A sulfided mxene catalyst and a preparation method and application thereof

Abstract

The application provides a sulfided MXene catalyst and a preparation method and application thereof, and relates to the technical field of catalyst preparation.The MXene material with a layered structure is sulfided in the application, the active sites required for a reaction are greatly increased, the electrocatalytic activity of an oxygen reduction reaction on hydrogen peroxide is improved, and the catalyst has good catalytic stability and mechanical stability, and can be used for a long time.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, and in particular to a sulfurized MXene catalyst, its preparation method, and its application in hydrogen peroxide production. Background Technology

[0002] Hydrogen peroxide (H2O2) is a green and important oxidant that has been widely used in the chemical industry, environmental remediation, and textile manufacturing. Currently, the industrial production of H2O2 mainly relies on energy-intensive anthraquinone technology, a multi-step process that requires complex and large-scale facilities and generates significant amounts of waste chemicals. Furthermore, high concentrations of H2O2 can lead to high costs and safety issues during storage and transportation. For these reasons, developing an energy-efficient route to reduce the costs of H2O2 synthesis, storage, and transportation has become an emerging trend. Recently, the electrochemical generation of H2O2 from the oxygen reduction reaction (ORR) via 2e transfer has attracted researchers' attention. However, developing highly selective and high-performance 2e ORR electrocatalysts is a prerequisite for H2O2 production.

[0003] Currently, the highest-performing catalysts used for the electrochemical synthesis of hydrogen peroxide are those made of noble metals such as gold, platinum, and palladium, exhibiting high ORR activity and H2O2 selectivity. However, their high cost and scarcity hinder their large-scale application. To achieve widespread application, research into efficient, noble metal-free electrocatalysts is crucial. Two-dimensional (2D) carbon-based materials have shown promising performance in the electrochemical synthesis of H2O2 due to their abundant reserves, tunable electronic structures, and compositional diversity. However, graphene, as the most promising 2D material, faces limitations in practical applications due to its simple chemical properties, carbon-only network structure, limited surface group types, and low electrical conductivity. Therefore, researchers have been developing other potential electrocatalysts.

[0004] MXenes are a novel two-dimensional layered metallic carbon / nitrogen compounds with the general formula M. n+1 X n T x Originating from the precursor MAX phase (M n+1 AX nMXenes, where n is 1, 2, or 3, M is an early transition metal, X is carbon, nitrogen, or both, A represents a Group IIIA or IVA element, T represents a surface terminal group such as fluorine, oxygen, chlorine, or hydroxyl, and x represents the surface functional group number. MXenes possess exceptional intrinsic properties such as high surface area, high metallic conductivity, ease of functionalization, environmental friendliness, antibacterial properties, chemical stability, activated metal hydroxide sites, and hydrophilicity, making them a preferred candidate material for applications in environmental remediation, energy storage, catalysis, sensors, and electronics. Unlike other two-dimensional materials, the functional group terminators in MXenes do not depend on any controlled reaction but are generated by the exfoliation process itself. MXenes overcome the shortcomings of graphene by combining the conductivity of transition metal carbides and the hydrophilicity of hydrogen or oxygen terminals with the excellent chemical and structural stability of ceramics. Therefore, since their discovery, people have conducted extensive and in-depth research on the synthesis, properties and applications of MXenes. It has been found that by modifying MXenes in different ways, their chemical and physical properties can be easily adjusted, and the catalytic activity of modified MXenes catalysts is similar to, or even better than, that of catalysts containing noble metals, making them a potential catalyst.

[0005] Patent CN113322485B discloses a modified MXene-supported Ni catalyst, its preparation method, and its application in hydrogen peroxide production. It describes the preparation of a catalyst using MXene as a precursor, which is then modified to support metallic Ni. MXene (Ti3C2) serves as the support, and Ni is the active component. The prepared catalyst was then used in experiments for the electrochemical synthesis of hydrogen peroxide. While this invention exhibits high selectivity and low electron transfer during the electrochemical synthesis of hydrogen peroxide, its catalytic stability is only about 3 hours, limiting its potential for industrial application. Summary of the Invention

[0006] This invention significantly increases the number of active sites required for the reaction by sulfiding the layered MXene material, thereby improving the electrocatalytic activity of the oxygen reduction reaction for hydrogen peroxide. Furthermore, the catalyst exhibits good catalytic and mechanical stability and can be used for extended periods.

[0007] One of the objectives of this invention is to provide a method for preparing a novel sulfide MXene catalyst.

[0008] The second objective of this invention is to provide a sulfurized MXene catalyst prepared by this method.

[0009] The third objective of this invention is to provide an application of the sulfurized MXene catalyst.

[0010] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0011] In a first aspect, the present invention provides a method for preparing a sulfurized MXene catalyst, comprising the following steps:

[0012] S1. Provide layered MXene material;

[0013] S2. Dissolve the layered MXene material in a solvent, add carbon disulfide, stir ultrasonically, and dry; sinter the dried powder at a higher temperature to obtain the sulfide MXene catalyst.

[0014] Step S1:

[0015] There are no special restrictions on the source of layered MXene materials; they can be obtained commercially or prepared in-house.

[0016] In some embodiments, the method for preparing the layered MXene material in step S1 includes the following steps:

[0017] (1) Add the precursor MAX to hydrofluoric acid, heat and etch, cool, wash and dry to obtain MXene powder;

[0018] (2) Disperse the MXene powder obtained in step (1) in water, add tetrabutylammonium hydroxide aqueous solution for ultrasonic treatment, collect the supernatant after separation, freeze dry to obtain layered MXene material.

[0019] Preferably, in step (1), the mass concentration of hydrofluoric acid is 35% to 50%;

[0020] Preferably, in step (1), the mass-to-volume ratio of precursor MAX to hydrofluoric acid is 1g:15mL to 1g:25mL;

[0021] Preferably, in step (1), the temperature of the heating etching process is 55-65°C and the time is 48-96h.

[0022] Preferably, in step (2), the mass concentration of the tetrabutylammonium hydroxide aqueous solution is 35% to 50%;

[0023] Preferably, in step (2), the mass-to-volume ratio of MXene powder to tetrabutylammonium hydroxide aqueous solution is 1g:1mL-1g:2mL.

[0024] Preferably, in step (2), the ultrasonic treatment temperature is room temperature and the ultrasonic treatment time is 20 to 40 minutes.

[0025] MXene materials include, but are not limited to, Mo2TiC2, Ti4C3, Ti3C2, Ti2C, Mo2C, V3C2, V2C, Hf3C2, Nb3C2, Nb2C, Cr3C2, Ta2C, Ti4N3, and V2N. A typical example is Mo2TiC2-MXene material, with the corresponding MAX precursor being Mo2TiAlC2.

[0026] Step S2:

[0027] In some embodiments, the solvent in step S2 is anhydrous ethanol.

[0028] In some embodiments, in step S2, the mass-to-volume ratio of layered MXene material to carbon disulfide is 1g:10mL-1g:30mL, preferably 1g:25mL.

[0029] In some embodiments, the ultrasonic stirring temperature in step S2 is room temperature, and the ultrasonic stirring time is 0.5 to 1.5 hours.

[0030] In some embodiments, the drying in step S2 is performed using a rotary evaporator at 40–55°C.

[0031] In some embodiments, the sintering temperature in step S2 is 500–700°C, and the sintering time is 2–3 hours.

[0032] In one specific embodiment, the method for preparing the sulfide MXene catalyst includes the following steps:

[0033] The first step is to add Mo2TiAlC2(g) powder and 40wt%HF(mL) in a ratio of 1:15 to 1:25 into a plastic bottle, and stir and react in an oil bath at 55 to 65°C for 48 to 96 hours; cool to room temperature, wash and centrifuge until the pH is neutral, and dry to obtain Mo2TiC2-MXene powder;

[0034] The synthesized dry powder was then dispersed in 50-700 mg of deionized water, and 0.5-1.5 mL of 40 wt% tetrabutylammonium hydroxide (TBAOH) was added. The mixture was ultrasonically treated for 20-40 min under continuous argon gas flow, and then centrifuged at 2000 rpm for 0.5 h. The supernatant in the test tube was collected, and the mixture was freeze-dried to obtain the layered Mo2TiC2-MXene powder.

[0035] The second step involves dissolving approximately 500 mg of the layered Mo2TiC2MXene powder obtained in the first step in 50 ml of anhydrous ethanol, then adding 5–15 ml of carbon disulfide (AR), and ultrasonically stirring for 0.5–1.5 h; then drying it using a rotary evaporator at 40–55 °C; finally, placing the resulting powder on a ceramic boat in the center of the furnace and heating it in argon atmosphere to 500–700 °C at a heating rate of 2–5 °C / min. -1 After maintaining the solution for 2 hours and cooling, a black, fluffy powder catalyst was obtained.

[0036] Secondly, the present invention provides a sulfurized MXene catalyst, prepared by the above-described preparation method, comprising layered MXene material and sulfur supported on the layered MXene material, wherein the sulfur content in the sulfurized MXene catalyst is 5-25 wt%, preferably 10-20 wt%.

[0037] The catalyst's main structure is based on layered Mo2TiC2-MXene. After sulfidation, the layered structure remains intact, and sulfur (S) reacts with the Mo layers to form Mo-S. The active components are primarily the Mo-S sites at the edges of the layered structures. Etching yields a layered MXene material with high conductivity, promoting electron transfer. Subsequent sulfidation significantly increases the number of active sites required for the reaction, enhancing the electrocatalytic activity of the oxygen reduction reaction for hydrogen peroxide. This allows the catalyst material to directly and in-situ electrocatalyze the synthesis of H2O2 at room temperature.

[0038] The catalyst is simple to prepare and the catalyst material is stable. Electrochemical tests showed that the catalyst can efficiently and selectively reduce oxygen to hydrogen peroxide, and it exhibits good catalytic and mechanical stability, allowing for long-term use and demonstrating great application potential.

[0039] Thirdly, the present invention provides an application of the above-mentioned sulfide MXene catalyst in the production of hydrogen peroxide.

[0040] In some implementations, the application includes the following steps:

[0041] The sulfide MXene catalyst, Nafion solution, ultrapure water and anhydrous ethanol were mixed to form a solution, which was then dropped onto a glass carbon disk and dried at room temperature to serve as the working electrode. A carbon rod was used as the counter electrode and an Hg / HgO electrode was used as the reference electrode to produce hydrogen peroxide.

[0042] Preferably, the added mass of MXene sulfide catalyst is 5-10 mg, and the mass-to-volume ratio of MXene sulfide catalyst to Nafion solution is 1:2 mg / μL to 1:4 mg / μL; the volume ratio of anhydrous ethanol to ultrapure water is 1:1 to 1:1.5, and the total volume is 1 mL.

[0043] The direct in-situ production method not only allows for continuous synthesis of H2O2, but also permits small-scale, decentralized production. Furthermore, the ORR electrochemical pathway is characterized by low energy consumption, low cost, and high efficiency.

[0044] Technical effects:

[0045] The catalyst of this invention is mainly based on MXene material (Mo2TiC2) as a support, which has been successfully sulfided to generate more active sites. The sulfur loading is 10-20 wt%. The prepared catalyst is then used to electrochemically synthesize hydrogen peroxide through a two-electron oxygen reduction reaction.

[0046] The catalyst of this invention has excellent electrocatalytic performance for producing hydrogen peroxide, and possesses high charge transfer capability and long-term stable operation capability: the H2O2 selectivity is over 90%, the charge transfer number is closer to 2e, and it can work continuously for 40 hours at a voltage of 0.7V vs. RHE.

[0047] The main reasons for its superior performance are:

[0048] 1. The catalyst obtained by sulfidation treatment of Mo2TiC2 material still maintains the layered structure, and the formation of the Mo-S structural layer will generate more edge sites. Moreover, the presence of the Ti layer can induce a large number of defects in the Mo-S structural layer, which helps to generate more Mo active sites, improve its inherent activity, and increase the electrical conductivity of the basal surface.

[0049] 2. The three-dimensional structure of the MXene support can highly facilitate the accessibility of ions from the electrolyte to the catalyst active site. The strong conjugation between the Mo-S structural layer and the Ti and C layers provides a resistance-free pathway that promotes charge transfer, resulting in lower charge transfer resistance, better electrochemical performance, and faster kinetics.

[0050] 3. Increased specific surface area of ​​the catalyst. The surface area most readily electrolyzed comes from the three-dimensional structure of the MXene support and the Mo-S structural layers. The multilayer interconnected three-dimensional structure of the S-Mo2TiC2 material greatly promotes the accessibility of abundant active sites in the catalyst, as well as electrolyte wetting and charge transfer, thereby achieving highly efficient electrocatalytic hydrogen peroxide production.

[0051] In summary, the novel sulfide MXene catalyst prepared in this invention exhibits high H2O2 selectivity, a charge transfer number closer to 2e, and good operational stability. This makes it a promising candidate catalyst with great potential for large-scale practical applications, further enhancing the industrial-scale potential of electrocatalytic H2O2 production.

[0052] The present invention has been described in detail above; however, the above embodiments are merely illustrative in nature and are not intended to limit the invention. Furthermore, this document is not limited to the foregoing prior art or the invention itself, or to any theory described in the following embodiments. Detailed Implementation

[0053] The present invention will be further described below with reference to the embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0054] Unless otherwise specified, the raw materials, reagents, and methods used in the embodiments are all conventional raw materials, reagents, and methods in the art.

[0055] Mo2TiAlC2 is from Jilin Yiyi Technology Co., Ltd.;

[0056] Tetrabutylammonium hydroxide is from Aladdin Reagent (Shanghai) Co., Ltd.;

[0057] Carbon disulfide was obtained from Aladdin Reagents (Shanghai) Co., Ltd.

[0058] Example 1

[0059] The preparation of catalyst S1 includes the following steps:

[0060] Step 1: Slowly add Mo2TiAlC2 powder (1.5 g) to 40 wt% HF (30 mL) and stir the solution in an oil bath at 60 °C for 72 h. After 72 h, cool the solution to room temperature and then wash and centrifuge continuously with deionized water. When the pH of the supernatant is neutral, freeze the bottom solid in a refrigerator to solidify, and then dry it with a freeze dryer to obtain catalyst M1.

[0061] Step 2: Disperse approximately 600 mg of catalyst M1 in 60 mL of deionized water, then add 1 mL of 40 wt% tetrabutylammonium hydroxide (TBAOH) aqueous solution. Sonicate the solution for 0.5 h under continuous argon gas flow, and centrifuge at 2000 rpm for 0.5 h. Collect the supernatant in the test tube to obtain the layered Mo2TiC2-MXene solution. Freeze the solution in a refrigerator until solidified, then dry it using a freeze dryer to obtain catalyst M2.

[0062] Step 3: Preparation of Mo2TiC2-based MXene sulfide material: Approximately 500 mg of M2 powder was dissolved in 50 ml of anhydrous ethanol, and then 10 ml of carbon disulfide was added. The solution was ultrasonically stirred for 1 h to form a homogeneous solution. The solution was then dried using a rotary evaporator at 45 °C. The resulting powder was placed on a ceramic boat in the center of a furnace and heated to 650 °C in argon atmosphere at a heating rate of 2 °C / min for 2 h. After cooling, catalyst S1 was finally obtained; the sulfur content was approximately 16.1 wt%.

[0063] Example 2

[0064] The preparation of catalyst S2 includes the following steps:

[0065] Steps 1 and 2 are the same as steps 1 and 2 in Example 1.

[0066] Step 3: Preparation of Mo2TiC2-based MXene sulfide material: Approximately 500 mg of catalyst M2 powder was dissolved in 50 ml of anhydrous ethanol, and then 10 ml of carbon disulfide was added. The mixture was ultrasonically stirred for 1 h to form a homogeneous solution. The solution was then dried using a rotary evaporator at 45 °C. The resulting powder was placed on a ceramic boat in the center of a furnace and heated to 650 °C in argon atmosphere at a heating rate of 2 °C / min for 4 h. After cooling, catalyst S2 was finally obtained, with a sulfur content of 20.3 wt%.

[0067] Example 3

[0068] The preparation of catalyst S3 includes the following steps:

[0069] Steps 1 and 2 are the same as steps 1 and 2 in Example 1.

[0070] Step 3: Preparation of Mo2TiC2-based MXene sulfide material: Approximately 500 mg of catalyst M2 powder was dissolved in 50 ml of anhydrous ethanol, and then 10 ml of carbon disulfide was added. The mixture was ultrasonically stirred for 1 h to form a homogeneous solution. The solution was then dried using a rotary evaporator at 45 °C. The resulting powder was placed on a ceramic boat in the center of a furnace and heated to 650 °C in argon atmosphere at a heating rate of 2 °C / min for 1 h. After cooling, catalyst S3 was finally obtained, with a sulfur content of 10.7 wt%.

[0071] Example 4

[0072] The preparation of catalyst S4 includes the following steps:

[0073] Steps 1 and 2 are the same as steps 1 and 2 in Example 1.

[0074] Step 3: Preparation of Mo2TiC2-based MXene sulfide material: Approximately 500 mg of catalyst M2 powder was dissolved in 50 ml of anhydrous ethanol, and then 10 ml of carbon disulfide was added. The mixture was ultrasonically stirred for 1 h to form a homogeneous solution. The solution was then dried using a rotary evaporator at 45 °C. The resulting powder was placed on a ceramic boat in the center of a furnace and heated to 650 °C in argon atmosphere at a heating rate of 5 °C / min for 2 h. After cooling, catalyst S4 was finally obtained, with a sulfur content of 13.4 wt%.

[0075] Example 5

[0076] The preparation of catalyst S5 includes the following steps:

[0077] Steps 1 and 2 are the same as steps 1 and 2 in Example 1.

[0078] Step 3: Preparation of Mo2TiC2-based MXene sulfide material. Approximately 500 mg of catalyst M2 powder was dissolved in 50 ml of anhydrous ethanol, followed by the addition of 10 ml of carbon disulfide. The solution was ultrasonically stirred for 1 h to form a homogeneous solution. The solution was then dried using a rotary evaporator at 55 °C. The resulting solid was placed on a ceramic boat in the center of a furnace and heated to 650 °C in argon atmosphere at a heating rate of 2 °C / min for 2 h. After cooling, catalyst S5 was finally obtained, containing 5.4 wt% sulfur.

[0079] Example 6

[0080] The preparation of catalyst S6 includes the following steps:

[0081] Steps 1 and 2 are the same as steps 1 and 2 in Example 1.

[0082] Step 3: Preparation of Mo2TiC2-based MXene sulfide material. Approximately 500 mg of catalyst M2 powder was dissolved in 50 ml of anhydrous ethanol, followed by the addition of 10 ml of carbon disulfide. The solution was ultrasonically stirred for 1 h to form a homogeneous solution. Then, it was dried using a rotary evaporator at 45 °C. The resulting solid was placed on a ceramic boat in the center of the furnace and heated to 500 °C in argon atmosphere at a heating rate of 2 °C / min for 2 h. After cooling, catalyst S6 was finally obtained, with a sulfur content of 8.3 wt%.

[0083] Comparative Example 1

[0084] Preparation of Mo2TiC2-based MXene sulfide material: Approximately 500 mg of catalyst M1 powder was dissolved in 50 ml of anhydrous ethanol, and then 10 ml of carbon disulfide was added. The solution was ultrasonically stirred for 1 h to form a homogeneous solution. The solution was then dried using a rotary evaporator at 45 °C. The resulting powder was placed on a ceramic boat in the center of a furnace and heated to 650 °C in argon atmosphere at a heating rate of 2 °C / min for 2 h. After cooling, catalyst S7 was finally obtained.

[0085] Comparative Example 2

[0086] Preparation of Mo2TiC2-based MXene oxide: Approximately 500 mg of catalyst M2 powder was placed in a ceramic boat and subjected to oxidation treatment in a muffle furnace. The mixture was heated to 650 °C in air at a rate of 2 °C / min and held for 2 hours. After cooling, catalyst O1 was finally obtained.

[0087] Test case

[0088] Preparation of the working electrode:

[0089] Add 5 mg of the catalyst to be tested, 10 μL of Nafion solution (5 wt%), 600 μL of ultrapure water, and 400 μL of anhydrous ethanol (ratio 1:2:120:80) to a centrifuge tube. After thorough mixing, sonicate for 0.5 h to form a uniform ink. Drop the ink onto a glass carbon disk and dry at room temperature.

[0090] A carbon rod is used as the counter electrode, and an Hg / HgO electrode is used as the reference electrode.

[0091] Performance testing of electrocatalytic hydrogen peroxide production:

[0092] All experiments in this paper on the electrochemical synthesis of hydrogen peroxide were performed using a CHI760E electrochemical workstation and a rotating electrode array. Tests were conducted at room temperature and pressure, using a 0.1M KOH solution (alkaline, pH = 13) as the electrolyte.

[0093] (I D : Disk current; I R (Circuit current).

[0094] Electrochemical performance (disk current and ring current) testing:

[0095] To eliminate air from the electrolyte as much as possible, the electrolyte was aerated with N2 for 30 minutes. Then, cyclic voltammetry (CV) curves were tested at a scan rate of 50 mV / s for at least 40 cycles until the CV curves stabilized. The electrolyte was then aerated with oxygen for 30 minutes. This cycle was then repeated 20 times at a scan rate of 10 mV / s until the CV curves stabilized. Finally, linear sweep voltammograms (LSV) of the oxygen-saturated electrolyte were measured using polarization curves and a rotating ring-disc electrode (RRDE). The ORR polarization curves were preserved by adjusting the rotating ring-disc electrode setup, maintaining the electrode rotation speed at 1600 rpm and the scan rate at 10 mV / s during measurement.

[0096] Stability test:

[0097] Using an electrochemical workstation with a constant controlled voltage, the voltage of the working electrode was controlled, and the change in current of the working electrode over time was measured. Specifically, under an applied voltage of 0.7V vs. RHE, the duration of continuous operation of the catalyst was investigated. The results showed that catalyst S1, with the best electrocatalytic hydrogen peroxide production performance, could operate stably for over 40 hours without significant overpotential changes, indicating that this catalyst has good stability and can be used for extended periods.

[0098] The selectivity of the catalysts prepared in the above examples and comparative examples for electrochemical hydrogen peroxide production was tested, and the test results are shown in Table 1.

[0099] Table 1 Selectivity test of catalyst electrochemical hydrogen peroxide production

[0100] catalyst Hydrogen peroxide selectivity / % M1 36 M2 53 S1 90 S2 76 S3 81 S4 85 S5 71 S6 75 S7 48 O1 40

[0101] As shown in Table 1, the catalyst S1 prepared using this invention exhibits a significantly improved hydrogen peroxide selectivity compared to the original Mo2TiC2-MXene catalyst. Furthermore, while catalysts prepared under different reaction conditions also showed improved hydrogen peroxide selectivity compared to the Mo2TiC2-MXene catalyst, the modification effect was reduced. This indicates that changes in reaction conditions affect the degree of sulfidation of the Mo2TiC2-MXene catalyst, failing to generate more active sites and thus impacting charge transfer and electrochemical hydrogen peroxide production capabilities.

[0102] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and substance defined by the claims of the present invention; and such modifications or substitutions are still within the scope defined by the claims of the present invention.

Claims

1. A method for preparing a sulfurized MXene catalyst, characterized in that, Includes the following steps: S1. Provide layered MXene material; S2. Dissolve the layered MXene material in a solvent, add carbon disulfide, stir ultrasonically, and dry; sinter the dried powder at a higher temperature to obtain the sulfide MXene catalyst. The MXene material is one of Mo2TiC2, Mo2C, and Cr3C2.

2. The preparation method according to claim 1, characterized in that, The preparation method of the layered MXene material in step S1 includes the following steps: (1) Add the precursor MAX to hydrofluoric acid, heat and etch, cool, wash and dry to obtain MXene powder; (2) Disperse the MXene powder obtained in step (1) in water, add tetrabutylammonium hydroxide aqueous solution for ultrasonic treatment, collect the supernatant after separation, freeze dry to obtain layered MXene material.

3. The preparation method according to claim 2, characterized in that, In step (1), the mass concentration of hydrofluoric acid is 35% to 50%; In step (1), the mass-to-volume ratio of precursor MAX to hydrofluoric acid is 1g:15mL to 1g:25mL; In step (1), the temperature of the heating etching process is 55-65℃ and the time is 48-96h.

4. The preparation method according to claim 2, characterized in that, In step (2), the mass concentration of the tetrabutylammonium hydroxide aqueous solution is 35% to 50%; In step (2), the mass-to-volume ratio of MXene powder to tetrabutylammonium hydroxide aqueous solution is 1g:1mL - 1g:2mL; In step (2), the ultrasonic treatment time is 20 to 40 minutes.

5. The preparation method according to claim 1, characterized in that, The MXene material is Mo2TiC2.

6. The preparation method according to claim 1, characterized in that, The solvent in step S2 is anhydrous ethanol.

7. The preparation method according to claim 1, characterized in that, In step S2, the mass-to-volume ratio of layered MXene material to carbon disulfide is 1g:10mL-1g:30mL; The drying in step S2 is performed using a rotary evaporator at 40–55°C. The sintering temperature in step S2 is 500-700℃, and the sintering time is 2-3 hours.

8. A sulfurized MXene catalyst, characterized in that, The sulfurized MXene catalyst is prepared by the preparation method according to any one of claims 1-7; The sulfurized MXene catalyst comprises layered MXene material and sulfur supported on the layered MXene material, wherein the sulfur content in the sulfurized MXene catalyst is 5~25wt%.

9. The sulfide MXene catalyst according to claim 8, characterized in that, The sulfur content in the sulfide MXene catalyst is 10~20wt%.

10. The use of the sulfide MXene catalyst of claim 8 or 9 in the production of hydrogen peroxide.

11. The application according to claim 10, characterized in that, The application includes the following steps: The sulfide MXene catalyst, Nafion solution, ultrapure water and anhydrous ethanol were mixed to form a solution, which was then dropped onto a glass carbon disk and dried at room temperature to serve as the working electrode. A carbon rod was used as the counter electrode and an Hg / HgO electrode was used as the reference electrode to produce hydrogen peroxide.