CN111017986A - Preparation method of reduced graphene oxide-CuO/ZnO gas-sensitive material - Google Patents
Preparation method of reduced graphene oxide-CuO/ZnO gas-sensitive material Download PDFInfo
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- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
- G01N27/125—Composition of the body, e.g. the composition of its sensitive layer
- G01N27/127—Composition of the body, e.g. the composition of its sensitive layer comprising nanoparticles
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Abstract
The invention discloses a preparation method of a reduced graphene oxide-CuO/ZnO gas-sensitive material, which comprises the following steps: adding zinc nitrate hexahydrate and copper nitrate trihydrate into deionized water to obtain a copper-zinc precursor solution; adding urea into the copper-zinc precursor solution; dispersing reduced graphene oxide in deionized water, and performing ultrasonic dispersion to obtain a reduced graphene oxide colloidal solution; mixing the colloidal solution with the precursor solution to obtain a suspension; transferring the suspension into a polytetrafluoroethylene-lined high-pressure reaction kettle, and putting the reaction kettle into an electric furnace for reaction to obtain a reduced graphene oxide-zinc-copper hydroxide carbonate compound; cooling, washing and drying the compound to obtain blue-gray powder; and (4) annealing the powder in a muffle furnace to obtain the gas-sensitive material. The invention is simple and easy to implement, the material has good low-temperature response performance, and the technical problems that the traditional ZnO-based material has poor selectivity to acetone gas and has no response at the low temperature of 150 ℃ or below are solved.
Description
Technical Field
The invention relates to the technical field of application of a chemically synthesized carbon-based semiconductor new material to a gas sensor, in particular to a preparation method of a reduced graphene oxide-CuO/ZnO gas-sensitive material.
Background
Among the current indoor and outdoor environmental gas pollutants, Volatile Organic Compounds (VOCs) are complex in components, are one of the most common pollutants in the environment, and have the greatest harm to human health. Certain VOCs, such as acetone, are central nervous system anesthetics and chronic exposure may cause damage to the central nerves, liver, kidney, and pancreas. In addition, different types of VOC in the exhaled gas of the human body can be used for pathological process monitoring, and then rapid screening and early auxiliary diagnosis of serious diseases are carried out through modern respiratory analysis and specific component detection. Such as acetone, that deviates from the normal concentration range, are endogenous VOC markers for the diagnosis of diabetic disease. At present, the conventional VOCs gas detection method mainly comprises a gas chromatography method, a liquid chromatography-mass spectrometry method and the like, analysis work is mainly completed in a laboratory, and the problems of complex and expensive device, long time consumption, high measurement cost and the like exist.
The gas sensor can realize rapid, low-cost and on-line detection, is a hotspot in the field of current gas detection, analysis research and application, and has huge demand prospect. At present, compared with the defects of high cost, large volume, easy poisoning, short service life and the like of an electrochemical sensor, the metal oxide semiconductor-based sensor has the mature technology and the most extensive application. The device has the advantages of sensitive response, simple structure, long service life, wide detection range, low cost, quick recovery, capability of working stably for a long time, easiness in carrying and the like.
The prior art sensors have the following problems: first, based on SnO2、NiO、ZnO、α-Fe2O3、WO3、In2O3、Co3O4And the conventional metal oxide semiconductor gas sensor generally has the defects of high power consumption and broad response spectrum to various VOCs gases and reducing gases (such as ethanol, methanol, formaldehyde, carbon monoxide, methane, hydrogen and ammonia). Secondly, the working temperature of the semi-conducting is usually too high, generally reaching 400 to 600 ℃, even the working temperature of the improved composite metal oxide is 350 to 500 ℃. Therefore, the heating work power consumption requirement of the sensor is very large, the future application of the sensor in the fields of medical health, intelligent equipment, intelligent home, mobile monitoring equipment and the like is prevented, and the application of the sensor in special safety risk scenes is also limited. Thirdly, the detection sensitivity of these sensors is not high, the detection limit is not low enough, and generally, the sensors can only detect gases with a medium or high concentration level of more than 10ppm, thus greatly limiting the application of the sensors in various analysis fields.
Disclosure of Invention
In order to solve the following technical problems, the invention provides a preparation method of a reduced graphene oxide-CuO/ZnO gas-sensitive material, which comprises the following steps: (1) the pure ZnO or Zn-based composite metal oxide material in the prior art can only respond to VOCs gas at the high temperature of 350-600 ℃, so that the low-temperature work is realized, and the power consumption of a semiconductor device is reduced; (2) the ZnO material in the prior art has broad-spectrum sensitivity to most of VOCs gas, poor selectivity to acetone gas, poor environmental interference resistance and lower sensitivity to gas with ppb level concentration. The method disclosed by the invention can be used for preparing the graphene-copper-zinc-based metal oxide composite gas-sensitive material which is used for detecting trace acetone gas in the air, has high sensitivity and high selectivity and can realize low-temperature work.
The invention adopts the following technical scheme:
a preparation method of a reduced graphene oxide-CuO/ZnO gas-sensitive material is characterized by comprising the following steps:
(1) adding zinc nitrate hexahydrate and copper nitrate trihydrate into deionized water, and performing ultrasonic dispersion for 5-60 min to obtain a copper-zinc precursor solution;
(2) adding urea into the copper-zinc precursor solution, and stirring at room temperature for 20-120 min;
(3) dispersing reduced graphene oxide in deionized water, and performing ultrasonic dispersion to obtain a reduced graphene oxide colloidal solution; mixing the reduced graphene oxide colloidal solution with the copper-zinc precursor solution obtained in the step (2), and uniformly stirring by magnetic force to obtain a suspension mixture;
(4) transferring the suspension mixture into a polytetrafluoroethylene-lined high-pressure reaction kettle, putting the polytetrafluoroethylene-lined high-pressure reaction kettle into an electric furnace for reaction, and obtaining a blue-gray precipitation product reduced graphene oxide-zinc-copper carbonate hydroxide compound after the reaction is finished;
(5) cooling the reduced graphene oxide-zinc copper hydroxide carbonate compound to room temperature, centrifugally washing and drying to obtain reduced graphene oxide-zinc copper hydroxide carbonate compound precursor blue-gray powder;
(6) and placing the blue-gray powder in a muffle furnace, and annealing the blue-gray powder in an air atmosphere to obtain black sintered powder, wherein the black sintered powder is a reduced graphene oxide-CuO/ZnO gas-sensitive material.
According to the preparation method, the input amount of the reduced graphene oxide in the gas sensitive material is 1.2-3.6% of the total input mass of anhydrous copper and zinc salt reagents used for preparing the gas sensitive material.
According to the preparation method, the input amount of the reduced graphene oxide in the gas sensitive material is 2.4% of the total mass of the anhydrous copper and zinc salt reagents used for preparing the gas sensitive material.
The production method is characterized in that the molar ratio of zinc nitrate hexahydrate to copper nitrate trihydrate in step (1) is (1 to 3): 2; the solid-liquid mass ratio of two solid substances of zinc nitrate-hexahydrate and copper nitrate-trihydrate to deionized water is 1: (32-41).
The preparation method is characterized in that the molar ratio of the metal salt zinc nitrate hexahydrate to the urea in the step (2) is 1: (2-4).
The preparation method is characterized in that the reaction temperature of the polytetrafluoroethylene-lined high-pressure reaction kettle in the step (4) in an electric furnace is 90-120 ℃, and the reaction time is 10-18 h; in the step (5), the reaction conditions for drying the reduced graphene oxide-zinc copper hydroxide carbonate compound are as follows: the drying temperature is 45-85 ℃, and the drying time is 12-24 h; and (6) placing the blue-gray powder in a muffle furnace, heating the blue-gray powder to 400-550 ℃ at a preset heating rate of 2-5 ℃/min under an air atmosphere, and annealing for 2-4 h.
Compared with the prior art, the invention has the following beneficial technical effects:
(1) by changing the preparation process of the gas sensitive material, the technical problems that a pure ZnO-based material or a Zn-based composite metal oxide material hardly responds to VOCs gas at the low temperature of 150 ℃ or below and hardly has selectivity to acetone gas are fundamentally solved. The reduced graphene oxide-CuO/ZnO gas-sensitive material prepared by the method realizes low-temperature, ultrasensitive and high-selectivity gas detection on acetone, and has the mechanism that the gas-sensitive material adsorbs oxygen and target gas in air on the surface thereof, adsorbed gas molecules can generate electron migration with the material, so that an oxidation-reduction reaction is generated, and the migration of carriers in the material can cause the change of the surface resistivity of the material, so that the signal response of a gas sensor is generated. The controlled morphology of the p-n junction of the graphene-ZnO oxide can expand the space charge region and improve the gas-sensitive functional characteristics. CuO has a special catalytic action on the oxidation of acetone gas, thereby improving the selection characteristics of the material on the acetone gas.
(2) The reduced graphene oxide-CuO/ZnO gas-sensitive material prepared by the method has high sensitivity and selectivity to acetone gas, can detect the acetone gas with the concentration of 20ppb at least, has extremely low response to common gases such as ethanol, formaldehyde, hydrogen, carbon monoxide, ammonia gas and the like, and has strong anti-interference capability. The specific catalytic oxidation action of CuO in the material improves the gas sensitivity of ZnO to acetone, and reduces the sensitivity of ZnO to other VOCs interfering gases, thereby improving the gas sensitivity selectivity of the material to acetone. The gas-sensitive element prepared by using the material as a sensitive material has the sensitivity of 72-103 to 200ppm acetone and the sensitivity of 10.9-15.2 to 5ppm acetone gas under the working condition of low temperature of 120-150 ℃, and the response and recovery time of 0.2-200 ppm acetone gas are not more than 35 seconds.
Drawings
FIG. 1 is a schematic flow diagram of a production process of the present invention;
FIG. 2 is a graph showing the concentration gradient of acetone gas when the gas-sensitive material prepared in example 1 of the present invention is applied to a gas sensor element;
fig. 3 is a graph showing selectivity of the gas sensitive material prepared in example 1 of the present invention applied to a gas sensor element.
Detailed Description
ZnO is a good semiconductor VOCs gas sensitive material, and the carbon nano material graphene has unique electrical and mechanical properties, has an ultra-large specific surface area, high electron mobility, high-quality crystal lattice, high carrier mobility and low noise, can well improve the sensitivity and selectivity of ZnO by doping graphene, and greatly reduces the working temperature. The controlled morphology of the p-n junction of the graphene-ZnO oxide can expand the space charge region and improve the gas-sensitive functional characteristics. Further, by varying the amount and distribution of the components to form unique material properties, different sensing mechanisms of p-type and n-type semiconductors can be advantageously utilized, and thus carbon nanomaterials, as represented by graphene and the like, are good candidates for improving the gas sensitivity of room temperature-sensitized semiconductor metal oxides. Meanwhile, CuO is adopted to carry out composite modification on the material, and has a special catalytic action on the oxidation of acetone gas, so that the selection characteristic of the material on the acetone gas can be improved greatly.
The preparation method of the reduced graphene oxide-CuO/ZnO gas-sensitive material comprises the following steps: (1) pre-oxidizing graphite powder, synthesizing Graphene Oxide (GO) and chemically reducing the GO to synthesize reduced graphene oxide sheets; the molar ratio is (1-3): 2, adding zinc nitrate hexahydrate and copper nitrate trihydrate into deionized water, wherein the solid-liquid mass ratio of two solid substances of the zinc nitrate hexahydrate and the copper nitrate trihydrate to the deionized water is 1: (32-41), carrying out ultrasonic dispersion for 5-60 min, and fully dissolving to obtain a copper-zinc precursor solution; preferably, the molar ratio of zinc nitrate hexahydrate to copper nitrate trihydrate is 1: 2. 1: 1 or 3: 2. (2) adding urea into a copper-zinc precursor solution, wherein the molar ratio of metal salt zinc nitrate hexahydrate precipitator urea is 1: (2-4). Stirring at room temperature for 20-120 min; preferably, the molar ratio of the metal salt zinc nitrate hexahydrate to the urea is 1: 2. 1: 3 or 1: 4. (3) dispersing reduced graphene oxide (rGO) in a small amount of deionized water, and performing ultrasonic dispersion to obtain a reduced graphene oxide colloidal solution; mixing the reduced graphene oxide colloidal solution with the copper-zinc precursor solution obtained in the step (2), and uniformly stirring by magnetic force to obtain a suspension mixture; (4) transferring the suspension mixture into a 50mL polytetrafluoroethylene-lined high-pressure reaction kettle, putting the polytetrafluoroethylene-lined high-pressure reaction kettle into an electric furnace for reaction at the temperature of 90-120 ℃ for 10-18 h, preferably at the temperature of 90 ℃, 95 ℃, 100 ℃, 110 ℃ or 120 ℃ for 10h, 12h, 14h, 16h or 18 h; the main purpose of controlling the reaction temperature and the reaction time is to adjust the grain size of the crystallized zinc oxide/copper oxide and to adjust the morphology of the porous structure. After the reaction is finished, obtaining a blue-gray precipitation product reduced graphene oxide-zinc copper hydroxide carbonate compound (rGO-zinc copper hydroxide carbonate compound, rGO-ZCCH); (5) cooling the reduced graphene oxide-zinc copper hydroxide carbonate compound to room temperature, centrifugally washing for several times, and drying to obtain reduced graphene oxide-zinc copper hydroxide carbonate compound precursor blue-gray powder; the washing may be performed by alternately performing centrifugal washing with ethanol and ultrapure water. The reaction conditions for drying the reduced graphene oxide-zinc-copper hydroxide carbonate compound are as follows: the drying temperature is 45-85 ℃, and the drying time is 12-24 h; preferably, the drying temperature is 45 ℃, 50 ℃, 60 ℃, 70 ℃ or 85 ℃, and the drying time is 12h, 16h, 18h, 20h or 24 h. (6) And (2) placing the blue-gray powder in a muffle furnace, heating the blue-gray powder to 400-550 ℃ at a preset heating rate of 2-5 ℃/min under an air atmosphere, and annealing for 2-4 h to obtain black sintered powder, wherein the black sintered powder is a multi-layer porous rGO-CuO/ZnO composite powder material, namely the reduced graphene oxide-CuO/ZnO gas-sensitive material. Preferably, the blue-gray powder is heated to 400 ℃, 450 ℃, 500 ℃ or 550 ℃ at a preset heating rate of 2 ℃/min, 3 ℃/min, 4 ℃/min or 5 ℃/min under an air atmosphere and annealed for 2h, 3h or 4 h.
The gas-sensitive material prepared by the method consists of multiple layers of reduced graphene oxide and porous copper oxide/zinc oxide composite bimetallic oxide nano-fibers. The input amount of the reduced graphene oxide in the gas sensitive material is 1.2-3.6% of the total input mass of anhydrous copper and zinc salt reagents used for preparing the gas sensitive material; preferably, the input amount of the reduced graphene oxide in the composite material is 1.2%, 2.4% or 3.6% of the total mass of the anhydrous copper and zinc salt reagents used for preparing the composite material. The gas sensitive material can be used as a sensitive material of an acetone gas sensitive element, and the method for manufacturing the gas sensitive element by utilizing the gas sensitive material comprises the following steps: mixing the gas-sensitive material prepared by the above method with deionized water or volatile alcohol solvent such as ethanol and isopropanol, and mixing in a ratio of 4: (1-0.5) uniformly mixing in a weight ratio to form a paste; wet grinding for 2-10 min, and continuously drying at 20-60 ℃ for 5-60 min to evaporate or volatilize the solvent so as to obtain a slurry sample; directly coating the slurry sample on an electrode area of a sensing element substrate of an alumina ceramic substrate which is pre-attached with a pair of Ag-Ag electrodes, and sintering for 2-4 h at 450-550 ℃; in order to improve the long-term stability, the sensing element is kept at the optimal working temperature of 120-150 ℃ for 2 days, and then the acetone gas sensing element is obtained. The sensitivity of the element to acetone gas is the ratio R of the resistance of the element in acetone gas to the resistance of the element in air at the working temperatureg/Ra. In the invention, the optimal base resistance of the acetone sensor can be adjusted according to the application amount of the gas sensitive material, generally 5-20 muL, and the resistance of the gas sensitive material prepared by the method is any value in the range of L0K-8M.
The preparation method of the reduced graphene oxide-CuO/ZnO gas-sensitive material of the present invention is described in detail below with reference to specific examples, but the present invention is not limited to the following examples.
Example 1
Adding 0.897g of zinc nitrate hexahydrate and 0.484g of copper nitrate trihydrate into 45mL of deionized water, carrying out ultrasonic dispersion for 5min, and fully dissolving to obtain a copper-zinc precursor solution; then, adding 0.36g of urea into the copper-zinc precursor solution, and stirring for 30min at room temperature; dispersing 22.6mg of reduced graphene oxide in a small amount of deionized water, performing ultrasonic dispersion to obtain a reduced graphene oxide colloidal solution, adding the reduced graphene oxide colloidal solution into the precursor solution, and magnetically stirring to obtain a uniform suspension mixture; transferring the suspension into a 50mL high-pressure reaction kettle with a polytetrafluoroethylene lining, and putting the high-pressure reaction kettle into an electric furnace to react for 10 hours at the temperature of 95 ℃; after the reaction is finished, obtaining a blue-gray precipitation product reduced graphene oxide-zinc-copper hydroxide carbonate compound; cooling and centrifuging the obtained blue-gray precipitate product, and alternately washing the product with water and absolute ethyl alcohol for a plurality of times; drying the product in an oven at 60 ℃ for 12h to obtain blue-gray powder of a rGO-zinc-copper hydroxide carbonate compound precursor; placing the collected blue-gray powder in a muffle furnace, heating to 450 ℃ at a heating rate of 2 ℃/min in an air atmosphere, and annealing for 2 h; the finally prepared black sintering powder is a multi-layer porous 2.4 wt% reduced graphene oxide-CuO/ZnO gas-sensitive material.
Example 2
Adding 0.299g of zinc nitrate hexahydrate and 0.484g of copper nitrate trihydrate into 25mL of deionized water, carrying out ultrasonic dispersion for 30min, and fully dissolving to obtain a copper-zinc precursor solution; then, adding 0.18g of urea into the copper-zinc precursor solution, and stirring for 20min at room temperature; dispersing 11.30mg of reduced graphene oxide in a small amount of deionized water so as to control the doping percentage of the reduced graphene oxide to be 1.2 wt%, performing ultrasonic dispersion to obtain a reduced graphene oxide colloidal solution, adding the reduced graphene oxide colloidal solution into the precursor solution, and magnetically stirring to obtain a uniform suspension mixture; transferring the suspension into a 50mL high-pressure reaction kettle with a polytetrafluoroethylene lining, and putting the high-pressure reaction kettle into an electric furnace to react for 12 hours at 90 ℃; after the reaction is finished, obtaining a blue-gray precipitation product reduced graphene oxide-zinc-copper hydroxide carbonate compound; cooling and centrifuging the obtained blue-gray precipitate product, and alternately washing the product with water and absolute ethyl alcohol for a plurality of times; drying the product in an oven at 45 ℃ for 24h to obtain blue-gray powder of the rGO-zinc-copper hydroxide carbonate compound precursor; placing the collected blue-gray powder in a muffle furnace, heating to 400 ℃ at a heating rate of 3 ℃/min in an air atmosphere, and annealing for 3 h; the finally prepared black sintering powder is a multi-layer porous 1.2 wt% reduced graphene oxide-CuO/ZnO gas-sensitive material.
Example 3
Adding 0.598g of zinc nitrate hexahydrate and 0.484g of copper nitrate trihydrate into 44mL of deionized water, performing ultrasonic dispersion for 60min, and fully dissolving to obtain a copper-zinc precursor solution; then, adding 0.48g of urea into the copper-zinc precursor solution, and stirring at room temperature for 120 min; dispersing 33.90mg of reduced graphene oxide in a small amount of deionized water, so that the doping percentage of the reduced graphene oxide is controlled to be 3.6 wt%, performing ultrasonic dispersion to obtain a reduced graphene oxide colloidal solution, adding the reduced graphene oxide colloidal solution into the precursor solution, and magnetically stirring to obtain a uniform suspension mixture; transferring the suspension into a 50mL high-pressure reaction kettle with a polytetrafluoroethylene lining, and putting the high-pressure reaction kettle into an electric furnace to react for 18h at 120 ℃; after the reaction is finished, obtaining a blue-gray precipitation product reduced graphene oxide-zinc-copper hydroxide carbonate compound; cooling and centrifuging the obtained blue-gray precipitate product, and alternately washing the product with water and absolute ethyl alcohol for a plurality of times; drying the product in an oven at 85 ℃ for 14h to obtain blue-gray powder of a rGO-zinc-copper hydroxide carbonate compound precursor; placing the collected blue-gray powder in a muffle furnace, heating to 550 ℃ at a heating rate of 5 ℃/min in an air atmosphere, and annealing for 4 h; the finally prepared black sintering powder is a multi-layer porous 3.6 wt% reduced graphene oxide-CuO/ZnO gas-sensitive material.
Test example 1
A certain amount of the product prepared in examples 1 to 3 was placed in a mortar, and mixed with deionized water at a ratio of 4: 1 weight ratio, wet-milling to form a paste, and then continuously drying at 60 c for 20min to partially evaporate deionized water, thereby obtaining a slurry-like sample. Uniformly dripping 10 mu L of slurry-shaped sample on an electrode area of a sensing element substrate of an alumina ceramic substrate which is pre-attached with a pair of Ag-Ag electrodes, naturally drying for 1h, transferring to a quartz boat, and sintering for 2h at 450 ℃ in a muffle furnace under nitrogen atmosphere. In order to improve the long-term stability, the sensing element is kept at the working temperature of 150 ℃ for 2 days, and then the acetone gas sensing element is prepared.
And (3) testing the gas-sensitive performance of the sensor by using a JF02F type gas sensing test system. The gas sensitivity of the gas sensors prepared from the products prepared in examples 1 to 3 and in the middle to air with different contents of acetone was measured at a working low temperature of 150 c, with a heating voltage set at 7.0V.
Fig. 2 shows a gas-sensitive material prepared according to embodiment 1 of the present invention, and a concentration gradient test chart of a gas sensing element on acetone gas, which is obtained based on the gas-sensitive material and the acetone gas sensing element and the test method provided in test embodiment 1. As can be seen from fig. 2, the acetone gas sensor element has a good linear relationship in a low concentration range, so that the acetone gas concentration can be accurately calculated from the degree of response.
FIG. 3 shows a selectivity test chart of an acetone gas sensing element prepared from the material of example 1 of the invention. As can be seen from FIG. 3, the sensor element is sensitive to a response of 5ppm acetone, and the response value Rg/Ra15.2 for 10 times concentration of 50ppm ethanol and NO2、NH3Has a very low sensitivity and a response value Rg/Ra4.56, 2.75 and 1.43, respectively, indicating that the sensing element has good selectivity for acetone.
While various exemplary embodiments of the invention have been shown and described, it will be understood and appreciated that the scope of the invention is to cover all such other modifications and changes without departing from the spirit and scope of the invention in the art.
Claims (6)
1. A preparation method of a reduced graphene oxide-CuO/ZnO gas-sensitive material is characterized by comprising the following steps:
(1) adding zinc nitrate hexahydrate and copper nitrate trihydrate into deionized water, and performing ultrasonic dispersion for 5-60 min to obtain a copper-zinc precursor solution;
(2) adding urea into the copper-zinc precursor solution, and stirring at room temperature for 20-120 min;
(3) dispersing reduced graphene oxide in deionized water, and performing ultrasonic dispersion to obtain a reduced graphene oxide colloidal solution; mixing the reduced graphene oxide colloidal solution with the copper-zinc precursor solution obtained in the step (2), and uniformly stirring by magnetic force to obtain a suspension mixture;
(4) transferring the suspension mixture into a polytetrafluoroethylene-lined high-pressure reaction kettle, putting the polytetrafluoroethylene-lined high-pressure reaction kettle into an electric furnace for reaction, and obtaining a blue-gray precipitation product reduced graphene oxide-zinc-copper carbonate hydroxide compound after the reaction is finished;
(5) cooling the reduced graphene oxide-zinc copper hydroxide carbonate compound to room temperature, centrifugally washing and drying to obtain reduced graphene oxide-zinc copper hydroxide carbonate compound precursor blue-gray powder;
(6) and placing the blue-gray powder in a muffle furnace, and annealing the blue-gray powder in an air atmosphere to obtain black sintered powder, wherein the black sintered powder is a reduced graphene oxide-CuO/ZnO gas-sensitive material.
2. The preparation method according to claim 1, wherein the input amount of the reduced graphene oxide in the gas sensitive material is 1.2-3.6% of the total mass of the anhydrous copper and zinc salt reagents used for preparing the gas sensitive material.
3. The preparation method of claim 2, wherein the input amount of the reduced graphene oxide in the gas sensitive material is 2.4% of the total mass of the anhydrous copper and zinc salt reagents used for preparing the gas sensitive material.
4. The production method according to claim 1, wherein the molar ratio of zinc nitrate hexahydrate to copper nitrate trihydrate in step (1) is (1 to 3): 2; the solid-liquid mass ratio of two solid substances of zinc nitrate-hexahydrate and copper nitrate-trihydrate to deionized water is 1: (32-41).
5. The method according to claim 1, wherein the molar ratio of the metal salt zinc nitrate hexahydrate to urea in step (2) is 1: (2-4).
6. The preparation method according to claim 1, wherein the reaction temperature of the polytetrafluoroethylene-lined high-pressure reaction kettle in the step (4) in an electric furnace is 90-120 ℃ and the reaction time is 10-18 h; in the step (5), the reaction conditions for drying the reduced graphene oxide-zinc copper hydroxide carbonate compound are as follows: the drying temperature is 45-85 ℃, and the drying time is 12-24 h; and (6) placing the blue-gray powder in a muffle furnace, heating the blue-gray powder to 400-550 ℃ at a preset heating rate of 2-5 ℃/min under an air atmosphere, and annealing for 2-4 h.
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| CN113120950A (en) * | 2021-03-04 | 2021-07-16 | 华南师范大学 | Gas-sensitive material, preparation method thereof, gas-sensitive electrode and gas-sensitive detection equipment |
| CN113758976A (en) * | 2021-09-14 | 2021-12-07 | 北京化工大学 | Preparation and application of hydrotalcite-based ammonia gas-sensitive material |
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| CN113120950A (en) * | 2021-03-04 | 2021-07-16 | 华南师范大学 | Gas-sensitive material, preparation method thereof, gas-sensitive electrode and gas-sensitive detection equipment |
| CN113120950B (en) * | 2021-03-04 | 2023-05-12 | 华南师范大学 | Gas-sensitive material, preparation method thereof, gas-sensitive electrode and gas-sensitive detection equipment |
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| WO2023025335A1 (en) * | 2021-08-24 | 2023-03-02 | Mendelova Univerzita V Brne | Reduced graphene oxide decorated with zinc and copper oxides, method of preparation thereof, and use thereof |
| CN113758976A (en) * | 2021-09-14 | 2021-12-07 | 北京化工大学 | Preparation and application of hydrotalcite-based ammonia gas-sensitive material |
| CN115117360A (en) * | 2022-08-31 | 2022-09-27 | 山东华太新能源电池有限公司 | Mercury-free active negative electrode material and preparation method thereof |
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