Heterogeneous metal atom-doped bi2s3 nanomaterials, methods of making same, gas sensors, and applications thereof

Abstract

The present application relates to the technical field of gas sensing, and particularly relates to a hetero-metal atom doped Bi2S3 nanomaterial, a preparation method thereof, a gas sensor and application, and the preparation method of the hetero-metal atom doped Bi2S3 nanomaterial comprises the following steps: mixing bismuth salt, bromine salt, a sulfur source, a surfactant and an organic solvent to obtain a mixture; mixing the mixture with a salt containing a hetero-metal atom, and obtaining the hetero-metal atom doped Bi2S3 nanomaterial after a solvothermal reaction. The hetero-metal atom doped Bi2S3 nanomaterial is successfully synthesized by a simple one-step solvothermal method. The morphology of the nanomaterial synthesized by the method includes one-dimensional nanowires, two-dimensional nanosheets and three-dimensional nanoflowers. The morphology has a high specific surface area, increases the sufficient contact between NO2 gas molecules and active sites, and accelerates the charge transport, thus being beneficial to improving the sensitivity in the gas sensing process.

Description

Technical Field

[0001] This invention relates to the field of gas sensing technology, and in particular to a heterogeneous metal atom-doped Bi2S3 nanomaterial, its preparation method, gas sensor, and applications. Background Technology

[0002] Over the past few decades, metal oxides have been widely used as the primary resistive gas sensing material. However, their wide band gaps lead to high power consumption and safety concerns due to their high operating temperatures (150℃-400℃). Furthermore, while metal oxides exhibit broad-spectrum responses to various gases, they are susceptible to interference from non-target atmospheres in complex environments. In contrast, metal sulfides possess narrow band gaps and high electron mobility, which are advantageous for gas-sensing responses at lower operating temperatures.

[0003] Currently, doping is commonly used to modify gas-sensitive materials. However, due to the lack of reliable functionalization strategies, the selection of doped metal atoms according to standards, the highly controlled and uniform functionalization method on metal sulfide-based sensing layers, and the limitations of doping on the integration of materials into micro or flexible devices, their application in sensing has been restricted.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a heterogeneous metal atom-doped Bi2S3 nanomaterial, its preparation method, gas sensor and application, aiming to solve the problems of weak interaction between existing gas-sensitive materials and target molecules and low sensitivity.

[0006] The technical solution of the present invention is as follows:

[0007] A method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials includes the following steps:

[0008] Bismuth salt, bromide salt, sulfur source, surfactant, and organic solvent are mixed to obtain a mixture;

[0009] The mixture was mixed with a salt containing heterogeneous metal atoms, and after a solvothermal reaction, heterogeneous metal atom-doped Bi2S3 nanomaterials were obtained.

[0010] The method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials, wherein the bismuth salt includes one or more of bismuth nitrate, bismuth chloride, bismuth sulfate, and bismuth acetate; and the sulfur source includes one or more of sodium sulfide, thiourea, sodium hydrosulfide, and thioacetamide.

[0011] The method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials, wherein the heterogeneous metal atoms include one or more of lead, tin, copper, iron, indium, and tungsten.

[0012] The method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials, wherein the bromide salt includes one or more of potassium bromide, sodium bromide, and lithium bromide.

[0013] The method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials, wherein the mass ratio of the bismuth salt, the bromide salt, the sulfur source and the salt containing heterogeneous metal atoms is (1-3):(2-5):(0.6-2):(0.05-0.3).

[0014] The method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials, wherein the temperature of the solvothermal reaction is 120℃-180℃ and the time of the solvothermal reaction is 2h-12h.

[0015] A heterogeneous metal atom-doped Bi2S3 nanomaterial was prepared using a method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials.

[0016] The heterogeneous metal atom-doped Bi2S3 nanomaterials described herein include one or more of the following morphologies: one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers.

[0017] A gas sensor includes a ceramic sheet printed with interdigitated electrodes and a gas sensing layer disposed on the interdigitated electrodes; the gas sensing layer is made of the heterogeneous metal atom-doped Bi2S3 nanomaterial.

[0018] Application of a gas sensor in a nitrogen dioxide detection device.

[0019] Beneficial Effects: This invention provides a heterogeneous metal atom-doped Bi₂S₃ nanomaterial, its preparation method, a gas sensor, and its application. The preparation method of the heterogeneous metal atom-doped Bi₂S₃ nanomaterial includes the following steps: mixing bismuth salt, bromide salt, sulfur source, surfactant, and organic solvent to obtain a mixture; mixing the mixture with a salt containing heterogeneous metal atoms, and then performing a solvothermal reaction to obtain the heterogeneous metal atom-doped Bi₂S₃ nanomaterial. This invention successfully synthesizes heterogeneous metal atom-doped Bi₂S₃ nanomaterial using a simple one-step solvothermal method. The morphologies of the nanomaterials synthesized by this method include one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers. These morphologies have a high specific surface area, increasing the sufficient contact between NO₂ gas molecules and active sites, and accelerating charge transport, thus improving the sensitivity in the gas sensing process. Furthermore, heterometallic atom doping introduces additional active sites, which can effectively regulate the band structure and carrier concentration of the material, enhancing the interaction between the material and the target gas molecules. This enables heterometallic atom-doped Bi2S3 nanomaterials to exhibit highly sensitive and rapid specificity for NO2 detection at room temperature. In addition, the entire preparation process of the nanomaterials is simple, efficient, and environmentally friendly, and the resulting nanomaterials can form stable colloidal solutions that integrate with the substrate, laying the foundation for industrial preparation and applications in wearable devices. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process flow for preparing a heterogeneous metal atom-doped Bi2S3 nanomaterial according to the present invention.

[0021] Figure 2 The images show the XRD patterns of the Pb-Bi2S3 nanowire powder prepared in Example 1 and the Bi2S3 nanomaterial prepared in Comparative Example 1.

[0022] Figure 3 SEM and TEM images of the Pb-Bi2S3 nanowire powder prepared in this embodiment;

[0023] Figure 4 Optical images of Pb-Bi2S3 flexible thin films on flexible substrates obtained by vacuum filtration;

[0024] Figure 5 A graph showing the room temperature sensing performance of a gas sensor for 10 ppm NO2.

[0025] Figure 6 Selectivity test data of gas sensor device to interfering gases. Detailed Implementation

[0026] This invention provides a heterogeneous metal atom-doped Bi₂S₃ nanomaterial, its preparation method, a gas sensor, and its applications. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0028] Metal ion doping is a commonly used strategy for modifying gas-sensitive materials, enhancing their gas-sensing performance by generating lattice distortions and defects on the crystal. First, dopant ions can alter the electronic structure of the matrix material. Second, metal doping introduces additional active sites, enhancing activity and selectivity when interacting with target analytes. Third, the strong metal-sulfur interaction between the metal atoms and the matrix contributes to improved performance stability and lifespan.

[0029] Based on this, such as Figure 1 As shown, this invention provides a method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials, comprising the following steps:

[0030] Step S10: Mix bismuth salt, bromide salt, sulfur source, surfactant and organic solvent to obtain a mixture;

[0031] Step S20: The mixture is mixed with a salt containing heterogeneous metal atoms, and after a solvothermal reaction, heterogeneous metal atom-doped Bi2S3 nanomaterials are obtained.

[0032] In this embodiment, heterometal-doped Bi₂S₃ nanomaterials were successfully synthesized using a simple one-step solvothermal method. The morphologies of the synthesized nanomaterials include one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers. These morphologies possess a high specific surface area, increasing the contact between NO₂ gas molecules and active sites and accelerating charge transport, thus improving the sensitivity in gas sensing. Furthermore, heterometal doping introduces additional active sites, effectively controlling the band structure and carrier concentration of the material, enhancing the interaction between the material and target gas molecules. This allows the heterometal-doped Bi₂S₃ nanomaterials to exhibit highly sensitive and rapid specificity for NO₂ detection at room temperature. In addition, the entire preparation process of the nanomaterials is simple, efficient, and environmentally friendly, and the resulting nanomaterials can form stable colloidal solutions and integrate with substrates, laying the foundation for industrial fabrication and applications in wearable devices.

[0033] Specifically, the limited gas sensitivity of traditional metal sulfides due to their low surface activity and incomplete recovery at room temperature, coupled with the large particle size of the matrix material or the instability of doped ions, hinders their integration into flexible or micro-devices. This invention introduces heterogeneous metal atoms through doping, enabling the modulation of the material's band structure and carrier concentration. Simultaneously, the strong metal-sulfur interaction between the matrix material and the dopant ions enhances the material's performance stability and lifespan, significantly improving its sensing performance at room temperature. Furthermore, the growth of bismuth sulfide nanomaterials is regulated by a combination of surfactants and bromide salts, achieving the preparation of nanomaterials and their uniform integration on flexible substrates. Moreover, heterogeneous metal atom-doped Bi₂S₃ nanomaterials are prepared using a simple solvothermal method and a chemical reagent-controlled strategy. This method is simple and low-cost. Metal doping modulates the material's band structure and surface structure, improving its sensitivity to NO₂ at room temperature and enabling rapid response recovery, showing broad application prospects in NO₂ detection. Simultaneously, this material is easily dispersed as a colloidal solution, simplifying device fabrication processes and enabling the fabrication of flexible thin films, thus possessing high commercial application value.

[0034] In some embodiments, the bismuth salt includes, but is not limited to, one or more of bismuth nitrate, bismuth chloride, bismuth sulfate, and bismuth acetate; the sulfur source includes, but is not limited to, one or more of sodium sulfide, thiourea, sodium hydrosulfide, and thioacetamide. Using the above-mentioned bismuth salt and sulfur source to provide Bi and S elements for the preparation of heterometal atom-doped Bi₂S₃ nanomaterials can yield high-purity heterometal atom-doped Bi₂S₃ nanomaterials, and these materials are inexpensive, which is beneficial for practical production and promotion.

[0035] In some embodiments, the heterometallic atoms include, but are not limited to, one or more of lead, tin, copper, iron, indium, and tungsten. Doping bismuth sulfide with the aforementioned heterometallic atoms can introduce additional active sites, effectively controlling the band structure and carrier concentration of the material, enhancing the interaction between the material and target gas molecules, and enabling M-Bi2S3 doped with heterometallic atoms M to exhibit a highly sensitive and rapid reaction rate for NO2 at room temperature, achieving specific detection.

[0036] In some embodiments, the surfactant includes, but is not limited to, one or more of polyvinylpyrrolidone, sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, and sodium dodecylbenzenesulfonate.

[0037] In some embodiments, the bromide salt includes, but is not limited to, one or more of potassium bromide, sodium bromide, and lithium bromide.

[0038] Specifically, the growth of bismuth sulfide nanomaterials was regulated by the combined action of surfactants and bromide salts, enabling the preparation of nanomaterials and their uniform integration on flexible substrates. By utilizing the combined action of surfactants and bromide salts, heterogeneous metal atom-doped Bi₂S₃ nanomaterials with morphologies of one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers can be prepared.

[0039] In some embodiments, the mass ratio of the bismuth salt, the bromide salt, the sulfur source, and the salt containing heterometallic atoms is (1-3):(2-5):(0.6-2):(0.05-0.3). Controlling the mass ratio of the bismuth salt, the bromide salt, the sulfur source, and the salt containing heterometallic atoms within the above range can improve the purity of the product and effectively regulate the band structure and carrier concentration of the material, thereby enhancing the interaction between the material and the target gas molecules.

[0040] In some embodiments, the organic solvent includes, but is not limited to, one of formamide, N,N-dimethylformamide, anhydrous ethanol, and N,N-dimethylacetamide solution.

[0041] In some embodiments, the solvothermal reaction temperature is 120℃-180℃, and the solvothermal reaction time is 2h-12h. Using a solvothermal reaction to dope heterometallic atoms into bismuth sulfide introduces additional active sites, effectively controlling the band structure and carrier concentration of the material, and enhancing the interaction between the material and target gas molecules. Using this temperature and time to control the growth of heterometallic atom-doped Bi2S3 nanomaterials can effectively control the size of the nanomaterials; excessively high temperatures or excessively long times result in larger heterometallic atom-doped Bi2S3 nanomaterials (e.g., thicker nanowires), while excessively low temperatures and excessively short times lead to poor crystallinity of the product. The aforementioned solvothermal reaction temperature and time range represents the equilibrium value for preparing heterometallic atom-doped Bi2S3 nanomaterials according to this invention.

[0042] In some embodiments, step S20 further includes centrifugal washing after the solvothermal reaction; specifically, it includes: after the solvothermal reaction is naturally cooled, the product is collected by centrifugation, then washed with formamide and water respectively, freeze-dried and the product is collected to obtain heterogeneous metal atom-doped Bi2S3 nanomaterials.

[0043] In addition, the present invention also provides a heterogeneous metal atom-doped Bi2S3 nanomaterial, which is prepared by a method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials.

[0044] In this embodiment, the nanomaterials synthesized using this method exhibit morphologies including one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers. These morphologies possess a high specific surface area, increasing the contact between NO2 gas molecules and active sites and accelerating charge transport, thus enhancing the sensitivity in the gas sensing process. Furthermore, heterometallic atom doping introduces additional active sites, effectively controlling the material's band structure and carrier concentration, and strengthening the interaction between the material and target gas molecules. This allows the heterometallic atom-doped Bi2S3 nanomaterials to achieve highly sensitive and rapid specific detection of NO2 at room temperature.

[0045] In some embodiments, the morphology of the heterometallic atom-doped Bi₂S₃ nanomaterial includes one or more of one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers. One-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflower-like nanomaterials have a high specific surface area, increasing the contact between NO₂ gas molecules and active sites, and accelerating charge transport, thus improving the sensitivity in the gas sensing process. Preferably, the morphology of the heterometallic atom-doped Bi₂S₃ nanomaterial is one-dimensional nanowires.

[0046] In some embodiments, the preparation of a heterogeneous metal atom-doped Bi2S3 flexible thin film using the aforementioned heterogeneous metal atom-doped Bi2S3 nanomaterial includes the following steps: dispersing the heterogeneous metal atom-doped Bi2S3 nanomaterial in water or other solvents to form a uniform dispersion with a concentration range of 2 mg / mL to 10 mg / mL, so as to facilitate large-area uniform film formation; then removing the solvent by vacuum filtration or spin coating to coat the dispersion onto the surface of a flexible substrate. At this time, by controlling the concentration of the dispersion, the thickness of the heterogeneous metal atom-doped Bi2S3 flexible thin film can be controlled to be approximately 0.8 mm to 3 mm. A moderate thickness can balance gas adsorption and diffusion, and make the device flexible.

[0047] In addition, the present invention also provides a gas sensor, including a ceramic sheet printed with interdigitated electrodes, and a gas sensing layer disposed on the interdigitated electrodes; the gas sensing layer is made of the heterogeneous metal atom-doped Bi2S3 nanomaterial.

[0048] In some embodiments, the fabrication method of the gas sensor includes the following steps: ultrasonically cleaning a ceramic sheet printed with silver-palladium interdigitated electrodes in acetone, water, and ethanol for 30 minutes each, followed by drying in an oven for subsequent testing; mixing the heterogeneous metal atom-doped Bi2S3 nanomaterial with water and ultrasonically dispersing it uniformly; drop-coating the uniformly dispersed solution onto the silver-palladium interdigitated electrodes using a pipette, and drying to obtain the gas sensor. Preferably, the flexible silver-palladium interdigitated electrodes serve as a flexible substrate, with a cutting specification of 0.8*1.5cm.

[0049] In addition, the present invention also provides an application of a gas sensor in a nitrogen dioxide detection device.

[0050] In this embodiment, metal doping modulates the band structure and surface structure of the material, improving the sensing sensitivity to NO2 at room temperature and enabling rapid response recovery, thus showing broad application prospects in NO2 detection. At the same time, the material is easily dispersed into a colloidal solution, the device fabrication process is simple, and it can be used to make flexible thin films, making it highly valuable for commercial applications.

[0051] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention.

[0052] Comparative Example 1

[0053] The comparative synthesis of Bi2S3 nanomaterials includes the following steps:

[0054] Weigh 2g of bismuth nitrate, 2g of polyvinylpyrrolidone (PVP), 1g of thiourea, and 3g of potassium bromide and place them in a polytetrafluoroethylene liner. Add 30ml of formamide solution to dissolve them completely. Then, transfer the reactor to an oven and solvothermal react at 150℃ for 8 hours. After natural cooling, collect the product by centrifugation, wash with formamide and water respectively, freeze-dry, and collect the product. (This is a control sample.)

[0055] Example 1

[0056] This embodiment prepares lead-doped Bi₂S₃ nanowires, Pb-Bi₂S₃ flexible thin films, and gas sensor devices, mainly including the following steps:

[0057] 1) Synthesis of Pb-Bi2S3 nanowires

[0058] Weigh 2g of bismuth nitrate, 2g of polyvinylpyrrolidone, 1g of thiourea, and 3g of potassium bromide and place them in a polytetrafluoroethylene liner. Add 30ml of formamide solution to dissolve the mixture completely. After the mixture is fully dispersed, weigh 0.2g of lead nitrate and add it to the liner. Then, transfer the reactor to an oven and react it in a solvothermal environment at 150℃ for 8 hours. After natural cooling, collect the product by centrifugation, wash it with formamide and water respectively, freeze-dry it, and collect the product to obtain Pb-Bi2S3 nanowire powder.

[0059] The Pb-Bi₂S₃ nanowire powder prepared in this embodiment and the Bi₂S₃ nanomaterial prepared in Comparative Example 1 were characterized, and their XRD patterns are shown below. Figure 2 As shown, there is no significant change in the sample spectral peaks before and after, indicating that lead exists in Bi2S3 in the form of ion doping, and corresponds to the standard card 17-0320 of bismuth sulfide.

[0060] The Pb-Bi2S3 nanowire powder prepared in this embodiment was characterized by microstructure, and its SEM and TEM images are shown below. Figure 3 As shown, where Figure 3 (a) and (b) are SEM images of Pb-Bi2S3, and (c) and (d) are TEM images of Pb-Bi2S3. It can be seen that the Pb-Bi2S3 nanowires are stacked together with an interlaced diameter of about 8 to 10 nm.

[0061] 2) Synthesis of Pb-Bi2S3 flexible thin films

[0062] A certain amount of Pb-Bi2S3 nanowire powder was weighed and dispersed in water to form a uniform solution with a concentration of 6 mg / mL, so as to form a large-area uniform film. Then, the solvent was removed by vacuum filtration and the film was uniformly coated on the surface of a flexible substrate. At this time, by controlling the concentration of the dispersion, the thickness of the flexible layer can be approximately 2 mm.

[0063] Optical images of Pb-Bi2S3 flexible films on flexible substrates obtained by vacuum filtration are shown below. Figure 4 As shown (including) Figure 4 As can be seen from (a)-(c)), the Pb-Bi2S3 flexible film has high flexibility and can be bent at more than 180 degrees.

[0064] 3) Fabrication of gas sensor devices

[0065] The ceramic sheet printed with silver-palladium interdigitated electrodes was ultrasonically cleaned sequentially in acetone, water, and ethanol for 30 min each, and then dried in a 60℃ oven for subsequent testing. A certain amount of Pb-Bi2S3 nanowire powder was placed in an aqueous solution and ultrasonically dispersed to a concentration of 6 mg / mL. 40 μL of the uniformly dispersed sample was pipetted onto the silver-palladium interdigitated electrodes. After drying, the resistance change was measured under a NO2 atmosphere. The flexible substrate was cut to 0.8*1.5 cm, and the resistance change was then measured at room temperature under a NO2 atmosphere.

[0066] The room temperature sensing performance data of the gas sensor for 10 ppm NO2 is shown in the figure below. Figure 5 As shown in the response and recovery curves, the response time for 10 ppm nitrogen dioxide is 96 s, the recovery time is 272 s, and the response value (the ratio of resistance before and after the response) is 10.

[0067] The selective test data of the gas sensor device to interfering gases is shown in the figure below. Figure 6 As shown, the comparison of the response values ​​of sample Pb-Bi2S3 to different gases proves the material's specific response to NO2.

[0068] In summary, this invention provides a heterogeneous metal atom-doped Bi₂S₃ nanomaterial, its preparation method, a gas sensor, and its applications. The preparation method of the heterogeneous metal atom-doped Bi₂S₃ nanomaterial includes the following steps: mixing bismuth salt, bromide salt, sulfur source, surfactant, and organic solvent to obtain a mixture; mixing the mixture with a salt containing heterogeneous metal atoms, and then performing a solvothermal reaction to obtain the heterogeneous metal atom-doped Bi₂S₃ nanomaterial. This invention successfully synthesizes heterogeneous metal atom-doped Bi₂S₃ nanomaterial using a simple one-step solvothermal method. The morphologies of the nanomaterials synthesized by this method include one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers. These morphologies have a high specific surface area, increasing the sufficient contact between NO₂ gas molecules and active sites, and accelerating charge transport, thus improving the sensitivity in the gas sensing process. Furthermore, heterometallic atom doping introduces additional active sites, which can effectively regulate the band structure and carrier concentration of the material, enhancing the interaction between the material and the target gas molecules. This enables heterometallic atom-doped Bi2S3 nanomaterials to exhibit highly sensitive and rapid specificity for NO2 detection at room temperature. In addition, the entire preparation process of the nanomaterials is simple, efficient, and environmentally friendly, and the resulting nanomaterials can form stable colloidal solutions that integrate with the substrate, laying the foundation for industrial preparation and applications in wearable devices.

[0069] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing heterogeneous metal atom-doped Bi₂S₃ nanomaterials, characterized in that, Including the following steps: Bismuth salt, bromide salt, sulfur source, surfactant, and organic solvent are mixed to obtain a mixture; The mixture was mixed with a salt containing heterogeneous metal atoms, and after a solvothermal reaction, heterogeneous metal atom-doped Bi2S3 nanomaterials were obtained. The bismuth salt includes one or more of bismuth nitrate, bismuth chloride, bismuth sulfate, and bismuth acetate; the sulfur source includes one or more of sodium sulfide, thiourea, sodium hydrosulfide, and thioacetamide; the heterogeneous metal atom includes one or more of lead, tin, copper, iron, indium, and tungsten; the bromine salt includes one or more of potassium bromide, sodium bromide, and lithium bromide; the surfactant includes one or more of polyvinylpyrrolidone, sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, and sodium dodecylbenzenesulfonate; and the organic solvent includes one of formamide, N,N-dimethylformamide, anhydrous ethanol, and N,N-dimethylacetamide solution. The temperature of the solvothermal reaction is 120℃-180℃, and the time of the solvothermal reaction is 2h-12h; the mass ratio of the bismuth salt, the bromide salt, the sulfur source and the salt containing heterogeneous metal atoms is (1-3):(2-5):(0.6-2):(0.05-0.3); The morphology of the heterogeneous metal atom-doped Bi2S3 nanomaterial includes one or more of the following: one-dimensional nanowires, two-dimensional nanosheets, and three-dimensional nanoflowers.

2. A heterogeneous metal atom-doped Bi₂S₃ nanomaterial, characterized in that, The material was prepared using the method for preparing heterogeneous metal atom-doped Bi2S3 nanomaterials as described in claim 1.

3. A gas sensor, characterized in that, It includes a ceramic sheet printed with interdigitated electrodes, and a gas sensing layer disposed on the interdigitated electrodes; the gas sensing layer is made of heterogeneous metal atom-doped Bi2S3 nanomaterial as described in claim 2.

4. The application of the gas sensor as described in claim 3 in a nitrogen dioxide detection device.

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