阅读说明：本技术 一种抗湿纳米Zn-In2O3三维结构传感器材料及其制备方法与应用 (Moisture-resistant nano Zn-In2O3Three-dimensional structure sensor material and preparation method and application thereof ) 是由 张文惠 杜帅航 王国乾 丁素军 岳鹿 关荣锋 许宁 于 2020-10-27 设计创作，主要内容包括：本发明公开了一种抗湿纳米Zn-In-2O-3三维结构传感器材料及其制备方法与应用,以不同摩尔比的Zn/In为前驱物,以甘油和乙醇作为溶剂相,利用Zn～(2+)对In-2O-3纳米结构调控作用,采用高温高压溶剂热反应,一步制备如杨桃状、雪饼状、梭状三种结构的Zn-In-2O-3三维纳米结构,该结构由于其结构特性和丰富的氧空位,将其制备成气体传感器,用于检测高湿度下乙醇气体材料应用其性能优异。此外,本发明采用的传感器结构是由涂敷在Al-2O-3绝缘陶瓷管上的Zn-In-2O-3半导体敏感材料、以及镍铬合金加热丝和加热器组成。器件制作工艺简单,适于大批量生产,在检测低浓度高湿度下的乙醇方面有广阔的应用前景。(The invention discloses a moisture-resistant nano Zn-In 2 O 3 A three-dimensional structure sensor material and a preparation method and application thereof are disclosed, wherein Zn/In with different molar ratios is taken as a precursor, glycerol and ethanol are taken as solvent phases, and Zn is utilized 2+ For In 2 O 3 The nano-structure regulation and control function adopts high-temperature high-pressure solvothermal reaction to prepare Zn-In with three structures of carambola, snow cake and spindle In one step 2 O 3 The three-dimensional nano structure is prepared into a gas sensor due to the structural characteristics and rich oxygen vacancies, and is used for detecting the ethanol gas material under high humidity, and the performance of the material is excellent. In addition, the sensor structure adopted by the invention is formed by coating Al 2 O 3 Zn-In on insulating ceramic tube 2 O 3 Semiconductor sensitive material, nickel-chromium alloy heating wire and heater. The device has simple manufacturing process, is suitable for mass production, and has wide application prospect in the aspect of detecting ethanol with low concentration and high humidity.)

1. Moisture-resistant nano Zn-In₂O₃The preparation method of the three-dimensional structure sensor material is characterized in that glycerol and ethanol are used as solvent phases, and Zn is utilized²⁺For In₂O₃The nano structure regulation and control function adopts the high-temperature high-pressure solvothermal reaction to prepare the Zn-In with uniform size In one step₂O₃A three-dimensional nanostructure.

2. The moisture-resistant nano Zn-In of claim 1₂O₃The preparation method of the three-dimensional structure sensor material is characterized by comprising the following steps:

step 1, mixing absolute ethyl alcohol and glycerol according to a volume ratio of 13: 3;

step 2, adding indium chloride into the mixed solution obtained in the step 1, and stirring until the indium chloride is dissolved uniformly to obtain a mixed solution I;

step 3, adding zinc acetate into a mixed solution of absolute ethyl alcohol and sodium hydroxide to form a mixed solution II;

step 4, uniformly mixing the mixed solution I and the mixed solution II, then filling the mixture into a polytetrafluoroethylene substrate, and carrying out solvothermal reaction;

step 5, collecting, washing and drying the materials subjected to the solvothermal reaction, and sintering the powder to obtain yellow powder, namely Zn-In₂O₃A nanostructure; the mol ratio of the indium chloride to the zinc acetate is 0.5-5: 1.

3. The moisture-resistant nano Zn-In of claim 2₂O₃The preparation method of the three-dimensional structure sensor material is characterized in that the concentration of the sodium hydroxide solution in the step 3 is 0.1-1 mmol/L.

4. The moisture-resistant nano Zn-In of claim 2₂O₃The preparation method of the three-dimensional structure sensor material is characterized in that the volume ratio of absolute ethyl alcohol to glycerol is 2-10: 1.

5. the moisture-resistant nano Zn-In of claim 2₂O₃The preparation method of the three-dimensional structure sensor material is characterized in that the hydrothermal time is 2-24h, and the reaction temperature is 100-200 ℃.

6. Moisture-resistant nano Zn-In prepared based on claim 1₂O₃A three-dimensional structure sensor material.

7. The moisture-resistant nano Zn-In of claim 6₂O₃A three-dimensional structure sensor material, characterized in that the three-dimensional structure is carambola-like, snow cake-like or fusiform.

8. Moisture-resistant nano Zn-In of claim 1 or claim 6₂O₃Application of the three-dimensional structure sensor material in detection of VOC gas.

9. Use according to claim 8, wherein said VOC gas is a high humidity ethanol gas.

Technical Field

The invention relates to the technical field of materials for detecting high-humidity ethanol gas, In particular to a moisture-resistant nano Zn-In₂O₃A three-dimensional structure sensor material, a preparation method and application thereof.

Background

The metal oxide semiconductor gas sensor is widely applied to detecting VOC gas due to the characteristics of high detection sensitivity, quick response and recovery, simple operation, low price and the like. A common representative semiconductor oxide is WO₃，ZnO，In₂O₃，SnO₂Etc. In which₂O₃Has high conductivity and is almost the highest of the representative semiconductor oxide sensing materials. However, low sensitivity, long response and recovery time, poor stability are bottlenecks that hinder the development of metal oxide semiconductor gas sensors, and In is In high humidity environments₂O₃The above problems of the gas sensor are more prominent. How to develop and search In having high performance In high humidity environment₂O₃Gas sensitive material of limited In₂O₃The key of the gas sensor.

In₂O₃Gas sensors have very important and widespread applications in real life, particularly in the detection of VOC gases. Ethanol vapor is always a potential risk factor for our daily life and production safety due to its flammable and explosive nature. Therefore, it is very meaningful to manufacture an ethanol gas sensor with a fast and accurate response.

Disclosure of Invention

The invention aims to provide a moisture-resistant nano Zn-In₂O₃The preparation method of the three-dimensional structure sensor material is simple and easy to implement and low in cost.

Hair brushThe second technical problem to be solved is to provide a moisture-resistant nano Zn-In₂O₃A three-dimensional structure sensor material.

The third technical problem to be solved by the invention is to provide Zn/In with high sensitivity energy₂O₃Application of the nano-structure material in detecting high-humidity ethanol gas.

In order to solve the technical problems, the invention adopts the technical scheme that:

moisture-resistant nano Zn-In₂O₃The preparation method of the three-dimensional structure sensor material takes glycerol and ethanol as solvent phases and utilizes Zn²⁺For In₂O₃The nano structure regulation and control function adopts the high-temperature high-pressure solvothermal reaction to prepare the Zn-In with uniform size In one step₂O₃A three-dimensional nanostructure.

The moisture-resistant nano Zn-In₂O₃The preparation method of the three-dimensional structure sensor material comprises the following steps:

step 1, preparing a mixed solution of absolute ethyl alcohol and glycerol, wherein the volume ratio of the glycerol to the ethyl alcohol is 3: 13;

step 2, adding indium chloride into the mixed solution, and stirring until the indium chloride is dissolved uniformly to obtain a mixed solution I;

step 3, weighing sodium hydroxide, adding the sodium hydroxide into a mixed solution of absolute ethyl alcohol and zinc acetate to form a mixed solution II;

step 4, uniformly mixing the mixed solution I and the mixed solution II, then filling the mixture into a polytetrafluoroethylene substrate, and carrying out solvothermal reaction;

step 5, collecting, washing and drying the materials subjected to the solvothermal reaction, and sintering the powder to obtain yellow powder, namely Zn-In₂O₃A nanostructure; the mol ratio of the indium chloride to the zinc acetate is 0.5-5: 1.

The improvement is that the concentration of the sodium hydroxide solution in the step 3 is 0.1-1 mmol/L.

The improvement is that the filling rate of the polytetrafluoroethylene substrate filled after the mixed solution I and the mixed solution II are mixed in the step 4 is 35% -60%.

The improvement is that the volume ratio of the absolute ethyl alcohol to the glycerol is 2-10: 1.

the improvement is that the solvothermal reaction time in the step 4 is 7-24 hours, and the reaction temperature is 150-200 ℃.

The moisture-resistant nano Zn-In obtained by the method₂O₃A three-dimensional structure sensor material.

As a refinement, the three-dimensional structure is in the shape of a carambola, a snow cake or a shuttle.

The moisture-resistant nano Zn-In₂O₃Application of the three-dimensional structure sensor material in detection of VOC gas.

As a refinement, the VOC gas is a high-humidity ethanol gas.

Compared with a two-dimensional structure or a one-dimensional structure, the three-dimensional structure material can reduce the agglomeration and stacking effect of samples in the coating process, so that the materials can be effectively and fully contacted with gas. At the same time, carambola-like Zn/In₂O₃The special nano structure can provide more defects and oxygen vacancies, and reduce the potential energy of chemical reaction, thereby effectively optimizing the sensitivity to ethanol gas. Therefore, the invention utilizes the special structure and advantages of the three-dimensional nano material to manufacture the sensor for detecting the ethanol gas, and can solve the problems in the prior art. Furthermore, more defects and oxygen vacancies are introduced into the three-dimensional nano structure prepared by the invention, so that the gas-sensitive performance can be further improved, and the problem of low sensitivity of the semiconductor nano material in a high-humidity environment is solved.

According to the characteristics of the metal oxide semiconductor for detecting the VOC gas, the invention takes the glycerol and the ethanol as solvent phases and utilizes Zn⁺²For In₂O₃The nano structure regulation and control function adopts the high-temperature high-pressure solvothermal reaction to prepare the Zn-In with uniform size In one step₂O₃A three-dimensional nanostructure.

In the method, the volume limit of the glycerol and the ethanol in the step 1 is 3:13, and the strict limit of the volume ratio of the glycerol and the ethanol is the key for successfully preparing the three-dimensional-like nano structure. Zn²⁺Not only do they contribute to regulationThe formation and growth of three-dimensional like nanostructures, but also the key to the formation of more defects and oxygen vacancies.

Has the advantages that:

compared with the prior art, the moisture-resistant nano Zn-In₂O₃The three-dimensional structure sensor material, the preparation method and the application thereof have the following advantages:

1. compared with other structures Zn-In the prior art₂O₃Of a material of, In particular Zn-In₂O₃The three-dimensional nano structure can provide more defects and oxygen vacancies, and reduce the potential energy of chemical reaction, thereby effectively optimizing the sensitivity performance, particularly the response value, of the ethanol gas. Further, Zn-In₂O₃The special structure can reduce the agglomeration effect of the sample in the manufacturing process, thereby effectively providing a large gas contact surface area, and ensuring that the prepared material can meet the requirement of keeping the response value of the prepared material to low-concentration ethanol gas in a high-humidity environment to be about 200.

2. The invention has the advantages of cheap raw materials, simple operation process, no environmental pollution and convenient industrial production. The invention improves the characteristic of low response of the sensor in a high-humidity environment. In addition, the method does not need any surfactant, has good repeatability and low cost, and has good potential of large-scale production.

Drawings

FIG. 1 is an XRD pattern of the materials obtained in examples 1-5, with XRD measured over a range of 10-80 °;

FIG. 2 is an SEM photograph of the materials obtained In examples 1-5, wherein (a) Zn/In₂O₃(1/1)，(b) Zn/In₂O₃（1/2），(c) Zn/In₂O₃(2/1), (d) pure In₂O₃(e) pure ZnO;

FIG. 3 is a graph showing the gas-sensitive properties of the materials obtained in examples 1 to 5.

Detailed Description

Embodiments of the invention are further described below with reference to the accompanying drawings: the following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples.

Example 1

Moisture-resistant nano Zn-In₂O₃The preparation method of the three-dimensional structure sensor material comprises the following steps:

1) a mixed solution was prepared from 13 mL of absolute ethanol and 3mL of glycerol.

2) Adding 0.3 g of indium chloride into the mixed solution, and stirring to uniformly dissolve the indium chloride to form a mixed solution I;

3) dispersing 0.2g of zinc acetate in a mixed solution of 13 mL of absolute ethyl alcohol and 5mL of sodium hydroxide (the concentration is 0.3 mmol/L) to form a mixed solution II;

4) uniformly mixing the two obtained mixed solutions, putting the mixture into a 50 mL polytetrafluoroethylene substrate, and carrying out solvothermal reaction at 170 ℃ for 8 hours;

5) collecting, washing and drying the reacted materials, and sintering the powder In a muffle furnace at 500 ℃ for 2h to obtain yellow powder, namely Zn-In₂O₃Nanostructured materials (noted as Zn/In)₂O₃（1/1））；

The prepared Zn-In₂O₃The nano-structure material and terpineol are fully ground to prepare dressing which is uniformly coated on Al₂O₃On an insulating ceramic tube, after film formation, sintering for 2h at 500 ℃ (the final coating thickness is about 0.2-0.4 mm), and passing a nickel-chromium alloy heating wire through Al₂O₃And (3) in an insulating ceramic tube, finally welding the manufactured components on a heater, and carrying out gas sensitivity test after the gas sensor is manufactured.

Example 2

The procedure was as in example 1, except that: the mol ratio of indium chloride to zinc acetate is 2/1, the concentration of sodium hydroxide solution is 0.1mmol/L, the volume ratio of the absolute ethyl alcohol and the glycerol mixed solution is 10, the hydrothermal time is 24h, and the reaction temperature is 100 ℃ (recorded as Zn/In)₂O₃（1/2））。

The prepared samples in this example were characterized for morphology using SEM, as shown in figure 3.

Example 3

The same operation as in example 1 was conducted except that the molar ratio of indium chloride to zinc acetate was 1/2, the concentration of the sodium hydroxide solution was 1mmol/L, the volume ratio of the mixed solution of anhydrous ethanol and glycerol was 2, the hydrothermal time was 2 hours, and the reaction temperature was 200 ℃. (as Zn/In)₂O₃（2/1））。

Example 4

The procedure is as In example 1, except that no zinc acetate (designated as pure In) is added₂O₃）。

Example 5

The procedure is as in example 1, except that no indium chloride (noted as pure ZnO) is added.

The morphological structure of the material and the gas-sensitive performance of the nano material prepared by the invention are tested and characterized by phase test.

XRD analysis

The XRD in FIG. 1 is the XRD pattern of the samples of examples 1-5. Zn/In prepared In example 1₂O₃All diffraction peaks of (1/1) belong to In₂O₃The crystal phase structure of (JCPDS card No. 71-2195). The diffraction peak of pure In prepared In example 4 is partially attributed to c-In₂O₃(JCPDS card No.71-2195), a part of which belongs to rh-In₂O₃(JCPDS card No.73-1809), indicating that the material prepared is of mixed crystal phase structure. Zn/In prepared In example 2 and example 3₂O₃(1/2) and Zn/In₂O₃(2/1) are each C^_In₂O₃(JCPDS card No.71-2195) and rh-In₂O₃ (JCPDS card No. 73-1809).

SEM analysis

FIG. 2 is an SEM image of samples of examples 1-5. From FIG. 2 (a) can be seen the Zn/In prepared In example 1₂O₃(1/1) is a carambola-like nanostructure having six edges. When the In/Zn ratioWhen the ratio of the example is increased to 2:1, FIG. 2 (b), the sample prepared in example 2, shows that the edges of the carambola-like nano-structure disappear and gradually grow into a discoid structure. FIG. 2 (c) corresponds to Zn/In prepared In example 3 when the In/Zn ratio is decreased from 2:1 to 1:2₂O₃(2/1) the sample exhibited a non-uniform size shuttle. Fig. 2 (d) and 2 (e) are SEM images of In and Zn of the samples prepared In example 4 and example 5. It can be seen that pure In exhibits blocky and fusiform structures of non-uniform size, and In the case of Zn, the appearance consists of hexagonal cubes.

Gas sensitive performance analysis

The tests of fig. 3 were all tested between 60-70% in the high humidity range. Wherein FIG. 3 (a) is a graph showing the response of the gas sensors prepared in examples 1 to 5 to 50ppm of ethanol at different temperatures. The response values of the gas sensors of examples 1-5 showed a tendency of rising first and then falling at 180-300 ℃ and the highest response value at 220 ℃, which were 201, 81, 38, 23.6 and 19.3, respectively, indicating that the optimal operating temperature of the gas sensors prepared in examples 1-5 was 220 ℃. FIG. 3 (b) is a graph showing the sensitivity of the gas sensors prepared In examples 1 to 5 to 50ppm of gases such as ethanol and acetone at 220 deg.C, from which Zn/In obtained In example 1 can be seen₂O₃(1/1) the response value of the prepared gas sensor to ethanol is much higher than that of other response values, and In addition, Zn/In obtained In example 1₂O₃(1/1) the gas sensor prepared responded much more to ethanol than other gases. Shows Zn/In₂O₃(1/1) the sensor has excellent selectivity for ethanol gas. FIG. 3 (c) is a continuous response curve of gas sensors made from the materials of examples 1-5 exposed to 5-1000 ppm ethanol at 220 ℃. FIG. 3 (d) is a graph of the recovery of three consecutive cycles of response at 220 deg.C to 50ppm ethanol for gas sensors made from the materials of examples 1-5. The sensitivity characteristics of the gas sensors prepared from the materials of examples 1-4 are substantially the same over three cycles, indicating that the cycling stability of the sensors is good. FIG. 3 (e) shows Zn/In obtained In example 1₂O₃(1/1) response of gas sensor prepared at 220 ℃ to 50ppm ethanol for fifteen consecutive daysCharacteristic diagram, Zn/In₂O₃The sensor of (1/1) has response value substantially maintained at about 200 within fifteen days of humidity range of 60-70%.

In conclusion, the invention prepares three-dimensional Zn/In within the protection scope₂O₃In the nano gas-sensitive material, the excellent gas-sensitive performance is shown under the range of high humidity of 60-70 percent, which can be attributed to the design of the special structure of the three-dimensional nano material and Zn²⁺This is an important advance and inventive step in the prior art.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and any simple modifications or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention are within the scope of the present invention.