Anatase TiO2 loaded RuCo nanocluster composite material and its preparation method and application

Abstract

The present invention discloses anatase TiO2-loaded RuCo nanocluster composite material, its preparation method and application, and belongs to the technical field of water electrolysis hydrogen production catalyst. The anatase TiO2-loaded RuCo nanocluster composite material has a two-dimensional lamellar structure, including two-dimensional lamellar anatase TiO2 and RuCo nanoclusters, and the RuCo nanoclusters are loaded on the surface of the two-dimensional lamellar anatase TiO2. The present invention loads RuCo nanoclusters on the two-dimensional lamellar MXene by impregnation method, and uses annealing to convert Ti3C2T x MXene is converted into anatase TiO2. The anatase TiO2 in this invention exhibits excellent thermodynamic and chemical stability while retaining a two-dimensional lamellar structure, which inhibits surface RuCo metal aggregation and reduces the amount of RuCo metal required. The RuCo metal, however, exists on the support surface as nanoclusters, exhibiting good dispersion, increasing the utilization of metal sites and exhibiting excellent catalytic activity.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts for hydrogen production by electrolysis of water, and in particular to anatase-type TiO2-loaded RuCo nanocluster composite materials, and a preparation method and application thereof. Background Art

[0002] Hydrogen production through water electrolysis uses electricity to split water into hydrogen and oxygen. This process typically takes place in an electrolyzer. To increase the solution's conductivity and reduce energy consumption, electrolytes are often added to the water to enhance its conductivity. Under the influence of direct current, the decomposition reaction occurs, with oxygen produced at the positive electrode (anode) and hydrogen at the negative electrode (cathode). Water electrolysis is an important method for producing high-purity hydrogen and is crucial for promoting the development of clean energy technologies such as hydrogen vehicles and fuel cells.

[0003] Depending on the type of electrolyte used, water electrolysis can be divided into two main methods: alkaline electrolysis and acidic electrolysis. Since acidic water electrolysis has the advantages of being able to operate at a higher current density and the system has the ability to start and stop quickly, it has become the current research and development focus in the field of water electrolysis for hydrogen production and has begun commercial application. However, acidic water electrolysis is highly oxidizing and corrosive, and only a few precious metal-based electrocatalysts such as platinum and iridium dioxide can exhibit good catalytic activity and stability under such working conditions. However, due to the high cost of these precious metals, more cost-effective alternatives need to be explored. Summary of the Invention

[0004] The purpose of the present invention is to provide anatase TiO2 loaded RuCo nanocluster composite material and its preparation method and application, so as to solve the problems of poor oxidation resistance and corrosion resistance and high cost of catalysts in the prior art.

[0005] To achieve the above-mentioned objectives, the present invention provides an anatase TiO2-loaded RuCo nanocluster composite material. The anatase TiO2-loaded RuCo nanocluster composite material has a two-dimensional lamellar structure, comprising two-dimensional lamellar anatase TiO2 and RuCo nanoclusters, wherein the RuCo nanoclusters are loaded on the surface of the two-dimensional lamellar anatase TiO2.

[0006] Preferably, the two-dimensional lamellar anatase TiO2 has a sheet diameter of 5-50 μm.

[0007] Preferably, the diameter of the RuCo nanoclusters is 1-5 nm.

[0008] Preferably, the mass ratio of Ru to Co in the RuCo nanoclusters is 40:(1-5).

[0009] The present invention also provides a method for preparing the above-mentioned anatase TiO2 loaded RuCo nanocluster composite material, wherein the RuCo nanocluster is loaded on a two-dimensional lamellar Ti3C2T x MXene surface, which is then annealed in a weak oxidizing atmosphere; in MAX, M stands for early transition metal, A stands for aluminum, and X stands for carbon. MAX is a general term for transition metal carbide materials; in Ti3C2T x In MXene, T x Represents the functional group produced by the reaction.

[0010] The following steps are involved:

[0011] (1) Preparation of Ti3AlC2MAX powder: titanium powder, aluminum powder and carbon powder are mixed and stirred evenly, the mixed powder is sintered under an inert gas atmosphere, and then crushed and ground to obtain Ti3AlC2MAX powder;

[0012] (2) Multilayer accordion-shaped Ti3C2T x Preparation of MXene: Take the Ti3AlC2MAX powder obtained in step (1), mix it with hydrofluoric acid solution, heat it in a water bath, and stir it continuously. Centrifuge the suspension after the reaction, take the precipitate and wash it repeatedly by centrifugation, filter it, and vacuum dry it to obtain a multi-layer accordion-shaped Ti3C2T x MXene;

[0013] (3) Two-dimensional lamellar Ti3C2T x Preparation of MXene: Take the multilayer accordion-shaped Ti3C2T obtained in step (2) x MXene is mixed with an intercalating agent and stirred to obtain a suspension, which is centrifuged until the pH value of the supernatant is 6.0-8.0. The precipitate is retained, and deionized water is repeatedly added to the precipitate for dispersion and then centrifuged for the first time. The suspension is ultrasonicated in an ice bath under the action of inert gas bubbling, and centrifuged for a long time to obtain a supernatant. The supernatant is freeze-dried to obtain an aerogel-like freeze-dried powder, that is, a two-dimensional lamellar Ti3C2T x MXene;

[0014] (4) Preparation of two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material: Take the two-dimensional lamellar Ti3C2T obtained in step (3) xMXene is added to deionized water, and a salt solution of RuCl3·3H2O and Co(NO3)2·6H2O is added dropwise, stirred, and ultrasonicated in an ice bath under the action of inert gas bubbling. The precipitate is centrifuged to obtain a precipitate, and the precipitate is repeatedly centrifuged and washed. The mixture containing the precipitate after final cleaning is freeze-dried to obtain a freeze-dried powder. The freeze-dried powder is then annealed and kept warm in a weak oxidizing gas with an oxygen content of less than 0.001% to obtain a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material.

[0015] Preferably, in step (1), the molar ratio of titanium powder, aluminum powder and carbon powder is 3:1.2:1.9;

[0016] The oxygen content in the inert gas atmosphere is less than 0.001%, and the flow rate of the inert gas in the tube furnace is 150-250cm 3 / min;

[0017] The sintering was carried out by a programmed temperature rising method. The heating rate from room temperature to 1200°C was 10°C / min, the heating rate from 1200°C to the sintering temperature was 2°C / min, the sintering temperature was 1300-1600°C, and the sintering time was 6-12h. The particle size of the Ti3AlC2MAX powder was 50-100 μm.

[0018] Typically, in this step, a mixed powder consisting of titanium powder, aluminum powder, and carbon powder is spread flat in a corundum crucible and placed in a tube furnace through a pressureless sintering method to prepare Ti3AlC2MAX powder. After sintering, the temperature is cooled to room temperature. After the sintered sample is removed, the sintered block is crushed with a carbide hammer and then ground into Ti3AlC2MAX powder with a grinding pestle in an agate mortar. The particle size of the ground Ti3AlC2MAX powder is controlled to ensure that the Ti3AlC2MAX powder is fully in contact with the etchant in the subsequent steps, thereby obtaining a better etching effect.

[0019] Preferably, in step (2), the mass concentration of hydrofluoric acid is 40-50%; the mass volume ratio of Ti3AlC2MAX powder to hydrofluoric acid solution is 1:(10-20) g / mL;

[0020] The water bath heating temperature is 40-60°C, the stirring speed is 300-500 r / min, and the water bath heating and stirring time is 48-72 hours; the centrifugal speed is 4000-6000 r / min, and the centrifugation time is 3-8 minutes; the standard for the completion of sediment cleaning is that the pH value of the supernatant is between 6.0-8.0; the vacuum drying time is 24-48 hours.

[0021] In this step, hydrofluoric acid solution is used as an etchant, and the Ti3AlC2MAX powder is etched by the etchant into multilayer Ti3C2Tx MXene, this multilayer Ti3C2T x MXene is accordion-shaped, and the etching process is usually carried out in a polytetrafluoroethylene container, and magnetic stirring is used to ensure full contact between the Ti3AlC2MAX powder and the etchant.

[0022] Preferably, in step (3), the intercalant is any one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, and the mass concentration of the intercalant is 10-15wt%; the multilayer accordion-shaped Ti3C2T x The mass volume ratio of MXene to intercalant is 1:(10-40) g / mL;

[0023] Step (3) is carried out in a weak oxidizing gas with an oxygen content of less than 0.001%. The speed of the initial centrifugation is 4000-6000 r / min, and the time is 3-8 minutes; the ultrasonic treatment time is 1-2 hours; the speed of the long-term centrifugation is 3000-4000 r / min, and the long-term centrifugation time is 50-70 minutes; and the freeze-drying time is 48-72 hours.

[0024] In this step, the multilayer accordion-shaped Ti3C2T x MXene and intercalation agent form a suspension, the suspension is separated by centrifugation, the precipitate is washed several times, and the intercalation agent is removed. After the intercalation agent is completely removed, the precipitate is dispersed again with deionized water. Usually, the amount of deionized water used is 10-20 times the mass of the precipitate. In addition, the multilayer accordion-shaped Ti3C2T x When mixing MXene and the intercalant, they can be mixed evenly by hand shaking. Usually, the mixing time is 5-15 minutes. This manual shaking is convenient to operate and can mix evenly.

[0025] Preferably, in step (4), the two-dimensional lamellar Ti3C2T x The mass volume ratio of MXene to deionized water is 2: (1-10) mg / mL; the mass concentrations of RuCl3·3H2O and Co(NO3)2·6H2O are both 10-20 mg / mL;

[0026] The stirring speed is 1000-1500 r / min, and the stirring time is 30-60 min; ultrasonication is carried out in a weak oxidizing gas with an oxygen content of less than 0.001% for 30-60 min; the centrifugal speed is 4000-6000 r / min, the centrifugal time is 3-8 min, and the number of centrifugation is 2-4 times; the freeze-drying time is 48-72 h; the freeze-dried powder is annealed and kept warm in a tube furnace, and the flow rate of the weak oxidizing gas in the tube furnace is 50-150 cm 3 / min; the heating rate from room temperature to annealing temperature is 5℃ / min, the annealing temperature is 400-600℃, and the holding time is 1-3 h.

[0027] The purpose of stirring and ice bath ultrasound in this step of the immersion method is to mix the solution so that RuCo metal ions can be successfully loaded on Ti3C2T x MXene surface. After repeated washing of the precipitate and the unloaded metal salt solution, the resulting precipitate is the precursor of a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material.

[0028] The anatase-type TiO2-loaded RuCo nanocluster composite material provided by the present invention is used in the field of preparing catalysts for hydrogen production by electrolysis of water.

[0029] The flaky anatase TiO2 in this invention possesses a two-dimensional lamellar structure. It is derived from the oxidation of two-dimensional lamellar Ti3C2Tx MXene via its own functional groups. This makes it an excellent catalytic material that combines the two-dimensional lamellar morphology of MXene with strong corrosion and oxidation resistance. Anatase TiO2 has a tetragonal crystal structure with space group I41 / amd. Its high electron mobility, low dielectric constant, excellent chemical stability, and corrosion resistance make it an important catalyst in a variety of applications.

[0030] The RuCo nanoclusters, composed of microscopic particles consisting of tens to hundreds of atoms, possess a large specific surface area, increasing the number of surface active sites and improving catalytic reaction efficiency while simultaneously reducing metal loading and significantly lowering catalyst costs. Furthermore, the synergistic effect between the Ru and Co metals in the RuCo nanoclusters microscopically regulates their electronic structures, further lowering the reaction energy barrier and promoting the occurrence of catalytic reactions.

[0031] Therefore, the present invention adopts the above-mentioned anatase TiO2-loaded RuCo nanocluster composite material and its preparation method and application, which has the following beneficial effects:

[0032] (1) The present invention first prepares Ti3AlC2MAX powder by pressureless sintering, which has the advantages of low cost, simple operation and safe operation; then, the present invention prepares Ti3AlC2MAX powder into few-layer Ti3C2T x MXene powder, RuCo nanoclusters loaded on Ti3C2T by impregnation method x The MXene carrier surface is simple to operate, has mild conditions, no special requirements for equipment, short production time and low production cost; finally, the rich functional groups on the MXene surface are annealed and kept warm in a weak oxidizing atmosphere (oxygen content is less than 0.001%), thereby realizing the formation of a two-dimensional layered Ti3C2Tx Conversion of MXene to two-dimensional lamellar anatase TiO2; therefore, the preparation method of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material of the present invention has mild conditions, does not require a high-pressure environment, has low cost, high yield, is easy to industrialize, and greatly reduces the production cost of the catalyst;

[0033] (2) The composite material structure of the present invention is a two-dimensional lamellar anatase TiO2 surface loaded with RuCo nanoclusters. The two-dimensional lamellar anatase TiO2 has a large specific surface area and excellent thermodynamic stability and corrosion resistance. At the same time, the RuCo nanoclusters not only have good catalytic activity, but also effectively reduce the loading of precious metals, thereby effectively reducing the production cost of the catalyst, and are widely used in water electrolysis hydrogen production catalysts.

[0034] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The hydrogen evolution polarization curves obtained by linear sweep voltammetry testing of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite materials obtained in Examples 1 to 3 of the present invention in an alkaline electrolyte;

[0036] Figure 2 The linear sweep voltammetry test of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-1 in alkaline electrolyte obtained in Example 1 of the present invention is converted into a hydrogen evolution Tafel slope curve;

[0037] Figure 3 The hydrogen evolution Tafel slope curve obtained by converting the linear sweep voltammetry test of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-2 in an alkaline electrolyte obtained in Example 2 of the present invention;

[0038] Figure 4 The hydrogen evolution Tafel slope curve obtained by converting the linear sweep voltammetry test of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-0.5 in alkaline electrolyte obtained in Example 3 of the present invention;

[0039] Figure 5 This is a hydrogen evolution polarization curve obtained by linear sweep voltammetry testing of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material obtained in Example 1 of the present invention in an acidic electrolyte;

[0040] Figure 6The hydrogen evolution Tafel slope curve obtained by converting the linear sweep voltammetry test of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material obtained in Example 1 of the present invention in an acidic electrolyte;

[0041] Figure 7 CV curves at different scan rates obtained by cyclic voltammetry testing of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material obtained in Example 1 of the present invention in an acidic electrolyte;

[0042] Figure 8 The X-ray diffraction pattern of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-1 obtained in Example 1 of the present invention;

[0043] Figure 9 This is a scanning electron microscope image of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-1 obtained in Example 1 of the present invention;

[0044] Figure 10 This is a scanning electron microscope image of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-1 obtained in Example 1 of the present invention;

[0045] Figure 11 This is a high-angle annular dark-field scanning transmission electron microscope image of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-1 obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0046] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0047] The present invention provides an anatase TiO2 loaded RuCo nanocluster composite material. The anatase TiO2 loaded RuCo nanocluster composite material has a two-dimensional lamellar structure, comprising two-dimensional lamellar anatase TiO2 and RuCo nanoclusters, wherein the RuCo nanoclusters are loaded on the surface of the two-dimensional lamellar anatase TiO2.

[0048] The two-dimensional lamellar anatase TiO2 has a flake diameter of 5-50 μm. The diameter of the RuCo nanoclusters is 1-5 nm. The mass ratio of Ru to Co in the RuCo nanoclusters is 40:(1-5).

[0049] The present invention also provides a method for preparing the above-mentioned anatase TiO2 loaded RuCo nanocluster composite material, wherein the RuCo nanocluster is loaded on a two-dimensional lamellar Ti3C2T x MXene surface, which is then annealed in a weak oxidizing atmosphere; in MAX, M stands for early transition metal, A stands for aluminum, and X stands for carbon. MAX is a general term for transition metal carbide materials; in Ti3C2T x In MXene, T x Represents the functional group produced by the reaction.

[0050] The following steps are involved:

[0051] (1) Preparation of Ti3AlC2MAX powder: titanium powder, aluminum powder and carbon powder are mixed and stirred evenly. The mixed powder is sintered under an inert gas atmosphere, and then crushed and ground to obtain Ti3AlC2MAX powder. In this step, the molar ratio of titanium powder, aluminum powder and carbon powder is 3:1.2:1.9; the oxygen content in the inert gas atmosphere is less than 0.001%, and the flow rate of the inert gas in the tube furnace is 150-250 cm 3 / min.

[0052] The sintering was carried out by a programmed temperature rising method. The heating rate from room temperature to 1200°C was 10°C / min, the heating rate from 1200°C to the sintering temperature was 2°C / min, the sintering temperature was 1300-1600°C, and the sintering time was 6-12h. The particle size of the Ti3AlC2MAX powder was 50-100 μm.

[0053] Typically, in this step, a mixed powder consisting of titanium powder, aluminum powder, and carbon powder is spread flat in a corundum crucible and placed in a tube furnace through a pressureless sintering method to prepare Ti3AlC2MAX powder. After sintering, the temperature is cooled to room temperature. After the sintered sample is removed, the sintered block is crushed with a carbide hammer and then ground into Ti3AlC2MAX powder with a grinding pestle in an agate mortar. The particle size of the ground Ti3AlC2MAX powder is controlled to ensure that the Ti3AlC2MAX powder is fully in contact with the etchant in the subsequent steps, thereby obtaining a better etching effect.

[0054] (2) Multilayer accordion-shaped Ti3C2T x Preparation of MXene: Take the Ti3AlC2MAX powder obtained in step (1), mix it with hydrofluoric acid solution, heat it in a water bath, and stir it continuously. Centrifuge the suspension after the reaction, take the precipitate and wash it repeatedly by centrifugation, filter it, and vacuum dry it to obtain a multi-layer accordion-shaped Ti3C2T xMXene. In this step, the mass concentration of hydrofluoric acid is 40-50%; the mass-to-volume ratio of Ti3AlC2MAX powder to hydrofluoric acid solution is 1:(10-20) g / mL. The water bath heating temperature is 40-60°C, the stirring speed is 300-500 rpm, and the water bath heating and stirring time is 48-72 hours. The centrifugation speed is 4000-6000 rpm, and the centrifugation time is 3-8 minutes. The precipitate cleaning standard is that the supernatant pH value is between 6.0 and 8.0. The vacuum drying time is 24-48 hours.

[0055] In this step, hydrofluoric acid solution is used as an etchant, and the Ti3AlC2MAX powder is etched by the etchant into multilayer Ti3C2T x MXene, this multilayer Ti3C2T x MXene is accordion-shaped, and the etching process is usually carried out in a polytetrafluoroethylene container, and magnetic stirring is used to ensure full contact between the Ti3AlC2MAX powder and the etchant.

[0056] (3) Two-dimensional lamellar Ti3C2T x Preparation of MXene: Take the multilayer accordion-shaped Ti3C2T obtained in step (2) x MXene is mixed with an intercalating agent and stirred to obtain a suspension, which is centrifuged until the pH value of the supernatant is 6.0-8.0. The precipitate is retained, and deionized water is repeatedly added to the precipitate for dispersion and then centrifuged for the first time. The suspension is ultrasonicated in an ice bath under the action of inert gas bubbling, and centrifuged for a long time to obtain a supernatant. The supernatant is freeze-dried to obtain an aerogel-like freeze-dried powder, that is, a two-dimensional lamellar Ti3C2T x MXene; In this step, the intercalation agent is any one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, and the mass concentration of the intercalation agent is 10-15wt%; multilayer accordion-shaped Ti3C2T x The mass volume ratio of MXene to intercalant is 1:(10-40) g / mL.

[0057] Step (3) is carried out in a weak oxidizing gas with an oxygen content of less than 0.001%. The speed of the initial centrifugation is 4000-6000 r / min, and the time is 3-8 minutes; the ultrasonic treatment time is 1-2 hours; the speed of the long-term centrifugation is 3000-4000 r / min, and the long-term centrifugation time is 50-70 minutes; and the freeze-drying time is 48-72 hours.

[0058] In this step, the multilayer accordion-shaped Ti3C2T xMXene and intercalation agent form a suspension, the suspension is separated by centrifugation, the precipitate is washed several times, and the intercalation agent is removed. After the intercalation agent is completely removed, the precipitate is dispersed again with deionized water. Usually, the amount of deionized water used is 10-20 times the mass of the precipitate. In addition, the multilayer accordion-shaped Ti3C2T x When mixing MXene and the intercalant, they can be mixed evenly by hand shaking. Usually, the mixing time is 5-15 minutes. This manual shaking is convenient to operate and can mix evenly.

[0059] (4) Preparation of two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material: Take the two-dimensional lamellar Ti3C2T obtained in step (3) x MXene is added to deionized water, and a salt solution of RuCl3·3H2O and Co(NO3)2·6H2O is added dropwise, stirred, and ultrasonicated in an ice bath under the action of inert gas bubbling. The precipitate is centrifuged to obtain a precipitate, and the precipitate is repeatedly centrifuged and washed. The mixture containing the precipitate after final cleaning is freeze-dried to obtain a freeze-dried powder. The freeze-dried powder is then annealed and kept warm in a weak oxidizing gas with an oxygen content of less than 0.001% to obtain a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material.

[0060] In step (4), the two-dimensional lamellar Ti3C2T x The mass-to-volume ratio of MXene to deionized water is 2:(1-10) mg / mL; the mass concentrations of RuCl3·3H2O and Co(NO3)2·6H2O are both 10-20 mg / mL. The stirring speed is 1000-1500 r / min for 30-60 min. Ultrasonication is performed in a weak oxidizing gas with an oxygen content of less than 0.001% for 30-60 min. The centrifugation speed is 4000-6000 r / min for 3-8 min, with 2-4 centrifugations. The freeze-drying time is 48-72 h. The freeze-dried powder is annealed and kept warm in a tube furnace with a flow rate of 50-150 cm / s of weak oxidizing gas in the tube furnace. 3 / min; the heating rate from room temperature to annealing temperature is 5℃ / min, the annealing temperature is 400-600℃, and the holding time is 1-3 h.

[0061] The purpose of stirring and ice bath ultrasound in this step of the immersion method is to mix the solution so that RuCo metal ions can be successfully loaded on Ti3C2T x MXene surface. After repeated washing of the precipitate and the unloaded metal salt solution, the resulting precipitate is the precursor of a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material.

[0062] The anatase-type TiO2-loaded RuCo nanocluster composite material provided by the present invention is used in the field of preparing catalysts for hydrogen production by electrolysis of water.

[0063] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments.

[0064] Furthermore, it should be understood that although this specification describes the embodiments, not every embodiment includes only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in the various embodiments may also be appropriately combined to form other embodiments that are understandable to those skilled in the art. These other embodiments are also encompassed within the scope of protection of the present invention.

[0065] Example 1

[0066] This embodiment provides a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material, the preparation method of which includes the following steps:

[0067] 1) Preparation of Ti3AlC2MAX powder

[0068] Take titanium powder, aluminum powder and carbon powder, mix them in a molar ratio of 3:1.2:1.9, stir them evenly, spread them in a corundum crucible and place them in a tube furnace; at a flow rate of 150 cm 3 / min in a weakly oxidizing atmosphere (oxygen content less than 0.001%), the temperature was raised from room temperature to 1200℃ at a rate of 10℃ / min, and from 1200℃ to 1550℃ at a rate of 2℃ / min. The sintering was carried out at 1550℃ for 6 h and then cooled to room temperature. The sintered block was crushed with a carbide hammer and then ground into Ti3AlC2MAX powder with a particle size of 100 μm in an agate mortar with a grinding pestle.

[0069] 2) Multilayer accordion-shaped Ti3C2T x Preparation of MXene

[0070] 2 g of Ti3AlC2 MAX powder obtained in step 1) was placed in a polytetrafluoroethylene container, and then 20 mL of a 40% hydrofluoric acid solution was added. The mixture was stirred at a water bath temperature of 50°C and a stirring speed of 500 r / min for 72 h to obtain a suspension. The suspension was centrifuged at a speed of 5000 r / min for 5 min to obtain a precipitate, which was washed with deionized water until the pH value of the supernatant was 6. The mixture was filtered and the sample was dried in a vacuum drying oven for 36 h to obtain a multi-layer accordion-shaped Ti3C2T x MXene.

[0071] 3) Two-dimensional lamellar Ti3C2T x Preparation of MXene

[0072] Take the multilayer accordion-shaped Ti3C2T obtained in step 2) x 0.6 g of MXene powder was added to 15 mL of tetramethylammonium hydroxide intercalant with a mass concentration of 10 wt%, and stirred by hand for 5 min to obtain a suspension; the suspension was centrifuged at 5000 r / min for 5 min to obtain a precipitate, which was dispersed with deionized water and continued to be centrifuged according to the same parameters until the pH value of the supernatant was 8. The precipitate was dispersed again with 30 mL of deionized water, and under the action of argon bubbling, it was ultrasonically treated in an ice bath for 1 h, and centrifuged at 3000 r / min for 60 min to obtain a supernatant; the supernatant was freeze-dried for 60 h to obtain an aerogel-like freeze-dried powder, namely, two-dimensional lamellar Ti3C2T x MXene.

[0073] 4) Preparation of two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composites

[0074] Take the two-dimensional lamellar Ti3C2T obtained in step 3) x 0.1 g of MXene powder was added to 50 mL of deionized water, and 2.5 mL of 10 mg / mL RuCl3·3H2O salt solution and 2.5 mL of 10 mg / mL Co(NO3)2·6H2O salt solution were added dropwise at a stirring speed of 1500 r / min; the mixture was stirred at a stirring speed of 1500 r / min for 30 min, and the suspension was ultrasonically treated in an ice bath for 1 h under the action of argon bubbling. The suspension was then centrifuged at a speed of 5000 r / min for 5 min to obtain a precipitate, which was washed with deionized water, repeated 3 times, and the precipitate was dispersed again with 30 mL of deionized water to obtain a mixture; the mixture was freeze-dried for 60 h to obtain a freeze-dried powder, which is the precursor of the two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material; the precursor was spread flat in a corundum crucible and placed in a tube furnace at a flow rate of 100 cm 3 / min in a weakly oxidizing atmosphere (oxygen content less than 0.001%), the heating rate from room temperature to 500℃ was 5℃ / min, the temperature was kept for 2h, and then the temperature was cooled to room temperature to obtain a two-dimensional lamellar anastase TiO2 loaded RuCo nanocluster composite material, which was named RuCo / TiO2-1.

[0075] Example 2

[0076] This embodiment provides a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material. The preparation method thereof differs from that of Example 1 only in that: Step 4) preparation of a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material. In this embodiment, Step 4) is as follows: taking the two-dimensional lamellar Ti3C2T x 0.1 g of MXene powder was added to 50 mL of deionized water, and 2.5 mL of 20 mg / mL RuCl3·3H2O salt solution and 2.5 mL of 10 mg / mL Co(NO3)2·6H2O salt solution were added dropwise at a stirring speed of 1500 r / min; the mixture was stirred at a stirring speed of 1500 r / min for 30 min, and the suspension was ultrasonically treated in an ice bath for 1 h under the action of argon bubbling. The suspension was then centrifuged at a speed of 5000 r / min for 5 min to obtain a precipitate, which was washed with deionized water, repeated 3 times, and the precipitate was dispersed again with 30 mL of deionized water to obtain a mixture; the mixture was freeze-dried for 60 h to obtain a freeze-dried powder, which is the precursor of the two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material; the precursor was spread flat in a corundum crucible and placed in a tube furnace at a flow rate of 100 cm 3 / min in a weakly oxidizing atmosphere (oxygen content less than 0.001%), the heating rate from room temperature to 500℃ was 5℃ / min, the temperature was kept for 2h, and then the temperature was cooled to room temperature to obtain a two-dimensional lamellar anastase TiO2 loaded RuCo nanocluster composite material, which was named RuCo / TiO2-2.

[0077] Example 3

[0078] This embodiment provides a composite material with two-dimensional lamellar anatase TiO2 loaded RuCo nanoclusters. The preparation method thereof differs from that of Example 1 only in that: Step 4) preparation of the two-dimensional lamellar anatase TiO2 loaded RuCo nanoclusters composite material. Step 4) of this embodiment is: taking the two-dimensional lamellar Ti3C2T obtained in step 3) x0.1 g of MXene powder was added to 50 mL of deionized water, and 2.5 mL of 10 mg / mL RuCl3·3H2O salt solution and 2.5 mL of 20 mg / mL Co(NO3)2·6H2O salt solution were added dropwise at a stirring speed of 1500 r / min; the mixture was stirred at a stirring speed of 1500 r / min for 30 min, and the suspension was ultrasonically treated in an ice bath for 1 h under the action of argon bubbling. The suspension was then centrifuged at a speed of 5000 r / min for 5 min to obtain a precipitate, which was washed with deionized water, repeated 3 times, and the precipitate was dispersed again with 30 mL of deionized water to obtain a mixture; the mixture was freeze-dried for 60 h to obtain a freeze-dried powder, which is the precursor of the two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material; the precursor was spread flat in a corundum crucible and placed in a tube furnace at a flow rate of 100 cm 3 / min in a weakly oxidizing atmosphere (oxygen content less than 0.001%), the heating rate from room temperature to 500℃ was 5℃ / min, the temperature was kept for 2 h, and then the temperature was cooled to room temperature to obtain anatase-type TiO2-loaded RuCo nanocluster composite material with a two-dimensional lamellar structure, which was named RuCo / TiO2-0.5.

[0079] Experiment 1

[0080] The three two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite materials obtained in Examples 1 to 3—RuCo / TiO2-1, RuCo / TiO2-2, and RuCo / TiO2-0.5—were used as triplicate samples. 10 mg of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material was uniformly mixed with 5 mg of acetylene black, and 200 μL of anhydrous ethanol and 200 μL of a 5% mass fraction Nafion solution were added. The mixture was ultrasonically treated for 10 minutes to obtain a suspension. The suspension was then slowly and evenly added dropwise to the surface of a carbon fiber cloth and vacuum dried for 10 minutes to prepare a carbon fiber cloth coated with the composite material. A platinum electrode holder was used to clamp the carbon fiber cloth coated with three samples as the working electrode, the platinum sheet was used as the counter electrode, and the Hg / HgO electrode was used as the reference electrode to form a three-electrode device. The device was placed on a CHI1140C electrochemical workstation produced by Shanghai Chenhua Instrument Co., Ltd. At 25°C and 1M KOH solution, at room temperature, the hydrogen evolution polarization curve of the composite material was determined by linear sweep voltammetry. The linear sweep voltammetry measurement was performed in the range of -0.9~-2.5V (relative to the Hg / HgO reference electrode) at 5 mV / s. The hydrogen evolution polarization curves obtained by the linear sweep voltammetry test of the three samples in alkaline electrolyte are shown as follows: Figure 1The linear sweep voltammetry test of three samples in alkaline electrolyte resulted in the converted hydrogen evolution Tafel slope curve as shown in Figure 2-4 The above experimental results are shown and converted into reversible hydrogen electrode (RHE) potentials and are listed in Table 1.

[0081] Table 1 Electrochemical measurement results of different composite materials in alkaline electrolyte

[0082] ;

[0083] Depend on Figure 1 、 Figure 2-4 As can be seen from Table 1, the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite materials provided by the present invention all exhibit good hydrogen evolution performance in alkaline electrolytes, among which the RuCo / TiO2-1 prepared in Example 1 has the lowest hydrogen evolution overpotential, which means that at the same current density, the catalyst can more effectively reduce the energy required for the reaction, thereby significantly reducing the cost of hydrogen production. The RuCo / TiO2-1 prepared in Example 1 has the lowest Tafel slope, indicating that the composite material has a slower growth rate of overpotential when the current density increases, and the catalyst can achieve a higher reaction rate at a relatively low overpotential.

[0084] Experiment 2

[0085] The two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material RuCo / TiO2-1 prepared in Example 1 was taken, 10 mg of the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material was uniformly mixed with 5 mg of acetylene black, and 200 μL of anhydrous ethanol and 200 μL of 5% Nafion solution were added, and the mixture was ultrasonically treated for 10 min to obtain a suspension. The suspension was slowly and evenly added dropwise to the surface of the carbon fiber cloth and vacuum dried for 10 min to prepare a carbon fiber cloth coated with the composite material. A platinum electrode holder was used to hold the carbon fiber cloth coated with Example 1 as the working electrode, a platinum sheet was used as the counter electrode, and a saturated calomel electrode was used as the reference electrode to form a three-electrode device. The device was placed on a CHI1140C electrochemical workstation produced by Shanghai Chenhua Instrument Co., Ltd. At 25°C and room temperature in a 0.5M H2SO4 solution, the hydrogen evolution polarization curve of the composite material was measured by linear sweep voltammetry. The linear sweep voltammetry measurement was performed in the range of -0.2 to -2 V (relative to the saturated calomel reference electrode) at a scan rate of 5 mV / s. The results are shown in FIG. Figure 5 As shown, the linear sweep voltammetry test is converted to the hydrogen evolution Tafel slope curve as shown in Figure 6The above results were converted into reversible hydrogen electrode (RHE) potentials and listed in Table 2. Cyclic voltammetry was used to measure the CV curves of the composite material at different scan rates to fit the electrochemical double layer capacitance of the composite material. The cycle stability was measured in the voltage window of -0.1~0 V (relative to saturated calomel reference electrode) at scan rates of 120, 100, 80, 60, 40 and 20 mV / s, respectively. The results are shown in Table 2. Figure 7 As shown, the fitting results in the table are listed in Table 2.

[0086] Table 2 Electrochemical measurement results of Example 1 in acidic electrolyte

[0087] ;

[0088] Depend on Figure 5 、 Figure 6 、 Figure 7 As can be seen from Table 2, the two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material of the present invention also has excellent catalytic activity in acidic electrolytes, has a low hydrogen evolution overpotential and an excellent Tafel slope at different current densities, and effectively reduces the energy required for acidic water electrolysis. Thanks to the excellent corrosion resistance of anatase TiO2, the two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material still has good stability in the strong oxidation and strong corrosion environment in the acidic electrolyte. Combined with the good dispersibility and low metal loading characteristics of RuCo nanoclusters, the cost of the catalyst is greatly reduced. The two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material of the present invention has a 21.0 mF / cm 2 The electrochemical double-layer capacitance means that it can provide more active sites during the electrolytic water decomposition reaction and accelerate the interaction between the catalyst reaction interface and the electrolyte.

[0089] Experiment 3

[0090] The two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material RuCo / TiO2-1 prepared in Example 1 was placed on an Empyrean X-ray diffractometer produced by PANalytical BV in the Netherlands for analysis. The results are as follows: Figure 8 As shown by Figure 8 It can be seen that the purity of anatase TiO2 in the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material of the present invention is extremely high, and no Ru or Co metal peaks can be found, which proves that RuCo metal has good dispersion and no obvious agglomeration phenomenon, thereby having a higher metal atom utilization rate.

[0091] Experiment 4

[0092] The two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material RuCo / TiO2-1 prepared in Example 1 was placed on a Quattro S scanning electron microscope produced by Thermo Fisher Scientific (TMO) in the United States for observation. The results are as follows: Figure 7 as well as Figure 8 As shown. Figure 9 and Figure 10 As can be seen, the two-dimensional lamellar anatase TiO2 in the present invention's RuCo nanocluster composite material has a flake diameter of 5-50 μm and is evenly distributed in the form of nanoflakes. The two-dimensional lamellar anatase TiO2 retains the two-dimensional lamellar structure of MXene, providing a large specific surface area for supporting RuCo nanoclusters, thereby enhancing the material's catalytic activity. Furthermore, the excellent thermodynamic stability and corrosion resistance of anatase TiO2 further inhibit corrosion of the catalytic material in acidic and alkaline environments, thereby effectively preserving the overall structure and active sites of the catalyst.

[0093] Experiment 5

[0094] The two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material prepared in Example 1 was placed on a Talos F200S scanning transmission electron microscope produced by Thermo Fisher Scientific (TMO) in the United States for observation. The results are as follows: Figure 11 shown.

[0095] Depend on Figure 11 As can be seen, the anatase TiO2 in the two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material of the present invention exists as thin flakes, exhibiting a large specific surface area. The RuCo nanoclusters are evenly distributed as bright spots on the surface of the two-dimensional lamellar anatase TiO2, significantly reducing the metal loading while retaining catalytic activity, thereby improving the utilization of active metal atoms.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. Anatase TiO2 loaded RuCo nanocluster composite material, characterized in that: The anatase TiO2-loaded RuCo nanocluster composite material is a two-dimensional lamellar structure, comprising two-dimensional lamellar anatase TiO2 and RuCo nanoclusters, wherein the RuCo nanoclusters are loaded on the surface of the two-dimensional lamellar anatase TiO2; The anatase TiO2 loaded RuCo nanocluster composite material adopts an impregnation method to load RuCo nanoclusters on two-dimensional lamellar Ti3C2T x MXene surface, which is then transformed by annealing in a weakly oxidizing atmosphere; The preparation method of the anatase TiO2-loaded RuCo nanocluster composite material comprises the following steps: (1) Preparation of Ti3AlC2 MAX powder: titanium powder, aluminum powder and carbon powder are mixed and stirred evenly. The mixed powder is sintered under an inert gas atmosphere, and then crushed and ground to obtain Ti3AlC2 MAX powder; (2) Multilayer accordion-shaped Ti3C2T x Preparation of MXene: Take the Ti3AlC2 MAX powder obtained in step (1), mix it with hydrofluoric acid solution, heat it in a water bath, and stir it continuously. Centrifuge the suspension after the reaction, take the precipitate and wash it repeatedly by centrifugation, filter it, and vacuum dry it to obtain a multi-layer accordion-shaped Ti3C2T x MXene; (3) Two-dimensional lamellar Ti3C2T x Preparation of MXene: Take the multilayer accordion-shaped Ti3C2T obtained in step (2) x MXene is mixed with an intercalating agent and stirred to obtain a suspension, which is centrifuged until the pH value of the supernatant is 6.0-8.

0. The precipitate is retained, and deionized water is repeatedly added to the precipitate for dispersion and then centrifuged for the first time. The suspension is ultrasonicated in an ice bath under the action of inert gas bubbling, and centrifuged for a long time to obtain a supernatant. The supernatant is freeze-dried to obtain an aerogel-like freeze-dried powder, that is, a two-dimensional lamellar Ti3C2T x MXene; (4) Preparation of two-dimensional lamellar anatase TiO2 loaded RuCo nanocluster composite material: Take the two-dimensional lamellar Ti3C2T obtained in step (3) x MXene is added to deionized water, and a salt solution of RuCl3·3H2O and Co(NO3)2·6H2O is added dropwise, stirred, and ultrasonicated in an ice bath under the action of inert gas bubbling. The precipitate is centrifuged to obtain a precipitate, and the precipitate is repeatedly centrifuged and washed. The mixture containing the precipitate after final cleaning is freeze-dried to obtain a freeze-dried powder. The freeze-dried powder is then annealed and kept warm in a weak oxidizing gas with an oxygen content of less than 0.001% to obtain a two-dimensional lamellar anatase TiO2-loaded RuCo nanocluster composite material.

2. The anatase TiO2-loaded RuCo nanocluster composite material according to claim 1, characterized in that: The two-dimensional lamellar anatase TiO2 has a sheet diameter of 5-50 μm.

3. The anatase TiO2-loaded RuCo nanocluster composite material according to claim 1, characterized in that: The diameter of the RuCo nanoclusters is 1-5 nm.

4. The anatase TiO2-loaded RuCo nanocluster composite material according to claim 1, characterized in that: The mass ratio of Ru to Co in the RuCo nanoclusters is 40:(1-5).

5. The anatase TiO2-loaded RuCo nanocluster composite material according to claim 1, characterized in that: In step (1), the molar ratio of titanium powder, aluminum powder and carbon powder is 3:1.2:1.9; The oxygen content in the inert gas atmosphere is less than 0.001%, and the flow rate of the inert gas in the tube furnace is 150-250 cm 3 / min; The sintering was carried out by a programmed temperature rising method. The heating rate from room temperature to 1200°C was 10°C / min, and the heating rate from 1200°C to the sintering temperature was 2°C / min. The sintering temperature was 1300-1600°C and the sintering time was 6-12h. The particle size of the Ti3AlC2 MAX powder was 50-100 μm.

6. The anatase TiO2-loaded RuCo nanocluster composite material according to claim 1, characterized in that: In step (2), the mass concentration of hydrofluoric acid is 40-50%; the mass volume ratio of Ti3AlC2 MAX powder to hydrofluoric acid solution is 1:(10-20) g / mL; The water bath heating temperature is 40-60°C, the stirring speed is 300-500 r / min, and the water bath heating and stirring time is 48-72 hours; the centrifugal speed is 4000-6000 r / min, and the centrifugation time is 3-8 minutes; the standard for the completion of sediment cleaning is that the pH value of the supernatant is between 6.0-8.0; the vacuum drying time is 24-48 hours.

7. The anatase TiO2-loaded RuCo nanocluster composite material according to claim 1, characterized in that: In step (3), the intercalant is any one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide, and the mass concentration of the intercalant is 10-15wt%; the multilayer accordion-shaped Ti3C2T x The mass volume ratio of MXene to intercalant is 1:(10-40) g / mL; Step (3) is carried out in a weak oxidizing gas with an oxygen content of less than 0.001%, the speed of the initial centrifugation is 4000-6000 r / min, and the time is 3-8 min; the ultrasonic treatment time is 1-2 h; the speed of the long-term centrifugation is 3000-4000 r / min, and the long-term centrifugation time is 50-70 min; and the freeze-drying time is 48-72 h.

8. The anatase TiO2-loaded RuCo nanocluster composite material according to claim 1, characterized in that: In step (4), the two-dimensional lamellar Ti3C2T x The mass volume ratio of MXene to deionized water is 2: (1-10) mg / mL; the mass concentrations of RuCl3·3H2O and Co(NO3)2·6H2O are both 10-20 mg / mL; The stirring speed is 1000-1500 r / min, and the stirring time is 30-60 min; ultrasonication is carried out in a weak oxidizing gas with an oxygen content of less than 0.001% for 30-60 min; the centrifugal speed is 4000-6000 r / min, the centrifugal time is 3-8 min, and the number of centrifugation is 2-4 times; the freeze-drying time is 48-72 h; the freeze-dried powder is annealed and kept warm in a tube furnace, and the flow rate of the weak oxidizing gas in the tube furnace is 50-150 cm 3 / min; the heating rate from room temperature to annealing temperature is 5℃ / min, the annealing temperature is 400-600℃, and the holding time is 1-3 h.

9. Use of the anatase TiO2-loaded RuCo nanocluster composite material according to any one of claims 1 to 8, characterized in that: The anatase TiO2-loaded RuCo nanocluster composite material is used in the field of preparing catalysts for hydrogen production by water electrolysis.

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