Method for transition metal ion intercalation regulation of Mo2C MXene interlayer spacing and superconducting performance

Abstract

The application discloses a method for adjusting the interlayer spacing and superconducting performance of Mo2C MXene by intercalating transition metal ions, which comprises the following steps: (1) weighing Mo2C MXene and a salt containing transition metal ions; (2) adding the salt containing transition metal ions into deionized water to obtain a transition metal ion salt solution; (3) placing the Mo2C MXene into the transition metal ion salt solution to perform a hydrothermal reaction; (4) after cooling, washing and drying by suction filtration, the Mo2C MXene material intercalated with transition metal ions is obtained. The hydrothermal synthesis method is adopted, so that the transition metal ions are uniformly and stably intercalated into the interlayer of the Mo2C MXene and form stronger coordination bonds, the intercalation product with larger interlayer spacing and more stable structure is obtained, the controllable adjustment of the interlayer spacing and superconducting performance of the Mo2C MXene material is realized, the process is simple, the repeatability is good, and the large-scale preparation is facilitated.

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 of the Invention

[0004] The technical problem this invention aims to solve is to address the shortcomings of the prior art by providing a method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation. This method employs a hydrothermal synthesis approach, enabling the uniform and stable intercalation of transition metal ions into the interlayer space of Mo2C MXene, forming stronger coordination bonds. This results in intercalated products with larger interlayer spacing and more stable structures, achieving controllable adjustment of the interlayer spacing and superconducting properties of Mo2C MXene. This solves the problems of low intercalation efficiency, uneven ion insertion, and limited and unstable interlayer spacing expansion in room temperature ion exchange methods, leading to poor regulation and repeatability of the superconducting properties of MXene materials.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a method for regulating the interlayer spacing and superconducting properties of Mo2C MXene by 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.

[0006] The above-mentioned method for regulating the interlayer spacing and superconducting properties of Mo2C MXene by transition metal ion intercalation is characterized in that the salt containing transition metal ions in step one is one or more of the transition metal nitrates, chlorides, sulfates and acetates.

[0007] The above-mentioned method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation is characterized in that the transition metal ion in step one is Fe, Co, Ni, Cu or Zn.

[0008] The above-mentioned method for regulating the interlayer spacing and superconducting properties of Mo2C MXene by intercalation of transition metal ions is characterized in that the molar ratio of Mo2C MXene and salt containing transition metal ions in step one is 1:0.05~0.3. The above-mentioned method for regulating the interlayer spacing and superconducting properties of Mo2C MXene through transition metal ion intercalation is characterized in that the hydrothermal reaction in step three is carried out at a temperature of 140℃~180℃ for 12h~24h.

[0009] Compared with the prior art, the present invention has the following advantages: 1. This invention employs a hydrothermal synthesis method, reacting Mo2C MXene with a salt containing transition metal ions under high temperature and high pressure. This provides higher kinetic energy to the transition metal ions, enabling them to overcome energy barriers and uniformly and stably intercalate into the interlayer space of Mo2C MXene. Furthermore, it allows them to form stronger coordination bonds with surface functional groups, thus stabilizing the interlayer spacing control effect and obtaining intercalated products with larger interlayer spacing and more stable structures. This achieves controllable and effective regulation of the superconducting transition temperature, i.e., the superconducting performance, of Mo2C MXene.

[0010] 2. The method of the present invention has wide applicability to the types of intercalated transition metal ions (Fe, Co, Ni, Cu, Zn, etc.) and the types of salts (nitrates, chlorides, sulfates, and acetates, etc.). At the same time, by simply adjusting the process parameters of the raw material molar ratio, hydrothermal reaction temperature, and time, the concentration of intercalated transition metal ions and the structure of the final product material can be precisely controlled, realizing "on-demand design" from material structure to physical properties.

[0011] 3. Compared with traditional intercalation methods that often use toxic organic solvents or highly corrosive reagents, the main medium used in this invention is deionized water, and the transition metal salts used are also easy to handle, making the entire process green and environmentally friendly. At the same time, the hydrothermal reaction is carried out in a closed reactor, which avoids the volatilization of harmful substances and improves operational safety.

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

[0013] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0014] Figure 1 Fe prepared in Example 1 of this invention 3+ XRD pattern of intercalated Mo2C MXene material.

[0015] Figure 2 Fe prepared in Example 1 of this invention 3+ MT spectrum of intercalated Mo2C MXene material.

[0016] Figure 3 Co prepared in Example 2 of this invention 2+ XRD pattern of intercalated Mo2C MXene material.

[0017] Figure 4 Co prepared in Example 2 of this invention 2+ MT spectrum of intercalated Mo2C MXene material.

[0018] Figure 5 Ni prepared in Example 3 of this invention 2+ XRD pattern of intercalated Mo2C MXene material.

[0019] Figure 6 Ni prepared in Example 3 of this invention 2+ MT spectrum of intercalated Mo2C MXene material. Detailed Implementation

[0020] Example 1 This embodiment includes the following steps: Step 1: Weigh Mo2C MXene and Fe(NO3)3·9H2O separately at a molar ratio of 1:0.3; Step 2: Place the weighed Fe(NO3)3·9H2O from Step 1 into the reaction vessel, add 40mL of deionized water and stir continuously until completely dissolved to obtain Fe(NO3)3 solution; Step 3: Place the Mo2C MXene weighed in Step 1 into the Fe(NO3)3 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 complete, cool to room temperature, wash with plenty of deionized water until neutral, filter and dry to obtain Fe. 3+ Intercalated Mo2C MXene material.

[0021] Figure 1 Fe prepared in this embodiment 3+ XRD patterns of intercalated Mo2C MXene materials, from Figure 1 It can be seen that after Fe 3+ After intercalation, a strong (002) peak appeared at approximately 8.76°, corresponding to an interlayer spacing of 10.09 Å. This is a characteristic peak of two-dimensional layered Mo2CMXene materials, indicating the successful preparation of Fe. 3+ Intercalated Mo2C MXene material. However, compared with the standard Mo2C MXene XRD pattern, the standard (002) peak is located at 8.39°, corresponding to an interlayer spacing of 10.53 Å. Fe 3+ After intercalation, the (002) peak shifts to a higher angle, indicating that the interlayer spacing of the Mo2C MXene material is compressed. The reason for this may be Fe. 3+The smaller ionic radius and higher charge of the ions result in stronger electrostatic attraction, leading to tighter interlayer bonding in Mo2C MXene materials and thus a reduction in interlayer spacing.

[0022] Figure 2 Fe prepared in this embodiment 3+ MT spectrum of intercalated Mo2C MXene material, from Figure 2 It can be seen that the Fe 3+ Superconducting transition temperature of intercalated Mo2C MXene materials T c It is 4.6K.

[0023] In this embodiment, the salt containing transition metal ions may also be one or more of the transition metal nitrates, chlorides, sulfates, and acetates, excluding transition metal nitrates; the transition metal ions may also be Cu or Zn.

[0024] Example 2 This embodiment includes the following steps: Step 1: Weigh Mo2C MXene and Co(NO3)2·6H2O separately at a molar ratio of 1:0.3; Step 2: Place the weighed Co(NO3)2·6H2O from Step 1 into the reaction vessel, add 40mL of deionized water and stir continuously until completely dissolved to obtain a Co(NO3)2 solution. Step 3: Place the weighed Mo2C MXene from Step 1 into the Co(NO3)2 solution from Step 2 and stir continuously for 30 minutes. Then place it in an oven and carry out a hydrothermal reaction at 180°C for 24 hours. Step 4: After the hydrothermal reaction in Step 3 is complete, cool to room temperature, wash with plenty of deionized water until neutral, filter and dry to obtain Co. 2+ Intercalated Mo2C MXene material.

[0025] Figure 3 Co prepared in this embodiment 2+ XRD patterns of intercalated Mo2C MXene materials, from Figure 3 It can be seen that after Co 2+ After intercalation, a strong (002) peak appeared at approximately 7.15°, corresponding to an interlayer spacing of 12.36 Å, indicating that Co was successfully prepared. 2+ Intercalated Mo2C MXene material. Co 2+ After intercalation, the (002) peak shifts to a lower angle, indicating that the interlayer spacing of Mo2C MXene increases.

[0026] Figure 4 Co prepared in this embodiment2+ 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 preparation of Ni. 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 transition metal ion salt solution in Step 2 and stir continuously. Then place it in an oven for hydrothermal reaction. The temperature of the hydrothermal reaction is 140℃~180℃ and the time is 12h~24h. 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.

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