阅读说明：本技术 高纯五氧化二钒纳米纤维无纺布的制备方法 (Preparation method of high-purity vanadium pentoxide nanofiber non-woven fabric ) 是由 倪伟 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种高纯五氧化二钒纳米纤维无纺布的制备方法,属于纳米材料技术领域。本发明的制备方法主要在于对合成过程中的晶体成核和生长调控,即将偏钒酸铵加入盐酸溶液在常温条件下搅拌溶解,之后在一定温度下进行水热反应,在特定的反应釜内壁揭下收集得到五氧化二钒纳米纤维无纺布。本发明制备的五氧化二钒纳米纤维无纺布纯度≥99.9％,厚度为0.01-10mm,其中五氧化二钒纳米纤维直径为10-5000nm；本发明的制备方法采用的原料简单且廉价,降低了生产成本；采用的一步法工艺,操作方便,便于工厂大规模生产,可有效解决现有制备五氧化二钒纳米纤维无纺布的方法较为复杂的问题。(The invention discloses a preparation method of high-purity vanadium pentoxide nanofiber non-woven fabric, and belongs to the technical field of nano materials. The preparation method mainly comprises the steps of regulating and controlling crystal nucleation and growth in the synthesis process, namely adding ammonium metavanadate into a hydrochloric acid solution, stirring and dissolving at normal temperature, then carrying out hydrothermal reaction at a certain temperature, and removing and collecting the ammonium metavanadate from the inner wall of a specific reaction kettle to obtain the vanadium pentoxide nanofiber non-woven fabric. The purity of the vanadium pentoxide nanofiber non-woven fabric prepared by the method is more than or equal to 99.9%, the thickness of the vanadium pentoxide nanofiber non-woven fabric is 0.01-10mm, and the diameter of the vanadium pentoxide nanofiber is 10-5000 nm; the preparation method of the invention adopts simple and cheap raw materials, and reduces the production cost; the one-step process is convenient to operate and convenient for large-scale production in factories, and can effectively solve the problem that the existing method for preparing the vanadium pentoxide nanofiber non-woven fabric is complex.)

1. the preparation method of the high-purity vanadium pentoxide nanofiber non-woven fabric is characterized by comprising the following steps of: mixing ammonium metavanadate and hydrochloric acid solution with the concentration of 2-200g/L according to the mass ratio of 0.5-10: 100, putting the mixture into a reaction container after fully dissolving, heating the mixture in a closed system to 100 ℃ and 250 ℃ for reaction for 6-72h, and then removing the mixture from the inner wall of the reaction container to obtain the vanadium pentoxide nano-fiber non-woven fabric.

2. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 1, characterized in that: the concentration of the hydrochloric acid solution is 10-100g/L, and the ammonium metavanadate and the hydrochloric acid solution are mixed according to the mass ratio of 1-3: 100.

3. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 1, characterized in that: putting the mixture into a reaction vessel and heating the mixture to the temperature of 180 ℃ and 220 ℃ in a closed system for reaction for 12 to 36 hours.

4. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 1, characterized in that: the reaction vessel is a hydrothermal reaction kettle with a high-temperature resistant lining or a reaction vessel with other inert material linings resistant to higher temperature.

5. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 4, characterized in that: the length-diameter ratio of the inner liner of the reaction vessel is more than or equal to 1.5.

6. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 1, characterized in that: after the vanadium pentoxide nanofiber non-woven fabric is obtained, the structure of the non-woven fabric is optimized through the steps of washing, drying and high-temperature annealing.

7. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 6, characterized in that: washing with deionized water and ethanol, drying at 50-150 deg.C for 2-48h, and annealing at 300-600 deg.C for 1-12 h.

8. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 7, characterized in that: drying at 80-110 deg.C for 10-24h, and annealing at 400-550 deg.C for 2-4 h.

9. The method for preparing the high-purity vanadium pentoxide nanofiber nonwoven fabric according to claim 1, characterized in that: the purity of the vanadium pentoxide nanofiber non-woven fabric is more than or equal to 99.9%, the thickness of the vanadium pentoxide nanofiber non-woven fabric is 0.01-10mm, and the diameter of the vanadium pentoxide nanofiber is 10-5000 nm.

Technical Field

The invention belongs to the technical field of nano materials, and particularly relates to a preparation method of a high-purity vanadium pentoxide nanofiber non-woven fabric.

Background

Vanadium pentoxide (V)₂O₅) Is the most important vanadium functional material and intermediate, and has important application value in the fields of special steel, glass ceramic industrial colorant, sulfuric acid petrochemical industrial catalyst and electrochemical energy storage material. The one-dimensional vanadium pentoxide nanowire has large specific surface area, many active points and good performanceThe catalyst has unique effect on the preparation of flexible electronic devices and the catalysis or mechanical reinforcement. At present, the method for synthesizing the one-dimensional vanadium pentoxide nanometer material mainly comprises a hydrothermal method (comprising hydrothermal recrystallization), a template method, a sol-gel method, a precipitation method and other physical methods.

The vanadium pentoxide nanowire woven non-woven fabric has wider and special application such as catalysis, energy storage and multi-stage structure materials due to the special macro morphology and microstructure, but the direct preparation of the large-area vanadium pentoxide nanofiber non-woven fabric is not reported. Theoretically, the vanadium pentoxide nanofiber non-woven fabric can be prepared by using vanadium pentoxide nanowires obtained by suction filtration or electrostatic spinning vanadium precursor compounds and calcining to obtain the large-area vanadium pentoxide fiber non-woven fabric, but the methods are relatively complex in process and relatively high in cost in practical application. Therefore, it is necessary to develop a preparation method of the vanadium pentoxide nanofiber non-woven fabric with simple process and low cost at the present stage.

Disclosure of Invention

The invention aims to solve the technical problem that the existing method for preparing the vanadium pentoxide nanofiber non-woven fabric is complex.

The technical scheme adopted by the invention for solving the technical problems is as follows: the preparation method of the high-purity vanadium pentoxide nanofiber non-woven fabric comprises the following steps: mixing ammonium metavanadate and hydrochloric acid solution with the concentration of 2-200g/L according to the mass ratio of 0.5-10: 100, putting the mixture into a reaction container after fully dissolving, heating the mixture in a closed system to 100 ℃ and 250 ℃ for reaction for 6-72h, and then removing the mixture from the inner wall of the reaction container to obtain the vanadium pentoxide nano-fiber non-woven fabric.

Further, the concentration of the hydrochloric acid solution is 10-100g/L, and the ammonium metavanadate and the hydrochloric acid solution are mixed according to the mass ratio of 1-3: 100.

Furthermore, the ammonium metavanadate can adopt industrial ammonium metavanadate waste, and the ammonium metavanadate is kept clear after being dissolved and cannot be interfered by suspended particles and the like, and is settled or filtered if necessary; the hydrochloric acid solution can be industrial hydrochloric acid.

Further, the mixture is put into a reaction vessel and heated to 220 ℃ in a closed system for reaction for 12-36 h.

Furthermore, the reaction vessel is a hydrothermal reaction kettle with a high-temperature resistant lining or a reaction vessel with other inert material linings resistant to higher temperature.

Furthermore, the reaction vessel is a general polytetrafluoroethylene lining hydrothermal reaction kettle in the market.

Furthermore, the length-diameter ratio of the inner lining of the reaction vessel is more than or equal to 1.5.

After the hydrothermal reaction is finished, non-woven fabrics are obtained on the inner wall of the reaction kettle, and the non-woven fabrics are cut open by scissors in the process of being torn open, so that the non-woven fabrics are completely stripped.

After the vanadium pentoxide nanofiber non-woven fabric is obtained, the structure of the non-woven fabric is optimized through the steps of washing, drying and high-temperature annealing, and the flatness, thickness and strength of the fiber non-woven fabric are guaranteed.

Further, washing with deionized water and ethanol, drying at 50-150 deg.C for 2-48h, and annealing at 300-600 deg.C for 1-12 h.

Furthermore, the drying is carried out for 10-24h at the temperature of 80-110 ℃, and the annealing is carried out for 2-4h at the temperature of 400-550 ℃.

The purity of the vanadium pentoxide nanofiber non-woven fabric is more than or equal to 99.9%, the thickness of the vanadium pentoxide nanofiber non-woven fabric is 0.01-10mm, and the diameter of the vanadium pentoxide nanofiber is 10-5000 nm.

The invention has the beneficial effects that: according to the invention, ammonium metavanadate and a hydrochloric acid solution are stirred and dissolved at normal temperature, and then hydrothermal reaction is carried out in a closed system at the temperature of 100-250 ℃, so that the processes of nucleation, stable growth and fiber staggered arrangement of vanadium pentoxide nanofibers on the inner wall surface of a reaction kettle are controlled.

The reaction process of the invention needs to be kept stable, can not be vibrated, and can keep the nucleation/adsorption of the solution on the inner surface of the reaction kettle, the concentration of the solution adopted by the invention is matched with the reaction time and the temperature, Van der Waals force or physical entanglement exists among the solution and the reaction time and the temperature, when the temperature of the kettle wall is high, nucleation and growth can be preferentially carried out under the action of temperature gradient, and the solution is gradually accumulated to form a fiber staggered structure; the reaction temperature is high, the reaction time is long, the reaction is facilitated, and the chemical reaction limit is improved; the concentration of the mixed solution is high, the number of fiber stacking layers is large, and the thickness or strength of the fiber cloth is favorably improved; the length-diameter ratio of the lining of the reaction vessel is preferably more than or equal to 1.5, so that the surface deposition ratio can be increased, and the bulk phase reaction or bottom excessive deposition can be reduced or avoided.

The purity of the vanadium pentoxide nanofiber non-woven fabric prepared by the method is more than or equal to 99.9%, the thickness of the vanadium pentoxide nanofiber non-woven fabric is 0.01-10mm, and the diameter of the vanadium pentoxide nanofiber is 10-5000 nm. The method has the advantages of cheap raw materials, one-step production process, convenient and simple process operation and convenient large-scale preparation, and the prepared vanadium pentoxide nanofiber non-woven fabric can be used in the fields of catalysts, electrochemical energy storage, special alloys and the like.

Drawings

FIG. 1 is a macroscopic topography of the original vanadium pentoxide nanofiber nonwoven fabric obtained in the example.

FIG. 2 is a microscopic topography (x 200) of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example.

FIG. 3 is a microscopic morphology (x 1000) of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example.

FIG. 4 is a microscopic morphology (x 3000) of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example.

FIG. 5 is a microscopic morphology (x 10000) of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example.

FIG. 6 is an XRD pattern of the original vanadium pentoxide nanofiber non-woven fabric obtained in the example and a high-temperature calcination XRD pattern thereof.

FIG. 7 shows selected points of an EDS (electronic Desorption System) chart of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example.

FIG. 8 is an EDS chart of elemental analysis of the vanadium pentoxide nonwoven fabric obtained in example.

Detailed Description

The technical solution of the present invention can be specifically implemented as follows.

The preparation method of the high-purity vanadium pentoxide nanofiber non-woven fabric comprises the following steps: mixing ammonium metavanadate and hydrochloric acid solution with the concentration of 2-200g/L according to the mass ratio of 0.5-10: 100, putting the mixture into a reaction vessel, heating the mixture in a closed system to the temperature of 100 ℃ and 250 ℃ for reaction for 6-72h, and then removing the mixture from the inner wall of the reaction vessel to obtain the vanadium pentoxide nanofiber non-woven fabric.

The growth time, the temperature and the concentration of the mixed solution are properly matched, which is beneficial to the reaction and improves the chemical reaction limit, therefore, the concentration of the hydrochloric acid solution is preferably 10-100g/L, and the ammonium metavanadate and the hydrochloric acid solution are mixed according to the mass ratio of 1-3: 100; putting the mixture into a reaction vessel and heating the mixture to the temperature of 180 ℃ and 220 ℃ in a closed system for reaction for 12 to 36 hours.

In order to reduce the production cost and simultaneously reduce the entry of impurities, the ammonium metavanadate can adopt industrial ammonium metavanadate waste, and the ammonium metavanadate is dissolved, is kept clear and cannot be interfered by suspended particles and the like, and is settled or filtered if necessary; the hydrochloric acid solution can be industrial hydrochloric acid.

In order to achieve better experimental effect, it is therefore preferable that the reaction vessel is a hydrothermal reaction kettle with a high temperature resistant lining or a reaction vessel with other inert material lining resistant to higher temperature; more preferably, the reaction vessel is a commercial polytetrafluoroethylene-lined hydrothermal reaction kettle.

In order to reduce or avoid bulk phase reactions or excessive bottom deposition, it is therefore preferred that the reactor vessel lining aspect ratio is ≧ 1.5.

After the hydrothermal reaction is finished, non-woven fabrics are obtained on the inner wall of the reaction kettle, and the non-woven fabrics are cut open by scissors in the process of being torn open, so that the non-woven fabrics are completely stripped.

In order to obtain the non-woven fabric with better flatness, thickness and strength, preferably, after the vanadium pentoxide nano-fiber non-woven fabric is obtained, the structure of the non-woven fabric is optimized through the steps of washing, drying and high-temperature annealing, so that the flatness, thickness and strength of the fiber non-woven fabric are ensured; preferably, deionized water and ethanol are used for washing, drying is carried out for 2-48h at the temperature of 50-150 ℃, and annealing is carried out for 1-12h at the temperature of 300-600 ℃; more preferably, the drying is carried out at a temperature of 80-110 ℃ for 10-24h, and the annealing is carried out at a temperature of 400-550 ℃ for 2-4 h.

The purity of the vanadium pentoxide nanofiber non-woven fabric is more than or equal to 99.9%, the thickness of the vanadium pentoxide nanofiber non-woven fabric is 0.01-10mm, and the diameter of the vanadium pentoxide nanofiber is 10-5000 nm.

The technical solution and effects of the present invention will be further described below by way of practical examples.

Examples

The invention provides a group of embodiments for preparing high-purity vanadium pentoxide nanofiber non-woven fabrics by adopting the method, the high-purity vanadium pentoxide nanofiber non-woven fabrics are prepared by a hydrothermal synthesis one-step method, and the steps comprise:

a. mixing an ammonium metavanadate solution and a hydrochloric acid solution with the concentration of 30g/L according to the mass ratio of 3: 100;

b. pouring the mixed solution obtained in the step a into a tetrafluoroethylene lining hydrothermal reaction kettle, heating the mixed solution to 150 ℃ in a closed system, and reacting for 24 hours to obtain the original vanadium pentoxide nanofiber non-woven fabric;

c. washing the original vanadium pentoxide nanofiber non-woven fabric obtained after the reaction with deionized water and ethanol for multiple times, and then placing the non-woven fabric in an oven to dry at 60 ℃;

d. and (3) placing the dried non-woven fabric in a muffle furnace for heat treatment at 500 ℃ for 4h to obtain the vanadium pentoxide nano-fiber non-woven fabric with higher crystallinity.

The macroscopic topography of the original vanadium pentoxide nanofiber non-woven fabric obtained in the step b of the embodiment is shown in fig. 1, and the fiber fabric is yellow, flexible and foldable, the size of the fiber fabric can be adjusted according to the size of the inner wall of the reaction kettle, and the fiber fabric can be cut into various shapes.

The vanadium pentoxide nanofiber nonwoven fabric obtained in the step d of the example was tested, and the microscopic morphology of the nonwoven fabric under different microscopic multiples is shown in fig. 2-5: FIG. 2 is a microscopic topography (x 200) of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example, which shows that the fiber fabric has shrinkage wrinkles after high-temperature annealing, and shows the form of the wrinkled nonwoven fabric; FIG. 3 is a microscopic topography (x 1000) of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example, from which it can be seen that the fiber fabric is composed of non-oriented fine fibers; FIG. 4 is a microscopic morphology (x 3000) of the non-woven fabric of vanadium pentoxide nanofibers obtained in the examples, from which it can be seen that the fiber fabric is composed of non-oriented submicron fibers, and is dense and uniform; fig. 5 is a microscopic morphology (x 10000) of the vanadium pentoxide nanofiber nonwoven fabric obtained in example 1, and it can be seen from the figure that the fiber fabric is composed of nanofibers and has a high aspect ratio.

The XRD pattern and the high-temperature calcination XRD pattern of the original vanadium pentoxide nanofiber non-woven fabric obtained in the embodiment are shown in figure 6, and it can be known from the figure that the non-woven fabric is of a vanadium pentoxide crystal structure, crystal forms before and after high-temperature annealing are unchanged, but the crystallinity after annealing is improved to some extent.

Elemental analysis is carried out on the vanadium pentoxide nanofiber non-woven fabric obtained in the example, the EDS diagram of the non-woven fabric is shown in figure 7, the EDS diagram of the elemental analysis is shown in figure 8, as can be seen from figure 7, the non-woven fabric nanofiber is obvious in characteristic, and different regions are selected to represent the distribution of material elements; as can be seen from fig. 8, the selected region components are vanadium (V) and oxygen (O); the data of EDS elemental analysis of the vanadium pentoxide nanofiber nonwoven fabric obtained in the example are shown in Table 1, and it can be seen from Table 1 that the molar ratio of V to O is basically about 2: 5, that is, the obtained product is the vanadium pentoxide nanofiber nonwoven fabric, and the purity is not less than 99.9%.

Table 1 elemental analysis data

Element(s)

Line type

Apparent concentration

k ratio

Wt％

Wt％Sigma

Standard sample label

O

K line system

17.54

0.05902

44.30

0.78

SiO2

V

K line system

74.62

0.74623

55.70

0.78

V

Total amount:

100.00