Copper-based micro-nano material with controllable phase and morphology and homogeneous synthesis method thereof

Abstract

The application discloses a homogeneous phase synthesis method of copper-based micro-nano materials with controllable phase and morphology, which comprises the following steps: (1) dissolving soluble copper salt in a mixed solvent of ethylene glycol and ethylenediamine, and stirring to obtain a clear homogeneous phase solution; (2) adjusting the adding amount of deionized water in the reaction system to determine the phase of the product as copper or cuprous oxide or a composite material of both; (3) under the determined phase system, adjusting the adding amount of ethylene glycol in the reaction system to control the micro-morphology and exposed crystal face of the product; and (4) performing low-temperature solvothermal reaction under sealed conditions, and obtaining the target product through centrifugation, washing and drying after the reaction is completed. The method has the advantages of simple process, no need of solid precursors and high-temperature calcination in the whole process, mild reaction condition, high product purity, good repeatability and the like, and effectively solves the problem that the prior art is difficult to simultaneously and accurately control the crystal structure and micro-morphology of copper-based materials in the same system.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology of nanomaterials, specifically to a method based on homogeneous solution thermal method, which achieves precise dual control over the chemical composition and physical morphology of copper and cuprous oxide materials by synergistically adjusting solvent components. Background Technology

[0002] Technical background and application value: Copper (Cu) and cuprous oxide (Cu2O) are extremely important functional materials with wide applications in catalysis, sensing, conductive pastes and photoelectric conversion.

[0003] Studies have shown that the physicochemical properties of materials depend not only on their chemical composition (phase) but also closely on their microstructure and exposed crystal facets. For example, in photocatalytic reactions, the {111} and {100} facets of Cu₂O often exhibit drastically different surface energies and catalytic activities. Therefore, achieving precise and synergistic control over the phase composition and crystal morphology of copper-based materials is crucial for improving their application performance.

[0004] Limitations of existing technologies: Although various methods exist for preparing copper-based nanomaterials, numerous technical bottlenecks remain in practical applications.

[0005] Pain Point 1: Limited control dimensions and lack of system universality. Existing methods can usually only be optimized for a single target product and cannot achieve flexible tailoring of phase or morphology in the same reaction system.

[0006] For example, patent CN105129835A can only prepare Cu2O with a specific morphology (icosahedron), but cannot obtain metallic Cu through this system;

[0007] Patent CN106513696A focuses on the preparation of micro / nano Cu powder and cannot synthesize Cu2O or Cu / Cu2O composite materials. This limitation of "one method and one material" greatly restricts the efficiency of material development and the breadth of its applications.

[0008] Pain Point 2: The reaction mechanism is complex and the residue of impurities is serious. In order to achieve morphology control or phase reduction, existing technologies generally rely on complex additive combinations (such as strong reducing agents, strong bases, surfactants, etc.), which not only increases the treatment pressure of chemical waste liquid, but also seriously affects the surface cleanliness of the product.

[0009] For example, the existing patent CN106513696A uses a chemical reduction method, which requires the introduction of reducing agents (ascorbic acid, glucose) and high-concentration strong bases (NaOH, KOH). This not only leads to high production costs, but also introduces a large number of inorganic impurity ions and organic residues that are difficult to completely remove through post-processing, and easily cover the surface active sites of the catalyst.

[0010] For example, existing patent CN105129835A also relies on an external reducing agent (glucose) and an alkaline regulator (sodium bicarbonate). In addition, this type of reaction is usually carried out in an aqueous phase at a lower temperature (<90°C), and the crystallinity of the resulting product is often not as good as that of the high-temperature solvothermal method, which affects the stability of the material.

[0011] Pain Point 3: Precursor limitations and the disadvantages of "top-down" control. Although existing technologies also involve ethylene glycol / ethylenediamine solvent systems (such as patent CN120961164A), their core process uses "solid powder (such as Cu2O powder) as a precursor, and the reaction is essentially an etching or modification of the solid surface, which must be followed by high-energy-consuming high-temperature calcination (>600℃)." This "top-down" approach makes it difficult to achieve precise control over crystal growth kinetics like the "homogeneous nucleation" process, thus making it difficult to grow uniform, well-defined, regular polyhedral structures (such as truncated octahedrons or cubes).

[0012] Based on the above problems, the technical problem to be solved by this invention is the urgent need to develop a mild, environmentally friendly, and highly controllable synthesis strategy. This invention aims to provide a preparation method based on a homogeneous solution system, eliminating the need for external reducing agents and strong bases. Starting directly with inexpensive, soluble copper salts, and by adjusting only a single variable (such as the amount of water added and the concentration of ethylene glycol), a continuous phase transition from metallic Cu to Cu₂O and precise tailoring of crystal morphology can be achieved at the microscopic scale. This has significant practical implications for promoting the basic research and industrial application of copper-based nanomaterials. Summary of the Invention

[0013] The technical problem this invention aims to solve is to overcome the shortcomings of existing copper-based micro / nanomaterial preparation techniques, such as limited control dimensions, complex reaction systems, reliance on solid precursors, and high-temperature calcination. This invention provides a homogeneous synthesis method for copper-based micro / nanomaterials with dual controllability of phase and morphology. Based on a homogeneous solution system, this method achieves precise and integrated tailoring of the product's chemical composition and microstructure simply by synergistically adjusting the solvent components.

[0014] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0015] A homogeneous synthesis method for copper-based micro / nanomaterials with controllable phase and morphology includes the following steps:

[0016] (1) Preparation of homogeneous precursor solution: Dissolve soluble copper salt in a mixed solvent of ethylene glycol (EG) and ethylenediamine (EDA), and stir until the solid is completely dissolved to form a clear and transparent homogeneous solution A;

[0017] (2) Phase regulation and morphology precursor preparation: A specific volume of deionized water is added to the homogeneous solution A and mixed evenly to obtain precursor solution B; the amount of deionized water added is used to regulate the phase composition of the final product.

[0018] (3) Solvent thermal reaction: The precursor solution B is placed in a closed reaction vessel and a solvothermal reaction is carried out at 160~200℃;

[0019] (4) Post-processing: After the reaction is completed, the product is centrifuged, washed and dried in sequence to obtain the target copper-based micro and nano materials;

[0020] The method does not require the addition of exogenous solid powder as a precursor, does not require high-temperature calcination treatment above 300°C, and does not add exogenous organic reducing agents or inorganic strong bases to the reaction system.

[0021] Furthermore, this invention employs a "dual solvent control strategy" to achieve customized synthesis of the product: First control—phase control: Water is used as a "reduction switch," and the phase composition of the product is controlled by adjusting the volume of deionized water added in step (2). When no deionized water is added or the water content is extremely low, the dominant reduction effect of ethylenediamine is strong, and metallic copper (Cu) is obtained; when deionized water in the first volume range is added, water molecules compete for coordination to reduce the reduction potential, and a composite material of cuprous oxide and metallic copper (Cu2O / Cu) is obtained; when deionized water in the second volume range is added, the oxidation-hydrolysis effect is dominant, and cuprous oxide (Cu2O) is obtained. Second control—morphology control: Ethylene glycol is used as a "crystal face sculpting agent," and the microstructure and exposed crystal faces of the product are controlled by adjusting the amount of ethylene glycol (EG) added in step (1) under the phase system determined by the amount of deionized water.

[0022] For the cuprous oxide (Cu2O) system: ethylene glycol plays a dual role as a solvent and a crystal plane selective adsorbent. Increasing its concentration can enhance adsorption on high-energy crystal planes such as {100}, inhibit the growth of this crystal plane, and thus drive the product morphology to evolve from spherical to regular polyhedra such as truncated octahedrons and cubes.

[0023] For the copper (Cu) system: increasing the concentration of ethylene glycol mainly improves the dispersibility of the reaction system, transforming the product from a rough spherical shape to a smooth and dense spherical shape.

[0024] Preferably, the copper salt in step (1) is copper chloride, copper nitrate, copper sulfate, or copper acetate.

[0025] Preferably, the hydrothermal crystallization reaction conditions in step (3) are: reaction at 160-200℃ for 6-14 hours.

[0026] Preferably, in step (4), the centrifugation speed is 4000-6000 rpm, the centrifugation time is 2-5 min, and the washing is done by alternating between deionized water and anhydrous ethanol 2-3 times each; the vacuum oven drying temperature is 60℃, and the drying time is 5-7 h.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] This invention pioneers a dual-control strategy, achieving integrated design of phase and morphology. Breaking through the limitations of traditional "one method, one substance" approaches, it reveals and utilizes the intrinsic mechanism that "water determines what is formed (phase), and ethylene glycol determines what shape is formed (morphology)." Within the same homogeneous system, by adjusting the ratio of only two simple solvent components (water and ethylene glycol), the chemical composition and exposed crystal faces of the product can be controlled separately and synergistically, greatly enhancing the flexibility of material design.

[0029] The phase regulation mechanism is clear, and the process is simple and efficient. This invention utilizes water as a "switch" in the reaction pathway, cleverly employing the competitive coordination mechanism between water molecules and ethylenediamine to regulate the reduction potential of the system. Without introducing external reducing agents (such as glucose or hydrazine hydrate) or a protective atmosphere, simply by changing the volume ratio of "water / ethylenediamine," a continuous transition from a strong reducing environment (generating Cu) to a weak reducing / hydrolysis environment (generating Cu₂O) can be achieved, realizing the full-spectrum controllable preparation of Cu, Cu / Cu₂O, and Cu₂O.

[0030] This invention achieves precise "crystal plane engineering" in a non-surfactant system. It eliminates the need for difficult-to-clean polymeric surfactants (such as PVP and CTAB), directly utilizing the selective adsorption of the solvent component ethylene glycol (EG) on specific crystal planes (such as the {100} plane of Cu2O) to successfully "sculpt" the microstructure of the product. This not only yields regular structures such as truncated octahedrons and cubes but also ensures the cleanliness of the product surface, facilitating the exposure of more active sites and enhancing the material's performance in catalysis and other fields.

[0031] The reaction system is green and mild, with broad prospects for industrialization. The entire preparation process starts with inexpensive copper salts and is carried out in a homogeneous solution at ≤220℃, avoiding the ball milling or high-temperature calcination (>600℃) processes required by the solid-phase precursor method (top-down), thus significantly reducing energy consumption. Furthermore, the system does not contain strong acids, strong bases, or toxic organic additives, making it environmentally friendly. The product has high purity, uniform morphology, and good batch-to-batch reproducibility, demonstrating excellent potential for large-scale production. Attached Figure Description

[0032] Figure 1 The X-ray diffraction (XRD) patterns of the three catalysts, Cu, Cu2O / Cu, and Cu2O, prepared in Examples 1-5 are shown to illustrate their phase changes.

[0033] Figure 2 The electron microscope (SEM) images of the three catalysts, Cu, Cu2O / Cu, and Cu2O, prepared in Examples 6-15 are shown to illustrate their morphological changes. Detailed Implementation

[0034] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

[0036] Example 1

[0037] (1) At room temperature and normal pressure, 3.98 g of Cu(CH3COO)2·H2O was placed in a 50 mL beaker, and 0.75 mL of ethylenediamine and 19.25 mL of ethylene glycol (volume ratio 1:25) were added in sequence. The mixture was magnetically stirred for 30 min until a colorless, clear, homogeneous solution was formed, which was denoted as solution A.

[0038] (2) Transfer solution A to a 150 mL stainless steel hydrothermal reactor lined with polytetrafluoroethylene, seal it immediately, and obtain suspension B;

[0039] (3) Place the hydrothermal reactor in a vacuum oven, heat it to 180°C and keep it at that temperature for 9 hours; after the reaction is complete, cool it naturally to room temperature to obtain a blue-purple suspension C;

[0040] (4) Centrifuge suspension C at 5000 rpm for 2 min and discard the supernatant; wash the precipitate twice with deionized water and 10 mL of anhydrous ethanol each time, and then dry it under vacuum at 60 °C for 5 h to obtain a dark red powder, which is recorded as sample 1.

[0041] Examples 2–15 are all based on Example 1, with only the experimental conditions changed as follows; all other unmentioned steps and parameters are the same as in Example 1.

[0042] Example 2: In step (2), 3.75 mL of deionized water was added to the lining of the hydrothermal reactor; the centrifugation time in step (4) was 3 min. A brownish-red powder was finally obtained, which was designated as sample 2.

[0043] Example 3: In step (2), 20 mL of deionized water was added to the lining of the hydrothermal reactor; the centrifugation time in step (4) was 3 min. A brownish-red powder was finally obtained, which was designated as sample 3.

[0044] Example 4: In step (2), 37.5 mL of deionized water was added to the lining of the hydrothermal reactor; the centrifugation time in step (4) was 3 min. A brownish-red powder was finally obtained, which was designated as sample 4.

[0045] Example 5: In step (2), 40 mL of deionized water was added to the lining of the hydrothermal reactor; the centrifugation time in step (4) was 3 min. A brownish-red powder was finally obtained, which was designated as sample 5.

[0046] Example 6: In step (1), 10 mL of ethylene glycol was used, and the magnetic stirring time was 20 min; in step (2), 40 mL of deionized water was added; in step (3), the hydrothermal reaction temperature was 160℃, and the constant temperature holding time was 8 h; in step (4), the centrifugation speed was 4000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a reddish-brown powder was obtained, which was recorded as sample 6.

[0047] Example 7: In step (1), 12 mL of ethylene glycol was used, and the magnetic stirring time was 20 min; in step (2), 40 mL of deionized water was added; in step (3), the hydrothermal reaction temperature was 160 °C, and the constant temperature holding time was 8 h; in step (4), the centrifugation speed was 4000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a reddish-brown powder was obtained, which was recorded as sample 7.

[0048] Example 8: In step (1), 15 mL of ethylene glycol was used, and the magnetic stirring time was 40 min; in step (2), 40 mL of deionized water was added; in step (3), the hydrothermal reaction temperature was 160℃, and the constant temperature holding time was 8 h; in step (4), the centrifugation speed was 6000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a reddish-brown powder was obtained, which was recorded as sample 8.

[0049] Example 9: In step (1), 18 mL of ethylene glycol was used, and the magnetic stirring time was 20 min; in step (2), 40 mL of deionized water was added; in step (3), the hydrothermal reaction temperature was 160℃, and the constant temperature holding time was 8 h; in step (4), the centrifugation speed was 4000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a reddish-brown powder was obtained, which was recorded as sample 9.

[0050] Example 10: In step (1), 20 mL of ethylene glycol was used, and the magnetic stirring time was 40 min; in step (2), 40 mL of deionized water was added; in step (3), the hydrothermal reaction temperature was 160 °C, and the constant temperature holding time was 8 h; in step (4), the centrifugation speed was 6000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a reddish-brown powder was obtained, which was recorded as sample 10.

[0051] Example 11: In step (1), the amount of ethylene glycol used was 10 mL, and the magnetic stirring time was 40 min; in step (2), no deionized water was added; in step (3), the hydrothermal reaction temperature was 200℃, and the constant temperature holding time was 6 h; in step (4), the centrifugation speed was 6000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a dark red powder was obtained, which was recorded as sample 11.

[0052] Example 12: In step (1), the amount of ethylene glycol used was 15 mL, and the magnetic stirring time was 40 min; in step (2), no deionized water was added; in step (3), the hydrothermal reaction temperature was 200℃, and the constant temperature holding time was 6 h; in step (4), the centrifugation speed was 6000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a dark red powder was obtained, which was recorded as sample 12.

[0053] Example 13: In step (1), the amount of ethylene glycol used was 20 mL, and the magnetic stirring time was 40 min; in step (2), no deionized water was added; in step (3), the hydrothermal reaction temperature was 200℃, and the constant temperature holding time was 6 h; in step (4), the centrifugation speed was 6000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a dark red powder was obtained, which was recorded as sample 13.

[0054] Example 14: In step (1), 10 mL of ethylene glycol was used, and the magnetic stirring time was 40 min; in step (2), 20 mL of deionized water was added; in step (3), the hydrothermal reaction temperature was 200℃, and the constant temperature holding time was 12 h; in step (4), the centrifugation speed was 6000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a brownish-red powder was obtained, which was recorded as sample 14.

[0055] Example 15: In step (1), 20 mL of ethylene glycol was used, and the magnetic stirring time was 40 min; in step (2), 15 mL of deionized water was added; in step (3), the hydrothermal reaction temperature was 200℃, and the constant temperature holding time was 12 h; in step (4), the centrifugation speed was 6000 rpm, the time was 5 min, and the vacuum drying time was 7 h. Finally, a brownish-red powder was obtained, which was recorded as sample 15.

[0056] Although the embodiments of this invention mainly use copper acetate as an example, those skilled in the art will understand that soluble copper salts such as copper chloride and copper nitrate can form stable copper-amine complex precursors (such as [Cu(en)2]) under the strong chelating action of ethylenediamine. 2+ They follow the same reduction and crystal growth mechanism, and therefore are all covered within the scope of protection of this invention.

[0057] Results Analysis and Reaction Mechanism

[0058] Combination Figure 1 (XRD pattern) and Figure 2 (SEM image) The above embodiments are analyzed in depth to reveal the dual regulation mechanism of the present invention.

[0059] 1. First-level regulation: Water's "reduction switch" effect (phase regulation). XRD analysis results in Examples 1-5 confirmed that deionized water plays a decisive role in phase selection within the system.

[0060] Extremely low water content environment (strong reducing): In Examples 1 and 2, when no deionized water was added or very little deionized water was added to the system, ethylenediamine exhibited extremely strong reducing power, reducing Cu... 2+ Completely reduced to zero-valent copper. XRD patterns show that the products are all pure-phase zero-valent copper (Cu).

[0061] Mechanism: In a low-water, high-temperature alkanolamine system, the solvation electrons are highly active and the reduction potential is extremely low, thermodynamically tending to generate zero-valent copper.

[0062] Medium water volume (competitive equilibrium): In Examples 3 and 4, an appropriate amount of water (e.g., 20 mL) was added. XRD patterns showed that the product was a composite material of cuprous oxide and metallic copper (Cu₂O / Cu).

[0063] Mechanism: The introduction of water molecules dilutes the concentration of ethylenediamine and causes competitive coordination, which moderately reduces the reducing power of the system, so that the reduction reaction and the hydrolysis-oxidation reaction are in a competitive equilibrium.

[0064] Water-rich environment (reduction inhibition): In Example 5, a large amount of water (e.g., 40 mL) was added. XRD patterns showed that the product was high-purity cuprous oxide (Cu2O).

[0065] Mechanism: The presence of a large amount of water significantly inhibits the reducing activity of ethylenediamine by altering the solvent polarity and protonation environment, thus blocking the reduction of Cu. + →Cu 0 The deep reduction pathway stabilizes the product in the +1 oxidation state.

[0066] 2. Secondary Regulation: The "Crystal Face Sculpting" Effect of Ethylene Glycol (Morphology Regulation) In a defined phase system, changes in ethylene glycol (EG) concentration lead to significant morphological evolution, confirming its crucial role as a "crystal face selective adsorbent":

[0067] In the Cu2O system (Examples 6-10):

[0068] Spherical (Sample 6): When the amount of EG is low (10 mL), the adsorption effect is weak, and the crystals grow isotropically, forming spherical shapes.

[0069] Octahedron (Sample 7): When the amount of EG was increased to 12 mL, the product transformed into a smooth octahedron.

[0070] Octahedral (Sample 8): When the amount of EG was increased to 15 mL, the product transformed into an octahedral structure. This indicates that EG began to adsorb on specific crystal faces.

[0071] Truncate octahedron (sample 9): When the amount of EG was increased to 18 mL, the product was transformed into a truncate octahedron.

[0072] Dodecahedron / Polyhedron (Sample 10): When the amount of EG reaches 20 mL, the product evolves into a dodecahedron with distinct edges.

[0073] Mechanism: As the concentration of ethylene glycol increases, the adsorption coverage of its molecules on the high-energy crystal planes of Cu₂O (mainly the {100} plane) increases significantly, greatly reducing the growth rate of these planes. According to the Wulff construction principle, the slowly growing crystal planes are eventually preserved as exposed surfaces, thereby driving the crystal to evolve from a spherical shape to a polyhedral structure with more exposed {100} planes.

[0074] In the Cu system (Examples 11-13):

[0075] The variation from sample 11 (10 mL EG, rough spherical particles) to sample 13 (20 mL EG, smooth spherical particles) indicates that, during the strong reduction to form zero-valent copper, high-concentration ethylene glycol primarily acts as an excellent solvent and dispersant, improving nucleation uniformity and preventing disordered particle aggregation. In particular, sample 12 (15 mL EG, 20:1 ratio) showed significantly improved dispersibility and smoothness, confirming that 20:1 is an effective threshold for morphology optimization.

[0076] In the Cu2O / Cu composite system (Examples 14-15):

[0077] Even in the mixed phase, increasing the amount of EG (10 mL → 15 mL) induced a regularization transformation of the morphology from octahedral (sample 14) to dodecahedral (sample 15), further verifying the universality of the ethylene glycol crystal face regulation mechanism.

[0078] In summary, this invention successfully achieved precise and continuous control over the phase and morphology of copper-based materials in the same homogeneous system by simply adjusting the amounts of deionized water and ethylene glycol.

Claims

1. A homogeneous synthesis method for copper-based micro / nanomaterials with dual controllability of phase and morphology, characterized in that, Includes the following steps: (1) Dissolve a soluble copper salt in a mixed solvent of ethylene glycol and ethylenediamine, wherein the volume ratio of ethylene glycol to ethylenediamine in the mixed solvent is 40:3 to 80:3, and stir to obtain a clear homogeneous solution. The microstructure of the target product is controlled by adjusting the amount of ethylene glycol added. (2) Add deionized water to the clear homogeneous solution obtained in step (1), and determine the phase of the target product as metallic copper, cuprous oxide or a composite of the two by adjusting the amount of deionized water added to the reaction system. Among them, according to the volume ratio V of deionized water to ethylenediamine H2O :V EDA To achieve continuous phase control: when V H2O :V EDA When the ratio is ≤5:1, the synthesized product is single-phase metallic copper; when the ratio is 5:1 <V H2O :V EDA When the ratio is ≤50:1, the synthesized product is a composite material of metallic copper and cuprous oxide; when V H2O :V EDA When the ratio is >50:1, the synthesized product is single-phase cuprous oxide; When the product is single-phase cuprous oxide, the volume ratio V of ethylene glycol to ethylenediamine can be adjusted. EG :V EDA This allows for continuous control of the morphology of cuprous oxide, when V EG :V EDA When the product ratio is less than 16:1, the product morphology is spherical or near-spherical; when 16:1 ≤ V EG :V EDA When V < 24:1, the product morphology is octahedral; when V EG :V EDA When the ratio is ≥24:1, the product morphology is a truncated octahedron, a dodecahedron, or a regular polyhedron; When the product is single-phase metallic copper, the volume ratio V of ethylene glycol to ethylenediamine can be adjusted. EG :V EDA To achieve surface morphology control of metallic copper: when V EG :V EDA When V < 20:1, the product consists of rough-surfaced spherical particles; when V EG :V EDA When the ratio is ≥20:1, the product transforms into smooth and dense spherical particles, and the dispersibility is improved; When the product is a composite material of metallic copper and cuprous oxide, the volume ratio V of ethylene glycol to ethylenediamine can be adjusted. EG :V EDA Achieving surface morphology control of composite materials of metallic copper and cuprous oxide: when V EG :V EDA When V < 20:1, the product is octahedral; when V EG :V EDA When the ratio is ≥20:1, the product transforms into a dodecahedron; (3) The solvothermal reaction was carried out under sealed conditions. After the reaction was completed, the target product was obtained by centrifugation, washing and drying.

2. The method according to claim 1, characterized in that, The copper salt mentioned in step (1) is selected from one or more of copper chloride, copper nitrate, copper sulfate and copper acetate.

3. The method according to claim 1, characterized in that, The temperature of the solvothermal reaction in step (3) is 160-200℃, and the reaction time is 6-12h.

4. The method according to claim 1, characterized in that, In step (3), the centrifugation speed is 4000-6000 rpm and the centrifugation time is 2-5 min. The washing is done by alternating between deionized water and anhydrous ethanol 2-3 times each. The vacuum oven drying temperature is 50-70℃ and the drying time is 5-7 h.

5. A copper-based micro / nanomaterial prepared by the method according to any one of claims 1 to 4.

Images