阅读说明：本技术 一种掺杂型MoO3纳米带、其制备方法及应用 (Doped MoO3Nanobelt, preparation method and application thereof ) 是由 杨树林 顾豪爽 王钊 徐火希 雷贵 于 2020-06-29 设计创作，主要内容包括：本发明公开了一种掺杂型MoO<Sub>3</Sub>纳米带、其制备方法及应用,该MoO<Sub>3</Sub>纳米带中掺杂有Fe元素,其制备步骤：步骤1)：边搅拌边向Na<Sub>2</Sub>MoO<Sub>4</Sub>溶液中缓慢加入浓硝酸,得到Na<Sub>2</Sub>MoO<Sub>4</Sub>的酸性溶液；步骤2)：配制Fe(NO<Sub>3</Sub>)<Sub>3</Sub>溶液；步骤3)：将所述Na<Sub>2</Sub>MoO<Sub>4</Sub>的酸性溶液和Fe(NO<Sub>3</Sub>)<Sub>3</Sub>溶液加入反应釜中,缓慢搅拌至混合均匀,进行反应,反应结束后,空冷至室温,抽滤或离心,获得初始样品；步骤4)：将得到的初始样品进行干燥,得到掺杂有Fe元素的掺杂型MoO<Sub>3</Sub>纳米带。该掺杂型MoO<Sub>3</Sub>纳米带用于制作氢气传感器元件。本发明掺杂型MoO<Sub>3</Sub>纳米带,具有优异的H<Sub>2</Sub>敏感性,可用于制作氢气传感器元件。(The invention discloses a doped MoO 3 Nanobelt, preparation method and application thereof, and MoO 3 The preparation method of the nano-belt comprises the following steps of doping Fe element in the nano-belt: step 1): stirring while adding Na 2 MoO 4 Adding concentrated nitric acid slowly into the solution to obtain Na 2 MoO 4 An acidic solution of (a); step 2): preparation of Fe (NO) 3 ) 3 A solution; step 3): mixing the Na 2 MoO 4 And Fe (NO) 3 ) 3 Adding the solution into a reaction kettle, slowly stirring until the solution is uniformly mixed, reacting, after the reaction is finished, cooling to room temperature in air, and performing suction filtration or centrifugation to obtain an initial sample; step 4): drying the obtained initial sample to obtain the doped MoO doped with Fe element 3 A nanoribbon. The doped MoO 3 Nano meterThe tape is used to make a hydrogen sensor element. The invention relates to a doped MoO 3 Nanobelt having excellent H 2 Sensitivity, can be used for manufacturing hydrogen sensor elements.)

1. Doped MoO₃Nanobelt characterized by the fact that the MoO₃The nanoribbon is doped with Fe element.

2. The doped MoO of claim 1₃The preparation method of the nanobelt is characterized by comprising the following steps of:

step 1): stirring while adding Na₂MoO₄Adding concentrated nitric acid slowly into the solution to obtain Na₂MoO₄An acidic solution of (a);

step 2): preparation of Fe (NO)₃)₃A solution;

step 3): mixing the Na₂MoO₄And Fe (NO)₃)₃Adding the solution into a reaction kettle, slowly stirring until the solution is uniformly mixed, reacting, after the reaction is finished, cooling to room temperature in air, and performing suction filtration or centrifugation to obtain an initial sample;

step 4): drying the obtained initial sample to obtain the doped MoO doped with Fe element₃A nanoribbon.

3. Doped MoO according to claim 2₃The preparation method of the nanobelt is characterized in that in the step 1), the Na is₂MoO₄The mass percentage concentration of the solution is 6 percent, the mass percentage concentration of the concentrated nitric acid is 65 percent, and Na is added₂MoO₄The volume ratio of the solution to the concentrated nitric acid is 5: 1.

4. Doped MoO according to claim 2 or 3₃The preparation method of the nanobelt is characterized in that in the step 2), Fe (NO) is adopted₃)₃The mass percentage concentration of the solution is 6 percent.

5. Doped MoO according to claim 4₃The preparation method of the nanobelt is characterized in that in the step 3), the Na is₂MoO₄And Fe (NO)₃)₃The volume ratio of the solution is (30-40): (1-10).

6. Doped MoO according to claim 5₃The preparation method of the nanobelt is characterized in that in the step 3), the Na is₂MoO₄And Fe (NO)₃)₃The volume ratio of the solution is 35 (1-5).

7. Doped MoO according to claim 2 or 3₃The preparation method of the nanobelt is characterized in that in the step 3), the reaction temperature is 80-220 ℃ and the reaction time is 1-48 h.

8. Doped MoO according to claim 2 or 3₃The preparation method of the nanobelt is characterized in that in the step 4), the drying temperature is 40-100 ℃, and the drying time is 12-72 hours.

9. The doped MoO of claim 1₃Nanobelt or doped MoO prepared by the preparation method of any one of claims 2 to 8₃Use of nanoribbons, characterized in that the doped MoO is₃The nanobelts are used to fabricate a hydrogen sensor element.

10. Doped MoO according to claim 9₃The application of the nanobelt is characterized by comprising the following steps of:

step a): ultrasonically cleaning a substrate by absolute ethyl alcohol and acetone, then washing by deionized water, and drying for later use;

step b): covering the dried substrate with a differential electrode mask, and depositing Ti with the thickness of 10-50 microns and Pt with the thickness of 50-150 microns on the substrate in an inert gas atmosphere or vacuum by adopting a direct current sputtering or evaporation mode to obtain a hydrogen sensing electrode;

step c): weighing 0.01-0.05g of the doped MoO of claim 1₃Nanobelt or doped MoO prepared by the preparation method of any one of claims 2 to 8₃Placing the nanobelts in a centrifuge tube;

step d): adding 5-30 μ L of anhydrous ethanol into the centrifuge tube, standing for 1-5min, and performing ultrasonic treatment with 60-150Hz ultrasonic wave for 0.5-3min to obtain pasty mixed solution;

step e): and (3) coating the pasty mixed solution on Pt of the hydrogen sensing electrode, drying at the temperature of 30-70 ℃, annealing at the temperature of 200 ℃ for 1-4h under the action of vacuum, and cooling to room temperature to obtain the hydrogen sensing element.

Technical Field

The invention belongs to the technical field of inorganic nano materials, and particularly relates to a doped MoO₃Nanobelts, and a preparation method and application thereof.

Background

With the rapid development of economic society, the consumption of traditional fossil fuels is increasing dramatically. However, the reserves of fossil fuels are limited, and alternative energy sources are actively being sought to better meet the needs of the development of economic society. Among them, hydrogen is considered as a clean energy source in the twenty-first century, has many advantages of wide sources, concentrated heat, no pollution of products and the like, and receives general attention from countries in the world. At present, many countries including China are actively developing relevant research on hydrogen and successfully applying the hydrogen to the fields of aerospace, industrial manufacturing, metal smelting, product anticorrosion, new energy automobiles and the like. However, hydrogen has small molecules, strong diffusion capability, no color, no shape and no smell, and is easy to leak and not easy to be perceived in the processes of production, storage, application and the like. When the hydrogen content in the air is 4-75%, explosion is easily caused by open fire, and great potential safety hazard is caused. Therefore, it is important to detect and monitor the concentration of hydrogen fed by the hydrogen sensor.

Compared with electrochemical and metal hydrogen sensors, semiconductor hydrogen sensors have the advantages of wide selectivity of sensitive materials, high response sensitivity, stable performance, long service life and better integration performance, and become a hotspot of current research. However, the existing semiconductor type hydrogen sensor based on oxide still needs to show better hydrogen sensitivity performance at higher temperature, but the high working temperature increases the potential safety hazard, increases the power consumption, and simultaneously reduces the gas selectivity of the sensor. It is reported that by metal doping of a semiconductor metal oxide, generation of oxygen vacancies can be induced inside the semiconductor by using a valence difference of a doping element, and gas-sensitive properties of the semiconductor can be improved. Farid et al successfully In by sonochemical methods₂O₃Carrying out Pb doping, the initial resistance value of the material in the air is as follows32.48K omega is improved to 101.98K omega, which is improved by 3.14 times, the resistance is improved to 3.13K omega from 2.28K omega in 100ppm ethanol gas, and the finally obtained response is improved to 32.57 from 14.2, which is improved by 2.29 times. M.Kashif et al, using a sol-gel method to dope a Pd-doped ZnO nanorod, found that the doping can effectively reduce the operating temperature of the element, and realized 40ppmH at room temperature₂Detection of (3). Wu Shihua et al of southern Kai university prepared Au-doped WO by peptization method₃Powder, results show that WO is relatively undoped₃As for the material, the response sensitivity, the response time and the recovery time of the material are improved, and meanwhile, the working temperature can be effectively reduced. Meanwhile, V.Guidi et al prepared Ti-doped orthorhombic MoO by RF sputtering₃Film, results show that relatively pure orthorhombic MoO₃Film, for 200ppm CO and 2ppm NO₂The optimal working temperature of the gas sensor is reduced from 400 ℃ to 300 ℃, and the response and recovery time is about 1-2min, which is caused by the doped orthorhombic MoO₃The conductivity of the film is improved by 2 orders of magnitude, so that the orthorhombic phase MoO is improved₃Gas-sensitive properties of (2). Thus, by constructing the doped MoO₃The nano material is expected to optimize the working temperature by improving the composition and the structure, reduce the power consumption of the device, reduce the size of the device, improve the response sensitivity to hydrogen at low temperature and realize high-sensitivity detection to hydrogen at room temperature.

Disclosure of Invention

Aiming at the technical problem, the invention provides a doped MoO₃Nanobelts, and a preparation method and application thereof.

The technical scheme adopted by the invention is as follows:

doped MoO₃Nanobelt characterized by the fact that the MoO₃The nanoribbon is doped with Fe element.

The doped MoO of claim 1₃The preparation method of the nanobelt is characterized by comprising the following steps of:

step 1): stirring while adding Na₂MoO₄Adding concentrated nitric acid slowly into the solution to obtain Na₂MoO₄An acidic solution of (a);

step 2): preparation of Fe (NO)₃)₃A solution;

step 3): mixing the Na₂MoO₄And Fe (NO)₃)₃Adding the solution into a reaction kettle, slowly stirring until the solution is uniformly mixed, reacting, after the reaction is finished, cooling to room temperature in air, and performing suction filtration or centrifugation to obtain an initial sample;

step 4): drying the obtained initial sample to obtain the doped MoO doped with Fe element₃A nanoribbon.

Further, in step 1), the Na₂MoO₄The mass percentage concentration of the solution is 6 percent, the mass percentage concentration of the concentrated nitric acid is 65 percent, and Na is added₂MoO₄The volume ratio of the solution to the concentrated nitric acid is 5: 1.

Further, in step 2), the Fe (NO)₃)₃The mass percentage concentration of the solution is 6 percent.

Still further, in step 3), the Na₂MoO₄And Fe (NO)₃)₃The volume ratio of the solution is (30-40): (1-10).

Still further, in step 3), the Na is₂MoO₄And Fe (NO)₃)₃The volume ratio of the solution is 35 (1-5).

Still further, in step 3), the Na₂MoO₄And Fe (NO)₃)₃The volume ratio of the solution was 35: 3.

Further, in the step 3), the reaction temperature is 80-220 ℃, and the reaction time is 1-48 h.

Further, in the step 4), the drying temperature is 40-100 ℃, and the drying time is 12-72 h.

The doped MoO₃Nanobelt or doped MoO prepared by the preparation method₃Use of nanoribbons, characterized in that the doped MoO is₃The nanobelts are used to fabricate a hydrogen sensor element.

Further, the method comprises the following steps:

step a): ultrasonically cleaning a substrate by absolute ethyl alcohol and acetone, then washing by deionized water, and drying for later use;

step b): covering the dried substrate with a differential electrode mask, and depositing Ti with the thickness of 10-50 microns and Pt with the thickness of 50-150 microns on the substrate in an inert gas atmosphere or vacuum by adopting a direct current sputtering or evaporation mode to obtain a hydrogen sensing electrode;

step c): weighing 0.01-0.05g of the doped MoO₃Nanobelt or doped MoO prepared by the preparation method₃Placing the nanobelts in a centrifuge tube;

step d): adding 5-30 μ L of anhydrous ethanol into the centrifuge tube, standing for 1-5min, and performing ultrasonic treatment with 60-150Hz ultrasonic wave for 0.5-3min to obtain pasty mixed solution;

step e): and (3) coating the pasty mixed solution on Pt of the hydrogen sensing electrode, drying at the temperature of 30-70 ℃, annealing at the temperature of 200 ℃ for 1-4h under the action of vacuum, and cooling to room temperature to obtain the hydrogen sensing element.

Still further, the substrate is a ceramic substrate or a quartz substrate.

Still further, in the step e), the coating method of coating the pasty mixed solution on the Pt of the hydrogen sensing electrode is hanging drop, spin coating or spray coating.

The invention can obtain the following technical effects:

1. doped MoO obtained by doping Fe₃Nanobelt having excellent H₂Sensitivity, can be used for manufacturing MoO based on Fe doping₃Nanoribbon hydrogen sensor elements. Compared with the existing report, Fe-doped MoO₃The hydrogen sensitive element of the nanobelt realizes high sensitivity to hydrogen at room temperature, short response time, simple device assembly process, stable performance, small device volume and easy integration, and can meet the requirements of industrial mass production and practical application.

2. With Na₂MoO₄And Fe (NO)₃)₃Solution preparation, Fe doped MoO₃The steps of the method are simpleIs effective.

Drawings

FIG. 1 shows the doped MoO obtained in examples 1 to 5₃XRD pattern of nanobelts;

FIG. 2 shows the resulting doped MoO of example 1₃SEM pictures of nanobelts;

FIG. 3 shows the resulting doped MoO of example 2₃SEM pictures of nanobelts;

FIG. 4 shows the resulting doped MoO of example 3₃SEM pictures of nanobelts;

FIG. 5 shows the resulting doped MoO of example 4₃SEM pictures of nanobelts;

FIG. 6 shows the resulting doped MoO of example 5₃SEM pictures of nanobelts;

FIGS. 7-a, 7-b, and 7-c show the doped MoO obtained in example 3₃XPS pictures of nanoribbons;

FIG. 8 shows the doped MoO obtained in example 1-example 5₃The dynamic response curve of the nanobelt to 500ppm hydrogen at room temperature;

FIGS. 9-a and 9-b show the doped MoO obtained in example 3₃The dynamic response curve of the nanobelt to 10-1500ppm hydrogen at room temperature;

FIG. 10 shows the resulting doped MoO of example 3₃A reproducibility data plot of nanoribbons to 1000ppm hydrogen at room temperature;

FIG. 11 shows the resulting doped MoO of example 3₃Data plot of selectivity of nanoribbons to 1000ppm of each type of gas at room temperature.

Detailed Description

In this part of the examples, 5 groups of Fe-doped MoO were prepared₃Nanoribbons, and then according to the 5 groups of doped MoO₃The nanobelts are respectively made of MoO based on Fe doping₃Nanoribbon hydrogen sensor elements. Firstly, preparing Fe-doped MoO₃Nano belt

Step 1): to 172.5ml of deionized water, 14.517g of Na were initially added with constant stirring₂MoO₄·2H₂O to Na₂MoO₄·2H₂After complete dissolution of O, 37.5ml of 65% concentrated nitric acid was slowly poured in to obtain Na₂MoO₄An acidic solution of (a);

step 2): to 6ml of deionized water, 0.4848g of Fe (NO) were added₃)₃·9H₂O, slowly stirring until Fe (NO)₃)₃·9H₂O is completely dissolved to obtain Fe (NO)₃)₃A solution;

examples 1-5 below Na obtained according to the above configuration₂MoO₄And Fe (NO)₃)₃Solution preparation of Fe-doped MoO₃A nanoribbon.