Quantum dot catalyst as well as preparation method and application thereof

Abstract

The invention provides a quantum dot catalyst as well as a preparation method and application thereof, the quantum dot catalyst comprises a graphdiyne matrix and metal quantum dots coating the outer surface of the graphdiyne matrix, and the metal quantum dots are connected with the graphdiyne matrix in a chemical bond form; wherein metal in the metal quantum dots is Au-Cu alloy. The quantum dot catalyst prepared by adopting the preparation method disclosed by the invention has a relatively high specific surface area, catalytic active sites are increased, relatively high catalytic activity is shown in an application process, and the comprehensive performance is relatively excellent.

Description

Technical Field

[0001] This application relates to the field of materials technology, and particularly to a quantum dot catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Electrocatalytic carbon dioxide reduction is a green energy technology that converts carbon dioxide into useful chemicals. With the continuous growth of global energy demand and the continuous increase of carbon dioxide emissions, finding sustainable energy and reducing greenhouse gas emissions have become an urgent need in today's society. The electrocatalytic carbon dioxide reduction technology uses an electric current as an external driving force, and promotes the reduction reaction of carbon dioxide molecules through a catalyst to convert it into high-value-added chemicals such as methane, ethylene, and methanol. In the process of electrocatalytic carbon dioxide reduction, the catalyst plays a crucial role. An effective catalyst should have high electrochemical activity, high selectivity, and stability. Currently, commonly used catalysts include noble metal catalysts (such as copper, silver, and gold), transition metal catalysts (such as iron, nickel, and cobalt), and metal oxide catalysts (such as vanadium dioxide and iron oxide). These catalysts can promote the reduction reaction of carbon dioxide molecules while minimizing side reactions and catalyst loss. In addition, the electrocatalytic carbon dioxide reduction technology also faces some other challenges. First, the solubility of carbon dioxide molecules in aqueous solution is low, resulting in a slow reaction rate. Second, the carbon dioxide reduction reaction is a multi-step reaction process, which involves the competition of multiple intermediate products and reaction paths. Therefore, understanding the reaction mechanism and optimizing the catalyst design are the keys to improving the reaction efficiency and selectivity.

[0003] Generally speaking, the electrocatalytic carbon dioxide reduction technology is a green energy technology with great potential. It is urgent to explore highly efficient catalysts to achieve efficient and sustainable carbon dioxide conversion, so as to contribute to solving energy and environmental problems.

[0004] Among various catalysts for electrocatalytic carbon dioxide reduction reactions, quantum dot catalysts have shown many excellent properties in catalytic reactions due to their advantages such as large specific surface area and high atomic utilization efficiency. Bimetallic alloy catalysts are based on the interaction of more than two elements in their crystal lattices to form metal alloys, and due to the different chemical and electrical properties of different metal elements, they can exhibit more excellent catalytic performance. However, the preparation conditions of traditional quantum dot catalysts are harsh and complex, which easily leads to their aggregation, inactivation, etc., severely limiting the practical application of quantum dot catalysts.

[0005] Based on this, in the face of the technical problems that the existing quantum dot catalysts in the prior art are either cumbersome in preparation process or extremely easy to aggregate and inactivate, resulting in poor catalytic performance during application and limiting their application scope, there is an urgent need to provide a quantum dot catalyst and a preparation method thereof to improve the above problems. Summary of the Invention

[0006] The main object of the present invention is to provide a quantum dot catalyst, a preparation method thereof and an application thereof, so as to solve the technical problems in the prior art that the quantum dot catalyst is either cumbersome in preparation process or extremely easy to aggregate and deactivate, resulting in poor catalytic performance during the application process and limiting its application scope.

[0007] To achieve the above object, according to one aspect of the present invention, there is provided a quantum dot catalyst, which includes: a graphdiyne matrix and metal quantum dots coated on the outer surface of the graphdiyne matrix, and the metal quantum dots are connected to the graphdiyne matrix in the form of chemical bonds; wherein, the metal in the metal quantum dots is an Au-Cu alloy.

[0008] Furthermore, the metal quantum dots are in the form of particles, and the average particle size thereof is 4-12 nm.

[0009] Furthermore, the graphdiyne matrix uses a carbon fiber cloth as a support material and is grown on the carbon fiber cloth.

[0010] To achieve the above object, according to one aspect of the present invention, there is provided a preparation method of a quantum dot catalyst, which includes: Step S1, taking hexaethynylbenzene, a metal catalyst and an organic solvent in a reaction vessel containing a carbon fiber cloth for a synthesis reaction to obtain a graphdiyne matrix; Step S2, taking the graphdiyne matrix, a reducing agent, a surfactant, and a metal-containing compound in deionized water for a reduction reaction to obtain a quantum dot catalyst.

[0011] Furthermore, the metal-containing compound is a gold-containing chloride and a copper-containing compound; preferably, the gold-containing chloride is selected from one or more of AuCl3, AuCl, HAuCl4 or HAuCl4·4H2O; more preferably, the gold-containing chloride is HAuCl4·4H2O.

[0012] Furthermore, by weight percentage, the mass ratio of hexaethynylbenzene, the gold-containing chloride to the copper-containing compound is 1:(0.01-0.1):(0.05-0.2).

[0013] Furthermore, the copper-containing compound is CuCl2 and / or CuCl2·2H2O.

[0014] Furthermore, by weight percentage, the weight ratio of the gold-containing chloride to the copper-containing compound is (2-5):1.

[0015] Furthermore, in Step S2, the reaction temperature of the reduction reaction is 5-10 °C, and the reaction time is 2-8 h.

[0016] Furthermore, the reducing agent is ascorbic acid.

[0017] Further, the surfactant is octadecyl trimethyl ammonium chloride.

[0018] Further, in step S2, the addition amount of the reducing agent is 6 to 20 times the weight of the metal-containing compound; preferably, the addition amount of the surfactant is 3 to 11 times the weight of the metal-containing compound.

[0019] Further, in step S2, after the reduction reaction, the reduction product needs to be washed and freeze-dried in sequence to obtain the quantum dot catalyst.

[0020] Further, the washing solvent is a mixed solution of ethanol and water; preferably, the treatment temperature for freeze-drying is -80 to -20 °C, and the treatment time is 12 to 48 h.

[0021] Further, in step S1, the carbon fiber cloth is the carbon fiber cloth after pretreatment; preferably, the pretreatment of the carbon fiber cloth includes: taking the carbon fiber cloth, ultrasonically washing it in ethanol, acetone, and deionized water in sequence, heating it in a concentrated nitric acid solution, then washing and drying it to obtain the pretreated carbon fiber cloth.

[0022] Further, in step S1, the metal catalyst is selected from copper foil and / or copper sheet.

[0023] Further, in step S1, the organic solvent is selected from one or more of ethyl acetate, dichloromethane, or pyridine.

[0024] Further, in step S1, the synthesis reaction is carried out under light-shielded conditions, the reaction temperature is 20 to 25 °C, and the reaction time is 3 to 7 days.

[0025] Further, in step S1, after the synthesis reaction, the synthesized material needs to be washed, soaked, washed a second time, and dried in sequence to obtain the graphdiyne matrix.

[0026] According to another aspect of the present invention, there is provided an application of the above-mentioned quantum dot catalyst, or a quantum dot catalyst obtained by the preparation method of the above-mentioned quantum dot catalyst, in the fields of hydrogen production by electrolysis of water and / or electrocatalytic reduction of carbon dioxide.

[0027] By applying the technical solution of the present invention, the prepared quantum dot catalyst has a relatively high specific surface area, increasing its catalytic active sites, showing relatively excellent catalytic activity during the application process, and having relatively excellent comprehensive performance. Description of the Drawings

[0028] The drawings here are incorporated into the specification and form a part of this specification, showing the embodiments consistent with this application, and are used together with the specification to explain the principles of this application. In the drawings:

[0029] Figure 1Shows the Faraday efficiency diagram of the quantum dot catalyst prepared in Example 3 of the present invention when applied to the catalytic reduction product of CO2;

[0030] Figure 2 Shows the TEM images of the quantum dot catalyst prepared in Example 3 of the present invention at different magnifications;

[0031] Figure 3 Shows the EDS elemental distribution map of the quantum dot catalyst prepared in Example 3 of the present invention;

[0032] Figure 4 Shows the C elemental distribution map in the quantum dot catalyst prepared in Example 3 of the present invention;

[0033] Figure 5 Shows the Au elemental distribution map in the quantum dot catalyst prepared in Example 3 of the present invention; and

[0034] Figure 6 Shows the Cu elemental distribution map in the quantum dot catalyst prepared in Example 3 of the present invention. Detailed implementation manners

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0036] As described in the background art section of the present invention, the quantum dot catalysts in the prior art have technical problems such as cumbersome preparation processes or being extremely prone to aggregation and deactivation, resulting in poor catalytic performance during application and restricting their application scope. To address the above problems, the present invention provides a quantum dot catalyst, which includes: a graphdiyne matrix and metal quantum dots coated on the outer surface of the graphdiyne matrix, and the metal quantum dots are connected to the graphdiyne matrix in a chemical bond form; wherein, the metal in the metal quantum dots is an Au-Cu alloy.

[0037] The present invention is based on graphdiyne, which is currently the only two-dimensional planar all-carbon material that can be synthesized gently and controllably at low temperature and atmospheric pressure on any substrate. Based on the above characteristics of graphdiyne, loading metal quantum dots on its surface can achieve stable anchoring of metal atoms and controllable adjustment of their valence states. Therefore, by using the growth method of in-situ nucleation induced by metal atom anchoring, it is expected to realize the controllable preparation of quantum dot catalysts, and further greatly improve the catalytic performance of the quantum dot catalysts. In particular, the present invention creatively loads metal quantum dots on the above-mentioned graphdiyne matrix, which has beneficial effects. First, the plasmonic effect of the metal quantum dots makes the quantum dots have good light absorption characteristics. Therefore, when used as a light-harvesting unit in a photocatalytic hydrogen production system, the light absorption ability can be further improved. Second, the metal quantum dots have intrinsic characteristics such as a high specific surface area and high atomic utilization efficiency, which can further greatly increase the electrochemically active area of the catalyst and improve the catalytic performance. Third, the metal in the above-mentioned metal quantum dots is an Au-Cu alloy, which has a high electron conductivity. In particular, the alloying of two different metals can further effectively adjust the electronic structure, thereby realizing the adjustment of the interaction between the catalyst and the key reaction intermediate products, thereby realizing the improvement of the hydrogen evolution catalytic performance and the adjustment of the proportion of carbon dioxide reduction products, further expanding its application scope and making its application fields wider.

[0038] In a preferred embodiment, the metal quantum dots are in the form of particles with an average particle size of 4-12 nm to further increase their specific surface area and increase the catalytic active sites to further improve their catalytic performance. Further preferably, the graphdiyne matrix is grown on a carbon fiber cloth as a support material.

[0039] Another aspect of the present invention provides a method for preparing a quantum dot catalyst, which includes: Step S1, taking hexaethynylbenzene, a metal catalyst and an organic solvent in a reaction vessel containing a carbon fiber cloth for a synthesis reaction to obtain a graphdiyne matrix; Step S2, taking the graphdiyne matrix, a reducing agent, a surfactant, and a metal-containing compound for a reduction reaction to obtain a quantum dot catalyst.

[0040] Those skilled in the art first place hexaethynylbenzene, a metal catalyst and an organic solvent in a reaction kettle containing a carbon fiber cloth for a synthesis reaction to obtain a graphdiyne matrix; then carry out a reduction reaction on the graphdiyne matrix, a reducing agent, a surfactant, and an aqueous solution of a metal-containing compound to obtain a quantum dot catalyst. The quantum dot catalyst has a high specific surface area, increases its catalytic active sites, shows excellent catalytic activity during application, and has excellent comprehensive performance. Moreover, the above preparation method is simple, easy to operate, suitable for large-scale production, and has broad industrial application prospects.

[0041] In a preferred embodiment, the metal-containing compound is a gold-containing chloride and / or a copper-containing compound. More preferably, the gold-containing chloride is one or more selected from AuCl3, AuCl, HAuCl4 or HAuCl4·4H2O; the gold-containing chloride is HAuCl4·4H2O; even more preferably, the copper-containing compound is CuCl2 and / or CuCl2·2H2O, so as to further promote the alloying of quantum dots, more effectively adjust the electronic structure, exert the electronic effect, and improve the catalytic activity of the quantum dot catalyst.

[0042] In order to further improve the catalytic performance of the quantum dot catalyst and more effectively adjust the electronic structure, so as to realize the adjustment of the interaction between the catalyst and the key reaction intermediate, by weight percentage, the mass ratio of the hexaethynylbenzene, the gold-containing chloride and the copper-containing compound is 1:(0.01-0.1):(0.05-0.2), thereby adjusting the proportion of carbon dioxide reduction products and expanding its application range.

[0043] In order to further increase the reaction rate of the reduction reaction and promote the full progress of the reaction, by weight percentage, preferably the weight ratio of the gold-containing chloride to the copper-containing compound is (2-5):1. Even more preferably, the reaction temperature of the reduction reaction is 5-10 °C and the reaction time is 2-8 h.

[0044] In a preferred embodiment, the reducing agent is ascorbic acid, so that the metal-containing compound in the reaction raw materials is fully reduced to metal, improving its catalytic activity; preferably, the surfactant is octadecyltrimethylammonium chloride, so as to further reduce the surface tension of the reaction liquid and improve the wetting performance, prevent the further polymerization or reaction of the reaction raw materials, improve the structural stability of the quantum dot catalyst, and further improve its catalytic performance.

[0045] In order to further save the preparation cost of the quantum dot catalyst and promote the full progress of the reduction reaction, preferably in step S2, the addition amount of the reducing agent accounts for 6-20 times the weight of the metal-containing compound; the addition amount of the surfactant accounts for 3-11 times the weight of the metal-containing compound.

[0046] In a preferred embodiment, in step S2, after the reduction reaction, the reduction product needs to be washed and freeze-dried in sequence, so as to further remove the impurities remaining on the surface of the catalyst, avoid the influence of impurities on the catalytic performance, and further improve the catalytic performance of the catalyst; even more preferably, the washing solvent is a mixed solution of ethanol and water, the treatment temperature of freeze-drying is -80 to -20 °C, and the treatment time is 12-48 h.

[0047] In a preferred embodiment, the carbon fiber cloth is made from the carbon fiber cloth after pretreatment. The pretreatment of the carbon fiber cloth includes: taking the carbon fiber cloth and ultrasonically washing it successively in ethanol, acetone and deionized water, heating it in a concentrated nitric acid solution, then washing and drying it to obtain the pretreated carbon fiber cloth. The ultrasonic time is 10 min, the heating temperature is 80 °C, the heating time is 12 h, washing with ethanol and water successively for 3 times, and drying in a vacuum oven at 60 °C for 6 h.

[0048] In order to further promote the full progress of the graphdiyne reaction and prepare a graphdiyne matrix with stable structure and excellent performance, preferably the metal catalyst is selected from copper foil and / or copper sheet, and the organic solvent is selected from one or more of ethyl acetate, dichloromethane or pyridine, so that the reaction raw materials are fully dissolved, making the reaction solution more uniform and stable, and promoting the full reaction of the synthesis reaction.

[0049] In a preferred embodiment, the synthesis reaction is carried out under light-shielded conditions, the reaction temperature is 20 - 25 °C, and the reaction time is 3 - 7 days; more preferably, after the synthesis reaction, the synthesized material needs to be washed, soaked, washed a second time and dried in sequence to obtain a graphdiyne matrix with stable structure and excellent performance.

[0050] On the other hand, the present invention also provides a quantum dot catalyst, or the application of the quantum dot catalyst prepared by the above method for preparing a quantum dot catalyst in the field of hydrogen production by electrolyzing water and / or electrocatalytic reduction of carbon dioxide.

[0051] The following further describes the present application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0052] Example 1

[0053] First, take a 1 cm × 1 cm carbon cloth, ultrasonically clean the carbon cloth with ethanol, acetone and deionized water for 10 min respectively. Then mix 100 mL of concentrated nitric acid with 50 mL of deionized water, heat and cook the carbon cloth at 100 °C for 24 h, then wash it with ethanol and deionized water successively for 3 times, and dry it in a vacuum oven at 60 °C for 6 h to obtain the pretreated carbon fiber cloth.

[0054] Then, place tetrahydrofuran in an ice-water bath and introduce argon. Dissolve 100 mg of hexakis((trimethylsilyl)ethynyl)benzene in the above tetrahydrofuran solution, add tetrabutylammonium fluoride (TBAF, concentration 1 mol / L, volume 1.2 ml, molar amount 1.2 mmol). The solution turns blue-violet. After reacting for 12 - 15 min in the dark, add ethyl acetate solution, then transfer it to a separatory funnel and extract three times with saturated brine. The supernatant after extraction is dried with anhydrous Na₂SO₄ and filtered. The further obtained solution is distilled under reduced pressure to obtain solid powder hexaethynylbenzene (HEB).

[0055] Again, dissolve the above hexaethynylbenzene (HEB) in ethyl acetate solution to obtain a 6 mg / mL hexaethynylbenzene solution. Mix the hexaethynylbenzene solution, dichloromethane, and pyridine in a volume ratio of 10:10:7. Place the pretreated carbon fiber cloth in the reaction solution and react in the dark for 7 days with a copper foil as a catalyst at a reaction temperature of 25 °C. Wash it thoroughly with hot acetone and N,N-dimethylformamide, soak it in dilute hydrochloric acid to remove the adsorbed copper ions on the surface, then wash it with deionized water and dry it in a vacuum drying oven at 60 °C for 6 h to obtain a graphdiyne matrix.

[0056] Finally, dissolve 41.18 mg of HAuCl₄·4H₂O in 10 mL of deionized water to obtain a 10 mM HAuCl₄·4H₂O solution; dissolve 171.6 mg of ascorbic acid in 10 mL of deionized water to obtain a 100 mM ascorbic acid solution; respectively take 1 mL of HAuCl₄·4H₂O solution, 2 mL of ascorbic acid solution, and 0.05 mmol of octadecyltrimethylammonium chloride and mix them in 50 mL of deionized water, then add them to the above graphdiyne matrix. React at 10 °C for 4 h, wash with an ethanol / water mixture, and finally freeze-dry at -40 °C for 24 h to obtain an Au quantum dot / graphdiyne catalyst, where the average particle size of the Au quantum dots is 12 nm.

[0057] Example 2

[0058] The difference from Example 1 is only that: instead of adding the HAuCl₄·4H₂O solution, a CuCl₂·2H₂O solution is used instead. The preparation steps of the CuCl₂·2H₂O solution include: dissolve 16.88 mg of CuCl₂·2H₂O in 10 mL of deionized water to obtain a 10 mM CuCl₂·2H₂O solution. A Cu quantum dot / graphdiyne catalyst is obtained, where the average particle size of the Cu quantum dots is 4 nm.

[0059] Example 3

[0060] It is only different from Example 1 in that: an additional CuCl2·2H2O solution is added. The preparation steps of the CuCl2·2H2O solution include: dissolving 16.88 mg of CuCl2·2H2O in 10 mL of deionized water to obtain a 10 mM CuCl2·2H2O solution. Among them, the weight ratio of hexaethynylbenzene:CuCl2·2H2O:HAuCl4·4H2O is 60:1.688:4.118, obtaining an Au-Cu alloy quantum dot / graphdiyne catalyst. Among them, the average particle size of the Au-Cu quantum dots is 4 nm, Figure 2 shows the TEM images of the Au-Cu alloy quantum dot / graphdiyne catalyst at different magnifications, and Figure 3 shows the EDS elemental distribution of the Au-Cu alloy quantum dot / graphdiyne catalyst. In particular, Figure 4 shows the C elemental distribution map therein, Figure 5 shows the Au elemental distribution therein; and, Figure 6 shows the Cu elemental distribution therein.

[0061] Performance test:

[0062] Electrochemical measurements were carried out using a typical three-electrode system. The catalytic electrode was used as the working electrode, the saturated calomel electrode (SCE) was used as the reference electrode, and the graphite rod was used as the counter electrode. Electrochemical measurements were carried out using an electrochemical workstation in a sealed H-type electrochemical cell separated by a cation exchange membrane (Nafion117). Each side of the cell contained 25 mL of 0.1 M KHCO3 electrolyte. It was carried out under a CO2 atmosphere at room temperature. During all experiments, the gaseous products at the cathode outlet were collected and detected by electrochemical gas chromatography. In addition, the electrolyte after the cathode reaction was collected, and the liquid products were quantified and analyzed by nuclear magnetic resonance (NMR) to obtain the percentage of the charge consumed by the target product and the total charge consumed by the total reaction, which was the Faraday efficiency of the CO2 catalytic reduction product. The reaction equation of the CO2 catalytic reduction product is as follows:

[0063] 2H + +2e - →H2;

[0064] CO2+8H + +8e - →CH4+2H2O;

[0065] CO2+2H + +2e - →CO+H2O;

[0066] CO2+2H + +2e - →HCOOH;

[0067] 2CO2 + 12H + + 12e - → C2H4 + 4H2O;

[0068] 2CO2 + 12H + + 12e - → C2H5OH + 3H2O。

[0069] The performance test results of the quantum dot catalyst prepared in the above embodiments are shown in the attached drawings.

[0070] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0071] From the test results of the above embodiments and comparative examples, it can be found that Figure 1 In a 0.1 M KHCO3 electrolyte saturated with CO2, the Faraday efficiency diagram of the CO2 catalytic reduction products of the Au-Cu alloy quantum dot / graphdiyne catalyst. It can be seen from this that when the ratio of Cu to Au elements in the raw material is 1:1, compared with the 100% hydrogen evolution Faraday efficiency of the pure graphdiyne material, the Faraday efficiency of the CO2 catalytic reduction products of the Au-Cu alloy quantum dot / graphdiyne catalyst has changed significantly. At -0.9 V vs RHE, the hydrogen evolution Faraday efficiency is 55.5%, and as the applied bias voltage continues to increase, 2+ the Faraday efficiency of the C 2+ product continues to increase. At -1.1 V vs RHE, the Faraday efficiency of the C

[0072] In summary, the quantum dot catalyst prepared by the present invention has a high specific surface area, which increases its catalytic active sites, shows excellent catalytic activity during application, and has excellent comprehensive performance.

[0073] Although this specification contains many specific implementation details, these should not be construed as limiting the scope of any invention or the scope of what is claimed, but are mainly used to describe the features of specific embodiments of a particular invention. Certain features described in multiple embodiments in this specification can also be combined and implemented in a single embodiment. On the other hand, various features described in a single embodiment can also be separately implemented in multiple embodiments or implemented in any suitable sub-combination. In addition, although features may function in certain combinations as described above and are even initially claimed as such, one or more features from the claimed combination can in some cases be removed from the combination, and the claimed combination can be directed to a sub-combination or a variant of the sub-combination.

[0074] Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring that these operations be performed in the particular order shown or performed sequentially, or requiring that all illustrated operations be performed to achieve the desired results. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system modules and components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product, or packaged into multiple software products.

[0075] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the particular order or sequential order shown to achieve the desired results. In some implementations, multitasking and parallel processing may be advantageous.

[0076] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0077] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A quantum dot catalyst, characterized in that, The quantum dot catalyst includes: a graphdiyne matrix and metal quantum dots coated on the outer surface of the graphdiyne matrix, and the metal quantum dots are connected to the graphdiyne matrix in a chemical bond form; wherein, the metal in the metal quantum dots is an Au-Cu alloy.

2. The quantum dot catalyst according to claim 1, wherein The metal quantum dots are in a granular form, and their average particle size is 4-12 nm.

3. The quantum dot catalyst according to claim 1 or 2, characterized in that, The graphdiyne matrix uses a carbon fiber cloth as a support material and is grown on the carbon fiber cloth.

4. A method for preparing the quantum dot catalyst according to any one of claims 1 to 3, characterized in that, The preparation method includes: Step S1, taking hexaethynylbenzene, a metal catalyst and an organic solvent in a reaction vessel containing a carbon fiber cloth for a synthesis reaction to obtain the graphdiyne matrix; Step S2, taking the graphdiyne matrix, a reducing agent, a surfactant, and a metal-containing compound in deionized water for a reduction reaction to obtain the quantum dot catalyst.

5. The preparation method of the quantum dot catalyst according to claim 4, wherein, The metal-containing compound is a gold-containing chloride and a copper-containing compound; and / or The gold-containing chloride is selected from one or more of AuCl3, AuCl, HAuCl4 or HAuCl4·4H2O; and / or The gold-containing chloride is HAuCl4·4H2O.

6. The preparation method of the quantum dot catalyst according to claim 5, wherein, By weight percentage, the mass ratio of the hexaethynylbenzene, the gold-containing chloride to the copper-containing compound is 1:(0.01-0.1):(0.05-0.2).

7. The preparation method of the quantum dot catalyst according to claim 5 or 6, characterized in that, The copper-containing compound is CuCl2 and / or CuCl2·2H2O.

8. The preparation method of the quantum dot catalyst according to any one of claims 5 to 7, characterized in that, By weight percentage, the weight ratio of the gold-containing chloride to the copper-containing compound is (2-5):

1.

9. The preparation method of the quantum dot catalyst according to any one of claims 4 to 8, characterized in that, In step S2, the reaction temperature of the reduction reaction is 5-10 °C, and the reaction time is 2-8 h.

10. The preparation method of the quantum dot catalyst according to any one of claims 4 to 9, characterized in that, The reducing agent is ascorbic acid.

11. The preparation method of the quantum dot catalyst according to any one of claims 4 to 10, characterized in that, The surfactant is octadecyltrimethylammonium chloride.

12. The preparation method of the quantum dot catalyst according to any one of claims 4 to 11, characterized in that, In step S2, the addition amount of the reducing agent accounts for 6-20 times the weight of the metal-containing compound; and / or The addition amount of the surfactant accounts for 3-11 times the weight of the metal-containing compound.

13. The preparation method of the quantum dot catalyst according to any one of claims 4 to 12, characterized in that, In step S2, after the reduction reaction, the reduction product needs to be washed and freeze-dried in sequence to obtain the quantum dot catalyst.

14. The preparation method of the quantum dot catalyst according to claim 13, characterized in that, The washing solvent is a mixed solution of ethanol and water; and / or The treatment temperature of the freeze-drying is -80 to -20 °C, and the treatment time is 12-48 h.

15. The preparation method of the quantum dot catalyst according to any one of claims 4 to 14, characterized in that, In step S1, the carbon fiber cloth is a carbon fiber cloth after pretreatment; and / or The pretreatment of the carbon fiber cloth includes: taking the carbon fiber cloth and ultrasonically washing it in ethanol, acetone and deionized water in sequence, heating it in a concentrated nitric acid solution, then washing and drying it to obtain the pretreated carbon fiber cloth.

16. The preparation method of the quantum dot catalyst according to any one of claims 4 to 15, characterized in that, In step S1, the metal catalyst is selected from copper foil and / or copper sheet.

17. The preparation method of the quantum dot catalyst according to any one of claims 4 to 16, characterized in that, In step S1, the organic solvent is selected from one or more of ethyl acetate, dichloromethane or pyridine.

18. The preparation method of the quantum dot catalyst according to any one of claims 4 to 17, characterized in that, In step S1, the synthesis reaction is carried out under light-shielded conditions, the reaction temperature is 20-25 °C, and the reaction time is 3-7 days.

19. The preparation method of the quantum dot catalyst according to any one of claims 4 to 18, characterized in that, In step S1, after the synthesis reaction, the synthesized material needs to be washed, soaked, washed a second time and dried in sequence to obtain the graphdiyne matrix.

20. Use of a quantum dot catalyst according to any one of claims 1 to 3, or a quantum dot catalyst obtained by the preparation method of a quantum dot catalyst according to any one of claims 4 to 19, in the field of hydrogen production by electrolysis of water and / or electrocatalytic reduction of carbon dioxide.

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