Two-dimensional mesoporous nanosheet material constructed by crosslinking metal oxide nanoparticles and preparation method and application of two-dimensional mesoporous nanosheet material

Abstract

The invention discloses a two-dimensional mesoporous nanosheet material constructed by cross-linking of metal oxide nanoparticles and a preparation method and application of the two-dimensional mesoporous nanosheet material. Mainly solves the problems of low mass transfer efficiency, large contact resistance and the like caused by disordered accumulation of metal oxide nanoparticles in practical application at present. The invention provides a two-dimensional mesoporous nanosheet material constructed by crosslinking metal oxide nanoparticles and a preparation method and application thereof, and the metal oxide nanoparticles with a unique two-dimensional lamellar structure are prepared by controlling the crosslinking reaction and subsequent pyrolysis process of metal and organic ligands. The structure has the characteristics of pore structure and low contact resistance, and the active substance utilization rate and the electron transmission efficiency of the nanoparticles are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nano material preparation, and in particular to a two-dimensional mesoporous nano sheet material constructed by cross-linking metal oxide nano particles, and a preparation method and application thereof. Background Art

[0002] Nanomaterials have shown great application potential in the fields of catalysis, energy storage and sensing due to their unique size and surface effects. Traditionally, metal oxide nanoparticles often exist in the form of powders and need to be prepared into macroscopic electrodes or bulk structures in practical applications. However, this simple stacking method will lead to disordered arrangement of nanoparticles, forming a closed pore structure, hindering the diffusion of reactants into the interior, reducing the utilization of active substances, and generating large inter-particle contact resistance, limiting the efficiency of electron transfer, and ultimately affecting the overall performance of the device.

[0003] Some studies have attempted to improve the utilization rate and conductivity of nanoparticles by adding conductive agents or using special preparation methods. For example, patent CN118811818A reported a method of using carbon nanotubes as a conductive network to improve the performance of nanoparticle electrodes, and patent CN113058614A proposed a method of preparing nanoparticles with a specific pore structure by a template method. However, these methods are usually complex and costly, and it is still difficult to effectively solve the mass transfer and electron transport problems caused by nanoparticle accumulation, and it is difficult to meet the demand for high-performance nanomaterials in practical applications.

[0004] In view of the common problems of nanoparticle accumulation, low mass transfer efficiency, and high contact resistance in the above-mentioned prior art, the present invention proposes a new type of two-dimensional sheet-interlinked metal oxide nanoparticles and a preparation method thereof, which can effectively solve these problems and significantly improve the catalytic, energy storage and sensing properties of nanomaterials. The material prepared by the present invention has the characteristics of porous structure and low contact resistance, thereby showing excellent performance in catalytic, energy storage and sensing applications, contributing to the technological progress in related fields, and is expected to promote the industrialization of related technologies, and promote energy conservation, emission reduction and sustainable development. Summary of the invention

[0005] In order to overcome the shortcomings of the background technology, the present invention provides a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles and its preparation method and application, which mainly solves the problems of low mass transfer efficiency and large contact resistance caused by disordered stacking of current metal oxide nanoparticles in practical applications.

[0006] The technical solution of the present invention is:

[0007] A method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles comprises the following steps:

[0008] Step 1, mixing a metal salt solution with an organic ligand and at least one nitrogen-containing organic compound;

[0009] Step 2, heating the mixture obtained in step 1 to obtain a solid mixture;

[0010] Step 3: calcining the solid mixture at a high temperature to obtain interconnected metal oxide nanocrystals, wherein the nanocrystals are cross-linked to form a two-dimensional mesoporous lamellar structure.

[0011] In step one, the metal salt solution is at least one of a metal halide solution, a metal nitrate solution or a metal acetate solution; the organic ligand is at least one of a polyhydroxy organic compound, a carboxylic acid or a derivative thereof; and the at least one nitrogen-containing organic compound is at least one of urea, an amino acid or an amide.

[0012] The heating temperature in step 2 is 50-250°C;

[0013] The calcination temperature in step 3 is 300-700° C. and the calcination time is 1-24 hours.

[0014] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles is prepared by the above-mentioned method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles.

[0015] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, whose structure is composed of cross-linked metal oxide nanoparticles and has the morphology of a two-dimensional mesoporous nanosheet.

[0016] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, wherein the metal oxide nanoparticles are selected from ruthenium oxide, cobalt oxide, nickel oxide, yttrium oxide, zirconium oxide, titanium oxide, cerium oxide, gallium oxide, tin oxide and mixtures thereof.

[0017] The pore size of the two-dimensional mesoporous nanosheet is 1-20 nm.

[0018] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as described above is used in catalysis, energy storage or sensing technology.

[0019] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as described above is used in electrode technology.

[0020] The beneficial effects of the present invention are as follows: the present invention provides a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, a preparation method and application thereof, and metal oxide nanoparticles with a unique two-dimensional sheet structure are prepared by controlling the cross-linking reaction of metal and organic ligand and the subsequent pyrolysis process. The structure has the characteristics of a porous structure and low contact resistance, which significantly improves the active material utilization rate and electron transmission efficiency of the nanoparticles. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The TEM (Transmission electron microscope) images of catalysts 1-4 and 1# obtained in Examples 1-4 and Comparative Example 1# are shown, wherein Figure 1 (ad) are TEM images of catalysts 1-4 obtained in Examples 1-4, respectively. Figure 1 (e) is the TEM image of catalyst 1# obtained in control example 1.

[0022] Figure 2 Shown is the XRD (X-ray diffraction) spectrum of catalyst 1-4 obtained in Example 1-4.

[0023] Figure 3 The BET test results of catalyst 3 obtained in Example 3 are shown, wherein Figure 3 (a) is the nitrogen adsorption-desorption isotherm of catalyst 3, Figure 3 (b) is the pore size distribution of catalyst 3.

[0024] Figure 4 Shown are the LSV curves of catalyst samples 1-4 and 1# obtained in Examples 1-4 and Comparative Example 1#, and commercial RuO2 catalyst 2# (Com-RuO2).

[0025] Figure 5 The catalyst 3 obtained in Example 3 is shown as 100 mA cm -2 The chronopotentiometry curve below.

[0026] Figure 6 The PEMWE performance test results of catalysts 1, 3 and 1# obtained in Examples 1, 3 and Comparative Example 1# and commercial RuO2 catalyst 2# (Com-RuO2) are shown, wherein Figure 6 (a) PEMWE polarization curves of catalysts 1, 3, 1# and 2# as anodes. Figure 6 (b) Overpotential contribution of catalysts 3 and 1# at different current densities.

[0027] Figure 7 The PEMWE of catalysts 3 and 2# obtained in Example 3 at 0.5 A cm -2Constant current potential curve under current density. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings: A method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles comprises the following steps:

[0029] Step 1, mixing a metal salt solution with an organic ligand and at least one nitrogen-containing organic compound;

[0030] Step 2, heating the mixture obtained in step 1 to obtain a solid mixture;

[0031] Step 3: calcining the solid mixture at a high temperature to obtain interconnected metal oxide nanocrystals, wherein the nanocrystals are cross-linked to form a two-dimensional mesoporous lamellar structure.

[0032] In step one, the metal salt solution is at least one of a metal halide solution, a metal nitrate solution or a metal acetate solution; the organic ligand is at least one of a polyhydroxy organic compound, a carboxylic acid or a derivative thereof; and the at least one nitrogen-containing organic compound is at least one of urea, an amino acid or an amide.

[0033] The heating temperature in step 2 is 50-250°C;

[0034] The calcination temperature in step 3 is 300-700° C. and the calcination time is 1-24 hours.

[0035] ① There are a large number of interconnected pores in the two-dimensional lamellar structure prepared by the present invention, which overcomes the problem of disordered arrangement of nanoparticles to form a blocked pore structure under the traditional simple stacking method, thereby hindering the diffusion of reactants to the inside, effectively promoting the mass transfer of reactants and significantly improving the utilization rate of active substances. ② The nanoparticles obtained by the present invention are tightly connected by chemical bonds, which greatly reduces the contact resistance between particles and improves the efficiency of electron transmission. ③ The preparation method adopted by the present invention is simple and easy to implement, and is easy to mass produce. ④ The preparation method adopted by the present invention is suitable for the preparation of a variety of metal oxides and has broad application prospects.

[0036] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles is prepared by the above-mentioned method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles.

[0037] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, whose structure is composed of cross-linked metal oxide nanoparticles and has the morphology of a two-dimensional mesoporous nanosheet. A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, whose structure is composed of cross-linked metal oxide nanoparticles and has the morphology of a two-dimensional mesoporous nanosheet (such as Figure 1ad), "cross-linking" refers to the connection between particles through bridging structures to form a network structure with a specific geometric arrangement. The effect of cross-linking not only enhances the interaction between nanoparticles, but also improves the mechanical and thermal stability of the catalyst. The three-dimensional or two-dimensional network constructed by cross-linking helps to provide stable catalytic active sites while avoiding the aggregation of single particles.

[0038] "Two-dimensional mesoporous nanosheets" refers to the catalyst having two-dimensional structural characteristics, usually in the form of thin sheets with very small thickness, usually between a few nanometers and tens of nanometers. Two-dimensional materials have unique physical and chemical properties, such as large specific surface area, good electronic conductivity and excellent catalytic performance.

[0039] "Mesoporous" refers to the pore structure inside these two-dimensional nanosheets, with pore sizes generally ranging from 2 to 50 nanometers. In this patent, it is a characteristic pore structure with a pore size of 1-20 nanometers. The mesoporous structure can provide a large number of surface active sites, greatly increase the surface area of ​​the catalytic reaction, and improve the diffusivity of the reactants. The pores of the mesopores are not only conducive to the transport of substances at the molecular level, but also provide a microenvironment during the reaction process to regulate the selectivity and efficiency of the catalytic reaction.

[0040] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, wherein the metal oxide nanoparticles are selected from ruthenium oxide, cobalt oxide, nickel oxide, yttrium oxide, zirconium oxide, titanium oxide, cerium oxide, gallium oxide, tin oxide and mixtures thereof.

[0041] The pore size of the two-dimensional mesoporous nanosheet is 1-20 nm.

[0042] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as described above is used in catalysis, energy storage or sensing technology.

[0043] A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as described above is used in electrode technology.

[0044] Example 1

[0045] Measure 250 μL of 200 mg / mL -1 The RuCl3 solution was added with 1g urea and 0.2g tannic acid, and then the mixture was stirred thoroughly to obtain a mixed solution. The mixed solution was heated at 150°C to obtain a solid mixture. The mixture was then calcined at 450°C for 6 hours and cooled to room temperature to obtain a two-dimensional cross-linked nanoparticle sample 1 based on iRuO2.

[0046] Example 2

[0047] 200 mg mL -1RuCl3 solution and 130 μL volume of 50 mg mL -1 The Ga(NO3)3·xH2O solution was mixed, 1g urea and 0.2g tannic acid were added to the quartz tube and stirred thoroughly to obtain a mixed solution. The mixed solution was heated at 150°C to obtain a solid mixture. It was then calcined at 450°C for 6 hours and cooled to room temperature to obtain gallium-doped ruthenium oxide named iGa. 0.1 Ru 0.9 Two-dimensional sheets of O2 cross-linked nanoparticle sample 2.

[0048] Example 3

[0049] 200 mg mL -1 of RuCl3 solution and 300 μL volume of 50 mg mL -1 The Ga(NO3)3·xH2O solution was mixed, 1g urea and 0.2g tannic acid were added to the quartz tube and stirred thoroughly to obtain a mixed solution. The mixed solution was heated at 150°C to obtain a solid mixture. It was then calcined at 450°C for 6 hours and cooled to room temperature to obtain a high concentration of gallium-doped ruthenium oxide iGa 0.2 Ru 0.8 Two-dimensional sheets of O2 cross-linked nanoparticle sample 3.

[0050] Example 4

[0051] 200 mg mL -1 of RuCl3 solution and 500 μL volume of 50 mg mL -1 The Ga(NO3)3·xH2O solution was mixed, 1g urea and 0.2g tannic acid were added to the quartz tube and stirred thoroughly to obtain a mixed solution. The mixed solution was heated at 150°C to obtain a solid mixture. It was then calcined at 450°C for 6 hours and cooled to room temperature to obtain a high concentration of gallium-doped ruthenium oxide iGa 0.3 Ru 0.7 Two-dimensional sheets of O2 cross-linked nanoparticle sample 4.

[0052] Comparative Example 1

[0053] 200 mg mL -1 of RuCl3 solution and 300 μL volume of 50 mg mL -1 The Ga(NO3)3·xH2O solution was mixed, and 1 g of urea was added to the quartz tube and stirred thoroughly to obtain a mixed solution. The mixed solution was heated at 150°C to obtain a solid mixture. Subsequently, it was calcined at 450°C for 6 hours and cooled to room temperature to obtain Ga-based 0.2Ru 0.8 O2 disordered stacked nanoparticle sample 1#.

[0054] The catalyst samples 1-4 and 1# obtained in Examples 1-4 and Comparative Example 1 were characterized by high-resolution transmission electron microscopy scanning TEM. The test results are shown in Figure 1 .Depend on Figure 1 It can be seen that the catalysts described in Examples 1-4 are all two-dimensional mesoporous nanosheet structures formed by connecting nanoparticles, while the TEM image of the catalyst described in Control Example 1 shows randomly dispersed isolated nanoparticles, and no formation of two-dimensional nanosheets connected by particles is observed.

[0055] Catalysts 1-4 obtained in Examples 1-4 and commercial RuO2 catalyst 2# (Com-RuO2) were subjected to X-ray diffraction analysis, and the obtained XRD spectra are as follows: Figure 2 As shown. Figure 2 It can be seen that catalyst sample 2-4 shows the same diffraction peak position as 2# and 1 (iRuO2), and the diffraction peak of Ga appears at a specific position, and the elemental composition is verified.

[0056] The catalyst sample 3 obtained in Example 3 was subjected to BET characterization, and the test results are as follows: Figure 3 As shown. Figure 3 (a) It can be seen that the nitrogen adsorption-desorption isotherm of catalyst sample 3 shows a type IV curve with H2 type hysteresis, indicating that it has a mesoporous structure; Figure 3 (b) It can be seen that the pore size distribution of catalyst sample 3 ranges from 3 nm to 10 nm.

[0057] The catalyst samples 1-4 and 1# obtained in Examples 1-4 and Comparative Example 1 and the commercial RuO2 catalyst 2# (Com-RuO2) were placed in a three-electrode system, respectively, and 1M HClO4 was used as the electrolyte to systematically evaluate their oxygen evolution reaction (OER) performance in water electrolysis. The test results are shown in FIG. Figure 4 Compared with the control catalyst sample 1# with disordered nanoparticle stacking and the commercial RuO2 catalyst 2# without any treatment, the catalyst samples 1-4 of the embodiment formed a two-dimensional mesoporous nanosheet structure connected by nanoparticles and showed excellent performance in OER activity. For example, sample 3 showed excellent OER activity at 10 mA cm -2 and 100mAcm -2 The overpotentials at the current density were 188 mV and 219 mV, respectively, which are significantly better than those of samples 1# and 2#, indicating that these catalysts have enhanced charge transfer capabilities and improved oxygen evolution reaction (OER) kinetics compared to samples 1# and 2#.

[0058] The catalyst sample 3 obtained in Example 3 was also placed in a three-electrode system, and its high current density (100 mA cm -2 ) conditions, the test results are as follows Figure 5 As shown. Compared with the rapid decay of the activity of sample 2 in the H-type electrolyzer within 20 hours, sample 3 did not show significant potential changes during the 800-hour test. This result shows that the introduction of gallium oxide and the interconnected nanostructure can effectively stabilize the rutile phase of RuO2, and its performance is better than most reported Ru-based electrocatalysts.

[0059] Catalyst samples 1, 3 and 1# obtained in Examples 1, 3 and Comparative Example 1 and commercial RuO2 catalyst 2# were sprayed on a membrane electrode assembly (MEA) as anode electrocatalysts, and a proton exchange membrane water electrolyzer (PEMWE) was successfully assembled. The PEMWE performance test was carried out. The test results are shown in FIG. Figure 5 As shown. Figure 6 (a) It can be seen that the PEMWE based on sample 3 achieves 3A cm at only 1.788V. -2 The performance of the PEMWE follows the order of sample 3>1>1#>2#, which highlights the significant advantages of the two-dimensional mesoporous nanosheet structure formed by the interconnection of nanoparticles in improving the performance of PEMWE. The overpotential analysis method is used to deeply understand the enhanced performance of the PEMWE based on sample 3. Figure 6 (b) It can be seen that compared with the PEMWE performance of catalyst 1# without nanosheet morphology, it is found that the nanosheet morphology of sample 3 has obvious advantages in improving the mass transfer efficiency under complex electrochemical conditions, thereby improving the overall performance of PEMWE. Figure 7 It can be seen that sample 3 can operate stably for more than 200 hours under industrial-grade current density conditions, which is far superior to commercial RuO2 catalysts.

[0060] The embodiments described with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention. The embodiments should not be regarded as limiting the present invention, but any improvements made based on the spirit of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, characterized in that: The following steps are included: Step 1, mixing a metal salt solution with an organic ligand and at least one nitrogen-containing organic compound; Step 2, heating the mixture obtained in step 1 to obtain a solid mixture; Step 3: calcining the solid mixture at a high temperature to obtain interconnected metal oxide nanocrystals, wherein the nanocrystals are cross-linked to form a two-dimensional mesoporous lamellar structure.

2. The method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles according to claim 1, characterized in that: In step one, the metal salt solution is at least one of a metal halide solution, a metal nitrate solution or a metal acetate solution; the organic ligand is at least one of a polyhydroxy organic compound, a carboxylic acid or a derivative thereof; and the at least one nitrogen-containing organic compound is at least one of urea, an amino acid or an amide.

3. The method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles according to claim 1 or 2, characterized in that: The heating temperature in step 2 is 50-250°C.

4. The method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles according to claim 1 or 2, characterized in that: The calcination temperature in step 3 is 300-700° C. and the calcination time is 1-24 hours.

5. A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles, characterized in that: The material is prepared by the method for preparing a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as described in any one of claims 1 to 4.

6. A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as claimed in claim 5, characterized in that: Its structure is composed of cross-linked metal oxide nanoparticles and has the morphology of two-dimensional mesoporous nanosheets.

7. A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as claimed in claim 5, characterized in that: The metal oxide nanoparticles are selected from ruthenium oxide, cobalt oxide, nickel oxide, yttrium oxide, zirconium oxide, titanium oxide, cerium oxide, gallium oxide, tin oxide and mixtures thereof.

8. A two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as claimed in any one of claims 5, characterized in that: The pore size of the two-dimensional mesoporous nanosheet is 1-20 nm.

9. Application of a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as described in any one of claims 5 to 7 in catalysis, energy storage or sensing technology.

10. Application of a two-dimensional mesoporous nanosheet material constructed by cross-linking metal oxide nanoparticles as described in any one of claims 5 to 7 in electrode technology.

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