Carbon sphere composite material loaded with macrocyclic conjugated molecules as well as preparation method and application of carbon sphere composite material

Abstract

The invention provides a carbon sphere composite material loaded with macrocyclic conjugated molecules, and belongs to the technical field of microplastic pollutant detection, the composite material comprises iron phthalocyanine molecules and carbon nanospheres, and the iron phthalocyanine molecules are uniformly modified on the surfaces of the carbon nanospheres. The electrochemical sensor constructed by adopting the composite material can realize specific recognition of bisphenol A, can rapidly detect bisphenol A in a low concentration range, has lower detection limit, good linear sensitivity and higher stability, effectively reduces the detection cost of bisphenol A, and improves the detection efficiency. The invention also provides a preparation method and application of the macrocyclic conjugated molecule loaded carbon sphere composite material.

Description

Technical Field

[0001] The present invention belongs to the technical field of microplastic pollutant detection, and particularly relates to a carbon sphere composite material loaded with macrocyclic conjugated molecules, a preparation method and an application thereof. Background Art

[0002] Bisphenol A, as an important chemical raw material, is widely used in the production of polycarbonate and epoxy resin. Products containing bisphenol A can penetrate into people's daily lives through reusable plastic bottles, tableware, food, beverage cans, etc. Human exposure to bisphenol A may cause a series of health problems, especially in terms of reproductive health and the endocrine system, and the risks for children and pregnant women are particularly prominent. Moreover, bisphenol A is difficult to decompose in the water environment, has long-term residual properties, and will also have a toxic impact on aquatic organisms.

[0003] Existing bisphenol A detection methods mainly include techniques such as high performance liquid chromatography (HPLC), gas chromatography (GC) and spectroscopic analysis. Although these methods can provide relatively high detection sensitivity and accuracy, they usually have problems such as complex operation, high cost and high requirements for instrument equipment. Therefore, developing a highly efficient, convenient, low-cost and highly sensitive bisphenol A detection method has important application value. Summary of the Invention

[0004] In order to solve the problems of high cost and low efficiency of existing bisphenol A detection methods, the present invention provides a carbon sphere composite material loaded with macrocyclic conjugated molecules. An electrochemical sensor constructed using this composite material can achieve specific recognition of bisphenol A, can rapidly detect bisphenol A within a low concentration range, has a low detection limit, good linear sensitivity and high stability, effectively reduces the detection cost of bisphenol A, and improves the detection efficiency.

[0005] The present invention also provides a preparation method and an application of a carbon sphere composite material loaded with macrocyclic conjugated molecules.

[0006] The present invention is realized through the following technical solutions:

[0007] The present invention provides a carbon sphere composite material loaded with macrocyclic conjugated molecules, and the composite material comprises iron phthalocyanine molecules and carbon nanospheres, and the iron phthalocyanine molecules are uniformly modified on the surface of the carbon nanospheres.

[0008] Further, the particle size of the carbon nanospheres is 600 - 800 nm.

[0009] Further, the linear dimension of the iron phthalocyanine molecules is 20 - 50 nm.

[0010] Further, in the composite material, the mass ratio of the iron phthalocyanine molecules to the carbon nanospheres is 1:(15 ± 0.1).

[0011] Based on the same inventive concept, the present invention provides an application of a carbon sphere composite material loaded with macrocyclic conjugated molecules in the detection of bisphenol A.

[0012] Based on the same inventive concept, the present invention provides an electrochemical sensor for detecting bisphenol A, and the electrochemical sensor contains the above carbon sphere composite material loaded with macrocyclic conjugated molecules.

[0013] Based on the same inventive concept, the present invention provides a preparation method of a carbon sphere composite material loaded with macrocyclic conjugated molecules, and the preparation method includes:

[0014] Disperse iron phthalocyanine molecules into N,N-dimethylformamide to obtain an iron phthalocyanine dispersion;

[0015] Add a carbon nanosphere dispersion to the iron phthalocyanine dispersion to obtain a mixed solution;

[0016] Stir the mixed solution, then perform solid-liquid separation, and wash the obtained solid to obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules.

[0017] Further, in the mixed solution, the mass ratio of the iron phthalocyanine molecules to the carbon nanospheres is 1:(15±0.1);

[0018] In the mixed solution, the concentration of the iron phthalocyanine molecules is 116.6 μmol / kg.

[0019] Further, the carbon nanospheres in the carbon nanosphere dispersion are prepared by the following method:

[0020] Disperse cetyltrimethylammonium bromide and sugar in water together to obtain a suspension;

[0021] The suspension is subjected to a hydrothermal reaction at 180±0.5 °C, and then cooled to obtain a reaction solution;

[0022] Perform solid-liquid separation on the reaction solution, and wash and dry the obtained solid to obtain a carbon nanosphere precursor;

[0023] Calcine the carbon nanosphere precursor in an inert atmosphere to obtain carbon nanospheres.

[0024] Further, the calcination temperature of the carbon nanosphere precursor is 800±50 °C, the calcination time is 60±1 min, and the heating rate is 10±1 °C / min.

[0025] Further, the stirring of the mixed solution, then the solid-liquid separation, and the washing of the obtained solid to obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules specifically includes:

[0026] Stir the mixed solution to uniformly modify the iron phthalocyanine molecules on the surface of the carbon nanospheres, and then perform solid-liquid separation. The obtained solid is washed successively with N-N dimethylformamide, deionized water, and ethanol to obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules.

[0027] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0028] 1. For the carbon sphere composite material loaded with macrocyclic conjugated molecules in the present invention, a low-cost carbon nanosphere (CSs) is used as a conductive carbon carrier, and the macrocyclic conjugated molecule iron phthalocyanine (FePc) is loaded on the surface of the carbon spheres to prepare an FePc / CSs nanocomposite material as a high-performance catalyst. The iron phthalocyanine molecules are uniformly dispersed on the surface of the CSs carrier through a π-π electron conjugation system, and no obvious aggregation occurs between the molecules. Through characterization and testing, it is found that the composite material FePc / CSs significantly improves the detection performance of the sensor for bisphenol A. The detection sensitivity of FePc / CSs to bisphenol A can reach 0.527 μA μM -1 , and the detection limit is as low as 0.031 μM, which is mainly attributed to the high catalytic activity of iron phthalocyanine and the conductivity of the carbon sphere carrier.

[0029] 2. For the electrochemical sensor for detecting bisphenol A in the present invention, a novel electrochemical sensor for detecting bisphenol A in microplastics based on the FePc / CSs nanocomposite material. Due to the highly exposed iron active centers on the surface of the CSs, the sensor exhibits excellent conductivity and electrocatalytic activity. The sensor shows a repeatable and stable response within 10 days, can ignore the interference of ordinary organic species, has good specificity. After the iron phthalocyanine molecules are combined with the carbon sphere carrier, they show higher stability, accelerate electron transfer, enhance electron conductivity, and improve electrochemistry activity. The sensor has a wide linear range, good reproducibility, stability, and selectivity. The sensor constructed with the FePc / CSs nanocomposite material has been successfully applied to the detection of bisphenol A in actual plastic products and environmental samples, effectively solving the problem that the electrochemical sensor has always had a relatively low sensitivity to bisphenol A.

[0030] 3. The preparation method of a carbon sphere composite material loaded with macrocyclic conjugated molecules according to the present invention is to fully dissolve iron phthalocyanine molecules in an N-N dimethylformamide (DMF) solution, add an appropriate amount of carbon nanospheres and stir vigorously, so that the iron phthalocyanine molecules are effectively modified on the surface of the carbon nanospheres, forming a highly efficient and stable carbon-supported composite material. This composite material has good catalytic activity, excellent electrical conductivity, and strong ability to adsorb bisphenol A (BPA). The electrochemical sensor constructed with this composite material can achieve specific recognition of bisphenol A, can rapidly detect bisphenol A in a low concentration range, has a low detection limit, good linear sensitivity, and high stability, and is applicable to fields such as water quality monitoring, food safety detection, and environmental pollutant monitoring, providing a simple and efficient detection path for bisphenol A.

[0031] 4. The preparation method of a carbon sphere composite material loaded with macrocyclic conjugated molecules according to the present invention is that CSs can still maintain the uniform spheres formed before calcination after high-temperature calcination. The diameter of the CSs spheres after calcination can be maintained at 600-800 nm. Uniform dispersion of them can increase the adsorption specific surface area. The active centers of iron phthalocyanine molecules are clear and the structure is adjustable. After being highly dispersed, they are anchored on the surface of the CSs carrier, highly improving the catalytic activity. The prepared carbon sphere composite material has a great improvement on the sensitivity of the sensor, and the required raw materials are relatively cheap and easy to obtain, the preparation cost is low, the product is easy to promote, effectively reducing the detection cost of bisphenol A and improving the detection efficiency. Brief Description of the Drawings

[0032] 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 description in the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0033] Figure 1 Scanning electron microscope pictures of the carbon nanosphere carrier before and after calcination obtained in Example 1 of the present invention: among them, (a) is the scanning electron microscope picture of the carbon nanosphere carrier before calcination; (b) is the scanning electron microscope picture of the carbon nanosphere carrier after calcination.

[0034] Figure 2 Scanning electron microscope pictures of the surface of the carbon nanosphere carrier loaded with the macrocyclic conjugated molecule iron phthalocyanine before and after in Example 2 of the present invention: among them, (a) is the scanning electron microscope picture of the surface of the carbon nanosphere carrier before loading the iron phthalocyanine molecule; (b) is the scanning electron microscope picture of the surface of the carbon nanosphere carrier after loading the iron phthalocyanine molecule.

[0035] Figure 3The aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images of the surface of the carbon nanosphere carrier loaded with the macrocyclic conjugated molecule iron phthalocyanine obtained in Example 2 of the present invention: Among them, (a) is the spherical aberration electron microscopy image of the surface of the carbon nanosphere carrier loaded with the iron phthalocyanine molecule; (b) is the elemental mapping diagram of the surface of the carbon nanosphere carrier loaded with the iron phthalocyanine molecule.

[0036] Figure 4 The X-ray photoelectron spectroscopy analysis diagrams before and after the surface of the carbon nanosphere carrier loaded with the iron phthalocyanine molecule obtained in Example 2 of the present invention.

[0037] Figure 5 The X-ray powder diffraction diagrams of the carbon nanosphere carrier obtained in Example 2 of the present invention and the surface of the carbon nanosphere carrier loaded with the iron phthalocyanine molecule before and after.

[0038] Figure 6 The linear test diagram of different concentrations of bisphenol A and the columnar comparison diagram of sensitivity and detection limit when constructing an electrochemical sensor with the carbon sphere composite material loaded with the macrocyclic conjugated molecule obtained in Example 2 of the present invention: Among them, (a) is the linear test diagram of different concentrations of bisphenol A when constructing an electrochemical sensor with the obtained FePc / CSs composite material, and the inset is the linear relationship diagram between different concentrations and current obtained by analysis and calculation; (b) is the comparison diagram of the detection sensitivity (red) and detection limit (gray) of bisphenol A when constructing an electrochemical sensor before and after the surface of the carbon nanosphere carrier alone and the carbon nanosphere carrier loaded with the iron phthalocyanine molecule.

[0039] Figure 7 The stability diagram of a certain concentration of bisphenol A when constructing an electrochemical sensor with the carbon sphere composite material loaded with the macrocyclic conjugated molecule obtained in Example 2 of the present invention: Among them, (a) is the multiple-cycle current response curve of 10 μM bisphenol A when constructing an electrochemical sensor with the FePc / CSs composite material; (b) is the current response curve of 10 μM bisphenol A tested after 5 days and 10 days of placement when constructing an electrochemical sensor with the FePc / CSs composite material.

[0040] Figure 8 The X-ray powder diffraction diagram of iron phthalocyanine and the iron phthalocyanine-loaded graphene composite material.

[0041] Figure 9 The electrochemical response diagram of the iron phthalocyanine-loaded graphene composite material detecting different concentrations of bisphenol A. Detailed implementation manners

[0042] The following will specifically describe the present invention in combination with the detailed implementation manners and examples, and the advantages and various effects of the present invention will be presented more clearly therefrom. Those skilled in the art should understand that these detailed implementation manners and examples are used to illustrate the present invention, rather than limiting the present invention.

[0043] Throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as having the meanings as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which the present invention pertains. In case of any contradiction, this specification shall prevail.

[0044] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0045] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.

[0046] The overall idea of the present invention is as follows:

[0047] Carbon-based materials, especially carbon nanomaterials, are widely used in the field of environmental pollutant detection due to their excellent electrochemical properties, good electrical conductivity, stability, and high specific surface area. As a metal-organic material with significant catalytic activity, iron phthalocyanine (FePc) has the characteristics of clear active centers and adjustable structures compared with other commonly used materials. This enables them to successfully change their interaction characteristics after being compounded with other materials and exhibit unique advantages in electrochemical sensing. However, FePc molecules are prone to aggregation, which hinders the maximum utilization of metal active centers. Therefore, the inventors compound FePc with carbon nanomaterials, hoping to improve the stability and sensitivity of the materials and provide a new idea for the rapid detection of bisphenol A.

[0048] A carbon sphere composite material loaded with macrocyclic conjugated molecules according to the present invention, wherein the composite material comprises iron phthalocyanine molecules and carbon nanospheres, and the iron phthalocyanine molecules are uniformly modified on the surface of the carbon nanospheres.

[0049] Further, the particle size of the carbon nanospheres is 600 - 800 nm;

[0050] The linear dimension of the iron phthalocyanine molecules is 20 - 50 nm.

[0051] In the present invention, the particle size of the carbon nanospheres is 600 - 800 nm. This particle size range can provide more reaction sites, which is beneficial to improving the activity and efficiency of the catalytic reaction, enabling the carbon nanospheres to maintain good electrical conductivity in the electrochemical reaction, promoting the rapid transfer of electrons, and helping to improve the sensitivity of the electrochemical sensor. The carbon nanospheres with a larger particle size have better structural stability, can maintain a longer service life and a stronger ability to resist external environmental interference, and are easy to load other catalysts or molecules. The linear dimension of the iron phthalocyanine molecule being 20 - 50 nm is beneficial in that it can provide more active sites, promote the occurrence of the catalytic reaction, and improve the catalytic efficiency. The size of 20 - 50 nm enables the iron phthalocyanine molecule to interact more effectively with the surface of the carbon nanospheres, enhancing the stability and loading capacity of the catalyst. The smaller linear dimension allows the iron phthalocyanine molecules to be evenly dispersed on the surface of the carrier, avoiding agglomeration, thereby enhancing the performance and service life of the catalyst.

[0052] Further, in the composite material, the mass ratio of the iron phthalocyanine molecule to the carbon nanospheres is 1:(15 ± 0.1).

[0053] In the present invention, the advantage of the mass ratio of the iron phthalocyanine molecule to the carbon nanospheres being 1:(15 ± 0.1) is that the role of the carbon nanospheres as a carrier is more prominent, and it can provide a sufficient surface area to help evenly load more iron phthalocyanine molecules. The appropriate ratio ensures the synergistic effect of the two, thereby improving the catalytic efficiency. In terms of improving conductivity, the higher proportion of carbon nanospheres provides a better conductive network, which helps the rapid transmission of electrons in the catalytic reaction, thus enhancing the conductivity performance of the entire composite material in the electrochemical reaction. In terms of reducing costs and enhancing operability, by increasing the proportion of carbon nanospheres, the cost of the catalyst can be reduced, which is of great significance for the recycling and economy of the catalyst in practical applications. The mass ratio of 1:15 can ensure that the interaction between the carbon nanospheres and the iron phthalocyanine molecules remains within an optimal range, which can not only give full play to the catalytic role of the iron phthalocyanine molecules but also prevent the surface of the carrier from being oversaturated due to excessive iron phthalocyanine, affecting the overall performance of the catalyst.

[0054] In the present invention, the principle of the FePc / CSs composite material for detecting the content of bisphenol A is that bisphenol A molecules lose electrons through an oxidation reaction on the electrode surface to form oxidation products (such as quinone substances of phenolic compounds). The catalytic action of FePc and the action of the carbon nanospheres are both beneficial to the oxidation of bisphenol A. The iron phthalocyanine molecules accelerate the oxidation reaction of bisphenol A and improve the current response. The carbon nanospheres provide good electrical conductivity and enhance the electron transfer efficiency, thereby promoting the oxidation process of bisphenol A.

[0055] A preparation method of a carbon sphere composite material loaded with macrocyclic conjugated molecules, the preparation method comprising:

[0056] Disperse iron phthalocyanine molecules into N,N-dimethylformamide to obtain an iron phthalocyanine dispersion;

[0057] Add a carbon nanosphere dispersion to the iron phthalocyanine dispersion to obtain a mixture;

[0058] Stir the mixture, then perform solid-liquid separation, and wash the obtained solid to obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules.

[0059] Further, in the mixture, the mass ratio of the iron phthalocyanine molecules to the carbon nanospheres is 1:(15±0.1);

[0060] In the mixture, the concentration of the iron phthalocyanine molecules is 116.6 μmol / kg.

[0061] Further, the carbon nanospheres in the carbon nanosphere dispersion are prepared by the following method:

[0062] Disperse cetyltrimethylammonium bromide and sugar together in water to obtain a suspension;

[0063] The suspension is subjected to a hydrothermal reaction at 180±0.5 °C, and then cooled to obtain a reaction solution;

[0064] Perform solid-liquid separation on the reaction solution, and wash and dry the obtained solid to obtain a carbon nanosphere precursor;

[0065] Calcine the carbon nanosphere precursor in an inert atmosphere to obtain carbon nanospheres.

[0066] Traditional methods for preparing carbon nanospheres may be difficult to precisely control the particle size distribution of carbon nanospheres, resulting in unstable certain properties. The present invention may adopt a more refined particle size control technique, such as adjusting the concentration of the reaction precursor and adding specific surfactants during the synthesis process, and using the green and environmentally friendly hydrothermal method to precisely control the particle size of carbon nanospheres. The effect is to reduce the energy consumption during the synthesis process, reduce the impact on the environment, and make the preparation process more green and environmentally friendly. The mild reaction conditions help to maintain the excellent structure of carbon nanospheres, reduce the equipment investment and operating costs, and have good prospects for industrial promotion. Precise control of the particle size helps to increase the specific surface area and reaction activity of carbon nanospheres, and optimize their performance in various applications. A more uniform particle size distribution can reduce the agglomeration phenomenon of the material and enhance its dispersibility and stability in the composite material.

[0067] Further, the calcination temperature of the carbon nanosphere precursor is 800±50 °C, the calcination time is 60±1 min, and the heating rate is 10±1 °C / min.

[0068] In the present invention, the calcination temperature of the carbon nanosphere precursor is 800 ± 50 °C, which can effectively promote the complete decomposition and carbonization of the organic matter in the precursor, generating carbon nanospheres with high purity. This temperature can ensure that the precursor is transformed into a carbon material with a high carbon content, effectively balancing the completeness of the carbonization reaction, the morphology control of the nanospheres, and thus enhancing the specific surface area. The carbon nanospheres generated at this temperature usually have good thermal stability, can adapt to higher temperatures and complex application environments, and improve their stability during long-term use. Excessive carbonization reactions at too high a calcination temperature may lead to unstable structures on the surface or inside of the carbon nanospheres, even causing agglomeration or defects, affecting their overall performance and application effects. However, if the calcination temperature is too low, the organic matter in the precursor may not be completely decomposed, resulting in low purity of the carbon nanospheres, with many impurities or residues, affecting their electrochemical and catalytic properties.

[0069] Next, a carbon sphere composite material loaded with macrocyclic conjugated molecules, a preparation method, and an application thereof according to the present invention will be described in detail with reference to examples and experimental data.

[0070] Example 1

[0071] This example provides a preparation of a carbon nanosphere carrier, and the preparation process is as follows:

[0072] (1) Disperse 5.95 g of glucose monohydrate and 0.18 g of cetyltrimethylammonium bromide in deionized water, and stir well for 4 h under a water bath condition of 50 °C to obtain a homogeneous solution; then, transfer the mixed suspension into a 50 mL stainless steel autoclave lined with Teflon, and place it in a forced-air drying oven at 180 °C for 5 h; after cooling to room temperature, collect the dark brown precipitate, transfer the solid-liquid mixture into a centrifuge tube and centrifuge at a speed of 8000 rpm. The obtained precipitate is washed alternately with ethanol and deionized water for multiple times until the supernatant is colorless and transparent, and then placed in a vacuum drying oven at 60 °C for drying overnight to finally obtain a carbon nanosphere precursor, that is, a carbonaceous nanosphere.

[0073] (2) Calcinate the above-obtained product under a nitrogen atmosphere, control the calcination temperature at 800 °C, the heating rate at 10 °C / min, calcinate for 30 min, and after cooling to room temperature, obtain a black carbon nanosphere carrier.

[0074] The carbon nanosphere carrier prepared in Example 1 was subjected to scanning electron microscopy detection before and after calcination, and the results are as Figure 1 shown: Refer to Figure 1 (a) shows the carbonaceous nanospheres before calcination. It can be seen that their morphology is spherical with uniform size, smooth surface, and the particle size is about 900 nm. Refer to Figure 1 (b) shows the carbon nanosphere carrier. It can be seen that the particle size is reduced to about 800 nm, and the surface is relatively rough.

[0075] Example 2

[0076] This example provides a method for preparing a carbon sphere composite material loaded with macrocyclic conjugated molecules, and the preparation process is as follows:

[0077] (1) Add 30 mg of the carbon nanosphere carrier prepared in Example 1 to 20 mL of deionized water solution, ultrasonicate for 30 min, and stir at room temperature for 30 min to obtain a uniform carbon nanosphere carrier dispersion, denoted as Solution A. Add 2 mg of iron phthalocyanine molecules to 10 mL of N,N-dimethylformamide solution, ultrasonicate for 30 min, and stir at room temperature for 30 min to obtain a uniform iron phthalocyanine molecule dispersion, denoted as Solution B.

[0078] (2) Mix the above-prepared Solutions A and B to obtain a mixed solution, vigorously stir at room temperature for 12 h, and collect the well-mixed reaction solution. Transfer the reaction solution into a centrifuge tube and centrifuge at a speed of 8000 rpm. Wash the obtained precipitate with N,N-dimethylformamide to remove the iron phthalocyanine molecules not adsorbed on the surface of the carbon spheres until the supernatant is clear, colorless, and transparent. Then wash it once with deionized water and ethanol respectively, dry it at 60 °C under vacuum, and collect the precipitate to finally obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules.

[0079] Comparative Example 1

[0080] This example provides a method for preparing a graphene composite material loaded with macrocyclic conjugated molecules, and the preparation process is as follows:

[0081] (1) Add 30 mg of graphene to 20 mL of deionized water solution, ultrasonicate for 30 min, and stir at room temperature for 30 min to obtain a uniform graphene dispersion, denoted as Solution A. Add 2 mg of iron phthalocyanine molecules to 10 mL of N,N-dimethylformamide solution, ultrasonicate for 30 min, and stir at room temperature for 30 min to obtain a uniform iron phthalocyanine molecule dispersion, denoted as Solution B.

[0082] (2) Mix the above-prepared Solutions A and B to obtain a mixed solution, vigorously stir at room temperature for 12 h, and collect the well-mixed reaction solution. Transfer the reaction solution into a centrifuge tube and centrifuge at a speed of 8000 rpm. Wash the obtained precipitate with N,N-dimethylformamide to remove the iron phthalocyanine molecules not adsorbed on the surface of the graphene until the supernatant is clear, colorless, and transparent. Then wash it once with deionized water and ethanol respectively, dry it at 60 °C under vacuum, and collect the precipitate to finally obtain a graphene composite material loaded with macrocyclic conjugated molecules.

[0083] Perform scanning electron microscopy (SEM) detection on the iron phthalocyanine molecule-loaded carbon sphere carrier before and after the preparation in Example 2, and the results are as Figure 2Shown: Scanning electron microscope images of iron phthalocyanine molecules before and after loading on carbon sphere carriers, where Figure 2 (a) Morphological characteristics of iron phthalocyanine molecules before loading on carbon sphere carrier, refer to Figure 2 (a) It can be seen that before the phthalocyanine iron molecules are loaded on the carbon ball carrier, serious aggregation occurs between the phthalocyanine iron molecules, and the morphology presents an irregular block structure. Figure 2 (b) is the morphological characteristics of the iron phthalocyanine molecules after loading the carbon ball carrier. Referring to the attached figure, it can be seen that after the iron phthalocyanine molecules and the carbon ball carrier are combined, the morphology and size do not change significantly compared with the carbon ball, and they still present a uniform sphere. In addition, the morphology of the iron phthalocyanine molecules is not observed on the surface of the carbon ball carrier, and there is no aggregation of the iron phthalocyanine molecules, which proves that the iron phthalocyanine molecules are uniformly dispersed and loaded on the surface of the carbon ball carrier.

[0084] The carbon sphere composite material loaded with macrocyclic conjugated molecules prepared in Example 2 was analyzed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy. Figure 3 Shown: Spherical aberration electron microscope image of carbon sphere composite material loaded with macrocyclic conjugated molecules, where Figure 3 (a) is a high-angle annular dark-field scanning transmission electron microscopy image of a carbon sphere composite material loaded with macrocyclic conjugated molecules after aberration correction, referring to Figure 3 (a) It can be clearly observed that there are obvious single bright spots in the carbon sphere composites loaded with macrocyclic conjugated molecules, which represent that the relatively heavy transition metal atoms are evenly dispersed on the lighter carbon matrix, proving that the Fe-N 4 The iron phthalocyanine molecules with the structure are evenly dispersed on the surface of the carbon spheres. Figure 3 (b) is the elemental mapping diagram of the surface of carbon nanosphere carrier after phthalocyanine iron molecules are loaded. Figure 3 (b) It can be seen that C, N, and Fe elements are evenly distributed on the surface of the carbon ball carrier, indicating that the iron phthalocyanine molecules are well loaded on the surface of the carbon ball and no molecular aggregation occurs.

[0085] The carbon sphere composite material loaded with macrocyclic conjugated molecules prepared in Example 2 was subjected to X-ray photoelectron spectroscopy analysis. Figure 4 This is an X-ray photoelectron spectrum analysis diagram of carbon sphere composite materials loaded with macrocyclic conjugated molecules, refer to Figure 4 It can be seen that after comparing with the X-ray photoelectron spectroscopy analysis diagram of iron phthalocyanine molecules, it is found that the X-ray photoelectron spectroscopy analysis diagram of iron phthalocyanine-loaded carbon spheres is composed of not only C, N and O atoms, but also Fe atoms. It can be clearly seen that the obtained product is an iron phthalocyanine-loaded carbon sphere composite material.

[0086] The carbon sphere composite material loaded with macrocyclic conjugated molecules prepared in Example 2 was subjected to X-ray single crystal powder diffraction. Figure 5 The X-ray single crystal powder diffraction pattern of the carbon sphere composite material loaded with macrocyclic conjugated molecules prepared in Example 2 is shown in FIG. Figure 5It can be seen that the characteristic diffraction peaks of the carbon spheres are located at 24.2° and 42.8°, corresponding to the (002) and (100) crystal planes respectively. The positions and intensities of the diffraction peaks of the obtained composite material are in agreement with those of the characteristic diffraction peaks of the carbon spheres, indicating that the obtained product is the carbon sphere composite material loaded with iron phthalocyanine molecules. After comparison with the characteristic diffraction peaks of iron phthalocyanine molecules, it is found that no diffraction peaks related to iron phthalocyanine molecules appear in the diffraction peaks of the composite material, indicating that the iron phthalocyanine molecules are evenly distributed on the surface of the carbon spheres and no aggregation occurs.

[0087] Performance Test

[0088] The carbon nanosphere carriers and the carbon sphere composite materials loaded with macrocyclic conjugated molecules obtained in Example 1 and Example 2 were respectively dispersed in ethanol and modified on the surface of a glassy carbon electrode. Before modification, the glassy carbon electrode (GCE, with a diameter of 3 mm) was polished successively with alumina powders of 1.0, 0.3, and 0.05 μm sizes. After polishing at each stage, it was ultrasonically treated in deionized water for 1 min. Then, the polished electrode was characterized by cyclic voltammetry in a ferricyanide solution of a certain concentration until a quasi-reversible redox reaction occurred. The alcohol suspensions containing the carbon nanosphere carriers and the FePc / CSs composite materials were dropped onto the pretreated glassy carbon electrode, and the electrochemical sensor devices modified with different nanomaterials were obtained after the materials dried.

[0089] The device was subjected to an electrochemical test for detecting bisphenol A. At room temperature, different concentrations of bisphenol A were added to the electrolyte for current response testing, and the results are as Figure 6 and Figure 7 shown:

[0090] Differential pulse voltammetry technology was used to study the electrochemical response of the FePc / CSs composite material modified electrode to different concentrations of bisphenol A, and the detection performances of the carbon spheres and iron phthalocyanine molecules were compared. Figure 6 (a) is the linear test graph of different concentrations of bisphenol A when constructing an electrochemical sensor with the FePc / CSs composite material. The inset is the linear relationship graph between different concentrations and current obtained by analysis and calculation; referring to Figure 6 (a), the current test curve of the FePc / CSs composite material in the range of 0 - 30 μΜ bisphenol A is shown, where the inset is the linear calibration curve. Obviously, as the concentration of bisphenol A increases, the peak current gradually increases. There are two different linear relationships in the overall test concentration range. In the low concentration range, bisphenol A on the surface of the FePc / CSs composite material modified electrode is rapidly reduced and undergoes an oxidation reaction (the hydroxyl group of bisphenol A loses hydrogen ions and electrons to undergo an oxidation reaction, and this reaction is reversible and immediately undergoes a reduction reaction), showing high sensitivity. Figure 6(b) is a comparison chart of the detection sensitivity and detection limit of bisphenol A when constructing an electrochemical sensor before and after the surface of a single carbon sphere carrier and a carbon nanosphere carrier loaded with iron phthalocyanine molecules. Refer to Figure 6 (b), it can be seen that the FePc / CSs composite material obtained in Example 2 has the highest sensitivity and the lowest detection limit for bisphenol A, indicating that the sensitivity is effectively improved after the carbon sphere carrier is combined with iron phthalocyanine molecules. This is mainly due to the sufficient combination of iron phthalocyanine molecules and carbon spheres, which increases the disordered structure on the surface of the carbon spheres and exposes more active sites.

[0091] Figure 7 This is the analysis of the reproducibility and stability of a certain concentration of bisphenol A when constructing an electrochemical sensor with the FePc / CSs composite material obtained in Example 2 of the present invention. Figure 7 (a) is the multiple cyclic current response curve of 10 μM bisphenol A when constructing an electrochemical sensor with the FePc / CSs composite material. The repeatability of the iron phthalocyanine-loaded carbon sphere composite material is evaluated by continuously measuring 12 times at a certain concentration. The inset corresponds to its current response curve for 10 μM bisphenol A. Refer to Figure 7 (a), it can be seen that after continuously measuring 12 times, the peak current of 10 μM bisphenol A does not change significantly, indicating that the iron phthalocyanine molecule-loaded carbon sphere composite material has good reproducibility. Figure 7 (b) is the current response curve of 10 μM bisphenol A measured after 5 days and 10 days of placement when constructing an electrochemical sensor with the FePc / CSs composite material. Refer to Figure 7 (b), it can be seen that the storage stability of the FePc / CSs composite material when constructing an electrochemical sensor is studied by measuring the current response curve once every 5 days. The results show that the current response of the FePc / CSs composite material to 10 μM bisphenol A does not change significantly after 5 days and 10 days, and the change in the current response compared with the initial value is small, indicating that the FePc / CSs composite material has good stability.

[0092] The graphene composite material loaded with macrocyclic conjugated molecules prepared in Comparative Example 1 was subjected to X-ray single crystal powder diffraction, and the results are as Figure 8 . Figure 8 is the X-ray single crystal powder diffraction pattern of iron phthalocyanine and iron phthalocyanine / graphene. Refer to Figure 8 it can be seen that the characteristic diffraction peaks of graphene are located at 25.2° and 43.5°, corresponding to the (002) and (200) crystal planes respectively. The positions of the diffraction peaks of the obtained composite material coincide with the characteristic diffraction peaks of graphene, but the intensity is slightly weaker. It is considered that there may be a layer of iron phthalocyanine molecules on the surface. No diffraction peaks related to iron phthalocyanine molecules appear in the diffraction peaks of the iron phthalocyanine / graphene composite material.

[0093] The iron phthalocyanine / graphene composite material prepared in Comparative Example 1 was dispersed in ethanol and then modified on the surface of a glassy carbon electrode (the same method as above). The obtained electrochemical sensor device was used for the electrochemical detection of bisphenol A. Under room temperature conditions, different concentrations of bisphenol A were added to the electrolyte for the current response test. The results are shown in Figure 9:

[0094] Figure 9 To study the electrochemical response of the iron phthalocyanine / graphene composite modified electrode to different concentrations of bisphenol A using differential pulse voltammetry technology. During the test, the test conditions were kept the same as those in Figure 7 completely. Referring to Figure 9 it can be seen that when the iron phthalocyanine / graphene composite material was used to detect different concentrations of bisphenol A, its current response was negligible. This indicates that: when the iron phthalocyanine / graphene composite material was used to detect bisphenol A, the adsorption ability of bisphenol A molecules on the electrode surface was low, or its electrochemical activity was not sufficient to cause obvious current changes. The sensing performance of the composite material for bisphenol A was poor, and it could not effectively react with bisphenol A or promote current changes. The iron phthalocyanine / graphene composite material may have poor recognition and selectivity for bisphenol A, resulting in no significant current response even when the concentration of bisphenol A changed. The molecular structure of bisphenol A may not match the surface characteristics of the composite material, resulting in an inactive electrochemical reaction mechanism and unable to significantly change the current.

[0095] Example 3

[0096] This sensor (the electrochemical sensor device prepared from the carbon sphere composite material loaded with macrocyclic conjugated molecules obtained in Example 2) was applied to the detection of bisphenol A in actual water samples (river water and tap water), supermarket receipts, and plastic water bottles.

[0097] The river water sample was taken from Chaohu Lake in Hefei, Anhui Province, China, and insoluble substances were removed by simple filtration. The tap water sample was obtained from the laboratory and used directly without further treatment. The supermarket receipts and mineral water bottles were pre-washed, dried, and cut into small pieces. 1 g of plastic water bottle or supermarket receipt was soaked in a flask containing 100 mL of deionized water, soaked at 70 °C for 60 minutes, and cooled to room temperature. The water samples were collected by filtration, and the practical application performance of the sensor was evaluated by the standard addition method. As shown in Table 1, the recovery rate of this sensor for BPA (when electrochemically detecting pollutants, the "recovery rate" refers to the ratio between the determination result obtained by electrochemically detecting pollutants in the actual sample and the known added amount (or standard sample). The recovery rate reflects the detection ability and accuracy of the electrochemical detection method for the target pollutant in the actual sample. However, due to the complexity of the sample matrix, the actual recovery rate may fluctuate) was 98.0 - 106.5%, and the relative standard deviation (RSD) was 1.72% - 4.96%.

[0098] Table 1 Recovery rates of BPA in actual samples determined by FePc / CSs GCE (n = 3).

[0099]

[0100]

[0101] Finally, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0102] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0103] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A carbon sphere composite material loaded with macrocyclic conjugated molecules, characterized in that: The composite material comprises iron phthalocyanine molecules and carbon nanospheres, and the iron phthalocyanine molecules are uniformly modified on the surface of the carbon nanospheres.

2. The carbon sphere composite material loaded with macrocyclic conjugated molecules according to claim 1, characterized in that: The particle size of the carbon nanospheres is 600-800 nm; The linear dimension of the iron phthalocyanine molecule is 20 to 50 nm.

3. The carbon sphere composite material loaded with macrocyclic conjugated molecules according to claim 1, characterized in that: In the composite material, the mass ratio of the iron phthalocyanine molecules to the carbon nanospheres is 1:(15±0.1).

4. Use of a carbon sphere composite material loaded with macrocyclic conjugated molecules as claimed in any one of claims 1 to 3 in the detection of bisphenol A.

5. An electrochemical sensor for detecting bisphenol A, characterized in that: The electrochemical sensor contains a carbon sphere composite material loaded with macrocyclic conjugated molecules according to any one of claims 1 to 3.

6. A method for preparing a carbon sphere composite material loaded with macrocyclic conjugated molecules according to any one of claims 1 to 3, characterized in that: The preparation method comprises: Dispersing iron phthalocyanine molecules in NN dimethylformamide to obtain an iron phthalocyanine dispersion; Adding the carbon nanosphere dispersion to the iron phthalocyanine dispersion to obtain a mixed solution; The mixed liquid is stirred, and then solid-liquid separation is performed, and the obtained solid is washed to obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules.

7. The method for preparing a carbon sphere composite material loaded with macrocyclic conjugated molecules according to claim 6, characterized in that: In the mixed solution, the mass ratio of the iron phthalocyanine molecules to the carbon nanospheres is 1:(15±0.1); In the mixed solution, the concentration of the iron phthalocyanine molecules is 116.6 μmol / kg.

8. The method for preparing a carbon sphere composite material loaded with macrocyclic conjugated molecules according to claim 6, characterized in that: The carbon nanospheres in the carbon nanosphere dispersion are prepared by the following method: dispersing cetyltrimethylammonium bromide and sugar in water to obtain a suspension; The suspension is subjected to a hydrothermal reaction at 180±0.5° C., and then cooled to obtain a reaction solution; The reaction liquid is subjected to solid-liquid separation, and the obtained solid is washed and dried to obtain a carbon nanosphere precursor; The carbon nanosphere precursor is calcined under an inert atmosphere to obtain carbon nanospheres.

9. The method for preparing a carbon sphere composite material loaded with macrocyclic conjugated molecules according to claim 8, characterized in that: The calcination temperature of the carbon nanosphere precursor is 800±50° C., the calcination time is 60±1 min, and the heating rate is 10±1° C. / min.

10. The method for preparing a carbon sphere composite material loaded with macrocyclic conjugated molecules according to claim 6, characterized in that: The mixed solution is stirred, and then solid-liquid separation is performed, and the obtained solid is washed to obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules, which specifically includes: The mixed solution is stirred to make the iron phthalocyanine molecules evenly modify the surface of the carbon nanospheres, and then solid-liquid separation is performed. The obtained solid is washed with N-N-dimethylformamide, deionized water and ethanol in sequence to obtain a carbon sphere composite material loaded with macrocyclic conjugated molecules.

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