Preparation method of two-dimensional iron oxide nanosheet

Abstract

The invention discloses a preparation method of a two-dimensional iron oxide nanosheet, and belongs to the technical field of nano materials. The preparation method comprises the following steps: 1) dissolving FeCl3. 6H2O, hexadecyl triethyl ammonium bromide and polyethylene glycol in deionized water, mixing, and carrying out ultrasonic treatment; 2) adding sodium citrate to adjust the pH value, transferring into a tetrafluoroethylene reaction kettle, and carrying out a hydrothermal reaction; and (3) after the reaction is finished, centrifugally washing, dispersing a product into an ethanol solution containing a silane coupling agent, mixing and stirring, washing and drying to obtain the two-dimensional iron oxide nanosheet. According to the preparation method, CTAB is taken as a main template agent, polyethylene glycol is taken as an auxiliary guiding agent, Fe < 3 + > is induced to directionally grow into the ultrathin nanosheets through hydrothermal reaction, and the ultrathin nanosheets can be widely applied to the fields of high-end automobile paint, electronic display devices and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of nanomaterials, and particularly relates to a method for preparing two-dimensional iron oxide nanosheets. Background Art

[0002] In recent years, nano-iron oxide has demonstrated significant application value in energy storage, environmental management, biomedicine, and other fields due to its unique magnetic, catalytic, and optoelectronic properties. Two-dimensional iron oxide nanosheets have become a research hotspot due to their high surface area, anisotropic structure, and abundant active sites. However, existing preparation methods generally suffer from complex processes, high costs, or insufficient morphology controllability, limiting their large-scale application.

[0003] The preparation method of nanomaterials is a key factor affecting the sample size, shape, particle size distribution, surface chemical properties and material performance. To date, a variety of preparation methods have been reported for the synthesis of nano-iron oxide, mainly including co-precipitation, hydrothermal synthesis, sol-gel, thermal decomposition, etc. Among them, co-precipitation is the most commonly used method for preparing nano-iron oxide. This method is simple and convenient, and the reaction is rapid, but the product growth is incomplete, the crystallinity is poor, and the magnetic properties are weak. The product obtained by the sol-gel method has high purity and uniformity, but the production cycle is long and agglomeration may occur during calcination. The product obtained by the thermal decomposition method has high crystallinity and uniform morphology, but the raw material cost is high and toxic gases may be produced.

[0004] Therefore, there is an urgent need to develop a method with a simple preparation process, cheap and readily available raw materials, and easy industrial production to meet the synthesis and application needs of two-dimensional iron oxide materials. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing two-dimensional iron oxide nanosheets, which has a simple preparation method, low cost and is easy to produce on a large scale.

[0006] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0007] A method for preparing two-dimensional iron oxide nanosheets comprises the following steps:

[0008] 1) Dissolve FeCl3·6H2O, cetyltriethylammonium bromide, and polyethylene glycol in deionized water, mix, and sonicate;

[0009] 2) adding sodium citrate to adjust the pH, transferring to a tetrafluoroethylene reactor, and performing a hydrothermal reaction;

[0010] 3) After the reaction is completed, the product is dispersed in an ethanol solution containing a silane coupling agent, mixed and stirred, and then washed and dried to obtain a two-dimensional iron oxide nanosheet.

[0011] Furthermore, in the step 1), the mass ratio of FeCl3·6H2O, hexadecyltriethylammonium bromide and polyethylene glycol is 1.35:1.5-2:0.1-0.2.

[0012] Furthermore, in the step 1), the ultrasonic time is 30 minutes.

[0013] Furthermore, in the step 2), the concentration of sodium citrate is 0.1 to 0.15 mol / L.

[0014] Furthermore, in the step 2), the pH value is adjusted to 1-2.

[0015] Furthermore, in the step 2), the temperature of the hydrothermal reaction is 160-180° C., and the time is 12-24 hours.

[0016] Furthermore, in the step 3), the silane coupling agent is KH-550.

[0017] Furthermore, in the step 3), the stirring temperature is 60° C. and the stirring time is 4 h.

[0018] Furthermore, the method for preparing two-dimensional iron oxide nanosheets prepares two-dimensional iron oxide nanosheets.

[0019] Furthermore, the thickness of the two-dimensional iron oxide nanosheets is 4-15 nm.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The present invention uses CTAB as the main template and polyethylene glycol as the auxiliary directing agent to induce Fe 3+ The ultra-thin nanosheets grown in a directional manner with a thickness of 4-15nm can be widely used in many fields such as high-end automotive paints and electronic display devices.

[0022] (2) The raw materials used in the present invention are cheap and easily available, the production cost is low, the process is simple, the safety is good, and it is easy to produce on a large scale. DETAILED DESCRIPTION

[0023] The present invention will be further illustrated below with reference to specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0024] In the following examples, the polyethylene glycol is PEG-400.

[0025] Example 1

[0026] A method for preparing two-dimensional iron oxide nanosheets comprises the following steps:

[0027] 1) Dissolve 5 mmol FeCl3·6H2O, 1.5 g CTAB (cetyltriethylammonium bromide), and 0.2 g PEG-400 in 50 mL deionized water and disperse by ultrasonication for 30 min.

[0028] 2) Add 0.1 mol / L sodium citrate to adjust the pH to 1.5, transfer to a tetrafluoroethylene reactor, and hydrothermally react at 180°C for 24 hours;

[0029] 3) After the reaction, the product was centrifuged and washed, and dispersed in an ethanol solution containing 2% KH-550 (wt%), stirred at 60°C for 4 hours, and then the obtained material was centrifuged and washed, and vacuum dried to obtain two-dimensional iron oxide nanosheets with a thickness of 5 to 10 nm and a specific surface area of ​​168 m 2 / g.

[0030] Example 2

[0031] A method for preparing two-dimensional iron oxide nanosheets comprises the following steps:

[0032] 1) Dissolve 5 mmol FeCl3·6H2O, 1.5 g CTAB (cetyltriethylammonium bromide), and 0.2 g PEG-400 in 50 mL deionized water and disperse by ultrasonication for 30 min.

[0033] 2) Add 0.1 mol / L sodium citrate to adjust the pH to 1.5, transfer to a tetrafluoroethylene reactor, and hydrothermally react at 160°C for 12 h;

[0034] 3) After the reaction, the product was centrifuged and washed, and dispersed in an ethanol solution containing 2% KH-550 (wt%), stirred at 60°C for 4 hours, and then the obtained material was centrifuged and washed and vacuum dried to obtain two-dimensional iron oxide nanosheets with a thickness of 8 to 15 nm and a specific surface area of ​​142 m 2 / g.

[0035] Example 3

[0036] A method for preparing two-dimensional iron oxide nanosheets comprises the following steps:

[0037] 1) Dissolve 5 mmol FeCl3·6H2O, 2 g CTAB (cetyltriethylammonium bromide), and 0.1 g PEG-400 in 50 mL deionized water and disperse by ultrasonication for 30 min.

[0038] 2) Add 0.15 mol / L sodium citrate to adjust the pH to 1.2, transfer to a tetrafluoroethylene reactor, and hydrothermally react at 180°C for 24 hours;

[0039] 3) After the reaction, the product was centrifuged and washed, and dispersed in an ethanol solution containing 2% KH-550 (wt%), stirred at 60°C for 4 hours, and then the obtained material was centrifuged and washed and vacuum dried to obtain two-dimensional iron oxide nanosheets with a thickness of 4 to 7 nm and a specific surface area of ​​178 m 2 / g.

[0040] Comparative Example 1

[0041] A method for preparing two-dimensional iron oxide nanosheets comprises the following steps:

[0042] 1) Dissolve 5 mmol FeCl3·6H2O and 1.5 g CTAB (cetyltriethylammonium bromide) in 50 mL deionized water and disperse by ultrasonication for 30 min.

[0043] 2) Add 0.1 mol / L sodium citrate to adjust the pH to 1.5, transfer to a tetrafluoroethylene reactor, and hydrothermally react at 180°C for 24 hours;

[0044] 3) After the reaction is completed, the product is centrifuged and washed, and dispersed in an ethanol solution containing 2% KH-550 (wt%), stirred at 60° C. for 4 h, and then the obtained material is centrifuged and washed and vacuum dried to obtain two-dimensional iron oxide nanosheets, which appear stacked.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing two-dimensional iron oxide nanosheets, characterized in that: The following steps are involved: 1) Dissolve FeCl3·6H2O, cetyltriethylammonium bromide, and polyethylene glycol in deionized water, mix, and sonicate; 2) adding sodium citrate to adjust the pH, transferring to a tetrafluoroethylene reactor, and performing a hydrothermal reaction; 3) After the reaction is completed, the product is dispersed in an ethanol solution containing a silane coupling agent, mixed and stirred, and then washed and dried to obtain a two-dimensional iron oxide nanosheet.

2. The method for preparing two-dimensional iron oxide nanosheets according to claim 1, wherein: In the step 1), the mass ratio of FeCl3·6H2O, hexadecyltriethylammonium bromide and polyethylene glycol is 1.35:1.5-2:0.1-0.

2.

3. The method for preparing two-dimensional iron oxide nanosheets according to claim 1, wherein: In the step 1), the ultrasonic time is 30 minutes.

4. The method for preparing two-dimensional iron oxide nanosheets according to claim 1, wherein: In the step 2), the concentration of sodium citrate is 0.1 to 0.15 mol / L.

5. The method for preparing two-dimensional iron oxide nanosheets according to claim 1, wherein: In the step 2), the pH value is adjusted to 1-2.

6. The method for preparing two-dimensional iron oxide nanosheets according to claim 1, wherein: In the step 2), the temperature of the hydrothermal reaction is 160-180° C., and the time is 12-24 hours.

7. The method for preparing two-dimensional iron oxide nanosheets according to claim 1, wherein: In the step 3), the silane coupling agent is KH-550.

8. The method for preparing two-dimensional iron oxide nanosheets according to claim 1, wherein: In the step 3), the stirring temperature is 60° C. and the stirring time is 4 h.

9. The method for preparing two-dimensional iron oxide nanosheets according to any one of claims 1 to 8, wherein the two-dimensional iron oxide nanosheets are prepared.

10. The two-dimensional iron oxide nanosheet according to claim 9, characterized in that: The thickness of the two-dimensional iron oxide nanosheets is 4-15 nm.