A mixed valence copper-based nanocomposite, and a preparation method and application thereof

Abstract

The present application relates to the technical field of copper-based nanomaterials, in particular to a mixed-valence copper-based nanocomposite material, a preparation method and application thereof, comprising a multi-level agglomerated structure, wherein the multi-level agglomerated structure is composed of multiple near-spherical particles, the particle size of the near-spherical particles is less than 100 nm, the micro-morphology of the multi-level agglomerated structure is in the shape of cauliflower, a loose three-dimensional network is formed between the multiple near-spherical particles, the three-dimensional network has a microporous and mesoporous composite pore structure, the specific surface area of the multi-level agglomerated structure is 14-23 m 2 / g, and the specific value of the specific surface area depends on the synthesis atmosphere. The present application prepares a copper-based nanocomposite material with different valence structures through controllable synthesis means, systematically reveals the removal behavior and mechanism difference of Sb(III) and Sb(V) in water, provides an adaptive material solution for different application scenarios, and clarifies the electronic transfer path of different valence component materials and its influence on the removal mechanism of Sb(III) and Sb(V).

Description

Technical Field

[0001] This invention relates to the field of copper-based nanomaterials technology, specifically to a mixed-valence copper-based nanocomposite material, its preparation method, and its application. Background Technology

[0002] Antimony (Sb) is a metalloid element with potential toxicity and environmental mobility, mainly derived from industrial activities such as mining, smelting, and the manufacture of flame-retardant materials. In water, antimony exists primarily in two forms: Sb(III) and Sb(V), which differ significantly in toxicity, hydrolysis behavior, and interaction with the environment. Adsorption is a commonly used technique for treating antimony-containing wastewater. In recent years, metal-based nanomaterials have attracted attention due to their high specific surface area and abundant interfacial active sites. Among them, zero-valent iron nanomaterials (nZVI) have been studied extensively in the removal of pollutants such as arsenic and chromium, but they suffer from problems such as easy aggregation, surface passivation, and limited electron transfer efficiency. Zero-valent copper nanomaterials (nZVC) possess higher electronic conductivity and relatively stable interfacial reaction characteristics, showing application potential in the removal of pollutants such as Cr(VI), U(VI), and Se(IV / VI).

[0003] Existing research on copper-based materials mainly focuses on the adsorption of arsenic, chromium, and other metals by copper oxides. However, there is a lack of in-depth research on the removal mechanism, valence state evolution, and electron transfer pathway of antimony, a specific pollutant. Furthermore, the evolution of copper in different valence states during the reaction process and its coupling relationship with the antimony oxidation-complexation-precipitation process are not clearly defined. Therefore, this research does not meet the current needs. To address this, we propose a mixed-valence copper-based nanocomposite material, its preparation method, and its application. Summary of the Invention

[0004] The purpose of this invention is to provide a mixed-valence copper-based nanocomposite material, its preparation method, and its application, in order to address the problem mentioned in the background art that existing research on copper-based materials mainly focuses on the adsorption of other metals such as arsenic and chromium by copper oxides, while lacking in-depth research on the removal mechanism, valence state evolution, and electron transfer pathway of antimony as a specific pollutant, and failing to clarify the evolution law of copper in different valence states during the reaction process and its coupling relationship with the antimony oxidation-complexation-precipitation process.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a mixed-valence copper-based nanocomposite material, comprising a multi-level agglomeration structure, wherein the multi-level agglomeration structure is composed of multiple near-spherical particles, wherein the particle size of the near-spherical particles is less than 100 nm, the microstructure of the multi-level agglomeration structure is cauliflower-like, and a loose three-dimensional network is formed between the multiple near-spherical particles, wherein the three-dimensional network has a composite pore structure of micropores and mesopores.

[0006] Preferably, the specific surface area of ​​the multi-level aggregated structure is 14-23 m². 2 / g, the specific value of which depends on the synthesis atmosphere.

[0007] Preferably, the surface of the multi-level agglomeration structure contains at least two of the three valence states of Cu(0), Cu(I) and Cu(II), and the valence state ratio of the surface of the multi-level agglomeration structure is controlled by the synthesis atmosphere, which is either air or the inert gas nitrogen.

[0008] Preferably, when the air is used as the synthesis atmosphere, the surface of the multi-level aggregated structure is mainly in the Cu(II) valence state and contains a small amount of Cu(O), and the specific surface area of ​​the multi-level aggregated structure is 21-23 m². 2 / g.

[0009] Preferably, when the inert gas nitrogen is used as the synthesis atmosphere, the surface of the hierarchical agglomerate structure is mainly in the valence states of Cu(O) and Cu(I) and contains almost no CuO. The specific surface area of ​​the hierarchical agglomerate structure is 14-16 m². 2 / g.

[0010] Preferably, the surface of the multi-level aggregated structure is rich in one of the sites of -OH and Cu-O. The multi-level aggregated structure can undergo ligand exchange reactions with antimony species in water to form an inner complex structure of ≡Cu-O-Sb. In the ligand exchange reaction, the surface of the multi-level aggregated structure undergoes valence state reconstruction and phase evolution.

[0011] A method for preparing a mixed-valence copper-based nanocomposite material includes the following steps: A1: Raw material preparation, prepare aqueous solution and reducing agent separately, specifically select CuCl2 to prepare an aqueous solution with a concentration of 0.05-0.2M, and select KBH4 to prepare a reducing agent with a concentration of 0.1-0.5M; A2: Synthesis atmosphere control. Under the condition of 15-35℃, the reducing agent is added dropwise to the copper salt solution at a rate of 10-30mL / min, and the reaction is continuously stirred for 20-60min. The valence state is controlled by controlling the reaction vessel and the type of synthesis atmosphere. A3: Synthesis in an air atmosphere was carried out in an open container, and the resulting material was mainly CuO with a small amount of Cu(0); A4: Synthesis under an inert atmosphere, carried out under nitrogen or argon protection, the resulting material is mainly Cu(0) and Cu2O; A5: Post-treatment: After settling, the mixture is separated and washed with deionized water and anhydrous ethanol alternately under ultrasonic assistance to remove residual ions. After freeze-drying, it is sealed and stored under anaerobic conditions to prevent surface oxidation.

[0012] A method for removing antimony from water using mixed-valence copper-based nanocomposites includes the following steps: B1: Basic operating conditions: material dosage is 0.1-1.0 g / L, reaction temperature is 15-35℃, oscillation rate is 100-300 rpm, and reaction time is 30-900 min. Adjustments should be made according to different concentrations and water quality requirements. B2: pH conditions, treat wastewater containing Sb(III) to pH 3-7, treat wastewater containing Sb(V) to pH 3; B3: Scenario-based material selection strategy. When treating high-concentration antimony-containing industrial wastewater, air-synthesized materials are used, with CuO as the main component. CuO has higher adsorption capacity, stronger reactivity, and relatively lower material preparation cost. When treating low-concentration antimony-containing water, inert atmosphere-synthesized materials are used, with either Cu(0) or Cu2O as the main component. CuO has good structural stability and low Cu release.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention is the first to systematically study the removal behavior, electron transfer path and phase evolution law of Sb(III) and Sb(V) by mixed valence state copper-based nanocomposites, providing an original technical solution for this field. At the same time, the maximum adsorption capacity of Sb(III) and Sb(V) is better than most reported iron-based and manganese-based adsorbents, and higher treatment efficiency can be achieved at the same dosage. 2. This invention can achieve directional control of the valence state structure of materials by simply controlling the synthesis atmosphere of air and inert gas, thereby obtaining different electron transfer paths and antimony removal mechanisms. It does not require complex equipment or additional modification steps, is easy to implement on a large scale, and proposes for the first time a strategy of selecting materials with different valence states based on application scenarios. Attached Figure Description

[0014] Figure 1 This invention relates to a method for preparing mixed-valence copper-based nanocomposites. Figure 2 This invention describes the phase structure of copper-based nanocomposites with mixed valence states synthesized under controlled atmosphere. Figure 3 This invention relates to a method for removing antimony from water using copper-based nanocomposites with mixed valence states. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0016] Please see Figure 2One embodiment of the present invention provides a mixed-valence copper-based nanocomposite material comprising a multi-level aggregated structure, wherein the specific surface area of ​​the multi-level aggregated structure is 14-23 m². 2 / g, the specific value of the specific surface area depends on the synthesis atmosphere. The surface of the multi-level aggregate structure is rich in one of the sites of -OH and Cu-O. The multi-level aggregate structure can undergo ligand exchange reaction with antimony species in water and form ≡Cu-O-Sb inner complex structure. The surface of the multi-level aggregate structure undergoes valence state reconstruction and phase evolution during the ligand exchange reaction. The multi-level aggregated structure is composed of multiple near-spherical particles with a particle size of less than 100 nm. The microstructure of the multi-level aggregated structure is cauliflower-like, and a loose three-dimensional network is formed between the multiple near-spherical particles. The three-dimensional network has a composite pore structure of micropores and mesopores.

[0017] The surface of the hierarchical agglomerate structure contains at least two of the three valence states: Cu(0), Cu(I), and Cu(II). The valence state ratio on the surface of the hierarchical agglomerate structure is controlled by the synthesis atmosphere, which is either air or the inert gas nitrogen. When air is used as the synthesis atmosphere, the surface of the hierarchical agglomerate structure is mainly Cu(II) with a small amount of Cu(0). The specific surface area of ​​the hierarchical agglomerate structure is 21-23 m². 2 / g; When inert nitrogen is used as the synthesis atmosphere, the surface of the hierarchical aggregate structure is mainly in the valence states of Cu(0) and Cu(I) and contains almost no CuO. The specific surface area of ​​the hierarchical aggregate structure is 14-16 m². 2 / g.

[0018] Please see Figure 1 A method for preparing a copper-based nanocomposite material with mixed valence states includes the following steps: A1: Raw material preparation, prepare aqueous solution and reducing agent separately, specifically select CuCl2 to prepare an aqueous solution with a concentration of 0.05-0.2M, and select KBH4 to prepare a reducing agent with a concentration of 0.1-0.5M; A2: Synthesis atmosphere control. Under the condition of 15-35℃, the reducing agent is added dropwise to the copper salt solution at a rate of 10-30mL / min, and the reaction is continuously stirred for 20-60min. The valence state is controlled by controlling the reaction vessel and the type of synthesis atmosphere. A3: Synthesis in an air atmosphere was carried out in an open container, and the resulting material was mainly CuO with a small amount of Cu(0); A4: Synthesis under an inert atmosphere, carried out under nitrogen or argon protection, the resulting material is mainly Cu(0) and Cu2O; A5: Post-treatment: After settling, the mixture is separated and washed with deionized water and anhydrous ethanol alternately under ultrasonic assistance to remove residual ions. After freeze-drying, it is sealed and stored under anaerobic conditions to prevent surface oxidation.

[0019] Please see Figure 3 A method for removing antimony from water using copper-based nanocomposites with mixed valence states includes the following steps: B1: Basic operating conditions: material dosage is 0.1-1.0 g / L, reaction temperature is 15-35℃, oscillation rate is 100-300 rpm, and reaction time is 30-900 min. Adjustments should be made according to different concentrations and water quality requirements. B2: pH conditions, treat wastewater containing Sb(III) to pH 3-7, treat wastewater containing Sb(V) to pH 3; B3: Scenario-based material selection strategy. When treating high-concentration antimony-containing industrial wastewater, air-synthesized materials are used, with CuO as the main component. CuO has higher adsorption capacity, stronger reactivity, and relatively lower material preparation cost. When treating low-concentration antimony-containing water, inert atmosphere-synthesized materials are used, with either Cu(0) or Cu2O as the main component. CuO has good structural stability and low Cu release.

[0020] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A mixed-valence copper-based nanocomposite material, comprising a multi-level aggregated structure, characterized in that: The multi-level aggregated structure is composed of multiple near-spherical particles. The microstructure of the multi-level aggregated structure is cauliflower-like. A loose three-dimensional network is formed between the multiple near-spherical particles. The three-dimensional network has a composite pore structure of micropores and mesopores.

2. The mixed-valence copper-based nanocomposite material according to claim 1, characterized in that: The near-spherical particles have a diameter of less than 100 nm and a specific surface area of ​​14-23 m² for their multi-level aggregated structure. 2 / g.

3. The mixed-valence copper-based nanocomposite material according to claim 2, characterized in that: The surface of the multi-level agglomeration structure contains at least two of the three valence states of Cu(0), Cu(I) and Cu(II), and the ratio of the valence states on the surface of the multi-level agglomeration structure is controlled by the synthesis atmosphere, which is either air or the inert gas nitrogen.

4. The mixed-valence copper-based nanocomposite material according to claim 3, characterized in that: When air is used as the synthesis atmosphere, the surface of the hierarchical aggregate structure is mainly in the Cu(II) valence state and contains a small amount of Cu(O). The specific surface area of ​​the hierarchical aggregate structure is 21-23 m². 2 / g.

5. The mixed-valence copper-based nanocomposite material according to claim 3, characterized in that: When inert nitrogen is used as the synthesis atmosphere, the surface of the hierarchical aggregate structure is mainly in the valence states of Cu(0) and Cu(I) and contains almost no CuO. The specific surface area of ​​the hierarchical aggregate structure is 14-16 m². 2 / g.

6. The mixed-valence copper-based nanocomposite material according to claim 3, characterized in that: The surface of the multi-level aggregated structure is rich in one of the sites of -OH and Cu-O. The multi-level aggregated structure can undergo ligand exchange reactions with antimony species in water to form an inner complex structure of ≡Cu-O-Sb. In the ligand exchange reaction, the surface of the multi-level aggregated structure undergoes valence state reconstruction and phase evolution.

7. A method for preparing a mixed-valence copper-based nanocomposite material, wherein the mixed-valence copper-based nanocomposite material according to any one of claims 1-6 is characterized in that: Includes the following steps: A1: Raw material preparation, prepare aqueous solution and reducing agent separately, specifically select CuCl2 to prepare an aqueous solution with a concentration of 0.05-0.2M, and select KBH4 to prepare a reducing agent with a concentration of 0.1-0.5M; A2: Synthesis atmosphere control. Under the condition of 15-35℃, the reducing agent is added dropwise to the copper salt solution at a rate of 10-30mL / min, and the reaction is continuously stirred for 20-60min. The valence state is controlled by controlling the reaction vessel and the type of synthesis atmosphere. A3: Synthesis in an air atmosphere was carried out in an open container, and the resulting material was mainly CuO with a small amount of Cu(0); A4: Synthesis under an inert atmosphere, carried out under nitrogen or argon protection, the resulting material is mainly Cu(0) and Cu2O; A5: Post-treatment: After settling, the mixture is separated and washed with deionized water and anhydrous ethanol alternately under ultrasonic assistance to remove residual ions. After freeze-drying, it is sealed and stored under anaerobic conditions to prevent surface oxidation.

8. A method for removing antimony from water using a mixed-valence copper-based nanocomposite material, wherein the mixed-valence copper-based nanocomposite material is described in any one of claims 1-6, characterized in that... Includes the following steps: B1: Basic operating conditions: material dosage is 0.1-1.0 g / L, reaction temperature is 15-35℃, oscillation rate is 100-300 rpm, and reaction time is 30-900 min. Adjustments should be made according to different concentrations and water quality requirements. B2: pH conditions, treat wastewater containing Sb(III) to pH 3-7, treat wastewater containing Sb(V) to pH 3; B3: Scenario-based material selection strategy. When treating high-concentration antimony-containing industrial wastewater, air-synthesized materials are used, with CuO as the main component. CuO has higher adsorption capacity, stronger reactivity, and relatively lower material preparation cost. When treating low-concentration antimony-containing water, inert atmosphere-synthesized materials are used, with either Cu(0) or Cu2O as the main component. CuO has good structural stability and low Cu release.

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