Selective adsorption method for copper ions by adopting aspartic acid silicon-based carbon dot material
By forming a stable chelate between aspartic acid silicon-based carbon dot material and copper ions, the problem of low copper ion adsorption efficiency in traditional methods is solved, achieving high selectivity and high capacity adsorption, reducing costs and improving processing efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HARBIN ENG UNIV
- Filing Date
- 2026-02-28
- Publication Date
- 2026-04-17
Smart Images
Figure CN121869304A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nanomaterial preparation and environmental pollution control technology, specifically relating to a method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials. Background Technology
[0002] Carbon dots are a class of zero-dimensional materials composed of carbon atoms at the nanoscale, typically exhibiting strong photofluorescence properties. They are usually smaller than 10 nanometers in size and emit bright fluorescence under ultraviolet light. Various methods exist for synthesizing carbon dots, including pyrolysis of carbon sources, chemical oxidation, and microwave synthesis. This experiment employed a hydrothermal method. Due to their excellent optical properties, low toxicity, and good biocompatibility, carbon dots are widely used in biolabeling, sensors, and optoelectronic devices. Silicon materials possess extremely high chemical stability and strong oxidation resistance, making them suitable for long-term use under various environmental conditions. Silicon dioxide, in particular, is widely used in optoelectronics, environmental monitoring, and materials science. Silicon dioxide exhibits excellent thermal and chemical stability, maintaining good performance even in complex environments. It also possesses certain semiconductor properties, and its conductivity and electron transport capabilities can be improved through surface modification or doping. Furthermore, its surface is rich in hydroxyl (-OH) groups, readily reacting with other organic or inorganic molecules, facilitating surface functionalization and enhancing sensing performance. These advantages make silica materials an ideal choice for preparing silicon-based carbon dots, which helps to improve the stability, functionality, and application potential of the synthesized materials in environmental monitoring.
[0003] Copper ions (Cu) 2+ Copper ions (C₂) are a significant pollutant in industrial wastewater and soil pollution, exhibiting high chemical toxicity. Their toxicity to organisms primarily stems from their ability to bind to active groups in biomolecules, interfering with normal physiological functions. Furthermore, C₂ ions are persistent in the environment, easily accumulating in organisms and posing a potential threat to ecosystems and human health. With rapid industrial development, the development of materials for efficient and selective adsorption of C₂ ions has become an urgent need in environmental pollution control and resource recycling. Efficient adsorption of C₂ ions requires high selectivity, high capacity, and strong environmental adaptability. Traditional methods for detecting and adsorbing C₂ ions rely heavily on large, precision instruments, resulting in high costs and low adsorption efficiency. Fluorescence detection methods are simple to operate, highly sensitive, and can achieve efficient adsorption based on the high selectivity of materials for C₂ ions while simultaneously detecting C₂ ion concentration. Current research on fluorescent detection materials for adsorbing C₂ ions focuses on three main areas: functionalized porous materials, nanocomposite materials, and bio-derived materials. This invention relates to aspartic acid composite materials in nanocomposite materials. The high selectivity of aspartic acid composite materials for C₂ ions is based on their unique physicochemical properties and surface functionalization design. Summary of the Invention
[0004] To address the complexity and inefficiency of traditional methods for copper ion adsorption, this invention provides a selective adsorption method for copper ions using aspartic acid silicon-based carbon dot materials.
[0005] This invention provides a method for selective adsorption of copper ions using aspartic silicon-based carbon dot material. The method involves mixing the aspartic silicon-based carbon dot material with an acid solution containing copper ions and then ultrasonically treating the mixture. The aspartic silicon-based carbon dot material adsorbs copper ions from the solution.
[0006] Furthermore, the preparation of the aspartic acid silicon-based carbon dot material includes the following steps:
[0007] Step 1: Dissolve aspartic acid and ethylenediamine in deionized water and stir to form a precursor solution;
[0008] Step 2: Perform a hydrothermal reaction on the precursor solution, and allow it to cool naturally to room temperature after the reaction is complete to obtain a reddish-brown carbon dot solution;
[0009] Step 3: The carbon dot solution is mixed with surfactant, alkaline solution and deionized water under water bath reflux and stirring. A silicon source is added to the mixed solution and the mixture is heated. Then, after filtration, washing, drying and grinding, the mixture is calcined at high temperature to obtain aspartic acid silicon-based carbon dot material.
[0010] Further, in step 1, the mass-to-volume ratio of aspartic acid, ethylenediamine, and deionized water is 4~6g:4~8mL:40~85mL; the stirring conditions are stirring at 120~150 r / min for 25~50 min at 20~35 ℃.
[0011] Furthermore, in step 2, the hydrothermal temperature is 180~250 ℃, and the reaction time is 10~15 h.
[0012] Further, in step 3, the surfactant is hexadecyltrimethylammonium bromide; the alkaline solution is sodium hydroxide; and the mass-volume ratio of the carbon dot solution, surfactant, and alkaline solution is 3~8 mL: 0.2~0.4 g: 0.5~1.0 mL: 30~60 mL.
[0013] Furthermore, in step 3, the water bath reflux stirring temperature is 80~120 ℃, and the time is 1~2 h.
[0014] Further, in step 3, the silicon source is tetraethyl orthosilicate, and the volume ratio of tetraethyl orthosilicate to the mixed solution is 1~5:45~75; the heating time after adding the silicon source is 1.5~3h.
[0015] Furthermore, in step 3, the drying temperature is 40~80 ℃ and the drying time is 8~10 h; the high-temperature calcination temperature is 550~700 ℃ and the drying time is 4~8 h.
[0016] Furthermore, the mass-to-volume ratio of the aspartic acid silicon-based carbon dot material to the copper-containing acid solution is 1-3 g: 100-300 mL; the copper-containing acid solution is a copper nitrate solution.
[0017] Furthermore, the ultrasonic power is 200~400 W, and the duration is 10~20 min.
[0018] Furthermore, the concentration of the copper-containing acid solution is 1~10 mg / L.
[0019] The beneficial effects of this invention are as follows:
[0020] 1. This invention innovatively employs aspartic acid silicon-based carbon dot materials to adsorb copper ions. Aspartic acid silicon-based carbon dot materials typically possess abundant surface functional groups (such as carboxyl-COOH, amino-NH2, etc.). These functional groups can bind to copper ions through coordination bonds. Introducing specific functional groups can selectively capture copper ions for coordination to form stable chelates. The aspartic acid silicon-based carbon dot materials have a stable structure, which can prevent material aggregation, maintain a high specific surface area, and expose more adsorption sites. The nanoscale size gives it quantum effects and surface defect sites, which can interact strongly with copper ions.
[0021] 2. The synthesis method of aspartic acid silicon-based carbon dot materials of the present invention is simple and low-cost: it adopts a water bath heating method, which is simple to operate and has a short reaction time compared with traditional synthesis methods, greatly reducing production costs and energy consumption. In addition, the raw materials used are usually relatively inexpensive and readily available organic compounds, further reducing production costs and making this method have strong potential for industrial application.
[0022] 3. The aspartic acid silicon-based carbon dot material prepared in this invention exhibits excellent selective adsorption performance for copper ions. The amino and carboxyl functional groups on its surface have a strong coordination matching relationship with copper ions, giving the material a higher binding priority for Cu²⁺. In systems with multiple coexisting metal ions, the material can preferentially recognize and adsorb copper ions, effectively reducing the competitive adsorption of other metal ions, thereby achieving highly efficient and selective separation of the target copper ions.
[0023] 4. The aspartic acid silicon-based carbon dot material constructed in this invention has a hierarchical porous structure, which can provide an effective channel for the diffusion and transport of copper ions, improve the migration efficiency of copper ions in solution to the active sites inside the material, thereby enhancing the adsorption kinetics performance of the material, enabling it to reach adsorption equilibrium in a shorter time and improving the overall processing efficiency. Attached Figure Description
[0024] Figure 1 This is a scanning electron microscope image of the aspartic acid silicon-based carbon dot material of the present invention. Detailed Implementation
[0025] The present invention will be further described in detail below with reference to specific embodiments. The examples given are only for illustrating the present invention and are not intended to limit the scope of the present invention.
[0026] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0027] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.
[0028] The medications used in the following examples were all purchased from the Maclean's website.
[0029] This invention discloses a method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials, comprising the following steps:
[0030] 1. Aspartic acid, ethylenediamine solution, and deionized water are mixed in a certain proportion and heated in a polytetrafluoroethylene-lined reactor to obtain a reddish-brown carbon dot solution; the carbon dot solution is mixed with hexadecyltrimethylammonium bromide, deionized water, and 2 mol / L sodium hydroxide solution, and stirred under reflux in a water bath; tetraethyl orthosilicate is added to the mixture, and the mixture is heated further. After filtration, washing, drying, and grinding, the mixture is calcined at high temperature to remove impurities, thus obtaining a silicon-based carbon dot nanocomposite material.
[0031] 2. Dissolve copper sulfate in nitric acid and add tertiary water to prepare a copper ion solution. Preliminary reaction of aspartic acid with the copper ion solution: Add the two materials to a centrifuge tube in the correct proportion and shake to allow them to come into contact. Complete reaction of aspartic acid with the copper ion solution: Operate an ultrasonic material disperser to agitate the material into a suspension for adsorption of copper ions.
[0032] In step 1 above, the carbon dot solution is prepared by hydrothermal reaction at a temperature of 180~250 ℃ and a reaction time of 10~15 h.
[0033] In step 1 above, the water bath heating and reflux stirring temperature can be 80~120 ℃, the stirring time is 60~120 min, and the stirring speed is 120 r / min~150 r / min.
[0034] In step 1 above, tetraethyl orthosilicate is added to the mixture, and heating continues for 1.5 to 3 hours at a temperature of 80-120 °C.
[0035] In step 2 above, the copper ion solution is a copper nitrate solution with a concentration range of 1~10 mg / L.
[0036] In step 2 above, the solid-liquid ratio of aspartic acid material to copper ion solution is 1~3 g: 100~300 mL.
[0037] In step 2 above, the ultrasonic dispersion power is 200~400 W and the time is 10~20 min.
[0038] Example 1
[0039] (1) Solid aspartic acid, ethylenediamine solution, and deionized water were mixed in a ratio of 5.04 g: 6432 μL: 60 mL and placed in a polytetrafluoroethylene-lined reactor. The mixture was heated in an electric heating drying oven at 180 °C for 14 hours to obtain a reddish-brown carbon dot solution. The silicon source was tetraethyl orthosilicate, and the surfactant was hexadecyltrimethylammonium bromide. 5 mL of the carbon dot solution and 0.2 g of hexadecyltrimethylammonium bromide were added to a mixed solution containing 43 mL of deionized water and 0.8 mL of 2 mol / L NaOH solution. The mixture was heated in a water bath at 80 °C and stirred under reflux for 1 hour until a white flocculent precipitate appeared. Then, 1 mL of tetraethyl orthosilicate was added, and the mixture was heated for another 1.5 hours. The resulting mixture was filtered, washed, dried, ground, and calcined at high temperature to remove impurities, resulting in a silicon-based carbon dot (aspartic acid) nanocomposite material.
[0040] (2) Weigh 100 mg of copper sulfate, dissolve it in a small amount of 1 mol / L nitric acid and heat until completely dissolved, transfer it to a 100 mL volumetric flask, and dilute to volume with tertiary water to obtain a 100 mg / L copper nitrate stock solution; dilute to a 3 mg / L copper sulfate solution, take 0.05 g of the aspartic acid material prepared above, add 5 mL of copper ion solution; treat with a 300W ultrasonic disperser for 15 minutes to form a uniform suspension; after simultaneous centrifugation (4000 rpm, 10 min), determine the copper ion concentration of the supernatant by ICP-MS, and the saturated adsorption capacity is 116.72 mg / g.
[0041] Example 2
[0042] (1) Solid aspartic acid, ethylenediamine solution, and deionized water were mixed in a ratio of 5.04 g: 6432 μL: 60 mL and placed in a polytetrafluoroethylene-lined reactor. The mixture was heated in an electric heating drying oven at 180 °C for 14 hours to obtain a reddish-brown carbon dot solution. The silicon source was tetraethyl orthosilicate, and the surfactant was hexadecyltrimethylammonium bromide. 5 mL of the carbon dot solution and 0.2 g of hexadecyltrimethylammonium bromide were added to a mixed solution containing 43 mL of deionized water and 0.8 mL of 2 mol / L NaOH solution. The mixture was heated in a water bath at 80 °C and stirred under reflux for 1 hour until a white flocculent precipitate appeared. Then, 1 mL of tetraethyl orthosilicate was added, and the mixture was heated for another 1.5 hours. The resulting mixture was filtered, washed, dried, ground, and calcined at high temperature to remove impurities, resulting in a silicon-based carbon dot (aspartic acid) nanocomposite material.
[0043] (2) Weigh 100 mg of copper sulfate, dissolve it in a small amount of 1 mol / L nitric acid and heat until completely dissolved, transfer it to a 100 mL volumetric flask, and dilute to volume with tertiary water to obtain a 100 mg / L copper nitrate stock solution; dilute to a 5 mg / L copper sulfate solution, take 0.05 g of the aspartic acid material prepared above, add 5 mL of copper ion solution; treat with a 300W ultrasonic disperser for 15 minutes to form a uniform suspension; after simultaneous centrifugation (4000 rpm, 10 min), determine the copper ion concentration of the supernatant by ICP-MS, and the saturated adsorption capacity is 120.45 mg / g.
[0044] Example 3
[0045] (1) Solid aspartic acid, ethylenediamine solution, and deionized water were mixed in a ratio of 5.04 g: 6432 μL: 60 mL and placed in a polytetrafluoroethylene-lined reactor. The mixture was heated in an electric heating drying oven at 180 °C for 14 hours to obtain a reddish-brown carbon dot solution. The silicon source was tetraethyl orthosilicate, and the surfactant was hexadecyltrimethylammonium bromide. 5 mL of the carbon dot solution and 0.2 g of hexadecyltrimethylammonium bromide were added to a mixed solution containing 43 mL of deionized water and 0.8 mL of 2 mol / L NaOH solution. The mixture was heated in a water bath at 80 °C and stirred under reflux for 1 hour until a white flocculent precipitate appeared. Then, 1 mL of tetraethyl orthosilicate was added, and the mixture was heated for another 1.5 hours. The resulting mixture was filtered, washed, dried, ground, and calcined at high temperature to remove impurities, resulting in a silicon-based carbon dot (aspartic acid) nanocomposite material.
[0046] (2) Weigh 100 mg of copper sulfate, dissolve it in a small amount of 1 mol / L nitric acid and heat until completely dissolved, transfer it to a 100 mL volumetric flask, and dilute to volume with tertiary water to obtain a 100 mg / L copper nitrate stock solution; dilute to a 10 mg / L copper sulfate solution, take 0.05 g of the aspartic acid material prepared above, add 5 mL of copper ion solution; treat with a 300W ultrasonic disperser for 15 minutes to form a uniform suspension; after simultaneous centrifugation (4000 rpm, 10 min), determine the copper ion concentration of the supernatant by ICP-MS, and the saturated adsorption capacity is 136.51 mg / g.
[0047] Comparative Example 1
[0048] (1) Aspartic acid solid, ethylenediamine solution, and deionized water were mixed in a ratio of 5.04 g: 6432 μL: 60 mL and placed in a polytetrafluoroethylene-lined reactor. The mixture was heated in an electric heating drying oven at 180 °C for 14 hours to obtain a reddish-brown carbon dot solution. The silicon source was tetraethyl orthosilicate. 5 mL of the carbon dot solution was added to a mixed solution containing 43 mL of deionized water and 0.8 mL of 2 mol / L NaOH solution. The mixture was heated in an 80 °C water bath and refluxed for 1 hour until a white flocculent precipitate appeared. Then, 1 mL of tetraethyl orthosilicate was added, and the mixture was heated for another 1.5 hours. The resulting mixture was filtered, washed, dried, ground, and calcined at high temperature to remove impurities.
[0049] (2) Weigh 100 mg of copper sulfate, dissolve it with a small amount of 1 mol / L nitric acid and heat until completely dissolved, transfer it to a 100 mL volumetric flask, and dilute to volume with tertiary water to obtain a 100 mg / L copper nitrate stock solution; dilute to a 10 mg / L copper sulfate solution, take 5 portions (0.05 g each) of each of the two composite materials with the best fluorescence performance, add 5 mL of copper ion solution of different concentrations (solid-liquid ratio 1 g / 100 mL); treat with a 30 W ultrasonic disperser for 15 minutes to form a uniform suspension; after simultaneous centrifugation (4000 rpm, 10 min), determine the copper ion concentration of the supernatant by ICP-MS, and the saturated adsorption capacity is 2.45 mg / g.
[0050] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for selective adsorption of copper ions using aspartic acid silicon-based carbon dots material, characterized by, Aspartic acid silicon-based carbon dot material was mixed with an acid solution containing copper ions and then ultrasonically treated. The aspartic acid silicon-based carbon dot material adsorbed the copper ions in the solution.
2. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 1, characterized in that... The preparation of the aspartic acid silicon-based carbon dot material includes the following steps: Step 1: Dissolve aspartic acid and ethylenediamine in deionized water and stir to form a precursor solution; Step 2: Perform a hydrothermal reaction on the precursor solution, and allow it to cool naturally to room temperature after the reaction is complete to obtain a reddish-brown carbon dot solution; Step 3: The carbon dot solution is mixed with surfactant, alkaline solution and deionized water under water bath reflux and stirring. A silicon source is added to the mixed solution and the mixture is heated. Then, after filtration, washing, drying and grinding, the mixture is calcined at high temperature to obtain aspartic acid silicon-based carbon dot material.
3. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 2, characterized in that, In step 1, the mass-to-volume ratio of aspartic acid, ethylenediamine, and deionized water is 4-6 g: 4-8 mL: 40-85 mL; the stirring conditions are stirring at 120-150 r / min for 25-50 min at 20-35 ℃.
4. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 2, characterized in that, In step 2, the hydrothermal temperature is 180~250 ℃, and the reaction time is 10~15 h.
5. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 2, characterized in that, In step 3, the surfactant is hexadecyltrimethylammonium bromide; the alkaline solution is sodium hydroxide; the mass-volume ratio of the carbon dot solution, surfactant and alkaline solution is 3~8 mL: 0.2~0.4 g: 0.5~1.0 mL: 30~60 mL; the water bath reflux stirring temperature is 80~120 ℃ and the time is 1~2 h.
6. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 2, characterized in that, In step 3, the silicon source is tetraethyl orthosilicate, and the volume ratio of tetraethyl orthosilicate to the mixed solution is 1~5:45~75; the heating time after adding the silicon source is 1.5~3h.
7. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 2, characterized in that, In step 3, the drying temperature is 40~80 ℃ and the drying time is 8~10 h; the high-temperature calcination temperature is 550~700 ℃ and the drying time is 4~8 h.
8. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 1, characterized in that, The mass-to-volume ratio of the aspartic acid silicon-based carbon dot material to the copper-containing acid solution is 1-3 g: 100-300 mL; the copper-containing acid solution is a copper nitrate solution.
9. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 1, characterized in that, The ultrasonic power is 200~400 W, and the duration is 10~20 min.
10. The method for selective adsorption of copper ions using aspartic acid silicon-based carbon dot materials according to claim 1, characterized in that, The concentration of the copper-containing acid solution is 1~10 mg / L.