore, the titanium dioxide particles obtained in these processes are mostly amorphous, requiring a crystal transformation at temperatures above 600 degrees Celsius to obtain anatase titanium dioxide films with high hydrogen sensitivity, which limits substrate selection and increases costs. Existing titanium dioxide thin-film gas-sensitive materials exhibit low responsivity and long response recovery times, failing to meet industrial requirements.

[0057] In view of this, this application provides a method for fabricating a hydrogen sensor, which uses microelectronic printing technology to fabricate the hydrogen sensor.

[0058] The following is an exemplary description of the method for manufacturing the hydrogen sensor provided in this application:

[0059] As an optional implementation, please refer to Figure 1 The method includes:

[0060] S102, sensor electrodes are fabricated based on a carrier.

[0061] S104. Titanium dioxide and palladium nanoparticles are fabricated on the sensor electrode using at least one of the following processes: microelectronic printing technology, screen printing, nanoimprinting, spin coating or scraping coating, and sputtering or vapor deposition in microelectronic processes, in order to create a gas-sensitive layer and form a hydrogen sensor, wherein the gas-sensitive layer is connected to the sensor electrode.

[0062] In this application, palladium and titanium dioxide nanoparticles are fabricated on sensor electrodes using at least one of the following processes: microelectronic printing, screen printing, nanoimprinting, spin coating, or blade coating, as well as sputtering and vapor deposition in microelectronic processes. This forms a hydrogen-sensitive layer of titanium dioxide nanofilm embedded with palladium nanoparticles. The hydrogen-sensitive layer consists of a titanium dioxide nanofilm and palladium nanoparticles, with the palladium nanoparticles highly dispersed within the titanium dioxide nanofilm system.

[0063] On the one hand, printing a gas-sensitive layer on the sensor electrode using microelectronic printing technology, screen printing, nanoimprinting, spin coating or blade coating, and at least one of the microelectronic processes such as sputtering and evaporation, simplifies the fabrication process. On the other hand, palladium nanoparticles possess excellent hydrogen absorption activity, enabling them to adsorb and dissociate more hydrogen and oxygen molecules, thereby shortening the response time and improving sensitivity. Furthermore, by printing titanium dioxide and palladium nanocomposite particles onto the sensor electrode, an active site with a high specific surface area can be prepared, exposing more gas molecule reaction sites, thus giving the nanoparticle film (i.e., the gas-sensitive layer) highly sensitive hydrogen sensing capabilities.

[0064] This application does not limit the material of the sensor electrode. For example, a silver electrode can be used, as it is easy to prepare and has a stable potential, resulting in good overall performance of the hydrogen sensor after fabrication. Of course, other materials can also be used for the sensor electrode, such as tungsten alloy electrodes, and this is not a limitation.

[0065] In one implementation, S102 includes:

[0066] Sensor electrodes are printed by applying adhesive to a plastic film using a microelectronic printer.

[0067] Please adopt Figure 2 and Figure 3 This application uses a plastic film as a carrier to fabricate sensor electrodes using dispensing printing technology. Due to the flexibility of the plastic film, the resulting hydrogen sensor is also a flexible sensor. A flexible hydrogen sensor not only improves the stability and reliability of the device and reduces its power consumption, but also lays a solid foundation for the subsequent fabrication of a flexible hydrogen sensor integrated system. Of course, in practical applications, other materials can also be used as the carrier for the silver electrodes, such as a rigid substrate; this is not a limitation.

[0068] Furthermore, it should be noted that in the hydrogen sensor provided in this application, the sensor electrode actually includes a first electrode and a second electrode, with a gap between them. The first electrode and the second electrode are connected by a gas-sensitive layer, thereby forming the sensor. Since the resistance of the gas-sensitive layer can change with the hydrogen concentration, the hydrogen concentration in the current environment can be measured by applying voltage through the hydrogen sensor.

[0069] Based on this, this application does not limit the specific structure of the first electrode and the second electrode. For a first implementation of this application, please refer to... Figure 4 The first electrode and the second electrode can be arranged in parallel and connected by a gas-sensitive layer.

[0070] As a second implementation of this application, please refer to Figure 5 The first electrode and the second electrode can also be set as interdigitated electrodes. By setting the interdigitated electrodes, the area of ​​the first electrode and the second electrode can be increased. After the relative area of ​​the first electrode and the second electrode is increased, the device performance can be improved.

[0071] It should be noted that this application does not limit the specific structure of the interdigital electrodes. Figure 5 The interdigitated electrode described herein is a zigzag-type interdigitated electrode; of course, an arc-type interdigitated electrode can also be used, such as... Figure 6 As shown, this structure can also increase the relative area between the first electrode and the second electrode.

[0072] also, Figure 5 and Figure 6 The diagram shows planar interdigitated electrodes. In one implementation, the first and second electrodes can also be 3D interdigitated electrodes, and no specific limitation is made here. When using a plastic film as a carrier, in order to ensure the stability of the hydrogen sensor fabrication, the plastic film used for printing needs to be cleaned and dried first, then placed in an ultraviolet cleaning machine to clean the surface of the plastic film, and then placed on the printing stage of the microelectronic printer.

[0073] Next, using microelectronic printing technology and silver paste as printing ink, the printed pattern is input into the printer, and the silver paste is applied to the surface of the plastic film substrate. The thickness of the electrodes is adjusted by setting the printing parameters. The printed silver circuit is placed on a heating platform at 120°C and heated for 25 minutes to promote solvent evaporation and prepare silver electrodes, thereby forming silver electrodes on the plastic film.

[0074] For example, in one specific implementation, the microelectronic printer used has a dispensing pressure of 20 kPa, a dispensing nozzle movement speed of 2 mm / min, and a printing spacing of 20 μm. The dispensing head controlled by a computer achieves the dispensing and printing of the required silver electrode pattern. Then, the silver circuit is cured by heating at 120°C for 10–25 minutes on a heating stage, thereby obtaining the required silver electrode pattern.

[0075] Subsequently, using microelectronic printing technology, anatase titanium dioxide-palladium nano-dispersion was used as printing ink. The printed pattern was input into the printer, and the anatase titanium dioxide-palladium nano-dispersion was inkjet printed onto the surface of a plastic film with silver circuitry. The thickness of the gas-sensitive layer was controlled by setting printing parameters, thereby creating the gas-sensitive layer and forming a hydrogen sensor.

[0076] Before step S104, please refer to [link / reference needed]. Figure 7 The method also includes:

[0077] S103 was used to prepare anatase titanium dioxide-palladium nanoparticle dispersion.

[0078] Compared to existing technologies that utilize photolithography and ion etching to fabricate hydrogen sensors, this application employs a co-hydrothermal method to prepare anatase-type titanium dioxide-palladium nanoparticle dispersion. Palladium nanoparticles are highly dispersed within the titanium dioxide nanoparticle system. These palladium nanoparticles exhibit excellent catalytic activity, and palladium doping allows for the adsorption and dissociation of more hydrogen and oxygen molecules, enabling greater interaction between hydrogen and oxygen anions adsorbed on the titanium dioxide surface, thus enhancing the hydrogen sensing performance of the nanoparticles. Furthermore, anatase-type titanium dioxide-palladium nanoparticles are most sensitive to hydrogen due to their small particle size and large specific surface area, facilitating good contact and reaction with the target gas. Simultaneously, palladium nanoparticles lower the activation energy of the reaction process, reducing the energy required for the redox reaction between oxygen and hydrogen. In addition, palladium nanoparticles possess excellent hydrogen adsorption activity, enabling the adsorption and dissociation of more hydrogen and oxygen molecules, thereby shortening the response time and improving sensitivity.

[0079] In one implementation, please refer to Figure 8 S103 includes:

[0080] S1031 utilizes a palladium compound and a titanium compound to form a mixed solution;

[0081] S1032, Place the mixed solution under heating for a preset time;

[0082] S1033, the mixed solution was centrifuged to obtain titanium dioxide-palladium nanocomposite particles;

[0083] S1034, wash and redisperse the titanium dioxide-palladium nanocomposite particles to obtain a titanium dioxide-palladium nanoparticle dispersion;

[0084] S1035, viscosity of titanium dioxide-palladium nanoparticle dispersion adjusted by adding a viscosity modifier.

[0085] In one specific implementation, when preparing anatase-type titanium dioxide-palladium nanoparticle dispersion printing ink, 0.086 g of 99.99% pure palladium chloride and 0.0214 g of 99.99% pure titanium sulfate are dissolved in an ethanol-water solution. The mixed solution is heated in a 160°C oven for 16 hours, and the solution is centrifuged to obtain titanium dioxide-palladium nanocomposite particles. The particles are washed and redispersed to obtain a nano-dispersion. Ethanol and isopropanol are added simultaneously to adjust the solution viscosity, ensuring that the palladium nanoparticles are highly dispersed in the titanium dioxide nanoparticle system. After filtration, a printable gas-sensitive layer ink is obtained.

[0086] When printing using a titanium dioxide-palladium nanoparticle dispersion, a microelectronic printer with a piezoelectric frequency of 20 Hz, two inkjet nozzles, a printing speed of 1 mm / min, and a printing pitch of 10 μm can be used to print a titanium dioxide-palladium nanoparticle film with a defined pattern at a specified location. The pattern is then dried by heating at 120°C for 10 minutes to promote solvent evaporation and prepare the titanium dioxide-palladium gas-sensitive layer film, thus obtaining the desired gas-sensitive layer film.

[0087] It should be noted that this application uses a microelectronic printer to print both the sensor electrode and the gas-sensitive layer, only requiring different printheads and inks, which simplifies the fabrication of the hydrogen sensor.

[0088] After printing the gas-sensitive layer film, the sensor surface can be cleaned to obtain a titanium dioxide nanofilm hydrogen gas-sensitive layer embedded with palladium nanoparticles.

[0089] Furthermore, after fabricating the hydrogen sensor, its performance needs to be tested. One method is to observe the morphology of the hydrogen sensor under a electron microscope (SEM) to determine its shape. For example... Figure 9 As shown, it can be observed that the surface of the plastic film is covered with titanium dioxide and palladium nanoparticles, which greatly improves the surface area-to-volume ratio of the sample.

[0090] On the other hand, in one embodiment, after S104, the method further includes:

[0091] Connect the electrodes of the hydrogen sensor to the external circuit for conductivity measurement.

[0092] In this method, test electrodes can be connected to both ends of the sample, which can then be placed in a gas-sensitive testing chamber for testing. A certain concentration of hydrogen gas can be introduced through a mass flow meter, mixed in a pipeline, and then flow through the testing chamber, causing a change in the sample's resistance. The resistance change curve of the sample was detected using a Metrohm Autolab BV electrochemical workstation and Nova 2.1 software, and the data was acquired and stored on a computer. The prepared sensor showed a sensitivity of 21% (S = Rg - Ra / Ra*100, where Ra is the sensor's resistance in air and Rg is the sensor's resistance in hydrogen gas) at room temperature with 50 ppm hydrogen gas, 26% at 500 ppm hydrogen gas, and 40% at 3000 ppm hydrogen gas. The sensor's reproducibility in five repeated tests at room temperature with hydrogen concentrations of 50, 500, and 3000 ppm was as follows. Figure 10 As shown, the sensor exhibits good cyclic response performance at room temperature.

[0093] In one specific example, the hydrogen sensor achieved a responsivity of 14.5% in a 10 ppm hydrogen atmosphere. The response time was 32 s and the recovery time was 88 s, demonstrating the superior hydrogen sensing performance of the palladium-nano titanium dioxide thin film gas-sensitive material.

[0094] Based on the above implementation, this application embodiment also provides a hydrogen sensor, which is manufactured using the above-described hydrogen sensor manufacturing method; the hydrogen sensor includes:

[0095] The components include a carrier, an electrode, and a gas-sensitive layer connected to the electrode. The gas-sensitive layer is composed of titanium dioxide and palladium nanoparticles, and its resistance changes with the concentration of hydrogen in the environment.

[0096] In this embodiment, both the electrode and the gas-sensitive layer are located on a carrier, which can be a flexible carrier such as a plastic film, and the electrode can be a silver electrode; no limitation is made here. Of course, in one implementation, the ear hydrogen sensor also includes an external circuit for measuring conductivity, which is connected to the electrode. A titanium dioxide nanofilm hydrogen gas-sensitive layer embedded with palladium nanoparticles is attached to the surface of a plastic film substrate with a silver circuit. The external circuit for measuring conductivity is connected to a metal microelectrode to detect the resistance or conductivity value of the hydrogen gas-sensitive film in real time.

[0097] The hydrogen gas-sensitive layer is composed of titanium dioxide nanofilm and palladium nanoparticles, with the palladium nanoparticles highly dispersed within the titanium dioxide nanoparticle system. This allows the nanoparticle lattice to possess highly sensitive hydrogen-sensing capabilities. Furthermore, since the dual nanoparticles contain noble metal nanoparticles with high catalytic activity, they can adsorb and dissociate more hydrogen and oxygen molecules, thereby improving the sensitivity and selectivity of the titanium dioxide nanoparticles in detecting hydrogen.

[0098] In one implementation, the size of the titanium dioxide nanoparticles is 1–1000 nm, and the size of the palladium nanoparticles is also 1–1000 nm. By setting these sizes, the titanium dioxide nanoparticles exhibit excellent hydrogen sensing ability. If the nanoparticle size is too large, it hinders the transfer between gas molecules, reducing the response speed. The titanium dioxide nanoparticle lattice, due to its small particle size, large specific surface area, and uniform grain size, is less prone to agglomeration, which facilitates better contact with gas molecules, giving the nanoparticles high hydrogen sensing sensitivity. For the palladium nanoparticles, this size provides good catalytic activity, promoting the dissociation of more gas molecules. The palladium nanoparticles are highly dispersed within the titanium dioxide nanoparticle system, exhibiting good catalytic activity, and can adsorb and dissociate more hydrogen and oxygen molecules. This allows more hydrogen to interact with the oxygen anions adsorbed on the titanium dioxide surface, improving the hydrogen sensing performance of the nanoparticles.

[0099] Optionally, the thickness of the gas-sensitive layer is 1 nm to 1000 μm, thereby forming a gas-sensitive layer thin film.

[0100] In summary, this application provides a hydrogen sensor and its fabrication method. First, a sensor electrode is fabricated on a carrier. Then, titanium dioxide and palladium nanoparticles are fabricated on the sensor electrode using microelectronic printing technology, screen printing, nanoimprinting, spin coating, or at least one of the microelectronic processes, such as sputtering or vapor deposition, to create a gas-sensitive layer and form the hydrogen sensor. The gas-sensitive layer is connected to the sensor electrode. On the one hand, this application directly uses microelectronic printing technology, screen printing, nanoimprinting, spin coating, or at least one of the microelectronic processes, such as sputtering or vapor deposition, to fabricate the gas-sensitive layer on the sensor electrode, making its fabrication process relatively simple and promising for applications. On the other hand, palladium nanoparticles have excellent hydrogen absorption activity, enabling them to adsorb and dissociate more hydrogen and oxygen molecules, thereby shortening the response time and improving the sensitivity of the hydrogen sensor.

[0101] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0102] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method of fabricating a hydrogen sensor, comprising: The method includes: Sensor electrodes were fabricated based on a carrier. A dispersion of anatase-type titanium dioxide-palladium nanocomposite particles was prepared, wherein the preparation steps included: A compound of palladium and a compound of titanium are mixed to form a mixed solution; The mixed solution is heated for a preset time to carry out a hydrothermal reaction; The mixed solution after the reaction was centrifuged to obtain titanium dioxide-palladium nanocomposite particles; The titanium dioxide-palladium nanocomposite particles are washed and redispersed to obtain a titanium dioxide-palladium nanoparticle dispersion; and a viscosity modifier is added to adjust the viscosity of the titanium dioxide-palladium nanoparticle dispersion. A hydrogen sensor is fabricated by using at least one of the following processes: microelectronic printing, screen printing, nanoimprinting, spin coating, blade coating, sputtering, or vapor deposition. The prepared anatase titanium dioxide-palladium nanoparticle dispersion is printed onto the sensor electrode to form a gas-sensitive layer connected to the sensor electrode.

2. The method of claim 1, wherein the hydrogen sensor is formed by a process comprising: The step of forming a mixed solution using palladium compounds and titanium compounds includes: Palladium chloride and titanium sulfate are dissolved in an aqueous ethanol solution to form a mixed solution.

3. The method of claim 1, wherein the hydrogen sensor is formed by a process comprising: The steps involved in fabricating sensor electrodes based on a carrier include: Sensor electrodes are printed by applying adhesive to a plastic film using a microelectronic printer.

4. The method of claim 1, wherein the hydrogen sensor is formed by a process comprising: After the step of fabricating a hydrogen sensor by printing the prepared anatase titanium dioxide-palladium nanoparticle dispersion onto the sensor electrode using at least one of microelectronic printing technology, screen printing, nanoimprinting, spin coating, blade coating, sputtering, or vapor deposition to form a gas-sensitive layer connected to the sensor electrode, the method further includes: Place the fabricated hydrogen sensor on a heating platform and heat it for a preset time. The surface of the hydrogen sensor is cleaned.

5. The method for manufacturing a hydrogen sensor as described in claim 1, characterized in that, After the step of fabricating a hydrogen sensor by printing the prepared anatase titanium dioxide-palladium nanoparticle dispersion onto the sensor electrode using at least one of microelectronic printing technology, screen printing, nanoimprinting, spin coating, blade coating, sputtering, or vapor deposition to form a gas-sensitive layer connected to the sensor electrode, the method further includes: The electrodes of the hydrogen sensor are connected to an external circuit for conductivity measurement to measure the performance of the hydrogen sensor.

6. A hydrogen sensor, characterized in that, The hydrogen sensor is manufactured by the hydrogen sensor manufacturing method according to any one of claims 1 to 5; the hydrogen sensor comprises: carrier; Electrodes located on the carrier; A gas-sensitive layer located on the carrier and connected to the electrode, wherein the gas-sensitive layer is composed of anatase titanium dioxide-palladium nanocomposite particles, and the resistance of the gas-sensitive layer changes with the hydrogen concentration in the environment.

7. The hydrogen sensor as described in claim 6, characterized in that, The titanium dioxide nanoparticles have a size of 1~1000 nm; the palladium nanoparticles have a size of 1~1000 nm.

8. The hydrogen sensor as described in claim 6, characterized in that, The thickness of the gas-sensitive layer is 1 nm to 1000 μm.

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