A method for preparing molybdenum-based mbenes without strong acid and strong base

Abstract

The application provides a method for preparing a molybdenum-based MBenes without strong acid and strong base, and the method comprises the following steps: carrying out a redox reaction on a mixed solution of MAB phase material and metal salt with oxidizability, and using the oxidizability of the high-valence metal salt to oxidize 0-valence Al in the MAB phase material into Al 3+ , so as to obtain a two-dimensional metal boride; the method is simple to operate, and avoids the use of dangerous solutions such as strong acid and strong base.

Description

Technical Field

[0001] This invention relates to the field of functional new materials technology, and in particular to a method for preparing molybdenum-based mbene without strong acids or bases. Background Technology

[0002] MXenes, as an important member of the two-dimensional (2D) nanomaterial family, have shown great potential in various research fields. Inspired by the successful synthesis of MXenes, researchers have been trying to extend X to other elements. Zhang et al. reported a novel MXene-like two-dimensional transition metal borides, named MBenes. Due to their excellent electrical conductivity, mechanical properties, and electrical properties, MBenes have attracted the interest of more researchers. Extensive experimental and theoretical studies have shown that they possess exciting potential for energy conversion and electrochemical storage.

[0003] The composition and structure of MAB (layered ternary transition metal borides) are highly similar to those of the MAX phase. In the MAB phase, MB bonds are covalent and ionic bonds with high bonding strength, while MA bonds are metallic bonds with relatively weak bonding strength, exactly as in the MAX stage. This similar bonding in MAB provides an opportunity to synthesize novel two-dimensional transition metal borides. Therefore, by separating the transition metal boride layer and the Al layer, it is hoped that two-dimensional transition metal borides can be obtained. However, due to the reactive nature of the boride phase and the tendency of the parent material to dissolve rather than selectively etch, fabricating similar boride materials has remained challenging.

[0004] In existing technologies, the synthesis of MBENS phases can be achieved using methods such as high-temperature dealloying, HF acid etching, and hydrothermal treatment with strong alkaline solutions. High-temperature dealloying is complex, time-consuming, and costly. Strong acid and strong alkaline etching involves highly corrosive solutions and poses a hazardous operational risk. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing molybdenum-based mbene to solve the problems existing in the prior art.

[0006] This invention involves a redox reaction between a mixed solution of MAB phase material and an oxidizing metal salt. Utilizing the oxidizing properties of high-valence Fe and Ce ions, the zero-valence Al in the MAB phase material is oxidized to Al. 3+ Two-dimensional metal borides are obtained; this method is simple to operate and avoids the use of dangerous solutions such as strong acids and strong bases.

[0007] Specifically, a solution of trivalent iron (tetravalent cerium) of a specific concentration is prepared in a reactor, the MAB phase material is dispersed in the solution, kept at a specific temperature for a period of time, cooled, washed several times with deionized water and ethanol, and dried to obtain two-dimensional metal borides (MBenes).

[0008] Furthermore, the oxidizing metal salt is a trivalent iron salt or a tetravalent cerium salt.

[0009] Furthermore, the oxidizing metal salt is ferric chloride, ferric bromide, ferric iodide, cerium sulfate, or cerium nitrate.

[0010] Furthermore, the molar ratio of metal ions to 0-valent Al in the MAB phase material is greater than 3:1.

[0011] Furthermore, the reaction temperature is 40℃~150℃, the time is 24~72 hours, and the reaction is carried out in a reaction vessel.

[0012] Furthermore, the MAB phase material is MoAlB, Mo x Cr 1-x AlB, Mo x W 1-x Any of ALB.

[0013] The beneficial effects of this invention are as follows: This invention utilizes the oxidizing properties of high-valence Fe ions and Ce ions to etch the MAB phase material through a redox reaction to obtain mbene; the method is simple to operate and avoids the use of dangerous solutions such as strong acids and strong bases. Attached Figure Description

[0014] Figure 1 Characterization of the two-dimensional sheet-like MBene obtained in Example 1, where a is the SEM image of the product, b is the XRD pattern of MoAlB, c is the XRD pattern of the product, and d is the XPS pattern of the product.

[0015] Figure 2 EDS image of the two-dimensional sheet-like MBene obtained in Example 1;

[0016] Figure 3 This is a SEM image of the two-dimensional sheet-like MBene obtained in Example 2;

[0017] Figure 4 This is a SEM image of the two-dimensional sheet-like MBene obtained in Example 3;

[0018] Figure 5 This is a SEM image of the two-dimensional sheet-like MBene obtained in Example 4;

[0019] Figure 6 This is a SEM image of the two-dimensional sheet-like MBene obtained in Example 5;

[0020] Figure 7 SEM image of the two-dimensional sheet-like MBene obtained in Example 3. Detailed Implementation

[0021] The present invention will be further described below with reference to the embodiments and accompanying drawings, but is not limited thereto.

[0022] Example 1:

[0023] Prepare 40 mL of 0.6 mol / L ferric chloride solution in a 100 mL reaction vessel. Add 0.5 g of MoAlB powder to the reaction vessel and disperse evenly. Place the reaction vessel in an oven and maintain the temperature at 150 °C for 24 hours. After cooling, centrifuge the suspension and wash several times with deionized water and ethanol. Then, disperse the sample in 50 mL of deionized water and sonicate for 1 hour. Centrifuge the resulting colloidal solution at 2500 rpm for 10 minutes, collect the supernatant, freeze-dry to obtain the product, see [link to product description]. Figure 1 and Figure 2 .

[0024] As can be seen from the figure, the product exhibits a plate-like structure, and the Mo and B elements are evenly distributed in the plate-like sample, indicating that MBene was successfully prepared in this embodiment. Figure 1 As can be seen from d, after the reaction with added Fe, the Al in the solution is in the +3 oxidation state, and a redox reaction occurs. It can be inferred that this invention utilizes the oxidizing property of high-valence Fe ions to etch MoAlB through a redox reaction to obtain MBenes.

[0025] Example 2:

[0026] Prepare 40 ml of 0.8 mol / L ferric chloride solution in a 100 ml reaction vessel. Add 0.5 g of MoAlB powder to the reaction vessel and disperse evenly. Place the reaction vessel in a water bath and incubate at 40 °C for 72 hours with stirring. After the reaction, centrifuge the suspension and wash several times with deionized water and ethanol. Then disperse the sample in 100 ml of deionized water and sonicate for 1 hour. Centrifuge the resulting colloidal solution at 2500 rpm for 10 minutes, collect the supernatant, and freeze-dry to obtain two-dimensional sheet-like MBene. See [link to relevant documentation]. Figure 3 .

[0027] Example 3:

[0028] Prepare 40 ml of 0.6 mol / L cerium sulfate solution in a 100 ml reactor. Add 0.5 g of MoAlB powder to the reactor and disperse evenly. Place the reactor in a water bath and maintain the temperature at 40 °C for 72 hours with stirring. After the reaction, centrifuge the suspension and wash several times with deionized water and ethanol. Then disperse the sample in 50 ml of deionized water and sonicate for 1 hour. Centrifuge the resulting colloidal solution at 2500 rpm for 10 minutes, collect the supernatant, and freeze-dry to obtain two-dimensional sheet-like MBene. See [link to relevant documentation]. Figure 4 and Figure 7 .from Figure 7It can be seen that the oxidizing power of high-valence cerium ions can also be used to etch MoAlB through redox reactions to obtain MBenes.

[0029] Example 4:

[0030] Prepare 40 ml of 0.8 mol / L ferric chloride solution in a 100 ml reaction vessel, and add 0.5 g of Mo... 0.6 Cr 0.4 AlB powder was poured into a reaction vessel and dispersed evenly. The reaction vessel was placed in a water bath and kept at 45°C for 72 hours with stirring. After the reaction, the suspension was centrifuged and washed several times with deionized water and ethanol. The sample was then dispersed in 100 ml of deionized water and sonicated for 1 hour. The resulting colloidal solution was centrifuged at 2500 rpm for 10 minutes, and the supernatant was collected and lyophilized to obtain two-dimensional sheet-like MBene. (See figure) Figure 5 .

[0031] Example 5:

[0032] Prepare 40 ml of 0.8 mol / L ferric chloride solution in a 100 ml reaction vessel, and add 0.5 g of Mo... 0.7 W 0.3 AlB powder was poured into a reaction vessel and dispersed evenly. The reaction vessel was placed in a water bath and kept at 40°C for 72 hours with stirring. After the reaction, the suspension was centrifuged and washed several times with deionized water and ethanol. The sample was then dispersed in 100 ml of deionized water and sonicated for 1 hour. The resulting colloidal solution was centrifuged at 2500 rpm for 10 minutes, and the supernatant was collected and lyophilized to obtain two-dimensional sheet-like MBene. (See figure) Figure 6 .

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing molybdenum-based MBenes without strong acids or bases, characterized in that, The method involves subjecting a mixed solution of MAB phase material and an oxidizing metal salt to a redox reaction, during which the zero-valent Al in the MAB phase material is oxidized to Al. 3+ Two-dimensional metal borides were obtained; The oxidizing metal salt is a trivalent iron salt or a tetravalent cerium salt; The MAB phase material is MoAlB, Mo x Cr 1-x AlB, Mo x W 1-x Any of the following in ALB; The molar ratio of metal ions to 0-valent Al in the MAB phase material is greater than 3:1, and the concentration of metal ions is 0.3~1. mol / L The concentration of the MAB phase material is 12.5 g / L; The redox reaction is carried out at a temperature of 40℃ to 150℃ for 24 to 72 hours. The reaction is conducted in a reaction vessel by stirring in a water bath, stirring in an oil bath, or heating in an oven.

2. The preparation method according to claim 1, characterized in that, The oxidizing metal salts are ferric chloride, ferric bromide, ferric iodide, cerium sulfate, and cerium nitrate.

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