Copper oxide / cuprous oxide heterogeneous nano-material with chiral morphology and preparation method of copper oxide / cuprous oxide heterogeneous nano-material

Abstract

The invention discloses a copper oxide / cuprous oxide heterogeneous nano-material with chiral morphology and a preparation method thereof, and the method comprises the following steps: 1, mixing a copper salt aqueous solution and a surfactant aqueous solution to obtain a mixed solution A, taking a chiral ligand aqueous solution to add into the mixed solution A under a stirring state, and stirring at room temperature to obtain a copper oxide / cuprous oxide heterogeneous nano-material; a copper ion reaction precursor solution is obtained; and 2, adding a sodium hydroxide aqueous solution into the copper ion reaction precursor solution, stirring at room temperature to obtain a mixed solution B, transferring the mixed solution B into a hydrothermal reaction kettle, putting the hydrothermal reaction kettle into a drying oven, reacting at 120-160 DEG C for 2-6 hours, after the reaction is finished, centrifugally separating out a precipitate, and sequentially washing and drying in vacuum to obtain the copper ion catalyst. The copper oxide / cuprous oxide heterogeneous nano material with chiral morphology is obtained. The preparation method is simple, low in cost and easy to implement, and the obtained chiral copper oxide / cuprous oxide heterogeneous nano material has good structural stability and crystallinity.

Description

Technical Field

[0001] The present invention relates to chiral inorganic nanomaterials, and specifically to a copper oxide / cuprous oxide heteronanomaterial with a chiral morphology and a preparation method thereof. Background Art

[0002] Chirality is a common symmetry-breaking phenomenon in nature and is of great significance in the living system. An object with chirality cannot be completely coincident with its mirror image through symmetry operations such as rotation and translation. Traditional chiral research mainly focuses on the field of organic molecules. With the development of nanoscience, the concept of chirality has been extended to inorganic nanomaterials.

[0003] Chiral inorganic nanomaterials have many advantages such as excellent thermodynamic and chemical stability, significant spin-orbit coupling interaction, significant responsiveness to electro-optics and magnetism, and the ability to exhibit multi-level chiral structures from atomic arrangement to nanomorphology. By regulating the material size, morphology, and composition, the physicochemical properties such as optical activity and catalytic selectivity can be precisely regulated, and they have broad application prospects in the fields of circularly polarized light detection, chiral catalysis, spin devices, quantum information encryption, and biomedicine. However, most inorganic materials in nature have symmetric crystal structures, and how to induce inorganic nanomaterials to form chiral morphologies and maintain the stability of chiral morphologies still faces great challenges.

[0004] Currently, there are mainly three ways to prepare chiral inorganic nanomaterials: First, chiral ligands are adsorbed on the surface of inorganic nanoparticles, and chiral transfer from chiral ligands to inorganic nanomaterials is achieved through the coordination between chiral ligands and the surface of inorganic nanoparticles; Second, organic or inorganic chiral templates are used to make inorganic nanoparticles arrange spatially according to the chiral pattern of the template, thereby obtaining chirality; Third, techniques such as glancing angle deposition and lithography or external fields such as circularly polarized light, magnetic fields, and eddy mechanical forces are used to assist the chiral growth or assembly of inorganic nanoparticles. However, these methods generally have the disadvantages of complex preparation processes, high technical requirements, and poor stability of the prepared chiral inorganic nanomaterials.

[0005] Therefore, how to prepare chiral inorganic nanomaterials with intrinsic morphologies is one of the important challenges in the field of chiral inorganic nanomaterials. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a copper oxide / cuprous oxide heteronanomaterial with a chiral morphology and a preparation method thereof, which not only has the advantages of simple preparation method, low cost, and easy implementation, but also the prepared chiral copper oxide / cuprous oxide heteronanomaterial has good structural stability and crystallinity.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions to be realized:

[0008] A preparation method of copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology, comprising the following steps:

[0009] Step 1, preparing a copper ion reaction precursor solution

[0010] Step 1.1, mixing an aqueous copper salt solution with a concentration of 0.1 - 0.4 mol / L and an aqueous surfactant solution with a concentration of 4 - 40 mg / mL according to a volume ratio of 1:(2.5 - 3.75) to obtain a mixed solution A;

[0011] Step 1.2, taking an aqueous chiral ligand solution with a concentration of 0.5 - 2.5 mol / L and adding it to the mixed solution A according to a volume ratio of 1:(15 - 20) under stirring, and stirring at room temperature to obtain a copper ion reaction precursor solution;

[0012] Step 2, preparing copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology

[0013] Step 2.1, taking an aqueous sodium hydroxide solution and adding it to the copper ion reaction precursor solution according to a molar ratio of copper ions to hydroxide ions of 1:(5 - 8), and stirring at room temperature to obtain a mixed solution B;

[0014] Step 2.2, transferring the mixed solution B to a hydrothermal reaction kettle, placing the hydrothermal reaction kettle in an oven, reacting at 120 - 160 °C for 2 - 6 h, after the reaction is completed, centrifuging to separate out the precipitate, washing and vacuum drying in sequence to obtain copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology.

[0015] Further, the aqueous copper salt solution in Step 1.1 is prepared from a copper salt and pure water, wherein: the copper salt is copper chloride or copper nitrate.

[0016] Further, the aqueous surfactant solution in Step 1.1 is prepared from a surfactant and ultrapure water, wherein: the surfactant is polyvinylpyrrolidone, sodium dodecyl sulfate or cetyltrimethylammonium bromide.

[0017] Further, the aqueous chiral ligand solution in Step 1.2 is prepared from a chiral ligand and ultrapure water, wherein: the chiral ligand is L-tartaric acid, D-tartaric acid, L-proline, D-proline, L-aspartic acid, D-aspartic acid, L-threonine, D-threonine, L-glutamic acid, D-glutamic acid, L-cysteine, D-cysteine, L-leucine, D-leucine, L-alanine, D-alanine, L-phenylalanine, D-phenylalanine, L-valine or D-valine.

[0018] Further, the stirring time in Step 1.2 is 10 - 20 min.

[0019] Further, the aqueous sodium hydroxide solution in step 2.1 is prepared by the following method: Take sodium hydroxide powder and add ultrapure water, and ultrasonically treat for 3 - 5 min to prepare a sodium hydroxide solution with a concentration of 0.85 - 1.35 mol / L.

[0020] Further, the stirring time in step 2.1 is 30 - 60 min.

[0021] Further, the washing in step 2.2 is cross - washing with deionized water and absolute ethanol for 3 - 5 times.

[0022] Further, the temperature of the vacuum drying in step 2.2 is 60 - 80 °C, and the time is 6 - 24 h.

[0023] A copper oxide / cuprous oxide heterogeneous nanomaterial with a chiral morphology is assembled by small nanorod units in the counter - clockwise direction.

[0024] Compared with the prior art, the present invention has the following technical effects:

[0025] 1), The present invention does not need to anchor chiral ligands on the surface of pre - synthesized achiral materials. Instead, an inorganic compound and a chiral ligand are directly combined. By directly inducing the nucleation and growth of inorganic nanoparticles by the chiral ligand, since the adsorption energy of different configurations of chiral ligands on the surface of inorganic particles is different, the growth rates of different crystal planes are different, thus realizing chiral ligand - dependent crystal plane - specific growth, and finally obtaining a twisted chiral morphology, thereby preparing a copper oxide / cuprous oxide heterogeneous nanomaterial with an intrinsic chiral morphology, which has good stability and crystallinity. Even after removing the chiral ligand by high - temperature calcination, it still maintains a good chiral structure and has broad application prospects.

[0026] 2), The present invention uses a simple and efficient hydrothermal method to synthesize a copper oxide / cuprous oxide heterogeneous nanomaterial with a chiral morphology, which has the advantages of easy control of reaction conditions, simple process and low cost, and is of great significance for constructing and regulating new chiral inorganic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the XRD pattern of the copper oxide / cuprous oxide heterogeneous nanomaterial with a chiral morphology prepared in Example 1 of the present invention;

[0028] Figure 2 It is the scanning electron microscope image of the copper oxide / cuprous oxide heterogeneous nanomaterial with a chiral morphology prepared in Example 1 of the present invention;

[0029] Figure 3TEM image of the chiral-shaped copper oxide / cuprous oxide heteronanomaterial prepared in Example 2 of the present invention;

[0030] Figure 4 High-magnification TEM image of the chiral-shaped copper oxide / cuprous oxide heteronanomaterial prepared in Example 2 of the present invention;

[0031] Figure 5 Circular dichroism spectrum of the chiral-shaped copper oxide / cuprous oxide heteronanomaterial prepared in Example 2 of the present invention after high-temperature calcination;

[0032] Figure 6 Circular dichroism spectra of the chiral-shaped copper oxide / cuprous oxide heteronanomaterials prepared in Example 1 and Example 2 of the present invention and the achiral copper oxide / cuprous oxide heteronanomaterial prepared in Comparative Example 1. Detailed implementation manners

[0033] The following further elaborates on the specific content of the present invention in conjunction with examples.

[0034] Before preparing the copper oxide / cuprous oxide heteronanomaterials in Examples 1 to 8 and Comparative Example 1, all containers were first cleaned. Specifically: the beakers were rinsed with deionized water, then ultrasonically cleaned, and then dried for later use; the hydrothermal reaction vessels were soaked in aqua regia, first cleaned with deionized water, then ultrasonically cleaned, and then dried for later use.

[0035] The chiral ligands selected in Examples 1 to 8 can be L-glutamic acid, D-glutamic acid, L-cysteine, D-cysteine, L-leucine, D-leucine, L-alanine, D-alanine, L-phenylalanine, D-phenylalanine, L-valine or D-valine in addition to L-tartaric acid, D-tartaric acid, L-proline, D-proline, L-aspartic acid, D-aspartic acid, L-threonine or D-threonine.

[0036] Example 1

[0037] Step 1. Preparation of a copper ion reaction precursor solution

[0038] Step 1.1. A copper chloride aqueous solution with a concentration of 0.25 mol / L and a polyvinylpyrrolidone aqueous solution with a concentration of 8 mg / mL were mixed according to a volume ratio of 1:3.125 to obtain a mixed solution A;

[0039] Step 1.2. Under stirring, an aqueous solution of D-tartaric acid with a concentration of 1.3 mol / L was added to the mixed solution A according to a volume ratio of 1:16.5, and stirred at room temperature for 10 min to obtain a copper ion reaction precursor solution;

[0040] Step 2: Prepare copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology

[0041] Step 2.1: Add sodium hydroxide powder to ultrapure water and ultrasonicate for 3 min to prepare a sodium hydroxide solution with a concentration of 1 mol / L.

[0042] Step 2.2: According to the molar ratio of copper ions to hydroxide ions of 1:6, add the sodium hydroxide aqueous solution to the copper ion reaction precursor solution and stir at room temperature for 30 min to obtain a mixed solution B.

[0043] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reaction kettle, place the hydrothermal reaction kettle in an oven, react at 160 °C for 2 h. After the reaction is completed, centrifuge at a speed of 9000 r / min for 5 min to separate the precipitate, wash it 3 times by cross-centrifugation with deionized water and absolute ethanol, then vacuum dry at 60 °C for 12 h, cool to room temperature to obtain copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology.

[0044] Figure 1 The XRD pattern of the copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology prepared in Example 1 shows that only the characteristic peaks of copper oxide (PDF#80-1917) and cuprous oxide (PDF#78-2076) are present, and no characteristic peaks of other substances appear, indicating that copper oxide / cuprous oxide was synthesized in Example 1 with high purity and crystallinity.

[0045] Figure 2 The SEM photograph of the copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology prepared in Example 1 shows that the copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology prepared in the example are assembled by small nanorod units in the counterclockwise direction, and it cannot coincide with its mirror image, resulting in chiral morphology.

[0046] Example 2

[0047] Step 1: Prepare a copper ion reaction precursor solution

[0048] Step 1.1: Mix an aqueous solution of copper chloride with a concentration of 0.25 mol / L and an aqueous solution of polyvinylpyrrolidone with a concentration of 8 mg / mL according to a volume ratio of 1:3.125 to obtain a mixed solution A.

[0049] Step 1.2: Under stirring, add an aqueous solution of L-tartaric acid with a concentration of 1.3 mol / L to the mixed solution A according to a volume ratio of 1:16.5 and stir at room temperature for 10 min to obtain a copper ion reaction precursor solution.

[0050] Step 2: Prepare copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology

[0051] Step 2.1: Add sodium hydroxide powder to ultrapure water and sonicate for 3 min to prepare a sodium hydroxide solution with a concentration of 1 mol / L.

[0052] Step 2.2: According to the molar ratio of copper ions to hydroxide ions of 1:6, add the sodium hydroxide aqueous solution to the copper ion reaction precursor solution and stir at room temperature for 30 min to obtain a mixed solution B.

[0053] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reaction kettle, place the hydrothermal reaction kettle in an oven, react at 160 °C for 2 h. After the reaction is completed, centrifuge at a speed of 9000 r / min for 5 min to separate the precipitate, wash it 3 times alternately with deionized water and absolute ethanol, then vacuum dry at 60 °C for 12 h, cool to room temperature to obtain copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology.

[0054] Figure 3 Figure 13 is the transmission electron microscopy image of the copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology prepared in Example 2. It can be clearly seen that it is assembled by small nanorods, which gives it a larger specific surface area and can expose more active sites. Since the rod body of the nanorods is relatively thick, the chiral morphology structure is not obvious under the transmission electron microscope.

[0055] Figure 4 Figure 17 is the high-magnification transmission electron microscopy image of the copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology prepared in Example 2. Selecting a single nanorod as the observation object, it can be seen that it has the lattices of both copper oxide and cuprous oxide, which proves again that the copper oxide / cuprous oxide heterogeneous nanomaterials have been successfully synthesized.

[0056] The copper oxide / cuprous oxide heterogeneous nanomaterials with chiral morphology prepared in Example 2 were calcined at a temperature of 500 °C for 6 h in an air atmosphere to obtain copper oxide / cuprous oxide heterogeneous nanomaterials after removing the chiral ligand. Its circular dichroism spectrum is as Figure 5 shown. It can be seen that the copper oxide / cuprous oxide heterogeneous nanomaterials after removing the chiral ligand still maintain good chiral optical activity.

[0057] Example 3

[0058] Step 1: Prepare a copper ion reaction precursor solution

[0059] Step 1.1: Mix an aqueous solution of copper chloride with a concentration of 0.1 mol / L and an aqueous solution of sodium dodecyl sulfate with a concentration of 4 mg / mL according to a volume ratio of 1:2.5 to obtain a mixed solution A.

[0060] Step 1.2: Under stirring, take an aqueous solution of L-proline with a concentration of 0.5 mol / L and add it to the mixed solution A according to a volume ratio of 1:15. Stir at room temperature for 10 min to obtain a copper ion reaction precursor solution;

[0061] Step 2: Prepare a chiral-shaped copper oxide / cuprous oxide heterogeneous nanomaterial

[0062] Step 2.1: Add sodium hydroxide powder to ultrapure water and sonicate for 3 min to prepare a sodium hydroxide solution with a concentration of 0.85 mol / L;

[0063] Step 2.2: Take an aqueous sodium hydroxide solution and add it to the copper ion reaction precursor solution according to a molar ratio of copper ions to hydroxide ions of 1:5. Stir at room temperature for 40 min to obtain a mixed solution B;

[0064] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reaction kettle, place the hydrothermal reaction kettle in an oven, react at 120 °C for 6 h. After the reaction is completed, centrifuge at a speed of 8000 r / min for 4 min to separate the precipitate. Wash it 4 times alternately with deionized water and absolute ethanol. Then, dry it in vacuum at 70 °C for 24 h, cool it to room temperature to obtain a chiral-shaped copper oxide / cuprous oxide heterogeneous nanomaterial.

[0065] Example 4

[0066] Step 1: Prepare a copper ion reaction precursor solution

[0067] Step 1.1: Mix an aqueous copper chloride solution with a concentration of 0.16 mol / L and an aqueous sodium dodecyl sulfate solution with a concentration of 10 mg / mL according to a volume ratio of 1:2.75 to obtain a mixed solution A;

[0068] Step 1.2: Under stirring, take an aqueous solution of D-proline with a concentration of 0.9 mol / L and add it to the mixed solution A according to a volume ratio of 1:16. Stir at room temperature for 20 min to obtain a copper ion reaction precursor solution;

[0069] Step 2: Prepare a chiral-shaped copper oxide / cuprous oxide heterogeneous nanomaterial

[0070] Step 2.1: Add sodium hydroxide powder to ultrapure water and sonicate for 3 min to prepare a sodium hydroxide solution with a concentration of 0.95 mol / L;

[0071] Step 2.2: Take an aqueous sodium hydroxide solution and add it to the copper ion reaction precursor solution according to a molar ratio of copper ions to hydroxide ions of 1:5.5. Stir at room temperature for 50 min to obtain a mixed solution B;

[0072] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reactor. Place the hydrothermal reactor in an oven and react at 130 °C for 5 h. After the reaction is completed, centrifuge at a speed of 10000 r / min for 6 min to separate the precipitate. Wash it 5 times alternately with deionized water and absolute ethanol. Then, dry it under vacuum at 80 °C for 6 h, cool it to room temperature to obtain a copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology.

[0073] Example 5

[0074] Step 1: Prepare a copper ion reaction precursor solution

[0075] Step 1.1: Mix an aqueous solution of copper nitrate with a concentration of 0.22 mol / L and an aqueous solution of cetyltrimethylammonium bromide with a concentration of 16 mg / mL according to a volume ratio of 1:3 to obtain a mixed solution A.

[0076] Step 1.2: Under stirring, take an aqueous solution of L-aspartic acid with a concentration of 1.5 mol / L and add it to the mixed solution A according to a volume ratio of 1:17.5. Stir at room temperature for 10 min to obtain a copper ion reaction precursor solution.

[0077] Step 2: Prepare a copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology

[0078] Step 2.1: Add sodium hydroxide powder to ultrapure water and ultrasonicate for 4 min to prepare a sodium hydroxide solution with a concentration of 1.1 mol / L.

[0079] Step 2.2: Take an aqueous solution of sodium hydroxide and add it to the copper ion reaction precursor solution according to a molar ratio of copper ions to hydroxide ions of 1:6.5. Stir at room temperature for 60 min to obtain a mixed solution B.

[0080] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reactor. Place the hydrothermal reactor in an oven and react at 140 °C for 4 h. After the reaction is completed, centrifuge at a speed of 8500 r / min for 7 min to separate the precipitate. Wash it 3 times alternately with deionized water and absolute ethanol. Then, dry it under vacuum at 65 °C for 10 h, cool it to room temperature to obtain a copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology.

[0081] Example 6

[0082] Step 1: Prepare a copper ion reaction precursor solution

[0083] Step 1.1: Mix an aqueous solution of copper nitrate with a concentration of 0.28 mol / L and an aqueous solution of cetyltrimethylammonium bromide with a concentration of 22 mg / mL according to a volume ratio of 1:3.25 to obtain a mixed solution A;

[0084] Step 1.2: Under stirring, take an aqueous solution of D-aspartic acid with a concentration of 1.8 mol / L and add it to the mixed solution A according to a volume ratio of 1:18. Stir at room temperature for 15 min to obtain a copper ion reaction precursor solution;

[0085] Step 2: Prepare a chiral-shaped copper oxide / cuprous oxide heterogeneous nanomaterial

[0086] Step 2.1: Add sodium hydroxide powder to ultrapure water and sonicate for 5 min to prepare a sodium hydroxide solution with a concentration of 1.2 mol / L;

[0087] Step 2.2: According to a molar ratio of copper ions to hydroxide ions of 1:7, take an aqueous solution of sodium hydroxide and add it to the copper ion reaction precursor solution. Stir at room temperature for 45 min to obtain a mixed solution B;

[0088] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reaction kettle. Place the hydrothermal reaction kettle in an oven and react at 150 °C for 3 h. After the reaction is completed, centrifuge at a speed of 9500 r / min for 8 min to separate the precipitate. Wash it 4 times alternately with deionized water and absolute ethanol. Then, dry it in vacuum at 75 °C for 18 h, cool it to room temperature to obtain a chiral-shaped copper oxide / cuprous oxide heterogeneous nanomaterial.

[0089] Example 7

[0090] Step 1: Prepare a copper ion reaction precursor solution

[0091] Step 1.1: Mix an aqueous solution of copper nitrate with a concentration of 0.34 mol / L and an aqueous solution of cetyltrimethylammonium bromide with a concentration of 30 mg / mL according to a volume ratio of 1:3.5 to obtain a mixed solution A;

[0092] Step 1.2: Under stirring, take an aqueous solution of L-threonine with a concentration of 2.2 mol / L and add it to the mixed solution A according to a volume ratio of 1:19. Stir at room temperature for 20 min to obtain a copper ion reaction precursor solution;

[0093] Step 2: Prepare a chiral-shaped copper oxide / cuprous oxide heterogeneous nanomaterial

[0094] Step 2.1: Add sodium hydroxide powder to ultrapure water and sonicate for 4 min to prepare a sodium hydroxide solution with a concentration of 1.3 mol / L;

[0095] Step 2.2: According to the molar ratio of copper ions to hydroxide ions of 1:7.5, take an aqueous sodium hydroxide solution and add it to the copper ion reaction precursor solution. Stir at room temperature for 35 min to obtain a mixed solution B.

[0096] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reaction kettle. Place the hydrothermal reaction kettle in an oven and react at 160 °C for 2 h. After the reaction is completed, centrifuge at a speed of 8000 r / min for 9 min to separate the precipitate. Wash it 5 times alternately with deionized water and absolute ethanol. Then, dry it under vacuum at 60 °C for 20 h, cool it to room temperature, and obtain a copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology.

[0097] Example 8

[0098] Step 1: Prepare a copper ion reaction precursor solution

[0099] Step 1.1: Mix an aqueous copper nitrate solution with a concentration of 0.4 mol / L and an aqueous polyvinylpyrrolidone solution with a concentration of 40 mg / mL according to a volume ratio of 1:3.75 to obtain a mixed solution A.

[0100] Step 1.2: Under stirring conditions, take an aqueous D-threonine solution with a concentration of 2.5 mol / L and add it to the mixed solution A according to a volume ratio of 1:20. Stir at room temperature for 10 min to obtain a copper ion reaction precursor solution.

[0101] Step 2: Prepare a copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology

[0102] Step 2.1: Add sodium hydroxide powder to ultrapure water and ultrasonicate for 4 min to prepare a sodium hydroxide solution with a concentration of 1.35 mol / L.

[0103] Step 2.2: According to the molar ratio of copper ions to hydroxide ions of 1:8, take an aqueous sodium hydroxide solution and add it to the copper ion reaction precursor solution. Stir at room temperature for 55 min to obtain a mixed solution B.

[0104] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reaction kettle. Place the hydrothermal reaction kettle in an oven and react at 120 °C for 4 h. After the reaction is completed, centrifuge at a speed of 8000 r / min for 10 min to separate the precipitate. Wash it 3 times alternately with deionized water and absolute ethanol. Then, dry it under vacuum at 80 °C for 15 h, cool it to room temperature, and obtain a copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology.

[0105] Comparative Example 1

[0106] Step 1: Prepare a copper ion reaction precursor solution

[0107] Step 1.1: Mix an aqueous solution of copper chloride with a concentration of 0.25 mol / L and an aqueous solution of polyvinylpyrrolidone with a concentration of 8 mg / mL according to a volume ratio of 1:3.125 to obtain a mixed solution A.

[0108] Step 1.2: Under stirring, add an aqueous solution of DL-tartaric acid with a concentration of 1.3 mol / L to the mixed solution A according to a volume ratio of 1:16.5, and stir at room temperature for 10 min to obtain a copper ion reaction precursor solution.

[0109] Step 2: Prepare chiral-shaped copper oxide / cuprous oxide heteronanomaterials

[0110] Step 2.1: Add sodium hydroxide powder to ultrapure water and sonicate for 3 min to prepare a sodium hydroxide solution with a concentration of 1 mol / L.

[0111] Step 2.2: Add an aqueous solution of sodium hydroxide to the copper ion reaction precursor solution according to a molar ratio of copper ions to hydroxide ions of 1:6, and stir at room temperature for 30 min to obtain a mixed solution B.

[0112] Step 2.3: Transfer the mixed solution B to a 50 mL hydrothermal reaction kettle, place the hydrothermal reaction kettle in an oven, react at 160 °C for 2 h. After the reaction is completed, centrifuge at a speed of 9000 r / min for 5 min to separate the precipitate, wash it 3 times alternately with deionized water and absolute ethanol, then vacuum dry at 60 °C for 12 h, cool to room temperature to obtain chiral-shaped copper oxide / cuprous oxide heteronanomaterials.

[0113] Figure 6 For the circular dichroism spectra of the chiral-shaped copper oxide / cuprous oxide heteronanomaterials prepared in Example 1 and Example 2 and the achiral copper oxide / cuprous oxide heteronanomaterials prepared in Comparative Example 1, it can be seen that the CD curves of the chiral-shaped copper oxide / cuprous oxide heteronanomaterials prepared in Example 1 and Example 2 are basically mirror-symmetric, while the CD curve of the achiral copper oxide / cuprous oxide heteronanomaterials prepared in Comparative Example 1 is basically maintained at 0, indicating that it does not have chirality.

Claims

1. A preparation method of a copper oxide / cuprous oxide heterogeneous nanomaterial with a chiral morphology, characterized in that, It includes the following steps: Step 1: Prepare a copper ion reaction precursor solution Step 1.1: Mix an aqueous copper salt solution with a concentration of 0.1 - 0.4 mol / L and an aqueous surfactant solution with a concentration of 4 - 40 mg / mL according to a volume ratio of 1:(2.5 - 3.75) to obtain a mixed solution A; Step 1.2: Under stirring, add an aqueous chiral ligand solution with a concentration of 0.5 - 2.5 mol / L to the mixed solution A according to a volume ratio of 1:(15 - 20), and stir at room temperature to obtain a copper ion reaction precursor solution; Step 2: Prepare a chiral - shaped copper oxide / cuprous oxide heteronanomaterial Step 2.1: Add an aqueous sodium hydroxide solution to the copper ion reaction precursor solution according to a molar ratio of copper ions to hydroxide ions of 1:(5 - 8), and stir at room temperature to obtain a mixed solution B; Step 2.2: Transfer the mixed solution B to a hydrothermal reaction kettle, place the hydrothermal reaction kettle in an oven, react at 120 - 160 °C for 2 - 6 h. After the reaction is completed, centrifuge to separate the precipitate, wash and vacuum - dry it in sequence to obtain a chiral - shaped copper oxide / cuprous oxide heteronanomaterial.

2. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that The aqueous copper salt solution in Step 1.1 is prepared from a copper salt and pure water, where the copper salt is copper chloride or copper nitrate.

3. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that, The aqueous surfactant solution in Step 1.1 is prepared from a surfactant and ultrapure water, where the surfactant is polyvinylpyrrolidone, sodium dodecyl sulfate or cetyltrimethylammonium bromide.

4. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that, The aqueous chiral ligand solution in Step 1.2 is prepared from a chiral ligand and ultrapure water, where the chiral ligand is L - tartaric acid, D - tartaric acid, L - proline, D - proline, L - aspartic acid, D - aspartic acid, L - threonine, D - threonine, L - glutamic acid, D - glutamic acid, L - cysteine, D - cysteine, L - leucine, D - leucine, L - alanine, D - alanine, L - phenylalanine, D - phenylalanine, L - valine or D - valine.

5. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that, The stirring time in Step 1.2 is 10 - 20 min.

6. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that, The aqueous sodium hydroxide solution in Step 2.1 is prepared by the following method: Add sodium hydroxide powder to ultrapure water and ultrasonicate for 3 - 5 min to prepare a sodium hydroxide solution with a concentration of 0.85 - 1.35 mol / L.

7. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that, The stirring time in Step 2.1 is 30 - 60 min.

8. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that, The washing in Step 2.2 is to cross - wash with deionized water and absolute ethanol 3 - 5 times.

9. The preparation method of the copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology according to claim 1, characterized in that, The temperature of the vacuum drying in Step 2.2 is 60 - 80 °C, and the time is 6 - 24 h.

10. A copper oxide / cuprous oxide heterogeneous nanomaterial with chiral morphology prepared by the method according to any one of claims 1 to 9, characterized in that, It is assembled by small nanorod units in the counter - clockwise direction.

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