CN109133177A

CN109133177A - Preparation method of manganese dioxide

Info

Publication number: CN109133177A
Application number: CN201811084691.2A
Authority: CN
Inventors: 高延利; 董玉静; 管文水
Original assignee: Xinyang University
Current assignee: Xinyang University
Priority date: 2018-09-18
Filing date: 2018-09-18
Publication date: 2019-01-04

Abstract

The invention discloses a preparation method of manganese dioxide, which comprises the steps of preparation and characterization, wherein MnSO is utilized in the preparation process ₄ ·H ₂ O and KMnO ₄ Through hydrothermal reaction, manganese dioxide with different morphologies is obtained under different reaction times, the characterization is realized by observing the morphologies of different samples obtained under different experimental parameters through SEM and analyzing the components of the different samples through XRD. The preparation method of the manganese dioxide firstly adjusts the types and the proportion of medicines and secondly adjusts the reaction time of hydrothermal reaction, thereby facilitating the experimental process and improving the experimental effect. By adjusting the experimental data, manganese dioxide with a single linear morphology and manganese dioxide with a single flower-ball morphology are obtained. The invention adopts a hydrothermal reaction method, the operation process is simple and easy to control, the raw materials are easy to obtain, the cost is lower, and the prepared manganese dioxide has ultrahigh purity and morphology unicity.

Description

Preparation method of manganese dioxide

Technical Field

The invention relates to a preparation method of manganese dioxide.

Background

Mn is widely distributed in nature in the form of compounds, and the average content of Mn in the earth's crust is about 1%, which is the eighth of the known element content. The manganese ore having industrial value is an oxide manganese ore, a carbonate ore, etc., and further, a silicate ore, a sulfide ore, etc. They are widely used in the steel industry, the battery industry, and in addition to chemical industry, medicine, chemical reagents, fuel, ceramics, glass, purification and defense industries as oxidants, discoloring agents, catalysts, colorants, clarifiers, and the like. It is estimated that the amount of various types of manganese dioxide consumed in the battery industry alone is over 40 tons every year, and the demand for manganese oxidation is increasing as the battery industry develops. Since the resource of manganese dioxide is gradually exhausted due to the exploitation for many years and the taste of natural manganese dioxide is gradually reduced, the search for a high-quality manganese dioxide raw material suitable for discharging is always an important subject of the battery industry. Scientist van. Atscale in the united states in 1918 first tried electrolytic manganese dioxide and found that the use of electrolytic manganese dioxide instead of natural manganese dioxide in dry cells contributed to improved cell discharge performance. Until the 40 s, the electrolytic manganese dioxide is industrialized in dry batteries, and the performance of the zinc-manganese batteries is greatly improved. However, electrolytic manganese dioxide has high cost, high power consumption, long production cycle and large investment, so that people have great interest in preparation of chemical manganese dioxide and research on properties of the chemical manganese dioxide in recent years, and the aim is to develop a process route with good product performance, low cost, short production cycle and small environmental pollution.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the preparation method of the manganese dioxide has the advantages of overcoming the defects of the prior art, having excellent purity and higher electrochemical performance, simple steps and low requirements on experimental conditions.

In order to solve the technical problems, the technical scheme of the invention is as follows: manganese dioxide comprises manganese dioxide with a linear microstructure, manganese dioxide with a flower-ball microstructure and manganese dioxide with a mixed morphology.

Further, the manganese dioxide is characterized in that: the microstructure is single, so that the capacitance performance of manganese dioxide with different morphologies can be distinguished conveniently through electrochemical tests.

The invention also provides a preparation method of manganese dioxide, which comprises the following steps:

step S1: the potassium permanganate KMnO is matched in the beaker (A) ₄ And (3) solution. MnSO manganese sulfate monohydrate is added into the beaker (B) ₄ ·H ₂ And (4) O solution. And mixing the two solutions to obtain a solution precursor for the hydrothermal reaction.

Step S2: transferring the mixed solution into a lining of a reaction kettle. The reaction kettle is put into an oven, heat treated for 1 to 3 hours at constant temperature of 120 to 140 ℃, and naturally cooled in the oven. And transferring the reactants in the reaction kettle to a centrifuge tube, and setting the rotation speed of a centrifuge to 7000 centrifugation times. For the first time, directly transferring the solution in the reaction kettle into a centrifugal tube for centrifugation; secondly, after precipitation, pure water is replaced for centrifugation; thirdly, ethanol is replaced and centrifuged after precipitation.

Further, in the step S1, potassium permanganate KMnO ₄ And manganese sulfate monohydrate MnSO ₄ ·H ₂ The mass of O was 1 (g) g and 0.4 (g), respectively, and pure water in beakers A and B was 40ml.

Further, in the step S1, mnSO ₄ ·H ₂ Heating the O solution in water bath to 50 ℃, then stirring by constant temperature and magnetic force, and simultaneously slowly adding potassium permanganate KMnO by a dropper ₄ The solution was then stirred at constant temperature for 15min.

Further, in the step S2, the temperature in the oven is subjected to constant temperature heat treatment for 1 to 3 hours. Naturally cooling to room temperature, and then centrifugally separating the reactant.

Further, the preparation method of the manganese dioxide also comprises a reactant treatment step, wherein the reactant obtained after centrifugation is put into an oven to be dried for 12 hours at 60 ℃ to obtain the manganese dioxide.

After the technical scheme is adopted, the invention has the following beneficial effects:

1) The manganese dioxide has excellent electrochemical properties and higher purity, and has great application prospects in the fields of supercapacitors, dry batteries and the like.

2) The invention is synthesized by a hydrothermal method, and has the advantages of easily-obtained raw materials, low cost and simple experimental process.

3) The preparation method is simple, and has less chemical reagents used in the whole process and less environmental pollution.

Drawings

FIG. 1 is a scanning electron micrograph of manganese dioxide according to the present invention; FIG. 2 is a scanning electron micrograph of manganese dioxide according to the present invention; FIG. 3 is a scanning electron micrograph of manganese dioxide according to the present invention; fig. 4 is an XRD characterization pattern of manganese dioxide of the present invention.

Detailed Description

In order that the manner in which the present invention is attained and can be understood in detail, a more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings.

The first embodiment is as follows:

manganese dioxide comprises manganese dioxide with a linear microstructure, manganese dioxide with a flower-ball microstructure and manganese dioxide with a mixed morphology.

As can be seen from the scanning electron micrograph of manganese dioxide of fig. 1, manganese dioxide has a linear microstructure; as can be seen from the scanning electron micrograph of manganese dioxide of fig. 2, the graphene fiber is composed of a two-layer structure including a flower ball morphology distributed around and a line morphology in the middle of the flower ball; as can be seen from the scanning electron micrograph of manganese dioxide in fig. 3, manganese dioxide has a flower-ball-like microstructure. The XRD characterization pattern of fig. 4 shows characteristic peaks of manganese dioxide.

The second embodiment:

step S1: the potassium permanganate KMnO is matched in the beaker (A) ₄ And (3) solution. MnSO manganese sulfate monohydrate is added into the beaker (B) ₄ ·H ₂ And (4) O solution. And mixing the two solutions to obtain a solution precursor for hydrothermal reaction.

Step S2: transferring the mixed solution into a lining of a reaction kettle. Putting the reaction kettle into an oven, carrying out heat treatment at constant temperature of 120-140 ℃ for 1-3 hours, and naturally cooling in the oven. And transferring the reactants in the reaction kettle to a centrifuge tube, and setting the rotation speed of a centrifuge to 7000 times for centrifugation. For the first time, directly transferring the solution in the reaction kettle into a centrifugal tube for centrifugation; secondly, precipitating, and then replacing pure water for centrifugation; thirdly, ethanol is replaced and centrifugation is carried out after precipitation.

Preferably, in the step S1, potassium permanganate KMnO ₄ And manganese sulfate monohydrate MnSO ₄ ·H ₂ The mass of O was 1 (g) g and 0.4 (g), respectively, and pure water in beakers A and B was 40ml.

Preferably, in the step S1, mnSO ₄ ·H ₂ Heating the O solution in water bath to 50 ℃, then stirring by constant temperature and magnetic force, and simultaneously slowly adding potassium permanganate KMnO by a dropper ₄ The solution was then stirred at constant temperature for 15min.

Preferably, in the step S2, the temperature in the oven is subjected to constant temperature heat treatment for 1 to 3 hours. Naturally cooling to room temperature, and then centrifugally separating the reactant.

Preferably, the preparation method of manganese dioxide further comprises a reactant treatment step, wherein the reactant obtained after centrifugation is dried in an oven at 60 ℃ for 12 hours to obtain the manganese dioxide.

The method is synthesized by a hydrothermal method, the raw materials are easily available, the cost is low, the experimental process is simple, and the morphology of the manganese dioxide obtained by the result can be changed by adjusting the hydrothermal reaction time; the manganese dioxide has excellent electrochemical properties and higher purity, and has huge application prospects in the fields of supercapacitors, dry batteries and the like; the preparation method is simple, uses less chemical reagents as a whole, and has less environmental pollution.

The above embodiments are described in further detail to solve the technical problems, technical solutions and advantages of the present invention, and it should be understood that the above embodiments are only examples of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Manganese dioxide, characterized in that: comprises manganese dioxide with a linear microstructure, manganese dioxide with a flower-ball microstructure and manganese dioxide with a mixed morphology of the two morphologies.

2. The capacitance performance of manganese dioxide with different morphologies can be distinguished conveniently through electrochemical tests.

3. The preparation method of manganese dioxide is characterized by comprising the following steps of:

step S1: the potassium permanganate KMnO is matched in the beaker (A) ₄ A solution; mnSO as manganese sulfate monohydrate is added into the beaker (B) ₄ ·H ₂ O solution; and mixing the two solutions to obtain a solution precursor for hydrothermal reaction.

4. Step S2: transferring the mixed solution into a lining of a reaction kettle.

5. Putting the reaction kettle into an oven, carrying out constant-temperature heat treatment at 120-140 ℃ for 1-3 hours, and naturally cooling in the oven; transferring the reactants in the reaction kettle to a centrifugal tube, and setting the rotating speed of a centrifugal machine to 7000 for three times; for the first time, directly transferring the solution in the reaction kettle into a centrifugal tube for centrifugation; secondly, precipitating, and then replacing pure water for centrifugation; thirdly, ethanol is replaced and centrifuged after precipitation.

6. The method of producing manganese dioxide according to claim 2, wherein: in the step S1, potassium permanganate KMnO ₄ And manganese sulfate monohydrate MnSO ₄ ·H ₂ The mass of O is 1 (g) g and 0.4 (g) g respectively, and pure water in beakers A and B is 40ml; mnSO ₄ ·H ₂ Heating the O solution in water bath to 50 ℃, then stirring by constant temperature and magnetic force, and simultaneously slowly adding potassium permanganate KMnO by a dropper ₄ Stirring the solution for 15min at constant temperature; in the step S2, carrying out heat treatment for 1-3 hours at constant temperature in an oven; naturally cooling to room temperature, and then centrifugally separating the reactant.

7. The method of preparing manganese dioxide according to claim 6, wherein: and centrifuging to obtain a reactant, and drying in an oven at 60 ℃ for 12 hours to obtain manganese dioxide.