Preparation method of nano copper oxide

Abstract

The invention provides a preparation method of nano copper oxide, and relates to the technical field of preparation of metal powder nano materials, the method comprises the following steps: step 1, preparing a copper salt into a copper precursor aqueous solution containing a surfactant, and preparing alkali into an alkaline aqueous solution; step 2, in an ultrasonic-assisted scene, adding the copper precursor aqueous solution containing the surfactant into the alkaline aqueous solution to obtain a copper-alkali mixed solution; 3, transferring the copper-alkali mixed solution into a polytetrafluoroethylene reaction kettle for hydrothermal reaction to obtain a nano-particle solution containing a copper compound; and 4, carrying out solid-liquid separation, washing, drying and roasting on the copper-containing compound nano-particle solution to obtain sea urchin-like nano copper oxide powder. The preparation efficiency of the nano copper oxide is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of metal powder nanomaterial preparation, and in particular to a method for preparing nano copper oxide. Background Art

[0002] Although there are many methods for synthesizing CuO nanomaterials with different morphologies, in the preparation process of CuO nanomaterials, it is necessary to add templates, use organic solvents or perform complex operations under high temperature conditions. Therefore, it not only increases the preparation cost of CuO nanomaterials, but also reduces the preparation efficiency of CuO nanomaterials.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] In view of this, a method for preparing nano copper oxide is provided, thereby overcoming the problems of high preparation cost and low preparation efficiency of CuO nanomaterials caused by the limitations and defects of related technologies at least to a certain extent.

[0005] According to one aspect of the present disclosure, a method for preparing nano copper oxide is provided, the method comprising the following steps:

[0006] Step 1, preparing the copper salt into a copper precursor aqueous solution containing a surfactant, and preparing the base into an alkaline aqueous solution;

[0007] Step 2: adding the copper precursor aqueous solution containing a surfactant to the alkaline aqueous solution under the assistance of ultrasound to obtain a copper-alkali mixed solution;

[0008] Step 3, transferring the copper-alkali mixed solution to a polytetrafluoroethylene reactor for hydrothermal reaction to obtain a nanoparticle solution containing a copper compound;

[0009] Step 4: performing solid-liquid separation, washing, drying and roasting on the copper compound nanoparticle solution to obtain sea urchin-like nano copper oxide powder.

[0010] In an exemplary embodiment of the present disclosure, the copper salt is at least one of copper chloride, copper acetate, copper sulfate or copper nitrate.

[0011] In an exemplary embodiment of the present disclosure, the surfactant is at least one of polyethylene glycol PEG, polyvinyl pyrrolidone PVP, cetyltrimethylammonium bromide CTAB, cetyltrimethylammonium chloride CTAC, sodium dodecylbenzene sulfonate SDBS, polydiallyldimethylammonium chloride PDDA and polysorbate.

[0012] In an exemplary embodiment of the present disclosure, the concentration of the copper precursor aqueous solution containing a surfactant is less than or equal to 70 g / L, and the mass content of the surfactant in the copper precursor aqueous solution containing a surfactant is less than or equal to 5%wt.

[0013] In an exemplary embodiment of the present disclosure, the alkaline aqueous solution includes at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate and ammonia water;

[0014] The concentration of the alkaline aqueous solution is less than or equal to 100 g / L.

[0015] In an exemplary embodiment of the present disclosure, in an ultrasound-assisted scenario, the frequency of the ultrasound is less than or equal to 4 MHz;

[0016] In the process of adding the copper precursor aqueous solution containing a surfactant into the alkaline aqueous solution, the adding method adopted is any one of dripping, peristaltic pump injection and atomization spraying.

[0017] In an exemplary embodiment of the present disclosure, in the process of transferring the copper-alkali mixed solution to a polytetrafluoroethylene reactor for hydrothermal reaction, the temperature of the hydrothermal reaction is 100° C. to 200° C.

[0018] In an exemplary embodiment of the present disclosure, in the process of solid-liquid separation of the copper compound nanoparticle solution, the solid-liquid separation method includes centrifugal separation or suction filtration separation;

[0019] In the process of washing the copper-containing compound nanoparticles after solid-liquid separation, the washing solution used includes water or ethanol;

[0020] In the process of drying the washed copper compound-containing nanoparticles, the drying method used includes heat drying or cold drying;

[0021] In the process of calcining the dried copper-containing compound nanoparticles, the calcination temperature used is 200°C to 500°C.

[0022] In an exemplary embodiment of the present disclosure, during the process of calcining the dried copper-containing compound nanoparticles, the atmosphere used is air.

[0023] In an exemplary embodiment of the present disclosure, the size of a single sea urchin-like nano-copper oxide is 1-2 μm, and the thickness of a single sea urchin-like nano-copper oxide sheet is 10-30 nm.

[0024] In a method for preparing nano copper oxide provided in an exemplary embodiment of the present disclosure, on the one hand, copper salt is configured as a copper precursor aqueous solution containing a surfactant, and alkali is configured as an alkaline aqueous solution; then, under the assistance of ultrasound, the copper precursor aqueous solution containing a surfactant is added to the alkaline aqueous solution to obtain a copper-alkali mixed solution; the copper-alkali mixed solution is then transferred to a polytetrafluoroethylene reactor for hydrothermal reaction to obtain a nanoparticle solution containing copper compounds; finally, the nanoparticle solution containing copper compounds is subjected to solid-liquid separation, washing, drying and roasting to obtain a sea urchin-like nano copper oxide powder; the preparation of nano copper oxide powder is achieved without the need to add a template and an organic solvent, thereby reducing the preparation cost of the nano copper oxide powder; on the other hand, the complexity of the preparation process of the nano copper oxide powder is reduced, and the preparation efficiency of the nano copper oxide powder is improved.

[0025] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0027] Figure 1 The flowchart schematically shows a method for preparing nano copper oxide powder according to an exemplary embodiment of the present disclosure.

[0028] Figure 2 The SEM image of the sea urchin-like nano copper oxide prepared based on Example 1 according to an exemplary embodiment of the present disclosure is schematically shown.

[0029] Figure 3 A size statistical diagram of sea urchin-like nano copper oxide prepared based on Example 1 according to an exemplary embodiment of the present disclosure is schematically shown.

[0030] Figure 4 The XRD diagram of the sea urchin-like nano copper oxide prepared based on Example 1 according to an exemplary embodiment of the present disclosure is schematically shown.

[0031] Figure 5The SEM image of spherical nano-copper oxide prepared based on Comparative Example 1 according to an exemplary embodiment of the present disclosure is schematically shown.

[0032] Figure 6 The SEM image of a hybrid structure nano copper oxide prepared based on Comparative Example 2 according to an exemplary embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0033] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0034] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0035] In recent years, the study of nanomaterial morphology has received extensive attention in the field of materials science. In practical applications, the size and morphology of nanomaterials have a significant impact on their physical and chemical properties; therefore, even nanomaterials with the same composition often exhibit very different properties due to differences in morphology.

[0036] Copper metal has become a hot topic of research due to its abundant reserves in nature, chemical stability, non-toxicity and easy preparation. In particular, copper oxide (CuO) nanomaterials are favored by more and more researchers because of their narrow bandgap, excellent semiconductor and optical properties, and their unique physical and chemical properties.

[0037] In the process of practical application, researchers have prepared a variety of CuO nanomaterials with different morphologies by regulating the nucleation and growth process of crystals, and by adding solvents, templates and surfactants, and conducted in-depth research on their special properties. For example, in some related technical solutions, CuO single crystals with porous spherical structures were successfully synthesized by multiphase dissolution and coordination-assisted methods; in other related technical solutions, polystyrene can be used as a template and combined with electrochemical deposition technology to prepare three-dimensional ordered macroporous CuO nanomaterials; in addition, octahedral CuO nanomaterials with a grain size in the range of 45 to 95 nm can be synthesized by using R-irradiated octylphenyl ether and polyethylene glycol water-oil microemulsion.

[0038] However, in the preparation process of the CuO nanomaterials listed above, it is necessary to add a template, use an organic solvent or perform complex operations under high temperature conditions. Therefore, not only the preparation cost of the CuO nanomaterial is increased, but also the preparation efficiency of the CuO nanomaterial is reduced.

[0039] Based on this, the exemplary embodiment of the present disclosure provides a method for preparing nano copper oxide powder. Specifically, refer to Figure 1 As shown, the preparation method of nano copper oxide powder may include the following steps:

[0040] Step S110. The copper salt is configured as a copper precursor aqueous solution containing a surfactant, and the base is configured as an alkaline aqueous solution;

[0041] Step S120. Under ultrasonic assistance, adding the copper precursor aqueous solution containing a surfactant to the alkaline aqueous solution to obtain a copper-alkali mixed solution;

[0042] Step S130. transferring the copper-alkali mixed solution to a polytetrafluoroethylene reactor for hydrothermal reaction to obtain a nanoparticle solution containing a copper compound;

[0043] Step S140: performing solid-liquid separation, washing, drying and roasting on the copper compound nanoparticle solution to obtain sea urchin-like nano copper oxide powder.

[0044] In the above-mentioned preparation method of nano copper oxide, on the one hand, the copper salt is configured as a copper precursor aqueous solution containing a surfactant, and the alkali is configured as an alkaline aqueous solution; then, under the scene of ultrasonic assistance, the copper precursor aqueous solution containing a surfactant is added to the alkaline aqueous solution to obtain a copper-alkali mixed solution; the copper-alkali mixed solution is then transferred to a polytetrafluoroethylene reactor for hydrothermal reaction to obtain a nanoparticle solution containing copper compounds; finally, the nanoparticle solution containing copper compounds is subjected to solid-liquid separation, washing, drying and roasting to obtain a sea urchin-like nano copper oxide powder; the preparation of nano copper oxide powder is achieved without the need to add a template and an organic solvent, thereby reducing the preparation cost of the nano copper oxide powder; on the other hand, the complexity of the preparation process of the nano copper oxide powder is reduced, and the preparation efficiency of the nano copper oxide powder is improved.

[0045] Hereinafter, each step involved in the method for preparing nano copper oxide will be explained and illustrated in detail with reference to the accompanying drawings.

[0046] First, the technical implementation principle of the exemplary embodiment of the present disclosure is explained and illustrated. Specifically, the preparation method of nano copper oxide recorded in the exemplary embodiment of the present disclosure adopts a common water-soluble copper precursor as a copper source, a low-cost water-soluble organic matter as a surfactant, and an ordinary alkaline solution as a control agent for regulating crystal nucleation growth, and by changing factors such as reaction temperature, pressure, reaction time and pH value, the reaction kinetics during crystal growth is regulated, the nucleation rate and growth mode are changed, thereby achieving a high-yield and controllable preparation of sea urchin-like nano copper oxide.

[0047] The following will Figure 1 The preparation method of the nano copper oxide shown in the figure is further explained and illustrated. Specifically:

[0048] In step S110 , the copper salt is configured as a copper precursor aqueous solution containing a surfactant, and the base is configured as an alkaline aqueous solution.

[0049] Among them, the copper salt recorded here is copper chloride, copper acetate, copper sulfate or copper nitrate, etc.; the surfactant recorded here is polyethylene glycol PEG, polyvinyl pyrrolidone PVP, hexadecyltrimethylammonium bromide CTAB, hexadecyltrimethylammonium chloride CTAC, sodium dodecylbenzene sulfonate SDBS, polydiallyldimethylammonium chloride PDDA and polysorbate (Tween), etc.; the concentration of the copper precursor aqueous solution containing surfactant recorded here is less than or equal to 70g / L, and the mass content of the surfactant in the copper precursor aqueous solution containing surfactant recorded here is less than or equal to 5%wt; further, the alkaline aqueous solution recorded here includes sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate and ammonia water, etc., the concentration of the alkaline aqueous solution is less than or equal to 100g / L, the pH value is between 7 and 9, and it is in a weakly alkaline state. It should be noted that the alkaline environment has a significant effect on the crystal growth of sea urchin-like nano copper oxide nanomaterials; therefore, the solubility of copper metal ions in alkaline solutions with high pH values ​​is low, and it is easy to saturate and nucleate; at the same time, by carefully adjusting the pH value, the nucleation density and growth rate of copper can be controlled, so that the difference in growth rate in different directions increases, thereby prompting the material to form a sea urchin-like structure with multiple branches; further, since the surfactant can effectively guide the growth direction of the nanomaterial, it is adsorbed on a specific crystal plane, inhibiting the growth in these plane directions, and promoting the growth in other directions to accelerate, thereby forming a sea urchin-like branched structure; and, by adjusting the concentration of the surfactant, the number, length and distribution of branches can be precisely controlled; therefore, in the process of actual application, by configuring a suitable surfactant, the material can grow radial "branches", which radiate evenly from the core area to form a sea urchin-like structure; further, the concentration of the copper salt aqueous solution, the type and content of the surfactant, and the type and concentration of the screened alkali meet the needs of regulating the nucleation growth and morphology size of the product nano copper oxide.

[0050] In step S120, under the assistance of ultrasonic waves, the copper precursor aqueous solution containing a surfactant is added to the alkaline aqueous solution to obtain a copper-alkali mixed solution.

[0051] Specifically, in the ultrasonic-assisted scenario, the frequency of the ultrasonic wave is less than or equal to 4MHz; at the same time, in the process of adding the copper precursor aqueous solution containing a surfactant to the alkaline aqueous solution, the addition method adopted is dripping, peristaltic pump injection, and atomization spraying, etc. It should be added here that the reason why the alkaline aqueous solution needs to be fused with the precursor aqueous solution in the ultrasonic-assisted scenario is that the ultrasonic frequency is conducive to the nano-scale dispersion and mixing of the copper salt aqueous solution containing a surfactant and the alkaline aqueous solution, which is helpful for the transmission and diffusion of the copper salt and the regulation of the copper compound by the alkaline solution during the crystal growth process.

[0052] In step S130, the copper-alkali mixed solution is transferred to a polytetrafluoroethylene reactor for hydrothermal reaction to obtain a nanoparticle solution containing copper compounds.

[0053] Among them, in the process of transferring the copper-alkali mixed solution to the polytetrafluoroethylene reactor for hydrothermal reaction, the temperature of the hydrothermal reaction is 100°C to 200°C, and the reaction time is 2 to 8 hours. It should be noted here that the reason why the hydrothermal reaction needs to be carried out under this condition is that the temperature has an important influence on the growth rate of sea urchin-like nano copper oxide. Higher temperatures can usually increase the diffusion rate of copper metal ions, promote their migration to the nucleation point, and thus accelerate crystal growth; at the same time, controlling the reaction time can also effectively affect the formation of sea urchin-like structures; in the process of practical application, if the reaction time is too short, it may cause the core area to fail to form a complete nanostructure; if the reaction time is too long, it may cause irregular overgrowth; therefore, the appropriate reaction time can ensure the uniform distribution and appropriate size of the branches; the hydrothermal reaction temperature used in the exemplary embodiment of the present disclosure is conducive to the growth of copper compounds around, thereby forming a sea urchin-like structure.

[0054] In step S140, the copper compound nanoparticle solution is subjected to solid-liquid separation, washing, drying, and calcination to obtain sea urchin-like nano copper oxide powder.

[0055] Specifically, in the process of solid-liquid separation of the copper compound nanoparticle solution, the solid-liquid separation method includes centrifugal separation or suction filtration separation; in the process of washing the copper compound nanoparticles after solid-liquid separation, the washing solution used includes water or ethanol; in the process of drying the washed copper compound nanoparticles, the drying method used includes hot drying or cold drying; in the process of calcining the dried copper compound nanoparticles, the calcination temperature used is 200°C to 500°C; in the process of calcining the copper compound nanoparticles, the temperature used is 150°C to 200°C; further, in the process of calcining the dried copper compound nanoparticles, the atmosphere used is air; in the process of calcining the copper compound nanoparticles, the atmosphere used is hydrogen.

[0056] At the same time, in the nano copper oxide powder prepared based on the above scheme, the size of a single sea urchin-shaped nano copper oxide is 1 to 2 μm, and the thickness of a single sea urchin-shaped nano copper oxide sheet is 10 to 30 nm; the size of a single copper powder is 1 to 2 μm, and the thickness of a single copper powder sheet is 10 to 30 nm.

[0057] At this point, the preparation method of the nano copper oxide powder described in the exemplary embodiment of the present disclosure has been fully realized. Based on the above-described contents, it can be known that the preparation method of the nano copper oxide powder described in the exemplary embodiment of the present disclosure first prepares a copper salt aqueous solution and an alkaline solution containing a surfactant, and mixes the two solutions with the assistance of ultrasound to create conditions for the nano-scale dispersion of the copper salt and the regulation of crystal nucleation and growth. Then, a hydrothermal synthesis method is used to optimize the reaction kinetics of crystal growth by changing the reaction temperature, pressure, time and pH, and nanoparticles of copper-containing compounds are obtained. After solid-liquid separation, washing, drying and roasting, the urchin-like nano copper oxide is decomposed to achieve the regulation of the morphology and size of the nano copper oxide. The preparation of nano copper oxide powder based on this method has at least the following advantages: on the one hand, since common water-soluble copper precursors can be used as copper sources, low-cost water-soluble organic matter can be used as surfactants, and ordinary alkaline solutions can be used as control agents for regulating crystal nucleation and growth, the morphology of nano copper oxide can be controlled, thereby reducing the preparation cost of nano copper oxide powder; on the other hand, the exemplary embodiment of the present disclosure ultrasonically disperses the copper salt aqueous solution containing surfactants and the alkaline aqueous solution, which is conducive to the transmission and diffusion of copper salts and the regulation of copper compounds by alkaline solution during crystal growth; on the other hand, the exemplary embodiment of the present disclosure adopts a hydrothermal synthesis method to optimize the reaction kinetic conditions of crystal growth by changing the reaction temperature, pressure, time and pH, so that the copper compound grows around four times, thereby achieving precise control of the morphology and size of the product copper compound nanoparticles; further, the exemplary embodiment of the present disclosure achieves precise control of the crystal structure, morphology and size of nano copper oxide by controlling the solid-liquid separation method, washing method, drying conditions and roasting method of the copper compound nanoparticles, which is conducive to obtaining sea urchin-like nano copper oxide.

[0058] The following will further explain and illustrate the preparation process of the nano copper oxide powder described in the exemplary embodiment of the present disclosure in combination with specific embodiments. Specifically:

[0059] Example 1

[0060] The preparation method of this embodiment comprises the following steps:

[0061] Step 1, preparing copper acetate, polyethylene glycol and sodium carbonate into a copper salt aqueous solution containing a surfactant and an alkaline aqueous solution respectively; the concentration of the copper salt aqueous solution containing a surfactant is 70 g / L, the mass content of the surfactant is 5%wt, and the concentration of sodium carbonate in the alkaline aqueous solution is 100 g / L;

[0062] Step 2, with the aid of a high-frequency ultrasonic dispersion device with a frequency of 4 MHz, gradually adding a copper salt aqueous solution containing a surfactant into an alkaline aqueous solution of sodium carbonate to prepare a copper-alkali mixed solution;

[0063] Step 3, transferring the copper-alkali mixed solution obtained in step 2 to a polytetrafluoroethylene reactor, using a hydrothermal synthesis method, the reaction temperature is 140° C., and collecting after two hours to obtain a nanoparticle solution containing a copper compound;

[0064] Step 4: centrifuge the copper compound nanoparticle solution collected in step 3, wash with 18.2MΩ ultrapure water, dry in an oven at 70°C, and then calcine at 300°C to 400°C in an air atmosphere to obtain a sea urchin-like nano copper oxide powder; the sea urchin-like nano copper oxide has a size of about 1 to 2 μm, and a thickness of a single sheet is about 10 to 30 nm.

[0065] The copper salt aqueous solution in step 1 of this embodiment can also be replaced by copper sulfate, copper nitrate or copper chloride; the surfactant can also be replaced by PEG, PVP, CTAB, CTAC, SDBS, PDDA or Tween; the alkaline aqueous solution can also be replaced by sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate or ammonia water.

[0066] Example 2

[0067] The preparation method of this embodiment comprises the following steps:

[0068] Step 1, preparing copper acetate, polyethylene glycol and sodium carbonate into a copper salt aqueous solution containing a surfactant and an alkaline aqueous solution respectively; the concentration of the copper salt aqueous solution containing a surfactant is 70 g / L, the mass content of the surfactant is 1%wt, and the concentration of sodium carbonate in the alkaline aqueous solution is 100 g / L;

[0069] Step 2, with the aid of a high-frequency ultrasonic dispersion device with a frequency of 4 MHz, gradually adding a copper salt aqueous solution containing a surfactant to an alkaline aqueous solution of sodium carbonate to prepare a copper-alkali mixed solution;

[0070] Step 3, transferring the copper-alkali mixed solution obtained in step 2 to a polytetrafluoroethylene reactor, using a hydrothermal synthesis method, the reaction temperature is 130° C., and collecting after two hours to obtain a nanoparticle solution containing a copper compound;

[0071] Step 4: centrifuge the copper compound nanoparticle solution collected in step 3, wash it with 18.2MΩ ultrapure water, and heat dry it in an oven at 70°C, then roast it at 300°C to 400°C in an air atmosphere, and reduce it at 150°C to 200°C in a hydrogen atmosphere to obtain sea urchin-like nano copper oxide and copper powder; obtain sea urchin-like nano copper oxide and copper powder; the size of the sea urchin-like nano copper oxide and copper is about 2 to 20 μm, and the thickness of a single sheet is about 10 to 100 nm.

[0072] The copper salt aqueous solution in step 1 of this embodiment can also be replaced by copper sulfate, copper nitrate or copper chloride; the surfactant can also be replaced by PEG, PVP, CTAB, CTAC, SDBS, PDDA or Tween; the alkaline aqueous solution can also be replaced by sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate or ammonia water.

[0073] Example 3

[0074] The preparation method of this embodiment comprises the following steps:

[0075] Step 1, preparing copper acetate, polyethylene glycol and sodium carbonate into a copper salt aqueous solution containing a surfactant and an alkaline aqueous solution respectively; the concentration of the copper salt aqueous solution containing a surfactant is 70 g / L, the mass content of the surfactant is 5%wt, and the concentration of sodium carbonate in the alkaline aqueous solution is 100 g / L;

[0076] Step 2, with the aid of a high-frequency ultrasonic dispersion device with a frequency of 4 MHz, gradually adding a copper salt aqueous solution containing a surfactant to an alkaline aqueous solution of sodium carbonate to prepare a copper-alkali mixed solution;

[0077] Step 3, transferring the copper-alkali mixed solution obtained in step 2 to a polytetrafluoroethylene reactor, using a hydrothermal synthesis method, the reaction temperature is 150° C., and collecting after two hours to obtain a nanoparticle solution containing a copper compound;

[0078] Step 4: centrifuge the copper compound nanoparticle solution collected in step 3, wash with 18.2MΩ ultrapure water, and heat dry in an oven at 70°C, then calcine at 300°C to 400°C in an air atmosphere, and reduce at 150°C to 200°C in a hydrogen atmosphere to obtain sea urchin-like nano copper oxide and copper powder; the size of the sea urchin-like nano copper oxide and copper is about 0.5 to 1 μm, and the thickness of a single sheet is about 5 to 20 nm.

[0079] The copper salt aqueous solution in step 1 of this embodiment can also be replaced by copper sulfate, copper nitrate or copper chloride; the surfactant can also be replaced by PEG, PVP, CTAB, CTAC, SDBS, PDDA or Tween; the alkaline aqueous solution can also be replaced by sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate or ammonia water.

[0080] Comparative Example 1

[0081] The preparation method of this embodiment comprises the following steps:

[0082] Step 1, preparing copper acetate, polyethylene glycol and sodium carbonate into a copper salt aqueous solution containing a surfactant and an alkaline aqueous solution respectively; the concentration of the copper salt aqueous solution containing a surfactant is 70 g / L, the mass content of the surfactant is 5%wt, and the concentration of sodium carbonate in the alkaline aqueous solution is 100 g / L;

[0083] Step 2, with the aid of a high-frequency ultrasonic dispersion device with a frequency of 4 MHz, gradually adding a copper salt aqueous solution containing a surfactant into an alkaline aqueous solution of sodium carbonate to prepare a copper-alkali mixed solution;

[0084] Step 3, transferring the copper-alkali mixed solution obtained in step 2 to a polytetrafluoroethylene reactor, using a hydrothermal synthesis method, the reaction temperature is 140° C., and collecting the nanoparticle solution containing the copper compound after half an hour;

[0085] Step 4: centrifuge the copper compound nanoparticle solution collected in step 3, wash with 18.2MΩ ultrapure water, dry in an oven at 70°C, and then calcine at 300°C to 400°C in an air atmosphere to obtain spherical nano copper oxide powder; the size of the spherical nano copper oxide is about 0.3 to 1 μm.

[0086] The copper salt aqueous solution in step 1 of this embodiment can also be replaced by copper sulfate, copper nitrate or copper chloride; the surfactant can also be replaced by PEG, PVP, CTAB, CTAC, SDBS, PDDA or Tween; the alkaline aqueous solution can also be replaced by sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate or ammonia water.

[0087] Comparative Example 2

[0088] The preparation method of this embodiment comprises the following steps:

[0089] Step 1, preparing copper acetate, polyethylene glycol and sodium carbonate into a copper salt aqueous solution containing a surfactant and an alkaline aqueous solution respectively; the concentration of the copper salt aqueous solution containing a surfactant is 70 g / L, the mass content of the surfactant is 5%wt, and the concentration of sodium carbonate in the alkaline aqueous solution is 100 g / L;

[0090] Step 2, with the aid of a high-frequency ultrasonic dispersion device with a frequency of 4 MHz, gradually adding a copper salt aqueous solution containing a surfactant into an alkaline aqueous solution of sodium carbonate to prepare a copper-alkali mixed solution;

[0091] Step 3, transferring the copper-alkali mixed solution obtained in step 2 to a polytetrafluoroethylene reactor, using a hydrothermal synthesis method, the reaction temperature is 140° C., and collecting after five hours to obtain a nanoparticle solution containing a copper compound;

[0092] Step 4: centrifuge the copper compound nanoparticle solution collected in step 3, wash with 18.2MΩ ultrapure water, dry it in an oven at 70°C, and then calcine it at 300°C to 400°C in an air atmosphere to obtain sea urchin-like nano copper oxide and flake nano copper oxide; the size of the flake nano copper oxide is about 3 to 5 μm and the thickness is about 100 nm.

[0093] The copper salt aqueous solution in step 1 of this embodiment can also be replaced by copper sulfate, copper nitrate or copper chloride; the surfactant can also be replaced by PEG, PVP, CTAB, CTAC, SDBS, PDDA or Tween; the alkaline aqueous solution can also be replaced by sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate or ammonia water.

[0094] The SEM image of the sea urchin-like nano copper oxide prepared in Example 1 can be referred to Figure 2 As shown, the size statistics of the sea urchin-like nano copper oxide prepared in Example 1 can be referred to Figure 3 The XRD pattern of the sea urchin-like nano copper oxide prepared in Example 1 can be referred to Figure 4 As shown; it should be noted here that the SEM image, size statistical graph and XRD graph of the sea urchin-like nano copper oxide prepared based on Examples 2 and 3 are similar to the SEM image, size statistical graph and XRD graph of the sea urchin-like nano copper oxide prepared based on Example 1, and will not be repeated here; further, the SEM image of the spherical nano copper oxide prepared based on Comparative Example 1 can be referenced Figure 5 As shown; the SEM image of the mixed structure nano copper oxide prepared based on Comparative Example 2 can be referenced Figure 6 shown.

[0095] Compared with spherical copper oxide, sea urchin-shaped copper oxide is composed of a large number of radial spikes or branch-like parts, and has special geometric characteristics and superior physical and chemical properties such as higher specific surface area, higher active site density, enhanced light scattering ability, excellent mass transfer performance and better mechanical stability, and shows greater advantages than sheet structures in the fields of catalysis, batteries, sensing and optoelectronics. In addition, the above-mentioned figures are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present disclosure, and are not intended to be limiting. It is easy to understand that the processes shown in the above-mentioned figures do not indicate or limit the time sequence of these processes. In addition, it is also easy to understand that these processes can be performed synchronously or asynchronously, for example, in multiple modules.

[0096] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0097] It should be understood that the present disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. The description and embodiments are to be regarded as exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A method for preparing nano copper oxide, characterized in that: The method comprises the following steps: Step 1, preparing the copper salt into a copper precursor aqueous solution containing a surfactant, and preparing the base into an alkaline aqueous solution; Step 2: adding the copper precursor aqueous solution containing a surfactant to the alkaline aqueous solution under the assistance of ultrasound to obtain a copper-alkali mixed solution; Step 3, transferring the copper-alkali mixed solution to a polytetrafluoroethylene reactor for hydrothermal reaction to obtain a nanoparticle solution containing a copper compound; Step 4: performing solid-liquid separation, washing, drying and roasting on the copper compound nanoparticle solution to obtain sea urchin-like nano copper oxide powder.

2. The method for preparing nano copper oxide according to claim 1, characterized in that: The copper salt is at least one of copper chloride, copper acetate, copper sulfate or copper nitrate.

3. The method for preparing nano copper oxide according to claim 1, characterized in that: The surfactant is at least one of polyethylene glycol PEG, polyvinyl pyrrolidone PVP, cetyl trimethyl ammonium bromide CTAB, cetyl trimethyl ammonium chloride CTAC, sodium dodecyl benzene sulfonate SDBS, polydiallyl dimethyl ammonium chloride PDDA and polysorbate.

4. The method for preparing nano copper oxide according to claim 1, characterized in that: The concentration of the copper precursor aqueous solution containing a surfactant is less than or equal to 70 g / L, and the mass content of the surfactant in the copper precursor aqueous solution containing a surfactant is less than or equal to 5%wt.

5. The method for preparing nano copper oxide according to claim 1, characterized in that: The alkaline aqueous solution includes at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate and ammonia water; The concentration of the alkaline aqueous solution is less than or equal to 100 g / L.

6. The method for preparing nano copper oxide according to claim 1, characterized in that: In the ultrasonic-assisted scenario, the frequency of the ultrasonic wave is less than or equal to 4 MHz; In the process of adding the copper precursor aqueous solution containing a surfactant into the alkaline aqueous solution, the adding method adopted is any one of dripping, peristaltic pump injection and atomization spraying.

7. The method for preparing nano copper oxide according to claim 1, characterized in that: In the process of transferring the copper-alkali mixed solution to the polytetrafluoroethylene reactor for hydrothermal reaction, the temperature of the hydrothermal reaction is 100° C. to 200° C.

8. The method for preparing nano copper oxide according to claim 1, characterized in that: In the process of solid-liquid separation of the copper compound nanoparticle solution, the solid-liquid separation method includes centrifugal separation or suction filtration separation; In the process of washing the copper-containing compound nanoparticles after solid-liquid separation, the washing solution used includes water or ethanol; In the process of drying the washed copper compound-containing nanoparticles, the drying method used includes heat drying or cold drying; In the process of calcining the dried copper-containing compound nanoparticles, the calcination temperature used is 200°C to 500°C.

9. The method for preparing nano copper oxide according to claim 1, characterized in that: During the calcination of the dried copper-containing compound nanoparticles, the atmosphere used is air.

10. The method for preparing nano copper oxide according to any one of claims 1 to 9, characterized in that: The size of a single sea urchin-like nano copper oxide is 1 to 2 μm, and the thickness of a single sea urchin-like nano copper oxide sheet is 10 to 30 nm.

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