阅读说明：本技术 放射型电场调控得到MnOx空心纳米管状多孔催化材料的制备办法 (Preparation method of MnOx hollow nano-tube-shaped porous catalytic material by regulating and controlling radiation type electric field ) 是由 韩昌报 郑嘉煜 赵文康 宋雪梅 严辉 汪浩 张永哲 李坤威 于 2019-09-29 设计创作，主要内容包括：放射型电场调控得到MnOx空心纳米管状多孔催化材料的制备办法,属于催化剂技术领域。通过外加直流放射型电场加速带某负电荷的MnO<Sup>4-</Sup>在溶液中定向迁移至负载材料附近,并发生氧化还原反应原位生长MnOx空心纳米管,从而达到反应过程时间短、负载多、生成物形貌改变的目的。并且在改变电场结构之后,改变了MnOx的形貌,得到一种可在室温下快速降解低浓度HCHO的MnOx空心纳米管状多孔催化材料。(A preparation method of MnOx hollow nano-tube-shaped porous catalytic material by regulating and controlling a radiation type electric field belongs to the technical field of catalysts. MnO with certain negative charge is accelerated by external direct current emission type electric field 4‑ The MnOx hollow nano-tube directionally migrates to the vicinity of a load material in solution and undergoes an oxidation-reduction reaction to grow in situ, thereby achieving the purposes of short reaction process time, more load and change of the appearance of the product. And after the structure of an electric field is changed, the shape of MnOx is changed, and the MnOx hollow nano-tube-shaped material capable of rapidly degrading low-concentration HCHO at room temperature is obtainedA porous catalytic material.)

1. A preparation method of MnOx hollow nano-tube-shaped porous catalytic material obtained by regulating and controlling a radiation type electric field is characterized by comprising the following specific operations: first, KMnO is configured₄The solution is characterized in that the cleaned Pt electrode plate is bent into a cylindrical structure and is connected with the negative electrode of a power supply through a lead, the copper wire is connected with the positive electrode of the power supply through the lead after the copper wire is tightly wound at the top end of the carbon fiber cloth, and finally the carbon fiber cloth wound by the copper wire is bent into a cylinder or a cylinder with a smaller diameter, so that the Pt electrode cylinder is coaxially nested with the carbon fiber cylinder or the cylinder, and the carbon fiber cylinder or the cylinder is coaxially nested with the PtThe electrode is positioned in the center, and the distance between the axes of the two electrodes is ensured to be 60 mm; after the above operations are completed, the two are fixed in KMnO₄In the reaction flask of the solution, the copper wire did not contact KMnO₄Sealing the solution, switching on an adjustable direct current power supply to control the voltage to be 5-25V under the condition of constant current, then placing the whole device in an oil bath pan for reaction at 60 ℃ for 80min, finally cleaning the taken-out carbon cloth with deionized water, and drying at 105 ℃ for 12 hours to obtain MnO_x-CCs composite material.

2. The method for preparing MnOx hollow nanotube-shaped porous catalytic material under the control of a radiation-type electric field according to claim 1, wherein KMnO is KMnO₄The concentration of the solution was 0.1M.

3. The MnOx hollow nanotube-shaped porous catalytic material prepared by the method of claim 1 or 2.

4. Use of the MnOx hollow nanotube-shaped porous catalytic material prepared according to the method of claim 1 or 2 for air purification, for purification of trace formaldehyde in air.

Technical Field

The invention relates to a preparation process of a MnOx hollow nano-tube-shaped porous catalytic material, belonging to the technical field of manganese oxide catalysts.

Background

With the development of society and the progress of science and technology, various home decorations, private vehicles convenient for going out and various living chemical products slowly advance the life of common people, so that the living standard of people is continuously improved. However, most of the industrial products bringing convenience to our lives release toxic and harmful gas pollutants which threaten human health in the using process, and HCHO is one of the main organic gas pollutants. Numerous researchers have actively sought a feasible solution for HCHO removal in real life, and technologies that have been developed to some extent can be broadly classified into adsorption and catalytic methods. The adsorption method generally fixes pollutants in the air through chemical or physical means to play a role in purifying the air, but does not really decompose and oxidize HCHO, but the catalytic oxidation method can lead organic pollutants to generate oxidation-reduction reaction to finally generate H₂O and CO₂. Catalytic oxidation methods are classified into photocatalytic oxidative decomposition, noble metal catalysis, and transition metal and oxide catalytic decomposition, wherein the photocatalytic oxidation requires light to oxidize HCHO, and thus has a certain limitation, while the noble metal catalysis can achieve a good catalytic effect at a low temperature, but the noble metal catalysis is still an insurmountable obstacle at present, and researchers aim at the transition metal oxide catalyst. In the transition metal oxide catalyst, due to MnO₂High catalytic activity and other characteristics of stability, safety and the like, so that the catalyst has relatively best catalytic performance.

CCs are used as electrodes to grow MnOx in situ to obtain the catalytic material loaded by the nano tube. The in situ growth of MnO on supports is mentioned in the literature_xPreparation of nanoparticles, e.g. by dipping carbon fibre cloths (CCs) in prepared KMnO₄In solution, at a certain temperature, MnO₄ ^-The manganese in the composite material is transferred with electrons between carbon atoms to produce redox reaction, and finally grows in situ (in-situ growth method: a novel method for preparing the composite material, wherein a specific material is taken as a substrate, and another functional body is grafted, polymerized, singly loaded and deposited on the substrate by an electrochemical or physical method to obtain the composite material which grows in situ on the substrate, and the composite material has the advantages of the manganese and the carbon)_xAnd (3) nanoparticles. Such a process may result in MnO being generated_xThe nano particles can be firmly attached to the carrier without any adhesive, so that the aggregation degree of the powder is reduced, and the specific surface area of the catalyst is increased, thereby greatly improving the catalytic effect. However, this method has a great limitation due to MnO formed by the redox reaction_xThe fine particles are difficult to uniformly adhere to the surface of the carrier due to the gravity action, and the preparation time is long and the adhesion efficiency is low.

The MnOx hollow nano-tube-shaped porous catalytic material can effectively catalyze and oxidize HCHO with low concentration at room temperature. MnOx is regarded as an ideal catalytic material for removing formaldehyde in air because of its advantages of low cost, easy preparation, high catalytic activity and the like. MnOx nanosheets, MnOx nanorods, MnOx nanowires and the like are reported in the field of removing HCHO by oxidation, but few studies on catalytic oxidation of low-concentration HCHO at room temperature are currently carried out. The shape of the MnOx hollow nanotube greatly enhances the specific surface area of the catalyst, is beneficial to the exposure of more active sites, thus improving the catalytic activity of the catalyst and having good catalytic effect on the ultralow-concentration HCHO under the condition of room temperature.

Disclosure of Invention

The invention aims to provide a preparation process of a MnOx hollow nano-tube-shaped porous catalytic material, which adopts an external direct current power supply and adopts KMnO₄An electric field is generated in the solution to induce negatively charged MnO^4-Accelerated migration to a load under the action of an electric field forceMnO is grown in situ on or near the surface of the material by oxidation-reduction reaction_xThe particles can shorten the preparation time, improve the adhesion efficiency and increase the adhesion uniformity, and finally the catalytic material which can be used for efficiently degrading low-concentration HCHO at room temperature is obtained.

In order to achieve the above object, the present invention adopts the following technical means.

A preparation method of MnOx hollow nano-tube-shaped porous catalytic material by regulating and controlling a radiation type electric field comprises the following steps of: KMnO₄Powder, a direct current power supply, a cathode material Pt electrode, an anode material (load material) CCs, a copper wire and an oil bath pan. The specific operation is as follows: first, KMnO is configured₄The cleaned Pt electrode plate is bent into a cylindrical structure and is connected with a power supply cathode through a lead (preferably 0.1M), the top end of the carbon fiber cloth is tightly wound with a copper wire, then the copper wire is connected with a power supply anode through the lead, and finally the carbon fiber cloth wound with the copper wire is bent into a cylinder or a column with a smaller diameter, so that the Pt electrode cylinder and the carbon fiber cylinder or column are coaxially nested (as shown in figure 4), the carbon fiber is positioned in the center, and the distance between the axes of the two electrodes is ensured to be 60 mm; after the above operations are completed, the two are fixed in KMnO₄In the reaction flask of the solution, the copper wire did not contact KMnO₄Sealing the solution, switching on an adjustable direct current power supply to ensure that the voltage is controlled between 5 and 25V, then placing the whole device in an oil bath pan for reaction at 60 ℃ for 80min, finally cleaning the taken carbon cloth with deionized water, and drying at 105 ℃ for 12 hours to obtain MnO_x-CCs composite material.

The MnOx hollow nano-tube-shaped porous catalytic material obtained by the invention is applied to purification in air, purification of trace formaldehyde in air and formaldehyde purifying agent.

The invention connects the positive and negative poles of the external power supply with two conductors, the anode electrode connected with the positive pole and the cathode electrode connected with the negative pole, the electrodes are immersed in the electrolyte solution, a built-in electric field can be generated in the solution, ions with positive and negative charges in the solution can rapidly move to the vicinity of the electrodes under the action of the electric field force,reacts with the material of the electrode end or the electrode material, thereby achieving the purposes of accelerating the reaction speed, adjusting the appearance of the product and increasing the generation amount. To achieve MnO_xRapid growth on carbon fiber fabrics to MnO^4-The ions rapidly move to the carbon fiber material as the anode electrode under the action of the electric field force and generate electrons with C atoms on the carbon fiber to form MnO_xThe particles are grown directly in situ onto the fabric. Using KMnO₄The solution is used as electrolyte solution, and MnO is provided by the solution^4-Ions since the purpose is to charge the MnO negatively^4-The ions move to the side of the carbon fiber material as an electrode, and KMnO is considered₄The strong oxidizing property of the solution, and the carbon fiber material and the Pt sheet are respectively selected as the anode material and the cathode material. MnO in electrolyte solution after power-on^4-The ions rapidly move to the vicinity of the anode electrode under the action of the electric field force and generate electron gain and loss with C atoms, and the load MnO is obtained by in-situ growth_xThe carbon fiber material of (1).

In the preparation of MnO_xIn the specific operation of loading the carbon fiber cloth material, the carbon fiber cloth has better conductivity and a meshed structure with holes as a central anode, so that MnO accelerated by a built-in electric field can be added in a shorter time^4-Oxidation-reduction reaction is carried out to MnO_xThe nano particles grow on CCs in situ and form a porous structure at the same time to obtain MnO_x-CCs composite material, namely finally obtaining the hollow nano-tube-shaped porous catalytic material.

The key points of the invention are as follows:

the key point of the invention is that CCs mesh cloth with good conductivity is directly used as an electrode, and the MnOx hollow nano-tubular porous catalytic material which can catalyze and degrade low-concentration HCHO at room temperature is prepared by an external high-voltage electric field.

Drawings

Fig. 1 is a schematic view.

Fig. 2 is a schematic diagram of a radiation type electrode.

FIG. 3 shows MnO_x-raman spectrum of CCs composite nanomaterial.

FIG. 4 shows MnO₂-CCs composite material catalytic degradation formaldehyde efficiency diagram.

FIG. 5 shows MnO_xComparative figures for nanomaterials.

Fig. 6 schematic diagram of the MnOx hollow nanotube growth process.

Detailed Description

The present invention will be further illustrated with reference to the following examples, but the present invention is not limited to the following examples.