Graphyne hollow multi-shell material, and preparation method and application thereof

Abstract

The application provides a graphdiyne hollow multi-shell material and a preparation method and application thereof, and comprises the following steps: (1) preparing a metal oxide hollow multi-shell; (2) reducing the metal oxide hollow multi-shell to obtain a metal hollow multi-shell; (3) in-situ growth preparation of a metal / graphdiyne hollow multi-shell material in a reaction solution by taking the metal hollow multi-shell as a template; and (4) finally, the metal hollow multi-shell template is removed by etching to prepare the graphdiyne hollow multi-shell material. According to the preparation method, the metal oxide hollow multi-shell can be converted into the metal hollow multi-shell while the morphology is kept through reduction, and the graphdiyne can be formed on the inner and outer surfaces of each layer of the metal hollow multi-shell through the in-situ growth method, and the graphdiyne hollow multi-shell is obtained after etching the metal template, and the graphdiyne hollow multi-shell can be used as a photothermal material for heavy metal ions and radioactive metal ion purification in water.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of functional materials, and relates to a graphdiyne hollow multi-shell material and a preparation method and application thereof, in particular, the present application relates to a graphdiyne hollow multi-shell material and a preparation method and application thereof for purifying heavy metal ions and radioactive metal ions in water through photothermal water evaporation. BACKGROUND

[0002] Solar energy is a clean and renewable energy. In the case of decreasing fossil fuels and global call for carbon emission reduction, the development and utilization of solar energy is particularly important. Solar photothermal water evaporation technology is a new high-efficiency photothermal conversion water purification technology. It uses absorbed sunlight to heat the water around the light absorber, and through evaporation and condensation collection or direct discharge to achieve the purpose of purification. However, during the evaporation process, a small amount of metal ions can be carried into the condensed water through the combination with water molecule clusters. For conventional metal ions, the ion concentration in the collected condensed liquid can be reduced to the discharge or even drinking water standard to achieve water purification or harmless effect. However, for wastewater containing radioactive metal ions, the discharge standard is extremely strict, and it is difficult to meet the requirements with general photothermal conversion materials. Therefore, it is necessary to find a material structure feature or special group to interact with water pollution, and then bind the water pollutants below the evaporation interface to further reduce the concentration of pollutants in the condensed liquid.

[0003] Graphdiyne is a new carbon material with uniform carbon network structure and large conjugated system. The electrons in the acetylene bond have a strong interaction with the empty orbit of the metal atom. In addition, the uniformly distributed pores composed of 18 carbon atoms in graphdiyne can play a sieving role for ions, which meets the above requirements for water purification materials.

[0004] Hollow multi-shell structure, a kind of micro / nano structure, plays an important role in light, wave absorption, energy conversion, mass transfer and other aspects due to its large effective specific surface area, multi-layer interface and independent and interconnected cavities. Studies have shown that the hollow multi-shell structure can make light scatter multiple times to extend the optical path, thereby enhancing the light trapping of the material and improving the photothermal conversion efficiency. In addition, the multi-level structure of the hollow multi-shell is conducive to the rapid transport and evaporation of water, and is conducive to improving the water evaporation efficiency. Therefore, designing and synthesizing graphdiyne hollow multi-shell material is expected to achieve high-efficiency photothermal water evaporation while improving the water purification efficiency.

[0005] At present, there are relevant literatures reported on the structural design of graphdiyne, such as diatomite-shaped graphdiyne prepared by using diatomite as a template (Li, J., Xu, J., Xie, Z., & Zhang, J. Adv. Mater. 2018, 30, 1800548). This is a graphdiyne with an independent three-dimensional structure. In addition, there is also a hollow spherical graphdiyne prepared by using the coating principle (Zhao, F., Li, X., He, J., Wang, K, & Huang, C. Chem. Eng. J. 2021, 413, 127486). But the multi-level graphdiyne with more complex structure and more abundant function has not been reported in detail. SUMMARY

[0006] The purpose of the present application is to provide a graphdiyne hollow multi-shell material and its preparation method and application, that is, to provide a new graphdiyne hollow multi-shell material, to improve the performance of graphdiyne, and to lay a foundation for meeting the actual water purification needs.

[0007] The present application is directed to the problems of instability and low efficiency of direct use of sunlight. The present application finds that the conjugated structure of graphdiyne connected by benzene rings through diacetylene bonds has wide-band absorption and porous characteristics, and the hollow multi-shell structure can effectively promote the efficient absorption and conversion of light by the material. On the other hand, ordinary photothermal materials are difficult to meet the higher requirements for the purification of wastewater containing radioactive metal elements (for example: Sr 90 , Cs 137 , U 238 , etc.). The interaction between the pi electrons of graphdiyne and the empty orbitals of metal atoms and the sieving effect of the pore formed by the 18 carbon atoms of graphdiyne can achieve efficient water purification.

[0008] To achieve the purpose of the present application, the present application adopts the following technical solutions:

[0009] In the first aspect of the present application, a preparation method of a graphdiyne hollow multi-shell material is provided. The method comprises the following steps:

[0010] (1) preparing a metal oxide hollow multi-shell layer; a carbon sphere template is obtained by hydrothermal reaction of a carbon source aqueous solution, the carbon sphere template is dispersed in a metal salt solution to adsorb metal ions, and then the metal oxide hollow multi-shell layer is prepared after filtration, drying and calcination.

[0011] (2) reducing the metal oxide hollow multi-shell layer obtained in step (1) with a reducing agent to obtain a metal hollow multi-shell layer;

[0012] (3) dispersing the metal hollow multi-shell obtained in step (2) in a reaction solution to obtain a metal / graphdiyne hollow multi-shell material, that is, using the metal hollow multi-shell as a template, the metal / graphdiyne hollow multi-shell material is prepared in situ in the reaction solution, wherein the reaction solution comprises hexaethynylbenzene, a nitrogen-containing ligand, a copper salt and a dispersant;

[0013] (4) dispersing the metal / graphdiyne hollow multi-shell material obtained in step (3) in an oxidizing agent to obtain a graphdiyne hollow multi-shell material, that is, the graphdiyne hollow multi-shell material is prepared by removing the metal hollow multi-shell template through etching of the oxidizing agent.

[0014] The preparation method of the present application can be used to prepare the graphdiyne hollow multi-shell material by designing the metal hollow multi-shell template and growing in situ, and the preparation method has mild conditions, simple operation and is suitable for large-scale production. The prepared graphdiyne hollow multi-shell material can be used for photothermal conversion water evaporation, purification of seawater, heavy metal ion contaminated water and water containing Sr, Cs and U.

[0015] In addition, the preparation method according to the present application can also have the following additional technical features:

[0016] According to the embodiment of the present application, the carbon source solution in step (1) comprises one or a combination of at least two of sucrose, fructose, glucose, citric acid, xylose, xylitol and sorbitol, and the metal salt solution is a salt solution known in the art.

[0017] The metal oxide includes one of copper oxide, iron oxide, nickel oxide, cobalt oxide, titanium oxide, manganese oxide, niobium oxide, zinc oxide, cerium oxide and tantalum oxide or a multi-element oxide composed of at least two of them, and the metal oxide hollow multi-shell has the same or different spherical or polyhedral shape.

[0018] According to the embodiment of the present application, the reducing agent in step 2) includes hydrogen, hydrazine hydrate, sodium borohydride, potassium borohydride or ammonia borane.

[0019] According to the embodiment of the present application, the in-situ growth temperature is 40-110℃.

[0020] According to the embodiment of the present application, the reaction time of step 3) is 1-4 days.

[0021] According to the embodiment of the present application, the nitrogen-containing ligand includes any one or a combination of at least two of tetramethyl ethylenediamine, pyridine, piperidine and triethylamine.

[0022] According to the embodiment of the present application, the copper salt includes one or a combination of at least two of copper nitrate, copper acetate, copper chloride, copper acetylacetonate, cuprous iodide and cuprous chloride.

[0023] According to an embodiment of the present application, the dispersant comprises one or a combination of at least two of acetone, pyridine, diethyl ether, tetrahydrofuran and N,N-dimethylformamide.

[0024] According to an embodiment of the present application, in the reaction system of step (3), the weight ratio of hexaethynylbenzene, metal hollow multi-shell, nitrogen-containing ligand, copper salt and dispersant is 1:(3-12):(50-550):(0.01-1):(1500-25000).

[0025] According to an embodiment of the present application, the oxidant comprises one or a combination of at least two of concentrated nitric acid, ferric chloride, ferric nitrate and ferric sulfate. The usage amount of the oxidant is (1-100):1 compared with the mass of the metal / graphyne hollow multi-shell material.

[0026] The second aspect of the present application provides a graphyne hollow multi-shell material.

[0027] According to an embodiment of the present application, the graphyne hollow multi-shell material is prepared by the method as described in the first aspect.

[0028] The graphyne hollow multi-shell material of the embodiments of the present application can significantly improve the photothermal water evaporation efficiency and the ion removal rate in water, so as to achieve the purpose of water purification.

[0029] The third aspect of the present application provides the application of the graphyne multi-shell material as described in the first aspect in the field of photothermal water evaporation.

[0030] According to an embodiment of the present application, the present application provides a light absorber for photothermal water evaporation. The light absorber in the photothermal water evaporation material is formed by the graphyne hollow multi-shell material, which is used for heavy metal ion and radioactive metal ion purification in water. Therefore, the photothermal water evaporation efficiency and the ion removal rate in water can be significantly improved, so as to achieve the purpose of water purification.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] The preparation method provided by the application can convert metal oxide hollow multi-shell into metal hollow multi-shell while maintaining the morphology through reduction, and can form graphdiyne on the inner and outer surfaces of each layer of the metal hollow multi-shell through in-situ growth, and obtain graphdiyne hollow multi-shell after etching the metal template, which can be used as a photothermal material for radioactive metal ion purification, and the concentration of Sr(II) ions is reduced by 6 orders of magnitude and the concentration of Cs(i) ions is reduced by 7 orders of magnitude after the material is treated, which reaches the national safety emission standard (GB14587-2011); the material can be used for photothermal water evaporation to remove heavy metal ions in water, and the concentrations of Cd(II) and Pb(II) ions are reduced by 7 orders of magnitude and the concentrations of Cu(II) and Cr(VI) ions are reduced by 8 orders of magnitude after the material is treated. The material can also be used for photothermal seawater desalination, and the salt ion concentration of the treated seawater can reach the drinking water health standard (GB5749-2006). BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a transmission electron microscope photo of the copper oxide hollow multi-shell of the embodiment 1 of the application;

[0034] Figure 2 is a transmission electron microscope photo of the copper hollow multi-shell of the embodiment 1 of the application;

[0035] Figure 3 is a transmission electron microscope photo of the copper / graphdiyne hollow multi-shell of the embodiment 1 of the application;

[0036] Figure 4 is an X-ray diffraction diagram of the copper oxide hollow multi-shell and the copper hollow multi-shell of the embodiment 1 of the application;

[0037] Figure 5 is a transmission electron microscope photo of the graphdiyne hollow multi-shell of the embodiment 1 of the application;

[0038] Figure 6 is a scanning electron microscope photo of the graphdiyne hollow multi-shell of the embodiment 1 of the application;

[0039] Figure 7 is a Raman spectrum of the graphdiyne hollow multi-shell of the embodiment 1 of the application;

[0040] Figure 8 is an X-ray photoelectron spectroscopy diagram of the graphdiyne hollow multi-shell of the embodiment 1 of the application;

[0041] Figure 9 is an ultraviolet-visible light absorption spectrum diagram of the graphdiyne hollow multi-shell of the embodiment 1 of the application;

[0042] Figure 10 is a performance diagram of the photothermal water evaporation of the graphdiyne hollow multi-shell of the embodiment 1 of the application;

[0043] Figure 11 is a concentration comparison chart of the graphdiyne hollow multi-shell layer of embodiment 1 for photothermal evaporation purification of a solution containing uranium, strontium and cesium;

[0044] Figure 12 is a purification effect chart of the graphdiyne hollow multi-shell layer of embodiment 1 for photothermal evaporation purification of a solution containing lead, cadmium and copper;

[0045] Figure 13 is an effect chart of the graphdiyne hollow multi-shell layer of embodiment 1 for photothermal seawater desalination;

[0046] Figure 14 is a comparison chart of the heavy metal ion removal effect of the graphdiyne hollow multi-shell layer of embodiment 1 with the materials reported in the literature. DETAILED DESCRIPTION

[0047] The application will be further described below in conjunction with specific embodiments.

[0048] The application provides a preparation method of a graphdiyne hollow multi-shell layer material, which comprises:

[0049] (a) a carbon source aqueous solution with a concentration of 1-10 M is loaded into a reaction kettle at 180-220 ℃ for hydrothermal reaction for 120-180 min, and after cooling, the carbon sphere template is obtained by suction filtration and drying, the carbon sphere template is dispersed in a metal salt solution with a concentration of 0.01-1 M to adsorb metal ions, and after filtration and drying, the metal oxide hollow multi-shell layer material is obtained by calcination; (b) 100-500 mg of the oxide hollow multi-shell layer material obtained in step (a) is reduced by a reducing agent, wherein the composition of the oxide hollow multi-shell layer is one of copper oxide, iron oxide, nickel oxide, cobalt oxide, titanium oxide, manganese oxide, niobium oxide, zinc oxide, cerium oxide and tantalum oxide or a combination of at least two thereof, the shape of the hollow multi-shell layer is a sphere or a polyhedron with the same or different inner and outer layer shapes, the reducing agent is hydrazine hydrate, sodium borohydride, potassium borohydride, ammonia borane or hydrogen, and the reaction is carried out at 25-200 ℃ for 20-150 min, and the obtained solid product is a metal hollow multi-shell layer template;

[0050] (c) dispersing the metal hollow multi-shell obtained in step (b) in a solution containing hexaethynylbenzene, nitrogen-containing ligand, copper salt. The weight ratio of hexaethynylbenzene, metal hollow multi-shell, nitrogen-containing ligand, copper salt, solvent in the system is 1:(3-12):(50-550):(0.01-1):(1500-25000). The nitrogen-containing ligand is any one or a combination of at least two of tetramethylethylenediamine, pyridine, piperidine and triethylamine; the dispersing agent is one or more than two of acetone, pyridine, diethyl ether, tetrahydrofuran and N,N-dimethylformamide; the copper salt includes one or more than two of copper nitrate, copper acetate, copper chloride, copper acetylacetonate, cuprous iodide and cuprous chloride. The reaction is carried out at 40-110 degrees Celsius for 1-4 days, the solid is filtered, washed with acetone, N,N-dimethylformamide, ethanol and deionized water for 2-6 times, and dried at 60-100 degrees Celsius for 5-15 hours to obtain the metal / graphdiyne hollow multi-shell material.

[0051] (e) dispersing the metal / graphdiyne hollow multi-shell material obtained in step (c) in a 0.05-1M oxidizing agent solution, wherein the oxidizing agent is one or more than two of concentrated nitric acid, ferric chloride, ferric nitrate and ferric sulfate. After stirring at 30-70 degrees Celsius for 10-24 hours, the solid is filtered, washed with deionized water and ethanol for 2-6 times, and dried at 50-100 degrees Celsius for 5-15 hours to obtain the graphdiyne hollow multi-shell material.

[0052] Example 1

[0053] A method for preparing a graphdiyne hollow multi-shell material, the method comprising:

[0054] (1) a 1M aqueous solution of sucrose is loaded into a reaction kettle at 200 degrees Celsius for hydrothermal reaction for 140 minutes, and after cooling, the solid is filtered and dried to obtain a carbon sphere template, which is dispersed in a 0.05M copper acetate solution to adsorb metal ions, and after filtration and drying, the copper oxide hollow multi-shell material is obtained by calcination;

[0055] (2) 100mg of the copper oxide hollow multi-shell obtained in step (1) is added to a 1M aqueous solution of sodium borohydride, and the reaction is carried out at room temperature for 30 minutes, after which the solid is filtered and washed for 3 times, and the product is dried at 60 degrees Celsius for 5 hours to obtain a copper hollow multi-shell template;

[0056] (3) 30mg of hexaethynylbenzene is dissolved in 150ml of acetone, 5ml of pyridine, 1ml of tetramethylethylenediamine and 5mg of copper chloride are added, and then the copper hollow multi-shell obtained in step (1) is dispersed in the above solution, and the reaction is carried out at 50 degrees Celsius for 1 day, after which the solid is filtered, washed with acetone, N,N-dimethylformamide, ethanol and deionized water for 3 times, and dried at 60 degrees Celsius for 5 hours to obtain the copper / graphdiyne hollow multi-shell material.

[0057] (4) The copper / graphyne hollow multi-shell material obtained in step (3) was dispersed in a 0.5M ferric chloride solution, stirred at 40°C for 12 hours, filtered, washed three times with deionized water and ethanol, and dried at 60°C for 5 hours to obtain the graphyne hollow multi-shell material.

[0058] Transmission electron microscopy (TEM) images of hollow multi-shell copper oxide are shown below. Figure 1 As shown, this is a two-shell hollow sphere. After reduction, the resulting electron micrograph of a copper hollow multi-shell sphere is as follows. Figure 2 As shown, the X-ray diffraction pattern is as follows: Figure 4 As shown, it retains the structural characteristics of a two-shell hollow sphere. The obtained electron micrographs of the copper / graphdiene hollow multi-shell structure are shown below. Figure 3 As shown, graphdiene was grown on the surface of each layer of the copper hollow multi-shell structure. After etching, the transmission electron microscope (TEM) images, scanning electron microscope (SEM) images, Raman spectra, and X-ray photoelectron spectroscopy (XPS) spectra of the obtained graphdiene hollow multi-shell material are shown below. Figures 5-8 As shown in the figure, the number of layers in the graphdiene hollow multi-shell material is twice that of the original template. Figure 9 The absorption spectroscopy results show that the graphdiene hollow multi-shell material exhibits strong light absorption characteristics across the entire wavelength range of the solar spectrum. For example... Figure 10 As shown at 100mW / cm 2 Under sunlight simulator irradiation, it can reach 2.7 kg / m 2 Efficient surface water evaporation was achieved at an evaporation rate of h. Furthermore, the water source for evaporation was broadened to include radioactive wastewater containing uranium, strontium, and cesium. The concentrations of uranium, strontium, and cesium in the water before and after evaporation were characterized using ICP, and the results are shown below. Figure 11 As shown, the uranium concentration decreased from 200 ppm to 4.1 × 10⁻⁶. -5 The concentration of strontium and cesium decreased by nearly seven orders of magnitude, fully meeting WHO standards; the concentrations of strontium and cesium decreased from 100 ppm to 1.7*10 ppm respectively. -4 ppm and 1*10 -5 The concentration in ppm decreased by nearly 6-7 orders of magnitude, meeting the national standards for radioactive wastewater discharge. Using this material for photothermal evaporation to remove heavy metal ions from water yielded the following results: Figure 12 As shown, after treatment, the levels of Cd(II) and Pb(II) ions decreased by 7 orders of magnitude, while the levels of Cu(II) and Cr(VI) ions decreased by 8 orders of magnitude. Figure 14 As shown, compared to existing technologies, this material exhibits superior performance in removing heavy metals from water. Furthermore, this material can also be used in photothermal seawater desalination, with similar results. Figure 13 As shown, the salt ion concentration of the treated seawater meets the standards for drinking water.

[0059] Example 2

[0060] A method for preparing a graphdiene hollow multi-shell material, the method comprising:

[0061] (1) A 1M sucrose aqueous solution was placed in a 200℃ reaction vessel and hydrothermally reacted for 140 min. After cooling, it was filtered and dried to obtain a carbon ball template. The carbon ball template was dispersed in a 0.05M copper acetate solution to adsorb metal ions. After filtration, drying, and calcination, copper oxide hollow multi-shell material was obtained.

[0062] (2) 200 mg of copper oxide hollow multi-shell layer was added to an aqueous solution containing 2 M potassium borohydride, reacted at room temperature for 60 min, the solid was filtered, and after washing 4 times, the product was dried at 80 °C for 10 h to obtain copper hollow multi-shell layer template.

[0063] (3) Dissolve 30 mg hexaethynylbenzene in 100 ml acetone and add 5 ml pyridine, 2 ml tetramethylethylenediamine, 1 ml triethylamine and 10 mg cuprous iodide. Then disperse the copper hollow multi-shell material obtained in step (1) in the above solution and react at 60 °C for 2 days. After filtration, the solid is washed 4 times with acetone, N,N dimethylformamide, ethanol and deionized water and dried at 80 °C for 10 h to obtain copper / graphyne hollow multi-shell material.

[0064] (4) The copper / graphyne hollow multi-shell material obtained in step (3) was dispersed in 1M ferric nitrate solution, stirred at 50°C for 20h, filtered, washed 4 times with deionized water and ethanol, and dried at 80°C for 10h to obtain the graphyne hollow multi-shell material.

[0065] Example 3

[0066] A method for preparing a graphdiene hollow multi-shell material, the method comprising:

[0067] (1) A 1M sucrose aqueous solution was placed in a reactor at 200℃ and hydrothermally reacted for 140 min. After cooling, the solution was filtered and dried to obtain a carbon sphere template. The carbon sphere template was dispersed in a 0.05M copper acetate solution to adsorb metal ions. After filtration, drying, and calcination, a copper oxide hollow multi-shell material was obtained.

[0068] (2) Add 120 mg of copper oxide hollow multishell obtained in step (1) to an aqueous solution containing 2 M hydrazine hydrate, react at room temperature for 90 min, filter the solid, and after washing twice, dry the product at 60 °C for 15 h to obtain copper hollow multishell template.

[0069] (3) Dissolve 10 mg hexaethynylbenzene in 100 ml N,N dimethylformamide and add 6 ml pyridine, 1 ml triethylamine and 3 mg copper acetate. Then disperse the copper hollow multi-shell material obtained in step (1) in the above solution and react at 100 degrees Celsius for 3 days. After filtration, the solid is washed twice with acetone, N,N dimethylformamide, ethanol and deionized water and dried at 60 degrees Celsius for 15 h to obtain copper / graphyne hollow multi-shell material.

[0070] (4) The copper / graphyne hollow multi-shell material obtained in step (3) was dispersed in 1M ferric sulfate solution, stirred at 30°C for 24h, filtered, washed twice with deionized water and ethanol, and dried at 60°C for 10h to obtain the graphyne hollow multi-shell material.

[0071] Example 4

[0072] A method for preparing a graphdiene hollow multi-shell material, the method comprising:

[0073] (1) A 1M sucrose aqueous solution was placed in a reactor at 200℃ and hydrothermally reacted for 140 min. After cooling, the solution was filtered and dried to obtain a carbon sphere template. The carbon sphere template was dispersed in a 0.03M nickel nitrate solution to adsorb metal ions. After filtration, drying, and calcination, a nickel oxide hollow multi-shell material was obtained.

[0074] (2) Add 200 mg of nickel oxide hollow multishell obtained in step (1) to a solution containing 1 M sodium borohydride, react at room temperature for 45 min, filter the solid, and after washing twice, dry the product at 60 °C for 15 h to obtain nickel hollow multishell template.

[0075] (3) Dissolve 20 mg hexaethynylbenzene in 100 ml tetrahydrofuran and add 5 ml pyridine, 5 ml triethylamine and 4 mg copper acetylacetonate. Then disperse the nickel hollow multi-shell material obtained in step (1) in the above solution and react at 100 degrees Celsius for 2 days. After filtration, the solid is washed twice with acetone, N,N dimethylformamide, ethanol and deionized water and dried at 60 degrees Celsius for 15 h to obtain nickel / graphyne hollow multi-shell material.

[0076] (4) The nickel / graphyne hollow multi-shell material obtained in step (3) was dispersed in 1M nitric acid solution, stirred at 30°C for 24h, filtered, washed twice with deionized water and ethanol, and dried at 60°C for 10h to obtain the graphyne hollow multi-shell material.

[0077] Example 5

[0078] A method for preparing a graphdiene hollow multi-shell material, the method comprising:

[0079] (1) A 1M sucrose aqueous solution was placed in a reactor at 200℃ and hydrothermally reacted for 140 min. After cooling, the solution was filtered and dried to obtain a carbon sphere template. The carbon sphere template was dispersed in a 0.04M cobalt nitrate solution to adsorb metal ions. After filtration, drying, and calcination, a cobalt oxide hollow multi-shell material was obtained.

[0080] (2) Add 100 mg of cobalt oxide hollow multishell obtained in step (1) to a solution containing 1 M sodium borohydride, react at room temperature for 45 min, filter the solid, and after washing twice, dry the product at 60 °C for 15 h to obtain a cobalt hollow multishell template.

[0081] (3) Dissolve 30 mg hexaethynylbenzene in 100 ml tetrahydrofuran and add 5 ml pyridine, 5 ml triethylamine and 2 mg cuprous iodide. Then disperse the iron hollow multi-shell material obtained in step (1) in the above solution and react at 100 degrees Celsius for 3 days. After filtration, the solid is washed twice with acetone, N,N dimethylformamide, ethanol and deionized water and dried at 60 degrees Celsius for 15 h to obtain cobalt / graphyne hollow multi-shell material.

[0082] (4) The cobalt / graphyne hollow multi-shell material obtained in step (3) was dispersed in 1M nitric acid solution, stirred at 30°C for 24h, filtered, washed twice with deionized water and ethanol, and dried at 60°C for 10h to obtain the graphyne hollow multi-shell material.

[0083] Example 6

[0084] A method for preparing a graphdiene hollow multi-shell material, the method comprising:

[0085] (1) A 1M sucrose aqueous solution was placed in a reactor at 200℃ and hydrothermally reacted for 140 min. After cooling, the solution was filtered and dried to obtain a carbon sphere template. The carbon sphere template was dispersed in a 0.03M ferric chloride solution to adsorb metal ions. After filtration, drying, and calcination, a hollow multi-shell material of iron oxide was obtained.

[0086] (2) Add 100 mg of iron oxide hollow multishell obtained in step (1) to a solution containing 1 M sodium borohydride, react at room temperature for 45 min, filter the solid, and after washing twice, dry the product at 60 °C for 15 h to obtain iron hollow multishell template.

[0087] (3) Dissolve 20 mg hexaethynylbenzene in 100 ml tetrahydrofuran and add 5 ml pyridine, 5 ml triethylamine and 3 mg cuprous iodide. Then disperse the iron hollow multi-shell material obtained in step (1) in the above solution and react at 100 degrees Celsius for 2 days. After filtration, the solid is washed twice with acetone, N,N dimethylformamide, ethanol and deionized water and dried at 60 degrees Celsius for 15 h to obtain iron / graphyne hollow multi-shell material.

[0088] (4) The iron / graphyne hollow multi-shell material obtained in step (3) was dispersed in 1M nitric acid solution, stirred at 30°C for 24h, filtered, washed twice with deionized water and ethanol, and dried at 60°C for 10h to obtain the graphyne hollow multi-shell material.

[0089] All aspects not described in detail in this invention can be covered using conventional technical knowledge in the field.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a graphdiyne hollow multi-shell material, comprising the following steps: 1) A carbon source aqueous solution is heated to obtain a carbon sphere template. The carbon sphere template is dispersed in a metal salt solution, and then filtered, dried and calcined to obtain a hollow multi-shell metal oxide. 2) Reduce the metal oxide hollow multishell obtained in step 1) with a reducing agent to obtain a metal hollow multishell; 3) Disperse the metal hollow multishell obtained in step 2) in a reaction solution to obtain a metal / graphyne hollow multishell material; the reaction solution includes hexaethynylbenzene, nitrogen-containing ligands, copper salts and dispersants; 4) Disperse the metal / graphyne hollow multi-shell material obtained in step 3) in an oxidant to obtain a graphyne hollow multi-shell material.

2. The preparation method according to claim 1, characterized in that, The carbon source aqueous solution in step 1) includes one or a combination of at least two of sucrose, fructose, glucose, citric acid, xylose, xylitol and sorbitol, and the metal oxide includes one or a combination of at least two of copper oxide, iron oxide, nickel oxide, cobalt oxide, titanium oxide, manganese oxide, niobium oxide, zinc oxide, cerium oxide and tantalum oxide; the hollow multi-shell shape of the metal oxide is a sphere or polyhedron with the same or different inner and outer shell shapes.

3. The preparation method according to claim 1, characterized in that, The reducing agent in step 2) includes hydrazine hydrate, sodium borohydride, potassium borohydride, ammonia borane, or hydrogen.

4. The preparation method according to claim 1, characterized in that, The reaction in the reaction solution in step 3) is an in-situ growth reaction, with a reaction temperature of 40–110°C and a reaction time of 1–4 days.

5. The preparation method according to claim 1, characterized in that, The nitrogen-containing ligand includes any one or a combination of at least two of tetramethylethylenediamine, pyridine, piperidine, and triethylamine; The copper salt includes one or a combination of at least two of copper nitrate, copper acetate, copper chloride, copper acetylacetone, cuprous iodide, and cuprous chloride; The dispersant includes one or a combination of at least two of acetone, pyridine, diethyl ether, tetrahydrofuran, and N,N-dimethylformamide.

6. The preparation method according to claim 1, characterized in that, In step 3), the weight ratio of hexaethynylbenzene, hollow metal multishell, nitrogen-containing ligand, copper salt, and dispersant is 1:(3-12):(50-550):(0.01-1):(1500-25000).

7. The preparation method according to claim 1, characterized in that, The oxidant in step 4) includes one or more of concentrated nitric acid, ferric chloride, ferric nitrate and ferric sulfate, or a combination of at least two of them; the mass ratio of the oxidant to the metal / graphyne hollow multi-shell material is (1~100):

1.

8. A graphdiyne hollow multi-shell material, characterized in that, The graphyne hollow multi-shell material is obtained by the preparation method described in any one of claims 1 to 7.

9. The application of the graphdiyne hollow multi-shell material according to claim 8 in the field of photothermal evaporation.

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