Selective doping of manganese oxide nanomaterials

Abstract

The application provides a selectively doped manganese oxide nanomaterial, and the composition and weight percentage of the selectively doped manganese oxide nanomaterial are as follows: 95-98% of multi-walled carbon nanotubes, 2-5% of MnO2, and 0.1-1% of lanthanum; the selectively doped manganese oxide nanomaterial comprises the following processes: an acid pickling process of the multi-walled carbon nanotubes, a first water washing process, a first drying process, a compounding process of the multi-walled carbon nanotubes, a filtering process, a second water washing process, and a second drying process; and the selectively doped manganese oxide nanomaterial in the application is added with lanthanum elements, so that the introduction of the lanthanum elements can improve the conductivity of the composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrode materials, and particularly to a selectively doped manganese oxide nanomaterial. BACKGROUND

[0002] Electrochemical supercapacitors (EC) are becoming consumable electrical storage devices in computers, power electronics, and electric vehicles that provide instantaneous high power. According to the different energy storage mechanisms, ECs can be divided into two categories. One is the double-layer capacitor (EDLC), in which activated carbon with high surface area is used as the electrode material; the other is the pseudo-capacitor, in which the fast reversible Faradic reaction is used for charge storage, metal oxide carbon nanotube (CNT) composite material, the conductivity and chemical stability of CNTs, and the high capacitance of metal oxides, among which, MnO2 / CNT composite material has attracted extensive attention in the academic field due to its high specific capacitance, environmental friendliness and cost-effectiveness, and has a wide application in the industry, although a higher specific capacitance has been achieved on MnO2 / CNT, the low conductivity of MnO2 is still a major problem for increasing the loading of MnO2 or MnO2 thin film; however, another problem is that the MnO2 / CNTs electrode is much lower than the MnO2 / CNT electrode of activated carbon, thereby making this new electrode material still have limited application at present, for this reason, the present application provides a selectively doped manganese oxide nanomaterial to solve the above problems. SUMMARY

[0003] The present application aims to provide a selectively doped manganese oxide nanomaterial to solve the problems presented in the background.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solution: a selectively doped manganese oxide nanomaterial, the composition and weight percentage of the selectively doped manganese oxide nanomaterial are as follows: multi-walled carbon nanotubes: 95-98%, MnO2: 2-5%, lanthanum: 0.1-1%;

[0005] The selectively doped manganese oxide nanomaterial comprises the following steps:

[0006] Step one: acid washing process of multi-walled carbon nanotubes, in the acid washing process of multi-walled carbon nanotubes, the multi-walled carbon nanotubes are washed by acid solution;

[0007] Step two: first water washing process, in the first water washing process, the multi-walled carbon nanotubes subjected to the acid washing process are washed again, and the multi-walled carbon nanotubes are subjected to draining treatment after the second washing;

[0008] Step three: first drying process, in the drying process, the multi-walled carbon nanotubes subjected to the draining treatment are subjected to drying treatment;

[0009] Step four: the compounding process of the multi-walled carbon nanotubes, in which the multi-walled carbon nanotubes, MnO2 and lanthanum are compounded by KMnO4 solution;

[0010] Step five: the filtering process, in which the compound suspension formed by the compounding process is filtered;

[0011] Step six: the secondary water washing process;

[0012] Step seven: the secondary drying process.

[0013] Preferably, in the acid washing process of the multi-walled carbon nanotubes, the acid solution used is a mixed acid composed of concentrated sulfuric acid and nitric acid.

[0014] Preferably, in the acid washing process of the multi-walled carbon nanotubes, the ratio of the concentrated sulfuric acid and the nitric acid is 3:1, the acid washing time is 30-40 minutes, and the acid washing temperature is 20-30℃.

[0015] Preferably, in the primary water washing process and the secondary water washing process, the water used is deionized water.

[0016] Preferably, in the compounding process of the multi-walled carbon nanotubes, KMnO4 (99.5%) is dissolved in distilled water to form a 0.1 mol·L-1 KMnO4 solution, and the solution is heated to 70℃, and then the pretreated multi-walled carbon nanotubes are added to the KMnO4 solution. -1

[0017] Preferably, in the compounding process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes need to be continuously stirred during the adding process until the mixture turns purple, and then the stirring is stopped.

[0018] Preferably, in the compounding process of the multi-walled carbon nanotubes, after the multi-walled carbon nanotubes are fully stirred and mixed, MnO2 and lanthanum are added to the mixture, and the stirring is continued until the purple color in the mixture disappears, and then the stirring is stopped to form a MnO2 / MWCNTs compound suspension.

[0019] Preferably, in the compounding process of the multi-walled carbon nanotubes, the solution PH is neutral, and the reaction formula is:

[0020]

[0021] The drying temperature in the secondary drying process is 100℃.

[0022] The drying environment in the secondary drying process is a vacuum environment, and the drying time is twenty-four hours.

[0023] ​Compared with the prior art, the beneficial effects of the present application are that: by designing a selective doped manganese oxide nanomaterial composed of an acid washing process of multi-walled carbon nanotubes, a first water washing process, a first drying process, a compounding process of multi-walled carbon nanotubes, a filtering process, a second water washing process and a second drying process, and adding lanthanum elements therein, the purpose of improving the conductivity of the composite material is achieved by the introduction of lanthanum elements. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0025] Embodiment one

[0026] The present application provides a technical solution: a selective doped manganese oxide nanomaterial, the composition and weight percentage of the selective doped manganese oxide nanomaterial are: multi-walled carbon nanotubes: 96.9%, MnO2: 3%, lanthanum: 0.1%;

[0027] The selective doped manganese oxide nanomaterial comprises the following steps:

[0028] Step one: an acid washing process of multi-walled carbon nanotubes, in the acid washing process of multi-walled carbon nanotubes, the multi-walled carbon nanotubes are washed by an acid solution;

[0029] Step two: a first water washing process, in the first water washing process, the multi-walled carbon nanotubes subjected to the acid washing process are washed again, and the multi-walled carbon nanotubes are subjected to a draining treatment after the second washing;

[0030] Step three: a first drying process, in the drying process, the multi-walled carbon nanotubes subjected to the draining treatment are subjected to a drying treatment;

[0031] Step four: a compounding process of multi-walled carbon nanotubes, in the compounding process of multi-walled carbon nanotubes, the multi-walled carbon nanotubes, MnO2 and lanthanum are subjected to a compounding treatment by a KMnO4 solution;

[0032] Step five: a filtering process, in the filtering process, the compound suspension formed by the compounding treatment is subjected to a filtering treatment;

[0033] Step six: a second water washing process;

[0034] Step seven: a second drying process.

[0035] In the acid washing process of multi-walled carbon nanotubes, the acid solution used is a mixed acid composed of concentrated sulfuric acid and nitric acid.

[0036] The ratio of concentrated sulfuric acid and nitric acid in the acid washing process of the multi-walled carbon nanotubes is 3:1, the acid washing time is 30 minutes, and the acid washing temperature is 25 DEG C.

[0037] The water used in the first water washing process and the second water washing process is deionized water.

[0038] In the compounding process of the multi-walled carbon nanotubes, KMnO4 (99.5%) is dissolved in distilled water to form a 0.1 mol / L KMnO4 solution, and the solution is heated to 70 DEG C, and then the pretreated multi-walled carbon nanotubes are added to the KMnO4 solution. -1

[0039] In the compounding process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes need to be continuously stirred during the adding process until the mixture is purple, and then the stirring is stopped.

[0040] In the compounding process of the multi-walled carbon nanotubes, after the multi-walled carbon nanotubes are fully stirred and mixed, MnO2 and lanthanum are added to the mixture, and the stirring is continued until the purple color in the mixture disappears, and then the stirring is stopped to form a MnO2 / MWCNTs composite suspension.

[0041] In the compounding process of the multi-walled carbon nanotubes, the solution PH is neutral, and the reaction formula is:

[0042]

[0043] The drying temperature in the second drying process is 100 DEG C.

[0044] The drying environment in the second drying process is a vacuum environment, and the drying time is twenty-four hours.

[0045] Example Two

[0046] The present application provides a technical solution: selectively doped manganese oxide nanomaterial, the composition and weight percentage of selectively doped manganese oxide nanomaterial are: multi-walled carbon nanotubes: 96.7%, MnO2: 3%, lanthanum: 0.3%;

[0047] The selectively doped manganese oxide nanomaterial comprises the following steps:

[0048] Step one: the acid washing process of the multi-walled carbon nanotubes, in the acid washing process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes are washed by acid solution;

[0049] Step two: the first water washing process, in the first water washing process, the multi-walled carbon nanotubes subjected to the acid washing process are washed again, and the multi-walled carbon nanotubes are subjected to draining treatment after the second washing;

[0050] ​Step three: once dry process, in the drying process, the multi-walled carbon nanotubes treated by draining are subjected to drying treatment;

[0051] Step four: multi-walled carbon nanotube composite process, in the multi-walled carbon nanotube composite process, the multi-walled carbon nanotubes, MnO2 and lanthanum are subjected to composite treatment by KMnO4 solution;

[0052] Step five: filtration process, in the filtration process, the composite suspension formed by the composite treatment is subjected to filtration treatment;

[0053] Step six: secondary water washing process;

[0054] Step seven: secondary drying process.

[0055] In the acid washing process of the multi-walled carbon nanotubes, the acid solution used is a mixed acid composed of concentrated sulfuric acid and nitric acid.

[0056] In the acid washing process of the multi-walled carbon nanotubes, the ratio of concentrated sulfuric acid to nitric acid is 3:1, the acid washing time is 30 minutes, and the acid washing temperature is 25°C.

[0057] In the primary and secondary water washing processes, the water used is deionized water.

[0058] In the composite process of the multi-walled carbon nanotubes, KMnO4 (99.5%) is dissolved in distilled water to form a 0.1 mol·L -1 KMnO4 solution, and the solution is heated to 70°C, and then the pretreated multi-walled carbon nanotubes are added to the KMnO4 solution.

[0059] In the composite process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes need to be continuously stirred during the addition process until the mixture turns purple and the stirring is stopped.

[0060] In the composite process of the multi-walled carbon nanotubes, after the multi-walled carbon nanotubes are fully stirred and mixed, MnO2 and lanthanum are added to the mixture, and the stirring is continued until the purple color in the mixture disappears and the stirring is stopped to form a MnO2 / MWCNTs composite suspension.

[0061] In the composite process of the multi-walled carbon nanotubes, the solution PH is neutral, and the reaction formula is:

[0062]

[0063] The drying temperature in the secondary drying process is 100°C.

[0064] The drying environment in the secondary drying process is a vacuum environment, and the drying time is twenty-four hours.

[0065] Example three

[0066] The application provides a technical scheme: the selective doping manganese oxide nanomaterial composition and weight percentage are as follows: multi-walled carbon nanotubes: 96.5%, MnO2: 3%, and lanthanum: 0.5%.

[0067] The selective doping manganese oxide nanomaterial comprises the following steps:

[0068] Step one: an acid washing process of the multi-walled carbon nanotubes, in which the multi-walled carbon nanotubes are washed by acid liquid.

[0069] Step two: a first water washing process, in which the multi-walled carbon nanotubes subjected to the acid washing process are washed again, and the multi-walled carbon nanotubes are subjected to draining treatment after the second washing.

[0070] Step three: a first drying process, in which the multi-walled carbon nanotubes subjected to the draining treatment are subjected to drying treatment.

[0071] Step four: a compounding process of the multi-walled carbon nanotubes, in which the multi-walled carbon nanotubes, MnO2 and lanthanum are subjected to compounding treatment by KMnO4 solution.

[0072] Step five: a filtering process, in which the compounding suspension formed by the compounding treatment is subjected to filtering treatment.

[0073] Step six: a second water washing process.

[0074] Step seven: a second drying process.

[0075] In the acid washing process of the multi-walled carbon nanotubes, the acid liquid used is a mixed acid composed of concentrated sulfuric acid and nitric acid.

[0076] In the acid washing process of the multi-walled carbon nanotubes, the ratio of the concentrated sulfuric acid and the nitric acid is 3:1, the acid washing time is 30 minutes, and the acid washing temperature is 25℃.

[0077] In the first water washing process and the second water washing process, the water used is deionized water.

[0078] In the compounding process of the multi-walled carbon nanotubes, KMnO4 (99.5%) is dissolved in distilled water to form a 0.1 mol·L-1 KMnO4 solution, and the solution is heated to 70℃, and then the pretreated multi-walled carbon nanotubes are added into the KMnO4 solution. -1

[0079] In the compounding process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes need to be continuously stirred during the adding process until the mixture is purple, and then the stirring is stopped.

[0080] ​In the compounding process of the multi-walled carbon nanotubes, after the multi-walled carbon nanotubes are fully stirred and mixed, MnO2 and lanthanum are added into the mixture, and stirring is continued until the purple color disappears in the mixture, and the stirring is stopped to form a MnO2 / MWCNTs composite suspension.

[0081] In the compounding process of the multi-walled carbon nanotubes, the solution PH is neutral, and the reaction formula is:

[0082]

[0083] The drying temperature in the secondary drying process is 100 DEG C.

[0084] The drying environment in the secondary drying process is a vacuum environment, and the drying time is twenty-four hours.

[0085] Example Four

[0086] The present application provides a technical solution: selective doping of manganese oxide nanometer material composition and weight percentage: multi-walled carbon nanotubes: 96.3%, MnO2: 3%, lanthanum: 0.7%;

[0087] The selective doping of the manganese oxide nanometer material comprises the following steps:

[0088] Step one: the acid washing process of the multi-walled carbon nanotubes, in the acid washing process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes are washed by the acid solution;

[0089] Step two: the first water washing process, in the first water washing process, the multi-walled carbon nanotubes after the acid washing process are washed twice, and the multi-walled carbon nanotubes are drained after the second washing;

[0090] Step three: the first drying process, in the drying process, the multi-walled carbon nanotubes after the draining treatment are dried;

[0091] Step four: the compounding process of the multi-walled carbon nanotubes, in the compounding process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes, MnO2 and lanthanum are compounded by the KMnO4 solution;

[0092] Step five: the filtering process, in the filtering process, the composite suspension formed by the compounding treatment is filtered;

[0093] Step six: the second water washing process;

[0094] Step seven: the second drying process.

[0095] In the acid washing process of the multi-walled carbon nanotubes, the acid solution used is a mixed acid composed of concentrated sulfuric acid and nitric acid.

[0096] The concentration ratio of concentrated sulfuric acid and nitric acid in the acid washing process of the multi-walled carbon nanotubes is 3:1, the acid washing time is 30 minutes, and the acid washing temperature is 25 DEG C.

[0097] The water used in the first water washing process and the second water washing process is deionized water.

[0098] In the compounding process of the multi-walled carbon nanotubes, KMnO4 (99.5%) is dissolved in distilled water to form a 0.1 mol / L KMnO4 solution, and the solution is heated to 70 DEG C, and then the pretreated multi-walled carbon nanotubes are added to the KMnO4 solution. -1

[0099] In the compounding process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes need to be continuously stirred during the adding process until the mixture is purple, and then the stirring is stopped.

[0100] In the compounding process of the multi-walled carbon nanotubes, after the multi-walled carbon nanotubes are fully stirred and mixed, MnO2 and lanthanum are added to the mixture, and the stirring is continued until the purple color in the mixture disappears, and then the stirring is stopped to form a MnO2 / MWCNTs composite suspension.

[0101] In the compounding process of the multi-walled carbon nanotubes, the solution PH is neutral, and the reaction formula is:

[0102]

[0103] The drying temperature in the second drying process is 100 DEG C.

[0104] The drying environment in the second drying process is a vacuum environment, and the drying time is twenty-four hours.

[0105] Example Five

[0106] The present application provides a technical solution: the selective doping of manganese oxide nanomaterial composition and weight percentage is: multi-walled carbon nanotubes: 96.1%, MnO2: 3%, lanthanum: 0.9%;

[0107] The selective doping of manganese oxide nanomaterial includes the following steps:

[0108] Step one: the acid washing process of the multi-walled carbon nanotubes, in the acid washing process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes are washed by acid solution;

[0109] Step two: the first water washing process, in the first water washing process, the multi-walled carbon nanotubes after the acid washing process are washed twice, and the multi-walled carbon nanotubes are drained after the second washing;

[0110] ​Step three: a first drying process, in which the multi-walled carbon nanotubes treated by draining are dried;

[0111] Step four: a compounding process of the multi-walled carbon nanotubes, in which the multi-walled carbon nanotubes, MnO2 and lanthanum are compounded by KMnO4 solution;

[0112] Step five: a filtering process, in which the compound suspension formed by the compounding process is filtered;

[0113] Step six: a second water washing process;

[0114] Step seven: a second drying process.

[0115] In the acid washing process of the multi-walled carbon nanotubes, the acid solution used is a mixed acid composed of concentrated sulfuric acid and nitric acid.

[0116] In the acid washing process of the multi-walled carbon nanotubes, the ratio of the concentrated sulfuric acid and the nitric acid is 3:1, the acid washing time is 30 minutes, and the acid washing temperature is 25°C.

[0117] In the first and second water washing processes, the water used is deionized water.

[0118] In the compounding process of the multi-walled carbon nanotubes, KMnO4 (99.5%) is dissolved in distilled water to form a 0.1 mol·L-1 KMnO4 solution, and the solution is heated to 70°C, and then the pretreated multi-walled carbon nanotubes are added to the KMnO4 solution. -1

[0119] In the compounding process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes need to be continuously stirred during the adding process until the mixture turns purple and the stirring is stopped.

[0120] In the compounding process of the multi-walled carbon nanotubes, after the multi-walled carbon nanotubes are fully stirred and mixed, MnO2 and lanthanum are added to the mixture, and the stirring is continued until the purple color in the mixture disappears and the stirring is stopped to form a MnO2 / MWCNTs compound suspension.

[0121] In the compounding process of the multi-walled carbon nanotubes, the solution PH is neutral, and the reaction formula is:

[0122]

[0123] The drying temperature in the second drying process is 100°C.

[0124] The drying environment in the second drying process is a vacuum environment, and the drying time is twenty-four hours.

[0125] Table 1 ​

[0126]

[0127]

[0128] Through the comparison experiment results of the four groups of examples and comparative examples, the corrosion-resistant mirror surface mold steels formed in example one, example two, example three, example four and example five gradually increase in the content of the selectively doped manganese oxide nanometer material lanthanum element, and the conductivity of the five is arranged in a gradually increasing trend, but when the amount of lanthanum element reaches a peak value, the strength of the material will be low, so according to the comparison of example one to example five, the scheme in example four is optimal.

[0129] The application adds lanthanum element in the selectively doped manganese oxide nanometer material composed of the acid washing process of multi-walled carbon nanotubes, the first water washing process, the first drying process, the composite process of multi-walled carbon nanotubes, the filtering process, the second water washing process and the second drying process, so as to improve the conductivity of the composite material by introducing the lanthanum element.

[0130] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A selectively doped manganese oxide nanomaterial, characterized in that, The selective doping manganese oxide nanomaterial composition and weight percentage are: multi-walled carbon nanotubes: 95-98%, MnO2: 2-5%, lanthanum: 0.3-0.7%; The selective doping manganese oxide nanomaterial includes the following steps: Step one: multi-walled carbon nanotube acid washing process, in which the multi-walled carbon nanotubes are washed by acid solution; Step two: first water washing process, in which the multi-walled carbon nanotubes after the acid washing process are washed again, and the multi-walled carbon nanotubes are drained after the second washing; Step three: first drying process, in which the multi-walled carbon nanotubes after the draining treatment are dried; Step four: multi-walled carbon nanotube compounding process, in which the multi-walled carbon nanotubes, MnO2 and lanthanum are compounded by KMnO4 solution; Step five: filtering process, in which the compound suspension formed by the compounding process is filtered; Step six: second water washing process; Step seven: second drying process; In the compounding process of the multi-walled carbon nanotubes, KMn04 is dissolved in distilled water to form a 0.1 mol-L -1 KMn04 solution, and the solution is heated to 70°C, and then the pretreated multi-walled carbon nanotubes are added into the KMn04 solution. In the compounding process of the multi-walled carbon nanotubes, the multi-walled carbon nanotubes need to be continuously stirred during the adding process until the mixture turns purple, and then the stirring is stopped; In the compounding process of the multi-walled carbon nanotubes, after the multi-walled carbon nanotubes are fully stirred and mixed, MnO2 and lanthanum are added to the mixture, and the stirring is continued until the purple color disappears in the mixture, and then the stirring is stopped to form a MnO2 / MWCNTs compound suspension.

2. The selectively doped manganese oxide nanomaterial of claim 1, wherein: In the acid washing process of the multi-walled carbon nanotubes, the acid solution used is a mixed acid composed of concentrated sulfuric acid and nitric acid.

3. The selectively doped manganese oxide nanomaterial of claim 2, wherein: In the acid washing process of the multi-walled carbon nanotubes, the ratio of concentrated sulfuric acid and nitric acid is 3:1, the acid washing time is 30-40 minutes, and the acid washing temperature is 20-30℃.

4. The selectively doped manganese oxide nanomaterial of claim 1, wherein: In the first and second water washing processes, the water used is deionized water.

5. The selectively doped manganese oxide nanomaterial of claim 1, wherein: In the compounding process of the multi-walled carbon nanotubes, the solution PH is neutral, and the reaction formula is: 4MnO4 - + 3C + H2O ⇌ 4MnO2+ CO3 2- + 2HCO3 - .

6. The selectively doped manganese oxide nanomaterial of claim 1, wherein: The drying temperature in the second drying process is 100℃.

7. The selectively doped manganese oxide nanomaterial of claim 6, wherein: The drying environment in the second drying process is a vacuum environment, and the drying time is twenty-four hours.

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