Method for preparing copper oxide nano-powder through coordination oxidation homogeneous precipitation

Abstract

The invention discloses a method for preparing copper oxide nano-powder by coordination oxidation homogeneous precipitation, which comprises the following steps: by taking polyvinyl alcohol as a template agent, promoting ordered arrangement and growth of nano-particles by polyvinyl alcohol in a heating reaction process, then calcining to form nano-scale oxidized particles, and generating no harmful by-products in the reaction process. Waste liquid after reaction can be recycled, the economic effect and environmental protection performance of production can be improved, the copper ammonia solution can be prepared from industrial waste copper and the like and ammonia water, and economic recycling and utilization of resources are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal powder, and particularly relates to a method for preparing copper oxide nano powder by coordination oxidation homogeneous precipitation. Background Art

[0002] Nano copper oxide (CuO-NPs) is an important semiconductor material, and shows good application prospects in fields such as catalysts and sensing materials due to its excellent antibacterial properties, electrical conductivity and thermal stability. In the field of biomedicine, nano copper oxide can be used for the treatment of bacterial pneumonia and wound infections; in the field of environmental protection, its applications include air purification, wastewater treatment and photocatalytic degradation of organic pollutants; in the field of energy materials, it is widely used as an electrode material for supercapacitors and energy storage batteries.

[0003] There are various methods for preparing nano copper oxide, including solid-phase method, gas-phase method and liquid-phase method, etc. However, these methods generally have problems such as particle agglomeration, too large and uneven particle size, and environmental pollution. In addition, many preparation technologies require the use of expensive chemical reagents, resulting in high production costs, which limits their industrial applications.

[0004] Chinese Patent CN104891551A discloses a scheme for synthesizing copper oxide using a copper ammonia complex solution as a raw material. The defect is that the particle size distribution of the obtained powder is 10 - 75 μm, the particle size of the powder is too large, the application field is limited, and improvement is needed. Summary of the Invention

[0005] To solve the above at least one technical defect, the present invention provides the following technical solutions:

[0006] This application document discloses a method for preparing copper oxide nano powder by coordination oxidation homogeneous precipitation, including the following steps:

[0007] A step of mixing a copper ammonia solution and polyvinyl alcohol and heating and reacting under alkaline conditions;

[0008] A step of solid-liquid separation of the reaction product and calcining the separated solid product.

[0009] Principle: Using polyvinyl alcohol as a template agent, the structural characteristics of polyvinyl alcohol can help control the particle size and morphology, and its excellent film-forming performance provides a uniform protective layer in the synthesis of nanoparticles, thus significantly reducing the particle agglomeration phenomenon. During the heating reaction process, polyvinyl alcohol promotes the orderly arrangement and growth of nanoparticles, and then nano-sized oxide particles are formed after calcination.

[0010] Furthermore, the concentration of polyvinyl alcohol in the reaction solution formed by mixing the copper ammonia solution and polyvinyl alcohol is 0.5 - 4%, and limiting the concentration can better promote the growth of nanoparticles.

[0011] Further, the alkaline condition refers to a pH value between 8 and 12.

[0012] Further, during the heating reaction, the temperature is 40 - 80°C and the time is 1 - 3 h. Limiting the heating temperature can contribute to the stable growth of the nanoparticles.

[0013] Further, grinding the calcined powder helps to improve the uniformity of the distribution of subsequent copper oxide nanoparticles.

[0014] Further, the calcination temperature is 200 - 500°C and the calcination time is 3 - 5 h, which helps to improve the quality of the copper oxide nanoparticles.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. The present invention uses polyvinyl alcohol as a template agent. During the reaction process, polyvinyl alcohol can promote the orderly arrangement and growth of nanoparticles, and can prepare nanoscale copper oxide powder to meet the application requirements of multiple fields.

[0017] 2. No harmful by-products are generated during the reaction process of the present invention, and the waste liquid after the reaction can be recycled, which helps to improve the economic effect and environmental protection performance of production.

[0018] 3. The present invention can prepare cuprammonium solution from industrial waste copper, etc. and ammonia water, realizing the economic recovery and utilization of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is the XRD spectrum of the samples obtained in Examples 1 - 6. Among them, 1 represents Example 1, 2 represents Example 2, 3 represents Example 3, 4 represents Example 4, 5 represents Example 5, and 6 represents Example 6.

[0021] Figure 2 It is the SEM image of the samples obtained in Examples 1 - 6. Among them, 1 represents Example 1, 2 represents Example 2, 3 represents Example 3, 4 represents Example 4, 5 represents Example 5, and 6 represents Example 6. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0023] In the following examples, the cuprammonium solution is prepared from a copper source and ammonia water. The copper source can be waste copper powder, waste copper plate, etc. The molar ratio of the copper source to ammonia water can be selected according to requirements. For example, the molar ratio of the copper source to ammonia water is 1:6, 1:3, 1:8, 1:10, 1:2, etc.

[0024] For polyvinyl alcohol, a low molecular weight type can be selected, such as a molecular weight in the range of 10,000 - 30,000, or a medium molecular weight type with a molecular weight in the range of 30,000 - 100,000, or a high molecular weight type with a molecular weight in the range of 100,000 - 300,000, which is selected according to requirements.

[0025] After mixing the cuprammonium solution and polyvinyl alcohol, water can be added according to requirements to adjust the concentration. The specific amount of water added can be selected according to requirements. For example, deionized water with the same volume as the mixed solution is added, deionized water with a volume accounting for 1 / 2 of the mixed solution is added, or deionized water with 2 times the volume of the mixed solution is added, etc.

[0026] Example 1

[0027] A method for preparing cupric oxide nano - powder by coordination oxidation and homogeneous precipitation includes the following steps:

[0028] Mix the cuprammonium solution (the molar ratio of the copper source to ammonia water is 1:6) with polyvinyl alcohol (molecular weight 13,000 - 23,000). After mixing, the concentration of polyvinyl alcohol in the solution is 0.5%. Add deionized water with a volume accounting for 1 / 2 of the mixed solution, adjust the pH to 9, and heat in a water bath to 50 °C for ammonia evaporation for 1.5 h.

[0029] Filter the reaction product for solid - liquid separation. Wash the filtered solid product alternately with deionized water and absolute ethanol. Add the washed solid product into a muffle furnace and calcine it in an air atmosphere at a calcination temperature of 300 °C for 3.5 h. After calcination, grind the black powder product with a mortar for about 5 min.

[0030] Example 2

[0031] Compared with Example 1, the difference in this example is that: the molar ratio of the copper source to ammonia water in the cuprammonium solution is 1:3, the water - bath heating temperature is 60 °C, the time is 2.5 h, the calcination temperature is 400 °C, and the time is 3 h.

[0032] Example 3

[0033] Compared with Example 1, the difference in this example is that: the molar ratio of the copper source to ammonia water in the cuprammonium solution is 1:8, the water - bath heating temperature is 40 °C, the time is 3 h, the calcination temperature is 500 °C, and the time is 4 h.

[0034] Example 4

[0035] Compared with Example 1, the difference in this example is that: polyvinyl alcohol is not added.

[0036] Example 5

[0037] Compared with Example 1, the difference in this example is that the concentration of polyvinyl alcohol is 4%.

[0038] Example 6

[0039] Compared with Example 1, the difference in this example is that the time for ammonia evaporation by water bath heating is 2 h.

[0040] The prepared copper oxide powder was subjected to XRD and SEM tests. For details, see Figure 1 and Figure 2 . It can be seen that the copper oxide particles in Example 4 are significantly larger and seriously agglomerated, while the copper oxide particles prepared in Examples 1-3, 5, and 6 are more uniformly dispersed. After testing, the particle size of the copper oxide particles prepared in Examples 1-3, 5, and 6 is 20-80 nm, and the particle size of the copper oxide particles prepared in Example 4 is in the micron level, not in the nanometer level.

[0041] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A method for preparing copper oxide nanopowder by coordinated oxidation uniform precipitation, characterized in that: The following steps are involved: The step of mixing the copper ammonia solution with polyvinyl alcohol and heating the mixture under alkaline conditions for reaction; The step of separating the reaction product into solid and liquid and calcining the separated solid product.

2. The method for preparing copper oxide nanopowder by coordinated oxidation uniform precipitation as claimed in claim 1, characterized in that: The concentration of polyvinyl alcohol in the reaction solution formed by mixing the copper ammonia solution and polyvinyl alcohol is 0.5-4%.

3. The method for preparing copper oxide nanopowder by coordinated oxidation uniform precipitation as claimed in claim 1, characterized in that: Alkaline conditions refer to pH values ​​between 8-12.

4. The method for preparing copper oxide nanopowder by coordinated oxidation uniform precipitation as claimed in claim 1, characterized in that: The heating reaction temperature is 40-80°C and the time is 1-3h.

5. The method for preparing copper oxide nanopowder by coordinated oxidation uniform precipitation as claimed in claim 1, characterized in that: The calcined powder is ground.

6. The method for preparing copper oxide nanopowder by coordinated oxidation uniform precipitation as claimed in claim 1, characterized in that: Calcination temperature: 200-500℃, calcination time: 3-5h.

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