CQDs@HOF-101 Composite Microcrystals, Their Preparation Methods and Applications

Abstract

This application discloses CQDs@HOF-101 composite microcrystals, their preparation method, and applications, relating to the field of photocatalytic materials technology, aiming to solve the technical problem of low light utilization rate of existing photocatalytic materials. The preparation method of the CQDs@HOF-101 composite microcrystals includes the following steps: HOF-101 small molecule 1,3,6,8-tetra(4-carboxyphenyl)pyrene is uniformly dissolved in a polar aprotic solvent, and then, along with carbon dots, is placed in a glass vial through an organic filter membrane. The vial is then placed in a beaker containing an alcohol solvent. After the alcohol solvent enters the organic solvent and crystals grow, the crystals are centrifuged to obtain a precipitate. The precipitate is then washed to obtain CQDs@HOF-101 crystals.

Description

Technical Field

[0001] This application relates to the field of photocatalytic materials technology, specifically to CQDs@HOF-101 composite microcrystals, their preparation methods, and applications. Background Technology

[0002] Among numerous renewable energy projects, photocatalysis technology stands out as one of the most promising and promising research directions due to its unique advantage of being able to directly utilize solar energy to drive chemical reactions, converting solar energy into chemical energy or achieving pollutant degradation.

[0003] With the continuous advancement of photocatalysis technology research, researchers have devoted considerable effort to developing a wide variety of photocatalytic materials. Graphitic carbon nitride (g-C3N4), as a typical non-metallic photocatalytic material, has attracted significant attention in areas such as photocatalytic water splitting for hydrogen production and the degradation of organic pollutants due to its simple synthesis, good chemical stability, and suitable band structure. Titanium dioxide (TiO2), with its excellent photocatalytic activity, high chemical stability, low cost, and non-toxicity, has long been a "star material" in the field of photocatalysis, widely used in practical applications such as air purification and self-cleaning coatings. Cadmium sulfide (CdS) has a narrow bandgap, effectively absorbing visible light and exhibiting certain advantages in visible light-driven photocatalytic reactions. Metal-organic frameworks (MOFs), with their highly tunable pore structure and abundant active sites, provide a unique microenvironment for photocatalytic reactions, demonstrating enormous application potential in photocatalytic hydrogen production and carbon dioxide reduction.

[0004] However, despite their respective advantages, these photocatalytic materials still face numerous bottlenecks in practical applications. The slow migration speed of photogenerated electron-hole pairs within the material, much like vehicles struggling on a congested road, hinders their ability to quickly reach reaction sites and participate in catalytic reactions. Furthermore, the rapid recombination of photogenerated carriers, like a strong "attraction" between electrons and holes, causes them to recombine before they can function, leading to a significant reduction in photocatalytic efficiency. In addition, the stability of materials under prolonged light exposure and chemical reaction processes cannot be ignored. Many photocatalytic materials exhibit reduced active sites and structural collapse after repeated cycles of use. This makes the construction of photocatalytic materials that combine stability and durability with high photocatalytic activity a pressing challenge for researchers. Only by overcoming these challenges can photocatalysis technology truly achieve large-scale industrial applications and provide practical and effective solutions to energy and environmental problems. Summary of the Invention

[0005] The main purpose of this application is to provide CQDs@HOF-101 composite microcrystals, their preparation methods and applications, in order to solve the technical problem of low light utilization of existing photocatalytic materials.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0007] In a first aspect, embodiments of this application provide a method for preparing CQDs@HOF-101 composite microcrystals, comprising the following steps:

[0008] After uniformly dissolving HOF-101 small molecule 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene in a polar aprotic solvent, the solution was filtered through an organic filter membrane and packaged together with carbon dots into a glass vial. The vial was then placed in a beaker containing an alcohol solvent. After the alcohol solvent entered the organic solvent and crystals grew, the solution was centrifuged to obtain a precipitate. The precipitate was washed to obtain CQDs@HOF-101 crystals.

[0009] As some optional embodiments of this application, before placing the vial into the beaker containing the alcohol solvent, the method further includes: sonicating for 10 minutes to mix it evenly.

[0010] The step of opening the vial and placing it in a beaker containing alcohol solvent, and waiting for the alcohol solvent to enter the organic solvent, means storing the vial with the cap open, placing the vial in a beaker containing alcohol solvent (the alcohol solvent should not submerge the vial), sealing the mouth of the beaker, and letting it stand for 24 hours to allow the alcohol solvent to enter the organic solvent.

[0011] As some optional embodiments of this application, the ratio of the HOF-101 small molecule 1,3,6,8-tetra(4-carboxyphenyl)pyrene to the polar aprotic solvent is 20mg-30mg: 2ml-3ml.

[0012] As some optional embodiments of this application, the polar aprotic solvent includes any one of N,N-dimethylformamide and dimethyl sulfoxide.

[0013] As some optional embodiments of this application, the organic filter membrane has a pore size of 0.22 μm.

[0014] As some optional embodiments of this application, the alcohol solvent includes either methanol or ethanol; 10 ml to 15 ml of alcohol solvent is used for every 20 mg to 30 mg of the HOF-101 small molecule 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene;

[0015] When washing the precipitate to obtain HOF-101 crystals, the solvents used for washing are methanol and acetone, and the washing is performed 3 times for each solvent.

[0016] As some optional embodiments of this application, the loading of the carbon dots is 0.5 wt%.

[0017] As some optional embodiments of this application, the centrifugation parameters are 10000 rpm and 10 min.

[0018] Secondly, embodiments of this application also provide a CQDs@HOF-101 composite microcrystal, which is prepared by the method described above.

[0019] Thirdly, this application also provides an application of CQDs@HOF-101 composite microcrystals, in which the CQDs@HOF-101 composite microcrystals are used to prepare photocatalytic materials.

[0020] Compared with the prior art, the beneficial effects of this application are:

[0021] In the current pursuit of breakthroughs in photocatalytic material research, the preparation method of CQDs@HOF-101 composite microcrystals described in this application demonstrates unique innovation and application value. This preparation process cleverly combines hydrogen-bonded organic framework (HOF) materials with carbon dots (CQDs) through meticulously designed steps. First, using the HOF-101 small molecule 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene as the building block, a polar aprotic solvent provides a suitable self-assembly environment. The interaction between the two drives the self-assembly process through intermolecular hydrogen bonds, much like building molecular-level "Lego bricks," gradually forming HOF-101 crystals with a regular porous structure.

[0022] Based on this, during the HOF-101 crystal growth process, carbon dots are uniformly dispersed in the system, allowing them to precisely embed into the channels or interstitial spaces of the HOF-101 crystal, avoiding the aggregation or uneven distribution problems that may occur with traditional loading methods. After the crystal growth is complete, the precipitate is separated by centrifugation, followed by multiple washings to remove unreacted impurities and excess solvent, ultimately obtaining pure CQDs@HOF-101 crystals.

[0023] From the perspective of raw material selection, this preparation method has significant advantages in terms of environmental protection and resource utilization. Using cellulose, a naturally sourced raw material with good biocompatibility, as the precursor for carbon dots not only fully leverages the wide availability and renewable nature of cellulose but also achieves high-value utilization of biomass. Transforming commonly used biomass materials into carbon dots with special functions reduces dependence on non-renewable resources and opens up new pathways for biomass resource utilization, aligning with the concept of sustainable development.

[0024] In terms of performance enhancement, the CQDs@HOF-101 composite material exhibits significant advantages. On one hand, the introduction of carbon dots effectively improves the inherent photogenerated electron transport efficiency of the HOF material. The unique conjugated structure and excellent conductivity of carbon dots act as a "high-speed channel" for photogenerated electrons, greatly shortening the electron migration path and reducing the probability of photogenerated electron-hole recombination. On the other hand, the porous structure and abundant active sites of the HOF-101 crystal provide a broad reaction interface and ample adsorption space for the photocatalytic reaction. The synergistic effect of these two factors gives the composite material excellent electron transport capabilities and good photocatalytic hydrogen evolution performance.

[0025] From an application perspective, this preparation method is simple and easy to implement, with mild preparation conditions, requiring no complex equipment or harsh reaction conditions, which is conducive to large-scale industrial production. The potential shown by CQDs@HOF-101 composite materials in the field of photocatalytic hydrogen evolution is expected to provide a new technical solution to the energy crisis; its good biocompatibility also lays the foundation for its application in the field of biomedical photocatalysis, such as photocatalytic antibacterial and controlled drug release, showing broad application prospects. Attached Figure Description

[0026] Figure 1 The image shows the powder X-ray diffraction analysis results of the CQDs@HOF-101 composite microcrystals involved in the embodiments of this application;

[0027] Figure 2 This is a transmission electron microscopy (TEM) analysis result of the CQDs@HOF-101 composite microcrystals involved in the embodiments of this application;

[0028] Figure 3 This is a graph showing the nitrogen adsorption analysis results of the CQDs@HOF-101 composite microcrystals involved in the embodiments of this application;

[0029] Figure 4 The image shows the photocurrent test results of the CQDs@HOF-101 composite microcrystals involved in the embodiments of this application;

[0030] Figure 5 This is a graph showing the electrochemical impedance spectroscopy results of the CQDs@HOF-101 composite microcrystals involved in the embodiments of this application;

[0031] Figure 6 The figure shows the hydrogen evolution performance test results of the CQDs@HOF-101 composite microcrystals involved in the embodiments of this application. Detailed Implementation

[0032] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0033] In the forefront of materials science, hydrogen-bonded organic frameworks (HOFs) have become a research hotspot due to their unique construction methods and potential applications. These materials form porous network structures through the self-assembly of small organic molecule structural units. Their appeal lies in the ability to precisely control the types and structures of functional groups in the structural unit molecules, enabling customized design of the porosity and functionality of HOFs. When constructing HOFs using molecular units containing large π-conjugated structures, the shape-matching π-π stacking strategy, like a precise intermolecular jigsaw puzzle, significantly enhances the stability of the pores, allowing them to maintain structural integrity even in complex environments. Simultaneously, the intramolecular DA (donor-acceptor) structure and proton transport channels cooperate to provide an ideal platform for efficient HER (hydrogen evolution reaction), bringing hope for the development of clean energy. However, in practical applications, HOFs face numerous challenges. The rapid recombination of photogenerated carriers acts as a major obstacle in photocatalysis, resulting in consistently low visible light utilization. Furthermore, the inherent instability of the materials themselves limits their application in many scenarios.

[0034] Carbon dots (CDs), as an emerging member of the carbon-based zero-dimensional nanomaterial family, have rapidly gained prominence due to their low cost, non-toxicity, environmental friendliness, and simple synthesis process. Their excellent photostability and conductivity make them highly promising semiconductor material candidates. Research has confirmed that CDs possess tunable energy level configurations, much like sophisticated molecular circuits, which can be optimized for different needs; their unique conjugated structure endows them with special optical and electrical properties. However, like two sides of a coin, carbon dots also have significant drawbacks: when used as photocatalysts, their photocatalytic efficiency is insufficient for practical applications, and inadequate solar energy utilization severely restricts their effectiveness; the presence of photobleaching further diminishes their stability under prolonged illumination.

[0035] It is noteworthy that there are currently no reports on the application of CDs / HOF composite materials in the field of photocatalysis. However, solution processing methods based on small molecules of HOF materials offer a new approach to overcoming the bottlenecks in the application of existing materials. This method can achieve in-situ coating of carbon dots, a process that is not only a simple combination of two materials but also an innovative practice in the utilization of biomass resources. The introduction of carbon dots can effectively improve the inherent photogenerated electron transport efficiency of HOF materials. The synergistic effect of the two is expected to construct high-performance HER composite materials. This preparation method does not require complex equipment or cumbersome processes, is simple to implement, and has controllable costs, showing broad application prospects in the future field of photocatalysis and potentially becoming a key breakthrough in promoting clean energy technology innovation.

[0036] Based on the above, this application provides the following technical solution:

[0037] A method for preparing CQDs@HOF-101 composite microcrystals includes the following steps:

[0038] After uniformly dissolving HOF-101 small molecule 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene in a polar aprotic solvent, the solution was filtered through an organic filter membrane and packaged together with carbon dots into a glass vial. The vial was then placed in a beaker containing an alcohol solvent. After the alcohol solvent entered the organic solvent and crystals grew, the solution was centrifuged to obtain a precipitate. The precipitate was washed to obtain CQDs@HOF-101 crystals.

[0039] Specifically, before placing the vial into the beaker containing the alcohol solvent, the process further includes: sonicating for 10 minutes to ensure uniform mixing.

[0040] The step of opening the vial and placing it in a beaker containing alcohol solvent, and waiting for the alcohol solvent to enter the organic solvent, means storing the vial with the cap open, placing the vial in a beaker containing alcohol solvent (the alcohol solvent should not submerge the vial), sealing the mouth of the beaker, and letting it stand for 24 hours to allow the alcohol solvent to enter the organic solvent.

[0041] More specifically, the ratio of the HOF-101 small molecule 1,3,6,8-tetra(4-carboxyphenyl)pyrene to the polar aprotic solvent is 20mg-30mg:2ml-3ml; preferably 20mg,2ml, to reduce the amount of organic solvent while ensuring complete dissolution as much as possible.

[0042] More specifically, the polar aprotic solvent includes any one of N,N-dimethylformamide and dimethyl sulfoxide to break hydrogen bonds and dissolve the HOF-101 small molecule.

[0043] More specifically, the organic filter membrane has a pore size of 0.22 μm to filter out most insoluble impurities.

[0044] More specifically, the alcohol solvent includes either methanol or ethanol; 10 ml to 15 ml of alcohol solvent is used for every 20 mg to 30 mg of the HOF-101 small molecule 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene; when washing the precipitate to obtain HOF-101 crystals, the washing solvents are methanol and acetone, and the washing times are 3 times each; it should be noted that the alcohol reagent system is a poor solvent, which can well precipitate HOF crystals. Methanol and acetone are chosen as washing reagents to remove the organic solvent (DMF, also known as N,N-dimethylformamide or DMSO, also known as dimethyl sulfoxide) in the channels, and acetone has a low boiling point and is easy to remove.

[0045] Specifically, the loading of carbon dots is 0.5 wt%, which is the optimal loading for hydrogen evolution performance. Too much loading will damage the crystal structure, while too little loading will result in low hydrogen evolution enhancement. The centrifugation parameters are 10,000 rpm and 10 min, which can completely centrifuge the precipitate.

[0046] Secondly, embodiments of this application also provide a CQDs@HOF-101 composite microcrystal, which is prepared by the method described above.

[0047] Thirdly, this application also provides an application of CQDs@HOF-101 composite microcrystals, in which the CQDs@HOF-101 composite microcrystals are used to prepare photocatalytic materials.

[0048] To facilitate understanding of the technical solution of this application by those skilled in the art, the technical solution of this application will be described in detail below with reference to specific embodiments:

[0049] The carbon dots described in the following examples are prepared by the following steps:

[0050] 2.00 g of microcrystalline cellulose was placed in 60.00 mL of deionized water and magnetically stirred at 500 rpm for 10 minutes. The suspension was then transferred to a polytetrafluoroethylene-lined hydrothermal reactor, which was subsequently placed in an electrically heated constant-temperature drying oven and reacted at 200 °C for 12 hours. After the reaction solution cooled to room temperature, it was centrifuged at 10,000 rpm for 10 minutes. The centrifuged solution was filtered through an aqueous pinhole membrane (0.22 μm), and the filtered solution was placed in a dialysis bag with a molecular weight cutoff of 1000 Da and dialyzed for 48 hours. Finally, lyophilization was performed to obtain cellulose carbon dots (CQDs).

[0051] Example 1: Raw materials: microcrystalline cellulose, 1,3,6,8-tetra(4-carboxyphenyl)pyrene;

[0052] Solvents: DMF and methanol;

[0053] Reaction apparatus: Oven;

[0054] The cellulose carbon dot / hydrogen bond organic framework composite material is made from the following raw materials by weight: 2g microcrystalline cellulose and 20mg 1,3,6,8-tetra(4-carboxyphenyl)pyrene.

[0055] The solvent is prepared in the following volumes: 2 ml of DMF and 15 ml of methanol;

[0056] After uniformly dissolving HOF-101 small molecule 1,3,6,8-tetra(4-carboxyphenyl)pyrene in a polar aprotic solvent, the solution was filtered through an organic filter membrane and placed into a 20 ml glass vial. Simultaneously, carbon dots were added to the glass vial, and the mixture was sonicated for 10 min to ensure uniform mixing. The vial was then placed in a beaker containing an alcohol solvent, the beaker was sealed, and the mixture was allowed to stand for 24 h to allow the alcohol solvent to enter the organic solvent. After crystal growth, the crystals were centrifuged to obtain a precipitate. The precipitate was then washed to obtain CQDs@HOF-101 crystals.

[0057] Specifically, the carbon point loading is 0.5 wt%. The alcohol solvent includes either methanol or ethanol. The precipitate is washed with methanol and acetone as solvents, three times each, and finally dried in a vacuum oven at 60°C for 24 hours; the centrifugation parameters are 10,000 rpm and 10 min.

[0058] Example 2: Raw materials: microcrystalline cellulose, 1,3,6,8-tetra(4-carboxyphenyl)pyrene;

[0059] Solvents: DMSO and ethanol;

[0060] Reaction apparatus: Oven;

[0061] The cellulose carbon dot / hydrogen bond organic framework composite material is made from the following raw materials by weight: 2g microcrystalline cellulose and 25mg 1,3,6,8-tetra(4-carboxyphenyl)pyrene.

[0062] The solvent is prepared in the following volumes: 2.5 ml of DMSO and 30 ml of ethanol;

[0063] After uniformly dissolving HOF-101 small molecule 1,3,6,8-tetra(4-carboxyphenyl)pyrene in a polar aprotic solvent, the solution was filtered through an organic filter membrane and placed into a 20 ml glass vial. Simultaneously, carbon dots were added to the glass vial, and the mixture was sonicated for 10 min to ensure uniform mixing. The vial was then placed in a beaker containing an alcohol solvent, the beaker was sealed, and the mixture was allowed to stand for 24 h to allow the alcohol solvent to enter the organic solvent. After crystal growth, the crystals were centrifuged to obtain a precipitate. The precipitate was then washed to obtain CQDs@HOF-101 crystals.

[0064] Specifically, the carbon point loading is 0.5 wt%. The alcohol solvent includes either methanol or ethanol; the precipitate is washed with methanol and acetone as solvents, three times each, and finally dried in a vacuum oven at 60°C for 24 hours; the centrifugation parameters are 10,000 rpm and 10 min.

[0065] Example 3: Raw materials: microcrystalline cellulose, 1,3,6,8-tetra(4-carboxyphenyl)pyrene;

[0066] Solvents: DMSO and ethanol;

[0067] Reaction apparatus: Oven;

[0068] The cellulose carbon dot / hydrogen bond organic framework composite material is made from the following raw materials by weight: 1.5 g microcrystalline cellulose and 25 mg 1,3,6,8-tetra(4-carboxyphenyl)pyrene.

[0069] The solvent is prepared in the following volumes: 2.5 ml of DMSO and 30 ml of ethanol;

[0070] After uniformly dissolving HOF-101 small molecule 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene in a polar aprotic solvent, the solution was filtered through an organic filter membrane and placed into a 20 ml glass vial. Simultaneously, carbon dots were added to the glass vial, and the mixture was sonicated for 10 min to ensure uniform mixing. The vial was then placed in a beaker containing an alcohol solvent, and the mouth of the beaker was sealed to allow crystals to grow. After crystal growth, the crystals were centrifuged to obtain a precipitate, which was then washed to obtain CQDs@HOF-101 crystals.

[0071] Specifically, the carbon point loading is 0.5 wt%. The alcohol solvent includes either methanol or ethanol; when washing the precipitate to obtain HOF-101 crystals, the washing solvents are methanol and acetone, and the washing is performed 3 times each; the centrifugation parameters are 10000 rpm and 10 min.

[0072] Experimental Example 1: The following structural analysis was performed on the CQDs@HOF-101 crystal prepared in Example 1:

[0073] 1) Powder X-ray diffraction: After drying the CQDs@HOF-101 crystal into powder, the crystal was qualitatively analyzed by X-ray diffraction.

[0074] The results are as follows Figure 1 As shown: the synthesized compound has a certain crystal structure, and the diffraction intensity decreases after loading.

[0075] 2) Transmission electron microscopy: CQDs@HOF-101 crystals were ultrasonically dispersed in ethanol until uniform. A drop of the dispersion was added to a copper grid and allowed to dry naturally at room temperature.

[0076] The results are as follows Figure 2 As shown: This demonstrates that carbon dots were successfully loaded onto HOF-101.

[0077] 3) Nitrogen adsorption: After activating the CQDs@HOF-101 crystals overnight in a nitrogen adsorption instrument, nitrogen adsorption tests were performed.

[0078] The results are as follows Figure 3As shown, the nitrogen adsorption capacity of HOF-101 decreased after loading carbon dots, indicating that carbon dots were successfully embedded in the pores.

[0079] Experimental Example 2: The following performance tests were performed on the CQDs@HOF-101 crystal prepared in Example 2:

[0080] 1) Photocurrent test: CQDs@HOF-101 was dispersed in ethanol, dropped onto the working electrode, and irradiated with a 1W LED lamp. The photocurrent was then tested on an electrochemical workstation.

[0081] The results are as follows Figure 4 As shown, the photocurrent response of CQDs@HOF-101 after loading carbon dots is significantly stronger than that of HOF-101, indicating that the separation of photogenerated electron-hole pairs and the bulk transport efficiency are more superior after loading carbon dots.

[0082] 2) Electrochemical impedance spectroscopy: CQDs@HOF-101 was dispersed in ethanol, dropped onto the working electrode, and photocurrent was measured on an electrochemical workstation.

[0083] The results are as follows Figure 5 As shown, the electrochemical impedance of CQDs@HOF-101 after loading carbon dots is lower than that of HOF-101, indicating that the transfer rate of photogenerated electrons and holes is faster and recombination loss is less.

[0084] 3) Hydrogen evolution performance test: Carbon dots (CQDs) and HOF-101 were added during the loading step, with the following mass ratios:

[0085] 0.3:100, named 0.3 CQDs@HOF-101;

[0086] 0.5:100, named 0.5 CQDs@HOF-101;

[0087] 0.7:100, named 0.7 CQDs@HOF-101;

[0088] 1.0:100, named 1.0 CQDs@HOF-101.

[0089] The results are as follows Figure 6 As shown, the hydrogen evolution performance of HOF-101 was improved after loading different masses of carbon dots, with 0.5 CQDs@HOF-101 exhibiting the best hydrogen evolution performance.

[0090] In summary, it can be seen that the preparation method of CQDs@HOF-101 crystals obtained in this application is simple, the preparation conditions are mild, and the use of biocompatible natural raw material cellulose as the precursor for carbon dots realizes the high-value utilization of biomass. This composite material exhibits excellent electron transport capabilities and good photocatalytic hydrogen evolution performance, showing great application potential.

[0091] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing CQDs@HOF-101 composite microcrystals, characterized in that, Includes the following steps: After uniformly dissolving HOF-101 small molecule 1,3,6,8-tetra(4-carboxyphenyl)pyrene in a polar aprotic solvent, the solution was filtered through an organic filter membrane and packaged together with carbon dots into a glass vial. The vial was sonicated for 10 minutes to ensure homogeneous mixing. The vial was then placed in a beaker containing an alcohol solvent. Once the alcohol solvent entered the organic solvent and crystals grew, the crystals were centrifuged to obtain a precipitate. The precipitate was washed to obtain CQDs@HOF-101 crystals. The ratio of HOF-101 small molecule 1,3,6,8-tetra(4-carboxyphenyl)pyrene to the polar aprotic solvent was 20 mg-30 mg: 2 ml-3 ml. The polar aprotic solvent included any one of N,N-dimethylformamide and dimethyl sulfoxide. The loading of the carbon dots was 0.5 wt%.

2. The method for preparing CQDs@HOF-101 composite microcrystals according to claim 1, characterized in that, The organic filter membrane has a pore size of 0.22 μm.

3. The method for preparing CQDs@HOF-101 composite microcrystals according to claim 1, characterized in that, The alcohol solvent includes either methanol or ethanol; 10 ml to 15 ml of alcohol solvent is used for every 20 mg to 30 mg of the HOF-101 small molecule 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene. When washing the precipitate to obtain HOF-101 crystals, the solvents used for washing are methanol and acetone, and the washing is performed 3 times for each solvent.

4. The method for preparing CQDs@HOF-101 composite microcrystals according to claim 1, characterized in that, The centrifugation parameters are 10,000 rpm and 10 min.

5. A CQDs@HOF-101 composite microcrystal, characterized in that, Prepared by the method described in any one of claims 1-4.

6. An application of CQDs@HOF-101 composite microcrystals, characterized in that, The CQDs@HOF-101 composite microcrystals as described in claim 5 are used to prepare photocatalytic materials.

Images