Covalent organic framework material loaded with platinum nanoparticles and preparation method of covalent organic framework material

Abstract

The invention belongs to the technical field of water electrolysis hydrogen production catalyst preparation, and particularly relates to a Pt nanoparticle-loaded two-dimensional covalent organic framework material and a preparation method thereof. The Pt nanoparticle-loaded two-dimensional covalent organic framework material comprises a two-dimensional covalent organic framework containing hexaaza-trinaphthalene (HATN) and Pt loaded on the two-dimensional covalent organic framework in the form of nanoparticles through a nitrogen atom complexing site in the HATN. The Pt nano-particle loaded two-dimensional covalent organic framework material is successfully constructed by virtue of the complexing ability of an HATN structure to metal, and the Pt nano-particle loaded two-dimensional covalent organic framework material can be found to be used as an efficient water electrolysis hydrogen production catalyst. The material is simple in preparation process, does not involve high temperature in the process, and has the characteristics of environmental protection, low preparation cost and large-scale popularization.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of catalysts for hydrogen production by electrolysis of water, and in particular relates to a covalent organic framework material loaded with platinum nanoparticles and a preparation method thereof. Background Art

[0002] As an important green energy production method, hydrogen production by water electrolysis has received increasing attention in recent years. Catalysts play a vital role in the process of water electrolysis to produce hydrogen. In particular, the optimized design of catalysts is of great significance in improving reaction efficiency, reducing energy consumption and improving catalyst stability. Precious metals, such as platinum (Pt), are widely used in water electrolysis catalytic reactions due to their excellent catalytic performance, but they are expensive and resources are limited. Therefore, how to design low-cost, efficient and stable Pt water electrolysis hydrogen production catalysts has become a hot topic of current research. Covalent organic frameworks (COFs) materials have become an ideal choice for catalyst supports due to their tunable structure, high porosity and excellent stability. However, traditional high-temperature reduction loading methods will destroy the structure of COFs, and high temperature will also lead to increased agglomeration of metal nanoparticles loaded on COFs.

[0003] Therefore, how to uniformly load precious metal nanoparticles on COFs at room temperature, effectively inhibit their agglomeration and protect the COFs structure from being destroyed, so that they can perform optimally in the electrolytic water catalytic reaction, has always been a technical challenge. Summary of the Invention

[0004] To solve the above problems, the present invention provides a covalent organic framework material loaded with platinum nanoparticles and a preparation method thereof, which is achieved through the following technical solutions.

[0005] A covalent organic framework material loaded with platinum nanoparticles, the two-dimensional covalent organic framework material loaded with Pt nanoparticles comprising a two-dimensional covalent organic framework comprising HATN and metal Pt loaded on the two-dimensional covalent organic framework in the form of nanoparticles via nitrogen atom complexing sites in HATN, wherein the HATN is hexaazatrinaphthene and the metal Pt is platinum;

[0006] The metal Pt is first complexed at the HATN position in the form of ions, and then reduced by a reducing agent to become nanoparticles that grow in situ in the pores of the two-dimensional covalent organic framework.

[0007] Furthermore, the covalent organic framework material loaded with platinum nanoparticles is prepared by forming an intermediate HATN by cyclohexanone and o-phenylenediamine and complexing Pt ions, and then dynamically exchanging the o-phenylenediamine in HATN with tetraaminoquinone monomer to form a two-dimensional covalent organic framework.

[0008] Further, the reducing agent is NaBH4 aqueous solution, and the concentration is 2-8 mol / L.

[0009] A preparation method of a platinum nanoparticle loaded covalent organic framework material, comprising the following steps:

[0010] S1, first, HKH, OPD and H2PtCl6·xH2O are added into a reaction tube, the reaction tube is provided with ethanol and trimethylbenzene, and the mixture is prepared by mixing and stirring for 15 min, the HKH is cyclohexanone·octahydrate, the OPD is o-phenylenediamine, and the H2PtCl6·xH2O is chloroplatinic acid solution;

[0011] S2, acetic acid is added into the obtained mixture, and the mixture is stirred for 15 min, and then the mixture is transferred to blue light LED light with a wavelength of 460 nm for irradiation, and the mixture is reacted for 4 h, so that the Pt3-HATN precursor is formed;

[0012] S3, TABQ and acetic acid are added into the reaction tube in which the Pt3-HATN precursor is formed, and then the mixture is irradiated for 12 h, so that the skeleton crystallization process is completed, and the π conjugated COFs with high crystallinity and ordered pores are obtained, and the TABQ is tetraamino-p-quinone monomer;

[0013] S4, the obtained product is washed with ethanol and then washed with water, and then the product is dried at 80 DEG C under vacuum for 12 h after water washing, so that the Pt / COF is obtained;

[0014] S5, 40 mg of the Pt / COF is dissolved in 5 ml of water, and then the mixture is ultrasonically treated for 30 min to obtain a suspension;

[0015] S6, then, the newly configured NaBH4 aqueous solution is quickly injected into the obtained suspension, and the mixture is stirred for 15 s, and then the mixture is left to stand for 24 h to obtain a mixture;

[0016] S7, the obtained mixture is filtered, and then the filtered mixture is washed with water, and then the washed mixture is dried at 80 DEG C under vacuum for 12 h, so that the Pt / COF-R is obtained.

[0017] Further, in the step S1, the HKH is 62.4 mg, the OPD is 64.8 mg, the H2PtCl6·xH2O is chloroplatinic acid aqueous solution (the content is 8 wt.%in H2O), the ethanol is 2 ml, and the trimethylbenzene is 2 ml.

[0018] Further, in the step S2, the acetic acid is 1 ml, and the concentration is 36%.

[0019] Furthermore, in step S3, the amount of TABQ is 50.4 mg, the amount of acetic acid is 1 ml, and the concentration is 36%.

[0020] Furthermore, in step S6, the NaBH4 aqueous solution is 5 ml.

[0021] The beneficial effect of the present invention is that the material utilizes the metal complexing ability of the hexaazatrinaphthylene structure to successfully construct a two-dimensional covalent organic framework loaded with Pt nanoparticles, and the material has excellent performance in the catalysis of hydrogen production by water electrolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the description of the specific implementation methods. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 : Material synthesis and characterization of a covalent organic framework material loaded with platinum nanoparticles and its preparation method described in the present invention;

[0024] Figure 2 : Analysis of the morphology and microstructure of the catalyst of the present invention;

[0025] Figure 3 : Electronic structure analysis of the catalyst of the present invention;

[0026] Figure 4 : Characterization of the electrochemical properties of the catalyst of the present invention. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] like Figure 1-4 As shown, the present invention has the following specific embodiments.

[0029] Example:

[0030] A covalent organic framework material loaded with platinum nanoparticles, wherein the two-dimensional covalent organic framework material loaded with Pt nanoparticles comprises a two-dimensional covalent organic framework comprising HATN and metal Pt loaded on the two-dimensional covalent organic framework in the form of nanoparticles via nitrogen atom complexing sites in HATN, wherein HATN is hexaazatrinaphthene and the metal Pt is platinum;

[0031] Metal Pt is first complexed at the HATN site in the form of ions, and then becomes nanoparticles after being reduced by a reducing agent and grows in situ in the pores of the two-dimensional covalent organic framework.

[0032] Furthermore, the covalent organic framework material loaded with platinum nanoparticles is prepared by forming an intermediate HATN by cyclohexanone and o-phenylenediamine and complexing Pt ions, and then dynamically exchanging the o-phenylenediamine in HATN by tetraaminoquinone monomer to form a two-dimensional covalent organic framework.

[0033] Furthermore, the reducing agent is a NaBH4 aqueous solution with a concentration of 2 to 8 mol / L.

[0034] A method for preparing a covalent organic framework material loaded with platinum nanoparticles comprises the following steps:

[0035] S1. First, HKH, OPD and H2PtCl6·xH2O are added to a reaction tube containing ethanol and trimethylbenzene, and the mixture is stirred for 15 minutes to prepare a mixture, wherein HKH is cyclohexanone·octahydrate, OPD is o-phenylenediamine, and H2PtCl6·xH2O is a chloroplatinic acid solution;

[0036] S2. Add acetic acid to the obtained mixture and stir it for 15 minutes. After stirring, transfer it to 460nm wavelength blue light LED irradiation and react for 4 hours to form a Pt3-HATN precursor;

[0037] S3, adding TABQ and acetic acid to a reaction tube for forming a Pt3-HATN precursor, and then irradiating the tube with light for 12 hours to complete the skeleton crystallization process, thereby obtaining π-conjugated COFs with high crystallinity and ordered pores, where TABQ is a tetraaminobenzoquinone monomer;

[0038] S4, the above-mentioned product is first washed with ethanol and then with water, and then dried at 80° C. under vacuum for 12 h to obtain Pt / COF;

[0039] S5. Dissolve 40 mg of the above Pt / COF in 5 ml of water and then ultrasonicate for 30 min to obtain a suspension.

[0040] S6. Then, a freshly prepared NaBH4 aqueous solution was quickly injected into the obtained suspension, stirred for 15 seconds, and allowed to stand for 24 hours to obtain a mixture;

[0041] S7. Filter the mixture obtained above, wash it with water, and then dry it at 80° C. under vacuum for 12 hours to obtain Pt / COF-R.

[0042] Specifically, in step S1, HKH is 62.4 mg, OPD is 64.8 mg, H2PtCl6·xH2O is an aqueous solution of chloroplatinic acid (its content is 8 wt.% in H2O), ethanol is 2 ml, and trimethylbenzene is 2 ml.

[0043] Specifically, in step S2, the amount of acetic acid is 1 ml, and the concentration is 36%.

[0044] Specifically, in step S3, TABQ is 50.4 mg, acetic acid is 1 ml, and the concentration is 36%.

[0045] Specifically, in step S6, the NaBH4 aqueous solution is 5 ml.

[0046] When synthesizing Pt / COF and Pt / COF-R:

[0047] ① Synthesis of Pt / COF: 62.4 mg of HKH, 64.8 mg of OPD, and a certain amount of HPtCl·xH2O were added to a reaction tube containing 2 mL of ethanol and 2 mL of trimethylbenzene. The mixture was stirred for 15 minutes. 1 mL of 36% acetic acid was then added to the mixture and stirred for an additional 15 minutes. The reaction was then transferred to 460 nm blue LED light for 4 hours to form the Pt3-HATN precursor. Subsequently, 50.4 mg of TABQ and another 1 mL of 36% acetic acid were added to the reaction tube. The reaction was then illuminated with blue light for 12 hours to complete the framework crystallization process, resulting in highly crystalline, pore-ordered π-conjugated COFs. The resulting powder precipitate was rinsed with ethanol and water, respectively, and then dried in vacuo at 80°C for 12 hours to obtain Pt / COF. Depending on the amount of H2PtCl6·xH2O added (25, 50, 100, and 200 μL), four samples, Pt / COF-1, Pt / COF-2, Pt / COF-3, and Pt / COF-4, were obtained. For comparison, we also synthesized pristine COFs without Pt addition (named: pure COF).

[0048] Five samples can be synthesized according to the amount of H2PtCl6·xH2O added:

[0049]

[0050] ② Synthesis of Pt / COF-R: First, 40 mg of Pt / COF was dispersed in 5 ml of water and sonicated for 30 minutes. Then, 5 ml of freshly prepared NaBH4 aqueous solution was rapidly injected into the suspension, stirred for 15 seconds, and allowed to stand for 24 hours. The above mixture was filtered, washed with water, and dried under vacuum at 80°C for 12 hours to obtain Pt / COF-R (i.e., Pt / COF-R1, Pt / COF-R2, Pt / COF-R3, and Pt / COF-R4).

[0051] like Figure 1 Shown are the material synthesis and characterization:

[0052] Figure 1 a is a schematic diagram of the synthesis of pure COF, Pt / COF and Pt / COF-R, wherein pure COF is synthesized by the condensation reaction between HKH and TABQ (i.e., assisted dynamic imine exchange reaction) under blue light illumination to form a π-conjugated porous structure. In the above condensation reaction, we focus on the intermediate of the process: hexaazatrinaphthol (HATN, such as Figure 1 As shown in the shaded area in a), HATN is an electron-deficient conjugated planar system that can coordinate a variety of metal ions to form M3-HATN. In view of the above characteristics, HATN was used as a dynamic precursor to construct Pt / COF. After the NaBH4-induced reduction reaction, Pt 4+ converted into Pt nanowires to obtain Pt / COF-R( Figure 1 a). Therefore, we can establish hydrogen overflow channels by assembling Pt nanowires on porous nitrogen-rich COFs with crystalline structures, which is conducive to hydrogen overflow and improves the performance of HER ( Figure 1 b). To find the optimal HER electrocatalyst, we synthesized a series of Pt / COF-R with different Pt contents, namely Pt / COF-R1, Pt / COF-R2, Pt / COF-R3 and Pt / COF-R4, and characterized them by Fourier transform infrared spectroscopy (FTIR, Figure 1 c), X-ray diffraction analysis (XRD, Figure 1 d and e) to determine their chemical composition, bonding configuration and structural characteristics. Figure 1 c, ~1620cm -1 and ~1240cm -1 The peaks are attributed to -C=C- and -C=N-, indicating the formation of a π-conjugated network. Interestingly, for both Pt / COF-3 and Pt / COF-R3, structural damage did not occur after the introduction of Pt ions and NaBH4 reduction. These results demonstrate that our synthesized COFs possess strong metal ion coordination capabilities and that their structures remain intact during this process. Figure 1The XRD patterns of d show that the crystal structure of Pt / COF-x (x = 1, 2, 3 and 4) is consistent with that of the original COF. The strong diffraction peaks at 16° and 28° are attributed to the (101) and (002) crystal planes of the AB stacking structure of COFs. After the reduction reaction, Pt / COF-Rx (x = 1, 2, 3 and 4) show similar diffraction peaks, while the diffraction peaks at 40° and 46° indicate the appearance of Pt nanowires (PDF#87-0640). Figure 1 e), and with the increase of the initial Pt content, the diffraction peak of the platinum nanowires gradually strengthened. XRD analysis shows that after the Pt grows on the COFs, the COFs structure is not destroyed and its characteristics are retained, which is conducive to the preservation of hydrogen overflow channels, thus facilitating the HER process.

[0053] like Figure 2 Shown is the catalyst morphology and microstructure analysis:

[0054] Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) further revealed the morphology and distribution of Pt / COF-R3, in which COFs existed in a nanotube-like morphology ( Figure 2 a, b). In the dark field (DF)-TEM images, it was observed that Pt nanowires were evenly distributed on the COFs nanotubes ( Figure 2 c). High-resolution transmission electron microscopy of Pt / COF-R3 ( Figure 2 d, e) show that the repetition distance of parallel lines is about 0.97 nm (3d), which is caused by the interplanar spacing of π stacking distance of ∼0.32 nm (consistent with the peak at ∼28° in the XRD spectrum, Figure 1 e). Figure 2 The selected area electron diffraction (SAED) pattern in f shows the results consistent with the characteristic diffraction rings of Pt. The high-resolution TEM image further reveals the lattice fringes of Pt nanowires, whose interplanar spacing is 0.19nm and 0.23nm, corresponding to Pt(200) and Pt(111), respectively ( Figure 2 Energy dispersive X-ray spectroscopy (EDS) further confirmed that the Pt nanowires were uniformly dispersed on the nitrogen-doped COFs matrix ( Figure 2 i) These results demonstrate the successful synthesis of nitrogen-rich COFs with clear pores and good crystallinity. More importantly, the COFs maintain their structural integrity after being successfully loaded with Pt nanowires.

[0055] like Figure 3 Shown is the electronic structure analysis of the catalyst: X-ray photoelectron spectroscopy

[0056] X-ray photoelectron spectroscopy (XPS) reveals the chemical valence states and electronic structures of Pt / COF and Pt / COF-R ( Figure 3 ).like Figure 3 a and b show typical characteristic binding energies of C, N, O, and Pt. The Pt contents of Pt / COF-R1, Pt / COF-R2, Pt / COF-R3, and Pt / COF-R4 are 1.11 wt%, 2.34 wt%, 3.58 wt%, and 7.32 wt%, respectively, indicating that the Pt content gradually increases with the initial addition of chloroplatinic acid solution. The C1s high-resolution XPS spectra of Pt / COF-Rx (x = 1, 2, 3, and 4) show that the peaks at 284.4, 284.8, 285.7, 286.7, 287.9, and 290.4 eV are attributed to C=C, C–C, C–N, C=N, C=O bonds, and π–π satellite peaks, respectively. Figure 3 c). Figure 3 As shown in Figure d, the XPS spectrum of N 1s can be separated into two peaks: 399.0eV and 400.6eV, which correspond to pyrazine-N and "pyrazine-N coordinated with metal", respectively. Interestingly, judging from the peak area, the proportion of "pyrazine-N coordinated with metal" in Pt / COF-R1 is 22.67%, which is lower than Pt / COF-R2 (23.02%), Pt / COF-R3 (25.50%) and Pt / COF-R4 (28.08%); that is, with the increase of Pt content, the proportion of "pyrazine-N coordinated with metal" bonds gradually increases, indicating that the N atoms in COF are the anchoring points of Pt. Figure 1 In the description of a, we mentioned: "HATN was used as a dynamic precursor to construct Pt / COF", which is consistent with the above analysis results. In addition, the Pt 4f spectrum of Pt / COF-R1 shows Pt 0 (71.1eV and 74.5eV) and Pt 4+ (73.0eV and 76.3eV) two valence states ( Figure 3 e); while in Pt / COF-R2, Pt / COF-R3 and Pt / COF-R4 samples, Pt 0 and Pt 4+ These peaks shift slightly toward the higher binding energy side, indicating the strong electronic interaction between atomic Pt and the COF matrix.

[0057] like Figure 4 Shown is the electrochemical performance characterization of the catalyst:

[0058] To evaluate the HER electrocatalytic activity of the prepared catalysts, the samples were tested in 0.5 M H2SO4 electrolyte, and the electrochemical hydrogen evolution performance of Pt / COF-Rx (x = 1, 2, 3 and 4) and 20 wt% commercial Pt / C was evaluated on a glassy carbon disk electrode ( Figure 4 ). Figure 4The HER polarization curve in a shows that Pt / COF-R1 reaches 10 mA cm –2 When the current density is 63mV, an overpotential (η 10 63mV), while the η values ​​of Pt / COF-R2 (47mV), Pt / COF-R3 (11mV) and Pt / COF-R4 (6mV) 10 It gradually decreases with the increase of Pt content. Figure 4 The Tafel slopes in b and c give consistent results, among which the Tafel slope of Pt / COF-R4 is the smallest (17.6 mV dec –1 ), which is lower than Pt / COF-R1 (70.8mV dec –1 )、Pt / COF-R2(58.6mV dec –1 )、Pt / COF-R3(19.5mV dec –1 ) and 20% Pt / C (18.3 mV dec –1 ). The reaction kinetics are studied by calculating the exchange current density (j0), such as Figure 4 As shown in d, the exchange current density (j0) of Pt / COF-R4 (4.40 mA cm –2 ) is much higher than Pt / COF-R1 (1.28 mA cm –2 )、Pt / COF-R2(1.63mA cm –2 )、Pt / COF-R3(2.74mA cm –2 ) and 20% Pt / C (0.49 mA cm –2 ), indicating that the reaction kinetics of Pt / COF-R4 is the highest. However, considering the utilization of Pt, combined with the electron transfer resistance (R ct , Figure 4 e) Mass activity ( Figure 4 f, g) and turnover frequency (TOF, Figure 4 h), Pt / COF-R3 has the best HER activity among the prepared catalysts; in particular, the mass activity of Pt / COF-R3 at an overpotential of 100 mV is 125 A mg –1 , TOF value is 49.0H2 s -1 (per Pt atom), which are 20 and 16 times that of 20% wt% Pt / C, respectively. Considering that Pt / COF-R3 has the highest HER comprehensive activity, we measured its cycling stability ( Figure 4 i). At a constant current density of 10 mA cm –2 When the overpotential increases by only 47 mV after running for 80,000 s, it indicates its good electrochemical stability.

[0059] In summary, the present invention provides a covalent organic framework material loaded with platinum nanoparticles and a preparation method thereof. The preparation process does not involve high temperature and has a simple process flow. It is a highly active catalyst for hydrogen production by electrolysis of water with great potential and has broad application prospects.

[0060] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A covalent organic framework material loaded with platinum nanoparticles, characterized in that: The two-dimensional covalent organic framework material loaded with Pt nanoparticles comprises a two-dimensional covalent organic framework comprising HATN and metal Pt loaded on the two-dimensional covalent organic framework in the form of nanoparticles via nitrogen atom complexing sites in HATN, wherein the HATN is hexaazatrinaphthene and the metal Pt is platinum; The metal Pt is first complexed at the HATN position in the form of ions, and then reduced by a reducing agent to become nanoparticles that grow in situ in the pores of the two-dimensional covalent organic framework.

2. The covalent organic framework material loaded with platinum nanoparticles according to claim 1, characterized in that: The covalent organic framework material loaded with platinum nanoparticles is prepared by forming an intermediate HATN by cyclohexanone and o-phenylenediamine and complexing Pt ions, and then dynamically exchanging the o-phenylenediamine in HATN by tetraaminobenzoquinone monomer to form a two-dimensional covalent organic framework.

3. The covalent organic framework material loaded with platinum nanoparticles according to claim 1, characterized in that: The reducing agent is a NaBH4 aqueous solution with a concentration of 2 to 8 mol / L.

4. A method for preparing a covalent organic framework material loaded with platinum nanoparticles according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. First, HKH, OPD and H2PtCl6·xH2O are added to a reaction tube containing ethanol and trimethylbenzene, and the mixture is stirred for 15 minutes to prepare a mixture, wherein the HKH is cyclohexanone octahydrate, the OPD is o-phenylenediamine, and the H2PtCl6·xH2O is a chloroplatinic acid solution; S2. Add acetic acid to the obtained mixture and stir for 15 minutes. After stirring, transfer the mixture to 460 nm wavelength blue LED light for 4 hours to form a Pt3-HATN precursor. S3. Adding TABQ and acetic acid to a reaction tube for forming a Pt3-HATN precursor, and then irradiating the tube with light for 12 hours, thereby completing the skeleton crystallization process to obtain a π-conjugated two-dimensional covalent organic framework with high crystallinity and ordered pores, wherein the TABQ is a tetraaminobenzoquinone monomer; S4, the above-mentioned product is first washed with ethanol and then with water, and then dried at 80° C. under vacuum for 12 h to obtain Pt / COF; S5. Dissolve 40 mg of the above Pt / COF in 5 ml of water and then ultrasonicate for 30 min to obtain a suspension. S6. Then, the newly prepared NaBH4 aqueous solution was quickly injected into the obtained suspension, stirred for 15 seconds, and allowed to stand for 24 hours to obtain a mixture; S7. Filter the mixture obtained above, wash it with water, and then dry it at 80° C. under vacuum for 12 hours to obtain Pt / COF-R.

5. The method for preparing a covalent organic framework material loaded with platinum nanoparticles according to claim 4, characterized in that: In step S1, the amount of HKH is 62.4 mg, the amount of OPD is 64.8 mg, the amount of H2PtCl6·xH2O is an aqueous solution of chloroplatinic acid (with a content of 8 wt.% in H2O), the amount of ethanol is 2 ml, and the amount of trimethylbenzene is 2 ml.

6. The method for preparing a covalent organic framework material loaded with platinum nanoparticles according to claim 4, characterized in that: In step S2, the amount of acetic acid is 1 ml, and the concentration is 36%.

7. The method for preparing a covalent organic framework material loaded with platinum nanoparticles according to claim 4, characterized in that: In step S3, the amount of TABQ is 50.4 mg, the amount of acetic acid is 1 ml, and the concentration is 36%.

8. The method for preparing a covalent organic framework material loaded with platinum nanoparticles according to claim 4, characterized in that: In step S6, the NaBH4 aqueous solution is 5 ml.

9. The covalent organic framework material loaded with platinum nanoparticles according to any one of claims 1 to 3, characterized in that: The covalent organic framework material is used as a catalyst in the hydrogen evolution reaction of water electrolysis.

Images