Method for preparing MXene through elementary substance etching

Abstract

The invention belongs to the technical field of MXene material preparation, and particularly discloses a method for preparing MXene through elementary substance etching. The method comprises the following steps: mixing an MAX phase corresponding to MXene with a simple substance material, and then heating to carry out an etching reaction; after the etching reaction is finished, washing to remove impurities to obtain MXene; the elementary substance material comprises Te, Se, S, P, As and Sb. According to the method, based on the intrinsic characteristics of elementary elements, the high-quality MXene material with functional groups such as Te and Se is directly prepared, meanwhile, the method also has an excellent etching effect on V and Nb-based high-binding-force MAX, the universal preparation of the MXene material is further realized in a real sense, and the process and the cost of large-scale preparation of the MXene material are also simplified.

Description

Technical Field

[0001] This invention relates to the field of MXene material preparation technology, and in particular to a method for preparing MXene using elemental etching. Background Technology

[0002] MXene is a two-dimensional material with a graphene-like sheet structure obtained by selectively etching A-site elements in the precursor MAX phase. In the MAX phase, M represents transition metal elements such as titanium (Ti), vanadium (V), chromium (Cr), and niobium (Nb); A typically refers to main group elements such as aluminum (Al), silicon (Si), and zinc (Zn); and X represents carbon (C) or nitrogen (N). The general chemical formula of MXene can be represented as M n+1 X n T x T x Representing surface functional groups, after etching, the MXene surface has a large number of functional groups attached due to the presence of unsaturated coordination bonds, mainly -O, -OH, -F, -Cl, and -Br elements, which endow the material with excellent surface chemical activity.

[0003] Existing MXene preparation processes primarily employ top-down etching methods, typically including fluorine-containing solution etching (HF or LiF / HCl), Lewis acid salt etching (such as CuCl2, NiBr2), and electrochemical etching. Despite their widespread application, these traditional routes have significant drawbacks: firstly, fluorine-containing systems inevitably introduce highly toxic HF, posing serious safety hazards; secondly, while other non-fluorine systems avoid strong acids, they often generate large amounts of byproducts, complicating purification and post-processing. Methods for preparing halogens are rarely reported, with only a few cases involving etching with Cl2, Br2, and I2. However, halogens generally possess high toxicity and corrosiveness, placing stringent requirements on equipment and the environment, thus limiting their application in MXene preparation.

[0004] Therefore, it is essential to disclose a method for preparing MXene by etching non-halogen elements, so that it can simultaneously serve as an etchant and a source of functional groups. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing MXene by etching with elemental materials, in order to solve the problems of existing etching methods being complex or having high toxicity and corrosivity.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing MXene using elemental etching includes the following steps: 1) Mix the MAX phase corresponding to MXene with the elemental material, and then heat to carry out the etching reaction; 2) After the etching reaction is complete, wash to remove impurities and obtain MXene; The elemental materials include Te, Se, S, P, As, and Sb.

[0007] Preferably, the molar ratio of the MAX phase to the elemental material is 1:0.5~4.

[0008] Preferably, the etching reaction includes a heating section and a holding section; The final temperature of the heating section is 500~900℃, and the heating rate is 5~50℃ / min; The insulation temperature of the insulation section is equal to the final temperature of the heating section, and the insulation time is 0~12h.

[0009] Preferably, the etching reaction is carried out under a protective atmosphere; The protective atmosphere includes one or more of nitrogen, helium, neon, and argon atmospheres.

[0010] Preferably, the detergent used in step 2) includes an acid solution or an alkaline solution; The acid solution includes hydrochloric acid solution and / or sulfuric acid solution; The alkaline solution includes potassium hydroxide solution and / or sodium hydroxide solution.

[0011] Preferably, the MAX phase includes one or more of Ti3AlC2, V2AlC, Ti2AlC, Nb2AlC, Ti2SnC, Ti3SiC2, Ti2SC, Nb2SnC, Ti3AlCN, Ti4AlN3, V4AlN3Ta2AlC, and Ti2AlN.

[0012] Preferably, the obtained MXene includes Ti3C2Te2, V2CTe2, Ti2CTe2, Zr2CTe2, Ti3C2S2, Ti4N3Te2, Ti3C2Se2 or Nb2CTe2.

[0013] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: Based on the intrinsic properties of elemental elements, this invention enables the direct preparation of high-quality MXene materials with functional groups such as Te and Se. At the same time, this method also has excellent etching effect for V and Nb groups with strong MAX binding force, further realizing the truly universal preparation of MXene materials and simplifying the process and cost of large-scale preparation of MXene materials.

[0014] The preparation method described in this invention uses only two substances: elemental substances (Te, Se, etc.) and the MAX phase. At high temperatures, the elemental substances are in a liquid state and can react directly with the MAX phase, thus avoiding the use of molten salt, reducing the use of molten salt environment and post-processing operations. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 X-ray diffraction of the MXene material prepared in Example 1 of this invention; Figure 2 These are secondary electronic microstructure characterization images of the MXene material prepared in Example 1 of this invention at different magnifications; Figure 3 X-ray diffraction of the MXene material prepared in Example 2 of this invention; Figure 4 These are secondary electronic microstructure characterization images of the MXene material prepared in Example 2 of this invention at different magnifications; Figure 5 X-ray diffraction of the MXene material prepared in Example 3 of this invention; Figure 6 The image shows the electronic microstructure characterization of the MXene material prepared in Example 3 of this invention. Figure 7 X-ray diffraction of the MXene material prepared in Example 4 of this invention; Figure 8 The image shows the electronic microstructure characterization of the MXene material prepared in Example 4 of this invention. Figure 9 X-ray diffraction of the MXene material prepared in Example 5 of this invention; Figure 10 The image shows the electronic microstructure characterization of the MXene material prepared in Example 5 of this invention. Among them, Intensity refers to strength. Detailed Implementation

[0017] This invention provides a method for preparing MXene using elemental etching, comprising the following steps: 1) Mix the MAX phase corresponding to MXene with the elemental material, and then heat to carry out the etching reaction; 2) After the etching reaction is complete, wash to remove impurities and obtain MXene.

[0018] In this invention, the elemental materials include Te, Se, S, P, As, and Sb.

[0019] In this invention, the molar ratio of the MAX phase to the elemental material is 1:0.5~4, preferably 1:1~3, and more preferably 1:2.

[0020] In this invention, the etching reaction includes a heating section and a holding section.

[0021] In this invention, the final temperature of the heating section is 500~900℃, specifically 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, or 850℃; the heating rate is 5~50℃ / min, specifically 8℃ / min, 10℃ / min, 15℃ / min, 20℃ / min, 25℃ / min, 30℃ / min, 35℃ / min, 40℃ / min, or 45℃ / min.

[0022] In this invention, the heat preservation temperature of the heat preservation section is equal to the final temperature of the heating section, and the heat preservation time is 0~12h, specifically 2h, 4h, 5h, 6h, 8h, or 10h.

[0023] In this invention, the etching reaction is carried out under a protective atmosphere.

[0024] In this invention, the protective atmosphere includes one or more of nitrogen, helium, neon, and argon atmospheres.

[0025] In this invention, the detergent used in step 2) includes an acid solution or an alkaline solution.

[0026] In this invention, the acid solution includes hydrochloric acid solution and / or sulfuric acid solution; the concentration of the acid solution is preferably 1 mol / L.

[0027] In this invention, the alkaline solution includes potassium hydroxide solution and / or sodium hydroxide solution; the concentration of the alkaline solution is preferably 1 mol / L.

[0028] In this invention, the MAX phase includes one or more of Ti3AlC2, V2AlC, Ti2AlC, Nb2AlC, Ti2SnC, Ti3SiC2, Ti2SC, Nb2SnC, Ti3AlCN, Ti4AlN3, V4AlN3Ta2AlC, and Ti2AlN.

[0029] In this invention, the obtained MXene includes Ti3C2Te2, V2CTe2, Ti2CTe2, Zr2CTe2, Ti3C2S2, Ti4N3Te2, Ti3C2Se2 or Nb2CTe2.

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] The preparation of Ti3C2Te2 MXene material includes the following steps: S1: Ti3AlC2 and Te were weighed out separately at a chemical ratio of 1:3 and mixed evenly in an agate mortar.

[0033] S2: Pour the material into a corundum crucible, place the crucible in an argon atmosphere tube furnace, heat it from room temperature to 700℃ at a rate of 10℃ / min, hold it at that temperature for 60min, and then cool it with the furnace.

[0034] S3: The product is a loose powder. It is washed with 1 mol / L NaOH solution for 60 minutes, then washed repeatedly with deionized water 3 times, and dried under vacuum at 60°C for 12 hours to obtain Ti3C2Te2MXene powder.

[0035] S4: Perform X-ray diffraction on the product as follows Figure 1 As shown, the secondary electron microstructure characterization is as follows: Figure 2 As shown. (Through) Figures 1-2 It can be seen that after etching with elemental Te, the diffraction peaks of the Ti3AlC2 MAX material disappear, and the microstructure of the product particles also shows that the particles exhibit a distinct accordion shape. All of the above effectively demonstrates the efficient etching of Ti3AlC2 MAX by elemental Te.

[0036] Example 2

[0037] The preparation of V2CTe2 MXene material includes the following steps: S1: V2AlC and Te were weighed out separately at a chemical ratio of 1:2 and mixed evenly in an agate mortar.

[0038] S2: Pour the material into a corundum crucible, place the crucible in an argon atmosphere tube furnace, heat it from room temperature to 600℃ at a rate of 10℃ / min, hold it at that temperature for 60min, and then cool it with the furnace.

[0039] S3: The product is a loose powder. It is washed with 1 mol / L hydrochloric acid solution for 60 minutes, then washed repeatedly with deionized water 3 times, and dried under vacuum at 60°C for 12 hours to obtain V2CTe2 MXene powder.

[0040] S4: Perform X-ray diffraction on the product as follows Figure 3 As shown, the secondary electron microstructure characterization is as follows: Figure 4 As shown. (Through) Figures 3-4 It can be seen that after etching with elemental Te, the diffraction peaks of the V2AlC MAX material disappear, and the microstructure of the product particles also shows that the particles exhibit a distinct accordion shape. All of the above effectively demonstrates the effective etching of V2AlC MAX by elemental Te.

[0041] Example 3

[0042] The preparation of Nb2CTe2 MXene material includes the following steps: S1: Nb2AlC and Te were weighed out separately at a chemical ratio of 1:2 and mixed evenly in an agate mortar.

[0043] S2: Pour the material into a corundum crucible, place the crucible in an argon atmosphere tube furnace, heat it from room temperature to 600℃ at a rate of 10℃ / min, hold it at that temperature for 60min, and then cool it with the furnace.

[0044] S3: The product is a loose powder. It is washed with 1 mol / L hydrochloric acid solution for 60 minutes, then washed repeatedly with deionized water 3 times, and dried under vacuum at 60°C for 12 hours to obtain Nb2CTe2 MXene powder.

[0045] S4: Perform X-ray diffraction on the product as follows Figure 5 As shown, the secondary electron microstructure characterization is as follows: Figure 6 As shown. (Through) Figures 5-6 It can be seen that after etching with elemental Te, the diffraction peaks of the Nb₂AlC MAX material disappear, and the microstructure of the product particles also shows that the particles exhibit a distinct accordion shape. All of the above effectively demonstrates the efficient etching of Nb₂AlC MAX by elemental Te.

[0046] Example 4

[0047] The preparation of Ti3C2Se2 MXene material includes the following steps: S1: Ti3SiC2 and Se were weighed out separately at a chemical ratio of 1:3 and mixed evenly in an agate mortar.

[0048] S2: Pour the material into a corundum crucible, place the crucible in an argon atmosphere tube furnace, heat it from room temperature to 700℃ at a rate of 10℃ / min, hold it at that temperature for 60min, and then cool it with the furnace.

[0049] S3: The product is a loose powder. It is washed with 1 mol / L hydrochloric acid solution for 60 minutes, then washed repeatedly with deionized water 3 times, and dried under vacuum at 60°C for 12 hours to obtain Ti3C2Se2 MXene powder.

[0050] S4: Perform X-ray diffraction on the product as follows Figure 7 As shown, the secondary electron microstructure characterization is as follows: Figure 8 As shown. (Through) Figures 7-8 It can be seen that after etching with elemental Se, the diffraction peaks of the Ti3SiC2 MAX material disappear, and the microstructure of the product particles also shows that the particles exhibit a distinct accordion shape. All of the above effectively demonstrates the efficient etching of Ti2SiC2 MAX by elemental Se.

[0051] Example 5

[0052] The preparation of Ti3C2Te2 MXene material includes the following steps: S1: Ti3AlC2 and Te were weighed out separately at a chemical ratio of 1:3 and mixed evenly in an agate mortar.

[0053] S2: Pour the material into a corundum crucible, place the crucible in an argon atmosphere tube furnace, heat it from room temperature to 700℃ at a rate of 10℃ / min, hold it at that temperature for 0min, and then cool it with the furnace.

[0054] S3: The product is a loose powder. It is washed with 1 mol / L hydrochloric acid solution for 60 minutes, then washed repeatedly with deionized water 3 times, and dried under vacuum at 60°C for 12 hours to obtain Ti3C2Te2 MXene powder.

[0055] S4: Perform X-ray diffraction on the product as follows Figure 9 As shown, the secondary electron microstructure characterization is as follows: Figure 10 As shown. (Through) Figures 9-10 It can be seen that after etching with elemental Te, the diffraction peaks of the Ti3AlC2MAX material disappear, and the microstructure of the product particles also shows that the particles exhibit a distinct accordion shape. All of the above effectively demonstrates the efficient etching of Ti2AlC2MAX by elemental Te.

[0056] Example 6

[0057] The preparation of Ti3C2S2 MXene material includes the following steps: S1: Ti3AlC2 and S were weighed out separately at a chemical ratio of 1:3 and mixed evenly in an agate mortar.

[0058] S2: Pour the material into a corundum crucible, place the crucible in an argon atmosphere tube furnace, heat it to 700℃ at a rate of 10℃ / min, hold it at that temperature for 90min, and then cool it with the furnace.

[0059] S3: The product is a loose powder. It is washed with 1 mol / L potassium hydroxide solution for 60 minutes, then washed repeatedly with deionized water 3 times, and dried under vacuum at 60°C for 12 hours to obtain Ti3C2S2 MXene powder.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing MXene using elemental etching, characterized in that, Includes the following steps: 1) Mix the MAX phase corresponding to MXene with the elemental material, and then heat to carry out the etching reaction; 2) After the etching reaction is complete, wash to remove impurities and obtain MXene; The elemental materials include Te, Se, S, P, As, and Sb.

2. The method for preparing MXene using elemental etching according to claim 1, characterized in that, The molar ratio of the MAX phase to the elemental material is 1:0.5~4.

3. The method for preparing MXene using elemental etching according to claim 2, characterized in that, The etching reaction includes a heating section and a holding section; The final temperature of the heating section is 500~900℃, and the heating rate is 5~50℃ / min; The insulation temperature of the insulation section is equal to the final temperature of the heating section, and the insulation time is 0~12h.

4. The method for preparing MXene using elemental etching according to claim 3, characterized in that, The etching reaction is carried out under a protective atmosphere. The protective atmosphere includes one or more of nitrogen, helium, neon, and argon atmospheres.

5. A method for preparing MXene using elemental etching according to any one of claims 1 to 4, characterized in that, The detergent used in step 2) includes acid solutions or alkaline solutions; The acid solution includes hydrochloric acid solution and / or sulfuric acid solution; The alkaline solution includes potassium hydroxide solution and / or sodium hydroxide solution.

6. The method for preparing MXene using elemental etching according to claim 5, characterized in that, The MAX phase includes one or more of Ti3AlC2, V2AlC, Ti2AlC, Nb2AlC, Ti2SnC, Ti3SiC2, Ti2SC, Nb2SnC, Ti3AlCN, Ti4AlN3, V4AlN3Ta2AlC, and Ti2AlN.

7. The method for preparing MXene using elemental etching according to claim 6, characterized in that, The obtained MXenes include Ti3C2Te2, V2CTe2, Ti2CTe2, Zr2CTe2, Ti3C2S2, Ti4N3Te2, Ti3C2Se2, or Nb2CTe2.

Images