Carbon dot doped zinc oxide, preparation method thereof and application of carbon dot doped zinc oxide in ethylene glycol gas sensing material
Carbon doped zinc oxide was prepared by hydrothermal method, which solved the stability and selectivity problems of zinc oxide gas-sensitive materials and achieved efficient detection of ethylene glycol gas. It has high response speed and good stability, and is low cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI UNIV
- Filing Date
- 2023-11-07
- Publication Date
- 2026-08-04
AI Technical Summary
Existing zinc oxide gas-sensitive materials suffer from high operating temperatures, poor stability, and low selectivity when detecting ethylene glycol. Doping with precious metals and rare earth elements is costly, and the composite material of carbon dots and zinc oxide has failed to effectively achieve doping and recovery capabilities.
Carbon doped zinc oxide was prepared by a hydrothermal method. By grinding ZnO powder and carbon dots in a solvent, carbon dot-doped zinc oxide was formed, and its electronic structure was optimized for use in ethylene glycol gas sensing materials.
It achieves high response speed, fast recovery time and high sensitivity to ethylene glycol gas, with good repeatability and long-term stability, and is low in cost and environmentally friendly.
Smart Images
Figure CN117658200B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of gas-sensitive materials and their preparation methods, and more particularly to a carbon doped zinc oxide, its preparation method, and its application in ethylene glycol gas sensing materials. Background Technology
[0002] Ethylene glycol, a common VOC in industry, can damage various internal organs and harm human health when inhaled. Therefore, a gas sensor capable of quickly and effectively detecting ethylene glycol is crucial.
[0003] Gas-sensitive materials respond to the presence, concentration, and type of gases through adsorption, dissociation, redox reactions, or surface reactions, thus enabling their application in chemical sensors to detect specific gas components. Metal-oxide-semiconductor (MOS) materials possess good conductivity and carrier mobility, and due to their abundant reserves, low cost, and stable properties, they have been widely studied and applied; gas-sensitive materials are one of their important application areas.
[0004] Metal oxide semiconductor gas-sensitive materials can be classified into n-type and p-type based on the type of charge carriers, such as zinc oxide, tin oxide, and titanium dioxide. These materials, which use electrons as charge carriers, belong to the n-type metal oxide semiconductor category. Zinc oxide, as a common, readily available, and widely used metal oxide gas-sensitive material, has advantages such as environmental friendliness, simple preparation, and good conductivity, making it a promising gas-sensitive sensing material and one of the most common types of gas sensors on the market. However, zinc oxide also faces challenges in application, including high operating temperature, poor stability, and low selectivity, thus limiting its application. Therefore, further exploration of methods to improve the gas-sensitive performance of zinc oxide is needed.
[0005] Currently, many methods have been developed to improve the gas-sensing performance of zinc oxide materials. Among these, numerous cases of noble metal doping and rare earth element doping have demonstrated that doping with noble metals / rare earth elements can significantly improve the gas-sensing performance of zinc oxide materials, effectively increasing sensitivity and shortening response time. However, noble metals and rare earth elements are scarce and difficult to obtain, which increases their application costs. Therefore, finding relatively inexpensive non-metallic materials as doping agents to replace noble metals and rare earth elements is of great significance.
[0006] Carbon dots (CDs), as zero-dimensional carbon nanomaterials with unique optoelectronic properties, have attracted widespread attention in various fields in recent years due to their unique optoelectronic properties, high stability, and rich surface structures. There are several reports on carbon dot / zinc oxide composites, such as: Ding et al. successfully prepared ZnO foam / CDs nanocomposites by dispersing combusted ZnO foam into a CDs solution (Materials Science in Semiconductor Processing, 2016, 47: 25-31); Liu et al. prepared ZnO / CDs heterojunctions by impregnating CDs on top of ZnO nanosheet arrays (Ceramics International, 2017, 43(6): 5329-5333); and CN110302822B used nitrogen-doped carbon dots and zinc oxide to prepare microcapsules. However, these methods have failed to achieve carbon doping of zinc oxide, and the carbon dots are gradually released during use, lacking recovery capability. Summary of the Invention
[0007] This application provides a carbon dot-doped zinc oxide, its preparation method, and its application in ethylene glycol gas sensing materials, in order to solve the problems mentioned in the above-mentioned technical background.
[0008] The first aspect of this application is to provide a method for preparing carbon doped zinc oxide, comprising: ZnO powder material and carbon dots (carbon nano dots) are provided and dispersed in a solvent to obtain a mixture. The ZnO powder material was ground together with the resulting mixture to obtain the carbon dot-doped zinc oxide.
[0009] Preferably, the weight ratio of the ZnO powder material to the carbon dots is 1:(0.01-0.5); more preferably 1:(0.03-0.45); even more preferably 1:(0.05-0.4); even more preferably 1:(0.07-0.35); even more preferably 1:(0.9-0.33); even more preferably 1:(0.1-0.3), such as 1:0.15, 1:0.18, 1:0.2, 1:0.23, 1:0.25, 1:0.27, 1:0.29, etc.
[0010] Preferably, the solvent can be a solvent capable of dissolving ZnO and / or carbon dots, or it can be a solvent that forms a suspension with ZnO and / or carbon dots, such as water, alcohol, ketone, aldehyde, hydrocarbon, ether, ester, carboxylic acid, etc.
[0011] Preferably, the mixture can be a solution or a suspension, and more preferably a solution.
[0012] Preferably, the ZnO mass-volume concentration (mass of ZnO per liter of mixture, g / L) in the mixture is 1-20%, more preferably 3-18%, more preferably 5-15%, more preferably 7-12%, and more preferably 8-10%.
[0013] In a preferred embodiment, the grinding duration is preferably at least 10 minutes, more preferably at least 15 minutes, more preferably at least 20 minutes, more preferably at least 25 minutes, and more preferably at least 30 minutes.
[0014] In a preferred embodiment, the step of providing ZnO powder material includes: Zinc salt and surfactant are dissolved in a second solvent, and then an alkaline compound is added to obtain a second mixture; The second mixture was subjected to hydrothermal treatment, and then the solids were collected. The collected solids were calcined to obtain ZnO powder material.
[0015] In a preferred embodiment, the zinc salt may be selected from organic zinc salts and / or inorganic acid salts, such as zinc sulfate, zinc nitrate, zinc chloride, zinc bromide, zinc phosphate, zinc formate, zinc acetate, zinc oxalate, zinc citrate, zinc sulfonate, zinc succinate, zinc benzoate, etc.
[0016] In a preferred embodiment, the alkaline compound may be a substance selected from those capable of ionizing in the second solvent to generate hydroxide ions, and / or substances that react with the second solvent to generate hydroxide ions, such as metal hydroxides, metal oxides, ammonia, etc. Specific examples include: sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium sodium hydroxide, calcium oxide, sodium oxide, potassium oxide, ammonia water, quaternary ammonium bases, sodium carbonate, etc.
[0017] Preferably, the surfactant can be selected from ionic surfactants (including cationic surfactants and anionic surfactants), nonionic surfactants, and amphoteric surfactants, and is preferably a nonionic surfactant, such as fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyether, Tween, Span, polyvinylpyrrolidone, etc.
[0018] Preferably, the amount of zinc salt and alkaline compound used is based on Zn 2+ With OH - The molar ratio is preferably 10:(0.5-10), more preferably 10:(1-8), and even more preferably 10:(3-6).
[0019] Preferably, the weight ratio of the zinc salt to the surfactant is 1:(0.05-0.5); more preferably 1:(0.07-0.45); even more preferably 1:(0.1-0.4); even more preferably 1:(0.15-0.3); even more preferably 1:(0.2-0.25).
[0020] Preferably, the second solvent is a solvent capable of dissolving zinc salts, especially a neutral solvent, such as water.
[0021] Preferably, the temperature of the hydrothermal treatment is 50-300℃, more preferably 100-250℃, such as 120℃, 150℃, 180℃, 200℃, 220℃, etc.
[0022] Preferably, the hydrothermal treatment time is 1-24 hours, more preferably 2-20 hours, more preferably 3-18 hours, more preferably 4-15 hours, more preferably 5-12 hours, more preferably 6-10 hours, such as 7 hours, 8 hours, or 9 hours.
[0023] Preferably, the calcination temperature is 300-800℃, more preferably 400-600℃, such as 450℃, 500℃, 550℃, etc.
[0024] Preferably, the calcination is carried out at a calcination temperature for at least 30 minutes, more preferably 0.5-5 hours, more preferably 1-4 hours, more preferably 1.5-3.5 hours, and more preferably 2-3 hours.
[0025] Preferably, in the calcination, the heating rate to reach the calcination temperature is preferably 0.5-5℃ / min, more preferably 1-4℃ / min, even more preferably 1.5-3.5℃ / min, even more preferably 2-3℃ / min, such as 2.5℃ / min.
[0026] In a preferred embodiment, the collected solids are ground before calcination; more preferably, the collected solids are dried before grinding.
[0027] In a preferred embodiment, the calcined product is further ground a second time.
[0028] Preferably, the second grinding process results in a ZnO material with a particle size of no more than 10 μm, more preferably no more than 8 μm, more preferably no more than 5 μm, and even more preferably no more than 3 μm.
[0029] A second aspect of this application is to provide carbon dot-doped zinc oxide. Preferably, the carbon dot-doped zinc oxide is prepared by the method described in the first aspect.
[0030] Preferably, the carbon doped zinc oxide contains three-dimensional spherical carbon doped zinc oxide particles composed of hexagonal prisms.
[0031] More preferably, the particle size of the three-dimensional spherical carbon doped zinc oxide particles is preferably 1-10 μm, more preferably 2-8 μm, more preferably 3-7 μm, and more preferably 5-6 μm.
[0032] Preferably, in the carbon doped zinc oxide, the molar ratio of Zn, O and C is preferably 1:(1-2):(0.3-0.6), more preferably 1:(1.1-1.8):(0.35-0.55), more preferably 1:(1.2-1.7):(0.4-0.5), more preferably 1:(1.3-1.6):(0.42-0.48), and even more preferably 1:(1.4-1.5):(0.44-0.46).
[0033] A third aspect of this application is to provide the application of the carbon dot-doped zinc oxide in ethylene glycol gas sensing materials, or the application of the carbon dot-doped zinc oxide in monitoring ethylene glycol gas, wherein the carbon dot-doped zinc oxide is used to prepare ethylene glycol gas sensing materials, and the ethylene glycol gas sensing composite material contains, and preferably is composed of, the carbon dot-doped zinc oxide.
[0034] This application provides a method for preparing carbon dot-doped zinc oxide, and successfully obtained a carbon dot-doped zinc oxide. The morphology and composition were characterized, confirming that zinc oxide and carbon dots were successfully combined.
[0035] The carbon doped zinc oxide prepared or provided in this application can effectively improve the surface state of the material and adjust its electronic structure. It can be used to prepare ethylene glycol gas sensing composite materials, which have high response speed, fast recovery time and high response value to ethylene glycol gas, and also have good repeatability and long-term stability.
[0036] In summary, this application utilizes a simple process and mild reaction conditions to synthesize zinc oxide materials with unique morphology via a hydrothermal method. Furthermore, the synthesis cost is low, the process is environmentally friendly, and it has the potential for large-scale production. The prepared carbon-doped zinc oxide exhibits high sensitivity and good selectivity to ethylene glycol, demonstrating significant practical application value. Attached Figure Description
[0037] The accompanying drawings, which constitute a part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a transmission electron microscope (TEM) image of carbon dot-doped zinc oxide prepared in this application; Figure 2 This is a scanning transmission image of carbon doped zinc oxide and an elemental distribution map of carbon, oxygen, and zinc obtained in this application; Figure 3 These are the XPS full spectrum and fine spectrum of carbon element of the carbon doped zinc oxide prepared in this application. The horizontal axis represents the binding energy and the vertical axis represents the diffraction intensity. Figure 4 This is a response / recovery curve of carbon doped zinc oxide prepared in this application to 100 ppm ethylene glycol gas at 220 °C; Figure 5 This is a cyclic test diagram of carbon doped zinc oxide prepared in this application against 100 ppm ethylene glycol gas. Detailed Implementation
[0038] This application provides carbon doped zinc oxide, its preparation method, and its application. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.
[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses.
[0040] Example 1: Dissolve 3.0 g zinc chloride and 0.6 g polyvinylpyrrolidone in 50 mL deionized water and stir magnetically for 30 min to form a clear solution.
[0041] When 0.3 g of sodium hydroxide was added to the resulting clear solution and stirred for 1 h, a homogeneous mixed solution was formed.
[0042] The above mixed solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and hydrothermally treated at 180 °C for 8 h.
[0043] After hydrothermal treatment, the obtained product was centrifuged and the solid was washed several times with deionized water and anhydrous ethanol. The white solid product was collected by centrifugation, dried in a vacuum oven for 12 hours, and then ground into a uniform powder.
[0044] The obtained powder was placed in a porcelain crucible and then placed in a muffle furnace. The temperature was increased to 500°C in air at a rate of 2°C / min and maintained for 2 hours. After natural cooling, the powder was ground again in a mortar. The resulting white sample was the prepared zinc oxide material.
[0045] Weigh 1 mg of zinc oxide material and place it in a mortar.
[0046] Weigh 0.1 mg of carbon dots and dissolve them in 10 mL of deionized water. After stirring for a period of time, a pale yellow homogeneous solution is formed. Measure 1 mL of the solution and add it dropwise into the mortar. Grind for 30 minutes to obtain carbon doped zinc oxide.
[0047] Example 2: Dissolve 3.0 g zinc chloride and 0.5 g polyvinylpyrrolidone in 50 mL deionized water and stir magnetically for 30 min to form a clear solution.
[0048] When 0.4 g of sodium hydroxide was added to the obtained clear solution and stirred for 1 h, a homogeneous mixed solution was formed.
[0049] The above mixed solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and hydrothermally treated at 150 °C for 8 h.
[0050] After hydrothermal treatment, the obtained product was centrifuged and the solid was washed several times with deionized water and anhydrous ethanol. The white solid product was collected by centrifugation, dried in a vacuum oven for 12 hours, and then ground into a uniform powder.
[0051] The obtained powder was placed in a porcelain crucible and then placed in a muffle furnace. The temperature was increased to 600°C in air at a rate of 2°C / min and maintained for 2 hours. After natural cooling, the powder was ground again in a mortar. The resulting white sample was the prepared zinc oxide material.
[0052] Weigh 1 mg of zinc oxide material and place it in a mortar.
[0053] Weigh 0.2 mg of carbon dots and dissolve them in 10 mL of deionized water. After stirring for a period of time, a pale yellow homogeneous solution is formed. Measure 1 mL of the solution and add it dropwise into the mortar. Grind for 30 minutes to obtain carbon doped zinc oxide.
[0054] Example 3: Dissolve 3.0 g zinc chloride and 0.8 g polyvinylpyrrolidone in 50 mL deionized water and stir magnetically for 30 min to form a clear solution.
[0055] When 0.5 g of sodium hydroxide was added to the resulting clear solution and stirred for 1 h, a homogeneous mixed solution was formed.
[0056] The above mixed solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and hydrothermally treated at 200 °C for 7 h.
[0057] After hydrothermal treatment, the obtained product was centrifuged and the solid was washed several times with deionized water and anhydrous ethanol. The white solid product was collected by centrifugation, dried in a vacuum oven for 12 hours, and then ground into a uniform powder.
[0058] The obtained powder was placed in a porcelain crucible and then placed in a muffle furnace. The temperature was increased to 450°C in air at a rate of 2°C / min and maintained for 2 hours. After natural cooling, the powder was ground again in a mortar. The resulting white sample was the prepared zinc oxide material.
[0059] Weigh 1 mg of zinc oxide material and place it in a mortar.
[0060] Weigh 0.15 mg of carbon dots and dissolve them in 10 mL of deionized water. After stirring for a period of time, a pale yellow homogeneous solution is formed. Measure 1 mL of the solution and add it dropwise into the mortar. Grind for 30 minutes to obtain carbon doped zinc oxide.
[0061] Example 4: Dissolve 3.0 g zinc chloride and 0.6 g polyvinylpyrrolidone in 50 mL deionized water and stir magnetically for 30 min to form a clear solution.
[0062] When 0.6 g of sodium hydroxide was added to the resulting clear solution and stirred for 1 h, a homogeneous mixed solution was formed.
[0063] The above mixed solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and hydrothermally treated at 160 °C for 7 h.
[0064] After hydrothermal treatment, the obtained product was centrifuged and the solid was washed several times with deionized water and anhydrous ethanol. The white solid product was collected by centrifugation, dried in a vacuum oven for 12 hours, and then ground into a uniform powder.
[0065] The obtained powder was placed in a porcelain crucible and then placed in a muffle furnace. The temperature was increased to 400°C in air at a rate of 2°C / min and maintained for 2 hours. After natural cooling, the powder was ground again in a mortar. The resulting white sample was the prepared zinc oxide material.
[0066] Weigh 1 mg of zinc oxide material and place it in a mortar.
[0067] Weigh 0.3 mg of carbon dots and dissolve them in 10 mL of deionized water. After stirring for a period of time, a pale yellow homogeneous solution is formed. Measure 1 mL of the solution and add it dropwise into the mortar. Grind for 30 minutes to obtain carbon doped zinc oxide.
[0068] Example 5: Dissolve 3.0 g zinc chloride and 0.4 g polyvinylpyrrolidone in 50 mL deionized water and stir magnetically for 30 min to form a clear solution.
[0069] When 0.3 g of sodium hydroxide was added to the resulting clear solution and stirred for 1 h, a homogeneous mixed solution was formed.
[0070] The above mixed solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and hydrothermally treated at 160 °C for 7 h.
[0071] After hydrothermal treatment, the obtained product was centrifuged and the solid was washed several times with deionized water and anhydrous ethanol. The white solid product was collected by centrifugation, dried in a vacuum oven for 12 hours, and then ground into a uniform powder.
[0072] The obtained powder was placed in a porcelain crucible and then placed in a muffle furnace. The temperature was increased to 550°C in air at a rate of 2°C / min and maintained for 2 hours. After natural cooling, the powder was ground again in a mortar. The resulting white sample was the prepared zinc oxide material.
[0073] Weigh 1 mg of zinc oxide material and place it in a mortar.
[0074] Weigh 0.2 mg of carbon dots and dissolve them in 10 mL of deionized water. After stirring for a period of time, a pale yellow homogeneous solution is formed. Measure 1 mL of the solution and add it dropwise into the mortar. Grind for 30 minutes to obtain carbon doped zinc oxide.
[0075] Example 6: Dissolve 3.0 g zinc chloride and 0.7 g polyvinylpyrrolidone in 50 mL deionized water and stir magnetically for 30 min to form a clear solution.
[0076] When 0.45 g of sodium hydroxide was added to the resulting clear solution and stirred for 1 h, a homogeneous mixed solution was formed.
[0077] The above mixed solution was transferred to a 100 mL Teflon-lined stainless steel autoclave and hydrothermally treated at 170 °C for 7 h.
[0078] After hydrothermal treatment, the obtained product was centrifuged and the solid was washed several times with deionized water and anhydrous ethanol. The white solid product was collected by centrifugation, dried in a vacuum oven for 12 hours, and then ground into a uniform powder.
[0079] The obtained powder was placed in a porcelain crucible and then placed in a muffle furnace. The temperature was increased to 470°C in air at a rate of 2°C / min and maintained for 2 hours. After natural cooling, the powder was ground again in a mortar. The resulting white sample was the prepared zinc oxide material.
[0080] Weigh 1 mg of zinc oxide material and place it in a mortar.
[0081] Weigh 0.25 mg of carbon dots and dissolve them in 10 mL of deionized water. After stirring for a period of time, a pale yellow homogeneous solution is formed. Measure 1 mL of the solution and add it dropwise into the mortar. Grind for 30 minutes to obtain carbon doped zinc oxide.
[0082] To verify the successful synthesis of the carbon dot-doped zinc oxide ethylene glycol gas sensing composite material in this application, its morphology and composition were characterized.
[0083] Figure 1 The image shows a transmission electron microscope (TEM) image of carbon doped zinc oxide prepared in this application. In the image, three-dimensional spherical particles composed of hexagonal prisms with a particle size of about 5 μm can be observed.
[0084] Figure 2 The carbon dot-doped zinc oxide scanning transmission images (images 2b and 2c) and elemental distribution maps of carbon, oxygen, and zinc prepared for the embodiments of this application are shown in images 2a and 2c. Figure 2 c) As can be seen from Figure 2b, three-dimensional spherical particles composed of hexagonal prisms can be seen. Figure 2C shows the distribution of Zn, O and C. It can be seen that carbon, oxygen and zinc are evenly distributed in the composite material, proving the successful composite of carbon dots and zinc oxide. Figure 2a shows a schematic diagram of calculating the atomic ratio of Zn, O and C based on the elemental distribution map of carbon, oxygen and zinc.
[0085] The molar percentages (%) of Zn, O, and C in the various embodiments of this application Zn O C Example 1 40.45 59.09 0.46 Example 2 40.42 59.11 0.47 Example 3 40.51 59.05 0.44 Example 4 40.52 59.05 0.43 Example 5 40.49 59.07 0.44 Example 6 40.47 59.1 0.43 Figure 3 The XPS full spectrum (3a) and fine spectrum (3b) of carbon doped zinc oxide prepared in this application are shown. The horizontal axis represents the binding energy, and the vertical axis represents the diffraction intensity. Peaks of Zn 2p, Zn 3s, Zn 3d, O 1s, N 1s, and C 1s can be observed in the XPS spectrum, proving the successful binding of zinc oxide with carbon dots.
[0086] Gas-sensing performance testing: Weigh 1 mg of the prepared carbon doped zinc oxide and place it in a mortar. Add an appropriate amount of turpentine and ethanol, grind to form a uniform paste, and use a scraper to evenly spread the paste on the surface of a hollow alumina ceramic tube to form a film of suitable thickness. Dry it in an oven.
[0087] A nickel / chromium alloy heating wire is inserted into a ceramic tube, and the ceramic tube and the heating wire are soldered to the sensor base to form a complete gas-sensitive element. The gas-sensitive element is placed on an aging bench and aged at 300°C for two days before its gas-sensitive performance is tested.
[0088] Figure 4 The response / recovery curves for 100 ppm ethylene glycol gas at 220℃ show that the carbon dot / zinc oxide composite material exhibits a high response value of over 1300 for 100 ppm ethylene glycol gas at 220℃, as well as a fast response time (approximately 45 s) and a fast recovery time (approximately 9 s).
[0089] Figure 5 This is a cyclic test chart of 100ppm ethylene glycol gas. After one week of testing, the response value of the carbon doped zinc oxide composite material to ethylene glycol fluctuates within a small error range, indicating that the sensor has good repeatability and long-term stability. The response value decreased by only about 14% within one week.
[0090] The specific embodiments of this application have been described in detail above, but they are merely examples, and this application is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to this application are also within the scope of this application. Therefore, all equivalent changes and modifications made without departing from the spirit and scope of this application should be covered within the scope of this application.
Claims
1. Use of carbon dots doped zinc oxide in monitoring ethylene glycol gas, characterized by the steps of include: A ZnO powder material and carbon dots are provided and dispersed in a solvent to obtain a mixture, wherein the weight ratio of the ZnO powder material to the carbon dots is 1:(0.01-0.5). The ZnO powder material was ground together with the obtained mixture to obtain the carbon dot-doped zinc oxide; The step of providing ZnO powder material includes: Zinc salt and surfactant are dissolved in water, and then an alkaline compound is added to obtain a second mixture; the alkaline compound is selected from substances capable of ionizing to produce hydroxide ions in the second solvent, and / or substances that react with the second solvent to generate hydroxide ions; the surfactant is polyvinylpyrrolidone, the alkaline compound is selected from sodium hydroxide, potassium hydroxide, and lithium hydroxide, and the zinc salt is selected from zinc sulfate, zinc nitrate, zinc chloride, and zinc bromide; the amount of zinc salt and alkaline compound is determined by Zn 2+ With OH - The molar ratio is 10:(0.5-10); the weight ratio of the zinc salt to the surfactant is 1:(0.05-0.5); the zinc salt is an inorganic acid salt. The second mixture is subjected to hydrothermal treatment, and then the solid is collected; the hydrothermal treatment temperature is 100-300℃, and the time is 1-24 hours. The collected solids are calcined for at least 30 minutes to obtain ZnO powder material. The calcination temperature is 300-800℃, and the heating rate to reach the calcination temperature is 0.5-5℃ / min. Carbon doped zinc oxide is thus prepared. The carbon doped zinc oxide is used to prepare ethylene glycol gas sensing materials.
2. Use according to claim 1, characterized in that, The weight ratio of ZnO powder material to carbon dots is 1:(0.03-0.45).
3. Use according to claim 2, characterized in that, The weight ratio of ZnO powder material to carbon dots is 1:(0.05-0.4).
4. Use according to claim 3, characterized in that, The weight ratio of ZnO powder material to carbon dots is 1:(0.07-0.35).
5. Use according to claim 4, characterized in that, The weight ratio of ZnO powder material to carbon dots is 1:(0.1-0.3).
6. Use according to claim 5, characterized in that, The weight ratio of ZnO powder to carbon dots is selected from 1:0.15, 1:0.18, 1:0.2, 1:0.23, 1:0.25, 1:0.27, and 1:0.
29.
7. The use according to claim 1, characterized in that, The solvent is a solvent capable of dissolving ZnO and / or carbon dots, or a solvent that forms a suspension with ZnO and / or carbon dots.
8. Use according to claim 7, characterized in that, The ZnO mass-volume concentration in the mixture is 1-20%.
9. Use according to claim 8, characterized in that, The ZnO mass-volume concentration in the mixture is 3-18%.
10. Use according to claim 9, characterized in that, The ZnO mass-volume concentration in the mixture is 5-15%.
11. Use according to claim 10, characterized in that, The ZnO mass-volume concentration in the mixture is 7-12%.
12. Use according to claim 11, characterized in that, The ZnO mass-volume concentration in the mixture is 8-10%.
13. The use according to claim 7, characterized in that, The solvent is selected from water, alcohol, ketone, aldehyde, hydrocarbon, ether, ester, and carboxylic acid.
14. The use according to claim 1, characterized in that, The zinc salt and the basic compound are used in a molar ratio of 10:(1-8) of Zn 2+ to OH - . The weight ratio of the zinc salt to the surfactant is 1:(0.07-0.45).
15. Use according to claim 14, characterized in that, The zinc salt and the basic compound are used in a molar ratio of 10:(3-6) with respect to OH 2+ . - .
16. The use according to claim 14, characterized in that, The weight ratio of the zinc salt to the surfactant is 1:(0.1-0.4).
17. Use according to claim 16, characterized in that, The weight ratio of the zinc salt to the surfactant is 1:(0.15-0.3).
18. The use according to claim 17, characterized in that, The weight ratio of the zinc salt to the surfactant is 1:(0.2-0.25).
19. The use according to claim 1, characterized in that, The temperature of the hydrothermal treatment is 100-250℃; The hydrothermal treatment time is 2-20 hours; The calcination temperature is 400-600℃; during the calcination, the calcination is carried out at the calcination temperature for 0.5-5 hours. During the calcination process, the heating rate to reach the calcination temperature is 1-4℃ / min.
20. The use according to claim 19, characterized in that, The hydrothermal treatment temperature is selected from 120℃, 150℃, 180℃, 200℃, and 220℃.
21. The use according to claim 19, characterized in that, The hydrothermal treatment time is 3-18 hours.
22. The use according to claim 21, characterized in that, The hydrothermal treatment time is 4-15 hours.
23. The use according to claim 22, characterized in that, The hydrothermal treatment time is 5-12 hours.
24. The use according to claim 23, characterized in that, The hydrothermal treatment time is 6-10 hours.
25. The use according to claim 24, characterized in that, The hydrothermal treatment time is selected from 7 hours, 8 hours, and 9 hours.
26. The use according to claim 19, characterized in that, The calcination temperature is selected from 450℃, 500℃, and 550℃.
27. The use according to claim 19, characterized in that, During the calcination process, the calcination is carried out at the specified calcination temperature for 1-4 hours.
28. The use according to claim 27, characterized in that, During the calcination process, the calcination is carried out at the specified calcination temperature for 1.5-3.5 hours.
29. The use according to claim 28, characterized in that, During the calcination process, the calcination is carried out at the specified calcination temperature for 2-3 hours.
30. The use of claim 19, wherein, During the calcination process, the heating rate to reach the calcination temperature is 1.5-3.5℃ / min.
31. The use according to claim 30, wherein During the calcination process, the heating rate to reach the calcination temperature is 2-3℃ / min.
32. The use according to claim 31, characterized in that During the calcination process, the heating rate to reach the calcination temperature is 2.5℃ / min.