Method for regulating and controlling interlayer spacing and superconducting performance of Mo2C MXene through transition metal ion intercalation

Abstract

The invention discloses a method for regulating and controlling interlayer spacing and superconducting performance of Mo2C MXene through transition metal ion intercalation. The method comprises the following steps: 1, weighing Mo2C MXene and salt containing transition metal ions; 2, adding salt containing transition metal ions into deionized water to obtain a salt solution of the transition metal ions; 3, putting Mo2C MXene into a salt solution of transition metal ions, and carrying out a hydrothermal reaction; and 4, cooling, washing, carrying out suction filtration, and drying to obtain the transition metal ion intercalated Mo2C MXene material. According to the preparation method, a hydrothermal synthesis method is adopted, so that transition metal ions are uniformly and stably intercalated into interlayers of Mo2C MXene, stronger coordinate bonds are formed, an intercalation product with larger interlayer spacing and more stable structure is obtained, controllable adjustment of the interlayer spacing and superconducting performance of the Mo2C MXene material is realized, and the preparation method is simple in process, good in repeatability and beneficial to large-scale preparation.

Description

Technical Field

[0001] This invention belongs to the field of two-dimensional material interlayer spacing control technology, specifically relating to a method for controlling the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation. Background Technology

[0002] MXenes, as a new class of two-dimensional inorganic compounds, have shown great potential in energy storage, catalysis, electromagnetic shielding, and superconductivity due to their excellent metallic conductivity, rich surface chemistry, and tunable interlayer structure. Among the many MXene members, molybdenum-based MXenes (especially Mo2CTx) have attracted much attention due to their unique electronic structure. Compared with the common Ti3C2T... x Compared to MXene, Mo₂C exhibits higher intrinsic conductivity and density of states, with its electronic states near the Fermi level primarily originating from the d orbitals of Mo. Theoretical calculations and preliminary experiments indicate that bulk Mo₂C is itself a conventional phonon-mediated Bardeen-Cooper-Schrieffer (BCS) superconductor, with a superconducting transition temperature (…). T c In bulk materials, the interlayer spacing is approximately a few K. However, when exfoliated into two-dimensional monolayer or few-layer structures, its superconductivity is significantly affected, or even suppressed, by dimensional effects and surface termination groups. Therefore, how to effectively control the interlayer spacing and superconducting properties of two-dimensional Mo2C MXene has become an important scientific problem.

[0003] Currently, there are various strategies for interlayer modification of MXene, including molecular intercalation (such as DMF, TBAOH) and ionic intercalation (such as Li). + Alkali metal ions such as Na⁺ and K⁺ and transition metal ion intercalation (such as Fe) 2+ Co 2+ Cu 2+ Transition metal ion intercalation offers unique advantages over other intercalators. Transition metal ions typically possess large ionic radii and high charge densities, potentially forming strong coordination or ionic bonds with the MXene surface termination groups. This strong interaction produces a more stable and permanent interlayer spacing widening effect, less prone to collapse under cycling or external conditions. Furthermore, some transition metal ions (such as Fe, Co, and Ni) possess unpaired d electrons, potentially introducing localized magnetic moments. While introducing magnetic elements into superconducting materials is generally considered a disadvantage (based on BCS theory), it provides a platform for studying novel physical phenomena such as unconventional superconductivity, Ising pairing, or the competition / coexistence of superconductivity and magnetism. Therefore, there is an urgent need to develop a transition metal ion intercalation technique to investigate the relationship between interlayer spacing variations and superconducting properties in Mo₂C MXene materials. SUMMARY

[0004] The technical problem solved by the present application is to provide a method for regulating the interlayer spacing and superconducting performance of Mo2C MXene by intercalating transition metal ions, aiming at the deficiencies of the prior art. The method uses a hydrothermal synthesis method to uniformly and stably intercalate transition metal ions into the interlayer of Mo2C MXene and form stronger coordination bonds, thereby obtaining intercalation products with larger interlayer spacing and more stable structure, realizing controllable regulation of the interlayer spacing and superconducting performance of Mo2C MXene material, and solving the problems of low intercalation efficiency, uneven ion intercalation, limited and unstable interlayer spacing expansion, poor regulation effect on the superconducting performance of MXene material, and poor repeatability of the room temperature ion exchange method.

[0005] To solve the above technical problems, the technical solution adopted by the present application is: a method for regulating the interlayer spacing and superconducting performance of Mo2C MXene by intercalating transition metal ions, characterized in that the method comprises the following steps: Step one, Mo2C MXene and a salt containing transition metal ions are weighed according to the designed molar ratio; Step two, the salt containing transition metal ions weighed in step one is placed in a reaction kettle, and after adding deionized water, it is continuously stirred until completely dissolved, obtaining a salt solution of transition metal ions; Step three, the Mo2C MXene weighed in step one is placed in the salt solution of transition metal ions in step two and continuously stirred, and then placed in an oven for hydrothermal reaction; Step four, after the hydrothermal reaction in step three is completed, it is cooled to room temperature, washed with deionized water until neutral, dried by suction filtration, and the Mo2C MXene material intercalated with transition metal ions is obtained.

[0006] The method for regulating the interlayer spacing and superconducting performance of Mo2C MXene by intercalating transition metal ions, wherein the salt containing transition metal ions in step one is one or more than two of nitrate, chloride, sulfate and acetate of transition metal.

[0007] The method for regulating the interlayer spacing and superconducting performance of Mo2C MXene by intercalating transition metal ions, wherein the transition metal ions in step one are Fe, Co, Ni, Cu or Zn.

[0008] The method for regulating the interlayer spacing and superconducting performance of Mo2C MXene by intercalating transition metal ions, wherein the molar ratio of Mo2C MXene and the salt containing transition metal ions in step one is 1:0.05-0.3. The method for regulating the interlayer spacing and superconducting performance of Mo2C MXene by intercalating transition metal ions has the characteristics that the temperature of the hydrothermal reaction in step three is 140 DEG C to 180 DEG C, and the time is 12 hours to 24 hours.

[0009] Compared with the prior art, the present application has the following advantages: 1. The present application uses a hydrothermal synthesis method to react Mo2C MXene and a salt containing transition metal ions under high temperature and high pressure, thereby providing the transition metal ions with higher kinetic energy, enabling them to overcome the energy barrier, uniformly and stably intercalate into the interlayer of Mo2C MXene, and form stronger coordination bonds with the surface functional groups, so that the interlayer spacing regulation effect is stable, and intercalated products with larger interlayer spacing and more stable structure are obtained, thereby realizing controllable and effective regulation of the superconducting transition temperature, i.e. superconducting performance, of Mo2C MXene.

[0010] 2. The method of the present application has wide adaptability to the types of intercalated transition metal ions (Fe, Co, Ni, Cu, Zn, etc.) and the types of salts (nitrate, chloride, sulfate and acetate, etc.), and can accurately regulate the concentration of intercalated transition metal ions and the structure of the final product material by simply adjusting the process parameters of the molar ratio of raw materials, the hydrothermal reaction temperature and time, thereby realizing "on-demand design" from material structure to physical properties.

[0011] 3. Compared with the traditional intercalation method which usually uses toxic organic solvents or strong corrosive reagents, the present application mainly uses deionized water as the medium, and the transition metal salt used is also easy to handle, so that the whole process is green and environmentally friendly; at the same time, the hydrothermal reaction is carried out in a closed reaction kettle, thereby avoiding the volatilization of harmful substances and improving the operation safety.

[0012] 4. The preparation method of the present application is simple and has good repeatability, which is conducive to large-scale preparation.

[0013] The technical solutions of the present application will be further described in detail below with the aid of drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Fe prepared for Example 1 of the present application 3+ XRD pattern of the intercalated Mo2C MXene material.

[0015] Figure 2 Fe prepared for Example 1 of the present application 3+ M-T pattern of the intercalated Mo2C MXene material.

[0016] Figure 3 Co prepared for Example 2 of the present application 2+ XRD pattern of the intercalated Mo2C MXene material.

[0017] Figure 4 Co prepared for the present embodiment 2 2+ M-T spectrum of the intercalated Mo2C MXene material.

[0018] Figure 5 Ni prepared for the present embodiment 3 2+ XRD spectrum of the intercalated Mo2C MXene material.

[0019] Figure 6 Ni prepared for the present embodiment 3 2+ M-T spectrum of the intercalated Mo2C MXene material. DETAILED DESCRIPTION

[0020] Embodiment 1 This embodiment includes the following steps: Step one, Mo2C MXene and Fe(NO3)3·9H2O were weighed according to the molar ratio of 1:0.3 respectively; Step two, Fe(NO3)3·9H2O weighed in step one was placed in a reaction kettle, and after adding 40 mL of deionized water, it was continuously stirred until completely dissolved to obtain a Fe(NO3)3 solution; Step three, Mo2C MXene weighed in step one was placed in the Fe(NO3)3 solution in step two and continuously stirred for 30 min, and then placed in an oven for hydrothermal reaction at 180℃ for 24 h; Step four, after the hydrothermal reaction in step three was completed, it was cooled to room temperature, washed with a large amount of deionized water until neutral, and dried by suction filtration to obtain Fe 3+ Intercalated Mo2C MXene material.

[0021] Figure 1 Fe prepared for the present embodiment 3+ XRD spectrum of the intercalated Mo2C MXene material, from Figure 1 It can be seen that after Fe 3+ intercalation, a strong (002) peak appeared around 8.76°, corresponding to an interlayer spacing of 10.09 Å, which is the marker peak of two-dimensional layered Mo2C MXene material, indicating that the Fe 3+ Intercalated Mo2C MXene material was successfully prepared. However, compared with the standard XRD spectrum of Mo2C MXene, the standard (002) peak is located at 8.39°, corresponding to an interlayer spacing of 10.53 Å. After Fe 3+ intercalation, the (002) peak moves to a high angle, indicating that the interlayer spacing of the Mo2C MXene material is compressed. The reason for this may be that Fe 3+The smaller ionic radius and the stronger electrostatic attraction caused by the high charge of Mo2C MXene material make the interlayer binding more compact, resulting in a smaller interlayer spacing.

[0022] Figure 2 Fe 3+ M-T spectrum of the intercalated Mo2C MXene material, from Figure 2 It can be seen that the Fe 3+ Superconducting transition temperature of the intercalated Mo2C MXene material T c is 4.6 K.

[0023] The salt containing transition metal ions in this embodiment can also be one or more of the following: nitrate, chloride, sulfate, and acetate of the transition metal, except for the nitrate of the transition metal; the transition metal ions can also be Cu or Zn.

[0024] Example 2 This embodiment includes the following steps: Step one, weigh Mo2C MXene and Co(NO3)2·6H2O according to the molar ratio of 1:0.3 respectively; Step two, place the weighed Co(NO3)2·6H2O in step one into the reaction kettle, add 40 mL of deionized water and continuously stir until completely dissolved to obtain a Co(NO3)2 solution; Step three, place the weighed Mo2C MXene in step one into the Co(NO3)2 solution in step two and continuously stir for 30 min, then place it in an oven for hydrothermal reaction at 180℃ for 24 h; Step four, after the hydrothermal reaction in step three is completed, cool to room temperature, rinse with a large amount of deionized water until neutral, and dry by suction filtration to obtain Co 2+ intercalated Mo2C MXene material.

[0025] Figure 3 Co 2+ XRD spectrum of the intercalated Mo2C MXene material, from Figure 3 It can be seen that after the Co 2+ intercalation, a strong (002) peak appears at about 7.15°, corresponding to an interlayer spacing of 12.36 Å, indicating that the Co 2+ intercalated Mo2C MXene material is successfully prepared. After the Co 2+ intercalation, the (002) peak moves to a lower angle, indicating that the interlayer spacing of Mo2C MXene increases.

[0026] Figure 4 Co2+ MT spectrum of intercalated Mo2C MXene material, from Figure 4 It can be seen that the Co 2+ Superconducting transition temperature of intercalated Mo2C MXene materials T c It is 4.9K.

[0027] Example 3 This embodiment includes the following steps: Step 1: Weigh Mo2C MXene and Ni(NO3)2·6H2O separately at a molar ratio of 1:0.3; Step 2: Place the Ni(NO3)2·6H2O weighed in Step 1 into the reaction vessel, add 40mL of deionized water and stir continuously until completely dissolved to obtain Ni(NO3)2 solution; Step 3: Place the Mo2C MXene weighed in Step 1 into the Ni(NO3)2 solution in Step 2 and stir continuously for 30 min. Then place it in an oven and carry out a hydrothermal reaction at 180℃ for 24 h. Step 4: After the hydrothermal reaction in Step 3 is completed, cool to room temperature, wash with plenty of deionized water until neutral, filter and dry to obtain Ni. 2+ Intercalated Mo2C MXene material.

[0028] Figure 5 Ni prepared in this embodiment 2+ XRD patterns of intercalated Mo2C MXene materials, from Figure 5 It can be seen that after Co 2+ After intercalation, a strong (002) peak appeared at approximately 7.09°, corresponding to an interlayer spacing of 12.47 Å, indicating successful Ni fabrication. 2+ Intercalated Mo2C MXene material. Ni 2+ After intercalation, the (002) peak shifts to a lower angle, indicating that the interlayer spacing of Mo2C MXene increases.

[0029] Figure 6 Ni prepared in this embodiment 2+ MT spectrum of intercalated Mo2C MXene material, from Figure 6 It can be seen that the Ni 2+ Superconducting transition temperature of intercalated Mo2C MXene materials T c It is 5.2K.

[0030] Example 4 This embodiment includes the following steps: Step 1: Weigh Mo2C MXene and Ni(NO3)2·6H2O separately at a molar ratio of 1:0.05; Step 2: Place the Ni(NO3)2·6H2O weighed in Step 1 into the reaction vessel, add 40mL of deionized water and stir continuously until completely dissolved to obtain Ni(NO3)2 solution; Step 3: Place the Mo2C MXene weighed in Step 1 into the Ni(NO3)2 solution in Step 2 and stir continuously for 30 min. Then place it in an oven and carry out a hydrothermal reaction at 140℃ for 12 h. Step 4: After the hydrothermal reaction in Step 3 is completed, cool to room temperature, wash with plenty of deionized water until neutral, filter and dry to obtain Ni. 2+ Intercalated Mo2C MXene material.

[0031] As can be seen from the test, Ni in this embodiment 2+ The XRD pattern of the intercalated Mo2C Mxene material showed a strong (002) peak at around 8.35°, indicating the successful preparation of Ni. 2+ Intercalated Mo2C MXene material. Compared to the standard sample, the (002) peak shift is smaller, indicating that Ni under this condition... 2+ The intercalation effect is not obvious, and it has little effect on the interlayer spacing of Mo2C MXene material.

[0032] Upon testing, the Ni 2+ Superconducting transition temperature of intercalated Mo2C MXene materials T c It is 5.6K.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation, characterized in that, The method includes the following steps: Step 1: Weigh Mo2C MXene and the salt containing transition metal ions according to the designed molar ratio; Step 2: Place the salt containing transition metal ions weighed in Step 1 into the reaction vessel, add deionized water and stir continuously until completely dissolved to obtain a salt solution of transition metal ions. Step 3: Place the Mo2C MXene weighed in Step 1 into the salt solution of transition metal ions in Step 2 and stir continuously, then place it in an oven for hydrothermal reaction. Step 4: After the hydrothermal reaction in Step 3 is completed, cool to room temperature, rinse with deionized water until neutral, filter and dry to obtain Mo2C MXene material with transition metal ion intercalation.

2. The method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation according to claim 1, characterized in that, The salt containing transition metal ions mentioned in step one is one or more of the transition metal nitrates, chlorides, sulfates and acetates.

3. The method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation according to claim 1, characterized in that, The transition metal ions mentioned in step one are Fe, Co, Ni, Cu or Zn.

4. The method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation according to claim 1, characterized in that, The molar ratio of Mo2C MXene and the salt containing transition metal ions in step one is 1:0.05~0.

3.

5. The method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation according to claim 1, characterized in that, The hydrothermal reaction in step three is carried out at a temperature of 140℃~180℃ for 12h~24h.

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