A copper-based ternary chalcogenide semiconductor material, and a preparation method and application thereof

Abstract

This invention discloses a copper-based ternary chalcogenide semiconductor material, its preparation method, and its applications. The material is prepared by mixing CuSn(OH)6 nanomaterials, thioacetamide, ethylenediaminetetraacetic acid, and water and carrying out a hydrothermal reaction to obtain Cu3SnS4 nanomaterials. This semiconductor material exhibits excellent photoelectrochemical properties. Photoelectrochemical sensors constructed based on this material demonstrate high detection accuracy, fast response speed, low detection limit, and strong stability, enabling rapid and accurate real-time detection of microplastic content. The preparation method is simple, low-cost, and suitable for industrial production.

Description

Technical Field

[0001] This invention relates to a semiconductor material, specifically a copper-based ternary chalcogenide semiconductor material, as well as its preparation method and application, belonging to the fields of semiconductor materials and biosensor technology. Background Technology

[0002] Microplastics refer to plastic particles with a diameter of less than 5 millimeters. Over the past few decades, microplastics have reached the ocean via wind transport, marine activities, and path currents, and can also enter soil through airborne transport, air deposition, and irrigation. Microplastics can even be transferred to higher nutrient levels through the food chain, ultimately harming human health. As a new type of environmental pollutant, they have attracted worldwide research attention. Currently, the main methods for detecting microplastics include optical microscopy, electron microscopy, pyrolysis gas chromatography-mass spectrometry, thermal extraction-desorption gas chromatography-mass spectrometry, and differential scanning calorimetry. However, these methods suffer from drawbacks such as being time-consuming and labor-intensive, requiring expensive equipment, having low accuracy, and high detection limits. Therefore, developing new and more advantageous detection methods is imperative.

[0003] Photoelectrochemical biosensing is a novel detection method that combines photoelectrochemical analysis technology with biosensing technology. It not only integrates the advantages of optical and electrochemical methods but also offers higher sensitivity, lower background signal, simpler operation, and lower cost compared to traditional analytical techniques. Its detection principle is based on determining the concentration of the analyte by the photoelectric conversion characteristics of photoactive materials. Photoelectrochemical biosensing inherits the high sensitivity and unique bioaffinity between reacting molecules from photoelectrochemical analysis technology, thus possessing enormous potential applications in the detection of small molecules and biomolecules. Screening high-performance photoelectrochemical materials and combining them with efficient signal amplification strategies play a crucial role in improving the analytical performance of photoelectrochemical biosensors and achieving highly sensitive detection. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the first objective of this invention is to provide a copper-based ternary chalcogenide semiconductor material. This material exhibits a narrow band gap, high photosensitivity, good photoconductivity, good thermal stability, and low toxicity.

[0005] The second objective of this invention is to provide a method for preparing copper-based ternary chalcogenide semiconductor materials. This method is simple, low-cost, and suitable for industrial production.

[0006] A third objective of this invention is to provide an application of a copper-based ternary chalcogenide semiconductor material. The photoelectrochemical sensor employing this copper-based ternary chalcogenide semiconductor material features high detection accuracy, high sensitivity, and a wide detection range, enabling rapid and accurate real-time detection of microplastic content.

[0007] To achieve the above-mentioned technical objectives, the present invention provides a method for preparing copper-based ternary chalcogenide semiconductor materials. The method involves mixing CuSn(OH)6 nanomaterials, thioacetamide, ethylenediaminetetraacetic acid, and water and carrying out a hydrothermal reaction to obtain Cu3SnS4 nanomaterials.

[0008] This invention uses CuSn(OH)6 nanomaterials as a precursor, thioacetamide as a sulfur source, and ethylenediaminetetraacetic acid as a metal ion chelating agent. ethylenediaminetetraacetic acid can form a stable water-soluble complex with the metal. Cu3SnS4 nanomaterials are obtained by hydrothermal reaction of the above raw materials.

[0009] As a preferred embodiment, the molar ratio of the CuSn(OH)6 nanomaterial to thioacetamide and ethylenediaminetetraacetic acid is 1:1 to 8:1 to 6. The amounts of these three substances will affect the morphology, structure, and photoelectric properties of the material. Controlling their amounts within a suitable range can yield semiconductor materials with excellent performance. Insufficient CuSn(OH)6 will result in a low yield of Cu3SnS4, while excessive amounts will lead to resource waste and increased costs. Insufficient or excessive thioacetamide will prevent the formation of Cu3SnS4, instead producing other substances such as Cu2SnS3. Insufficient ethylenediaminetetraacetic acid will result in incomplete Cu3SnS4 formation, while excessive amounts will also lead to resource waste and increased costs.

[0010] As a preferred embodiment, the hydrothermal reaction conditions are: temperature of 150–200°C and time of 2–9 hours.

[0011] As a preferred embodiment, the CuSn(OH)6 nanomaterial is obtained by reacting tin chloride with an alkali and copper chloride sequentially. The reaction principle is as follows: SnCl4 + 6NaOH + CuCl2 → CuSn(OH)6↓ + 6NaCl.

[0012] As a preferred embodiment, the molar amount of the alkali is 6 to 6.5 times that of tin chloride.

[0013] As a preferred embodiment, the molar amount of copper chloride is 1 to 1.2 times that of tin chloride.

[0014] The present invention also provides a copper-based ternary chalcogenide semiconductor material, which is prepared by the above method.

[0015] This invention also provides an application of a copper-based ternary chalcogenide semiconductor material in a photoelectrochemical sensor.

[0016] As a preferred embodiment, the construction steps of the photoelectrochemical sensor are as follows:

[0017] 1) Disperse Cu3SnS4 nanomaterials in a dimethylformamide solution containing polyvinylidene fluoride to obtain a mixed solution containing Cu3SnS4 nanomaterials;

[0018] 2) A mixture containing Cu3SnS4 nanomaterials was dropped onto a glass surface containing indium tin oxide, and the working electrode was obtained after drying.

[0019] 3) Chitosan solution, glutaraldehyde solution, bovine serum albumin solution, and polystyrene microsphere solution are sequentially added dropwise to the working electrode.

[0020] As a preferred embodiment, the solid-liquid ratio of the Cu3SnS4 nanomaterial to the dimethylformamide solution containing polyvinylidene fluoride is 1.5–7.5 mg: 1 mL.

[0021] As a preferred embodiment, the chitosan solution has a mass concentration of 0.005 wt% to 0.05 wt%.

[0022] As a preferred embodiment, the mass concentration of the glutaraldehyde solution is 0.1 wt% to 5 wt%.

[0023] As a preferred embodiment, the bovine serum albumin solution has a mass-volume concentration of 10–500 μg / mL.

[0024] As a preferred embodiment, the mass ratio of the polystyrene microsphere solution is 0.5–500 μg / mL.

[0025] As a preferred embodiment, the volume ratio of the chitosan solution, glutaraldehyde solution, bovine serum albumin solution, and polystyrene microsphere solution is 1:1 to 2:1 to 3:1 to 5.

[0026] As a preferred embodiment, the photoelectrochemical sensor is used for microplastic detection.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The copper-based ternary chalcogenide semiconductor material prepared by this invention has a narrow band gap, high photosensitivity, good photoconductivity, good thermal stability, low toxicity, and excellent photoelectrochemical properties.

[0029] (2) The photoelectrochemical sensor based on the copper-based ternary chalcogenide semiconductor material of the present invention has high detection accuracy, fast response speed, low detection limit and strong stability, and can realize rapid and accurate real-time detection of microplastic content, providing a new way for efficient detection of microplastics;

[0030] (3) The material preparation method is simple and low in cost, making it suitable for large-scale industrial production. Attached Figure Description

[0031] Figure 1 The images show electron microscope (EM) images of CuSn(OH)6 nanorods and Cu3SnS4 nanoflowers prepared in Example 1. A–B are scanning electron microscope (SEM) images of CuSn(OH)6 nanorods; C–D are SEM and transmission electron microscope (TEM) images of Cu3SnS4 nanoflowers, respectively; E is a high-resolution TEM image of Cu3SnS4 nanoflowers; F is a selected area electron diffraction (SED) pattern of Cu3SnS4 nanoflowers; and G is an X-ray energy dispersive spectroscopy (EDS) analysis of Cu3SnS4 nanoflowers.

[0032] Figure 2 The images show scanning electron microscope (SEM) images of polystyrene microspheres of different particle sizes, as well as images of 100 nm polystyrene microspheres aggregated with bovine serum albumin. Image A is a scanning electron microscope image of 100 nm polystyrene microspheres aggregated with bovine serum albumin; images B through E are scanning electron microscope images of 50–60 nm, 100 nm, 140 nm, and 200 nm polystyrene microspheres, respectively.

[0033] Figure 3 The image shows the photoelectric response performance of the photoelectrochemical biosensor constructed based on the Cu3SnS4 nanoflower material prepared in Example 1. In the image, A represents the photocurrent response of the electrode during different modification processes, and B represents the electrochemical impedance spectroscopy of the electrode during different modification processes.

[0034] Figure 4 The fitted curves show the photoelectric detection performance and polystyrene microsphere concentration response of the photoelectrochemical biosensor constructed based on the Cu3SnS4 nanoflower material prepared in Example 1.

[0035] Figure 5 The graphs show the stability test results of the photoelectrochemical biosensor constructed based on the Cu3SnS4 nanoflower material prepared in Example 1. In the graphs, A represents the long-term stability test result of the modified electrode; B represents the long-term stability test result of the modified electrode; and C represents the repeatability test result of the modified electrode.

[0036] Figure 6 This image shows the real-time detection of microplastic concentration using a photoelectrochemical biosensor constructed based on the Cu3SnS4 nanoflower material prepared in Example 1. In the image, A represents the real-time detection result; B is a schematic diagram of the real-time detection device; and C represents the real-time detection photocurrent versus logC. PS Calibration curve (100nm). Detailed Implementation

[0037] The specific embodiments of the invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] (1) Preparation of CuSn(OH)6 nanorods

[0040] Step 1: Dissolve and disperse 5 mmol of tin chloride pentahydrate (SnCl4·5H2O) and 30 mmol of sodium hydroxide (NaOH) in 180 mL of deionized water, and label it as solution A.

[0041] Step 2: Dissolve and disperse 5 mmol of copper chloride monohydrate (CuCl2·H2O) in 100 mL of its deionized water, and label it as solution B.

[0042] Step 3: Pour solution B into solution A and stir vigorously for 15 minutes.

[0043] Step 4: Let the solution obtained in Step 3 stand for 6 hours.

[0044] Step 5: Pour off the supernatant to obtain a blue precipitate, and wash it with deionized water and anhydrous ethanol at 8000 rpm. Carefully remove the supernatant and dry the precipitate in a vacuum oven at 60°C to obtain CuSn(OH)6 nanorods.

[0045] (2) Preparation of Cu3SnS4 nanoflowers

[0046] Step 1: Dissolve and disperse 0.5 mmol of CuSn(OH)6, 2 mmol of thioacetamide and 1.5 mmol of ethylenediaminetetraacetic acid in 50 mL of deionized water and sonicate for 15 minutes.

[0047] Step 2: Pour the solution obtained in Step 1 into a 100mL Teflon reaction vessel and place it in a 150℃ drying oven for 9 hours.

[0048] Step 3: The black precipitate obtained from the reaction was washed with deionized water and anhydrous ethanol at 8000 rpm by centrifugation. The supernatant was carefully removed, and the precipitate was placed in a vacuum oven at 60°C overnight to obtain Cu3SnS4 nanoflower materials.

[0049] The CuSn(OH)6 nanorods and Cu3SnS4 nanoflower materials prepared in Example 1 were characterized and tested, such as... Figure 1 As shown. Figure 1Images A through B are scanning electron microscope (SEM) images of CuSn(OH)6. Figure 1 As seen in A to B, CuSn(OH)6 is hexagonal prism-shaped. Further hydrothermal treatment transforms the hexagonal prism-shaped CuSn(OH)6 into a sheet-like structure. This converts the clustered hexagonal prisms into clustered nanosheets, thus successfully forming a flower-like structure in Cu3SnS4. Figure 1 C). Furthermore, the morphology of Cu3SnS4 was further analyzed using transmission electron microscopy (TEM) and selected electron diffraction (SAED) pattern calibration. TEM images are shown below. Figure 1 As shown in Figure D, the morphology of Cu3SnS4 consists of many irregular lamellar structures, consistent with the SEM results. A 0.32 nm interplanar spacing (1E) is marked on the HRTEM image of Cu3SnS4, consistent with the characteristic interplanar spacing of 0.313 nm for the (112) plane of Cu3SnS4. The SAED image of Cu3SnS4 is shown below. Figure 1 As shown in Figure F, the interplanar spacing of Cu3SnS4 was calculated. The calculated values ​​of Cu3SnS4 are consistent with the standard values ​​of crystal planes (112), (220), and (132), and are also consistent with the XRD analysis results. Bright diffraction rings confirm the polycrystalline nature of the material. Figure 1 The EDS results in G showed that Cu, Sn, and S were present in the Cu3SnS4 composite material.

[0050] The Cu3SnS4 nanoflower material prepared in Example 1 was used in a photoelectrochemical sensor. The specific construction steps are as follows:

[0051] Step 1: Add 1 mg Cu3SnS4 to 1 mL of polyvinylidene fluoride / dimethylformamide (PVDF / DMF) solution and sonicate for 30 minutes to form a homogeneous mixture.

[0052] Step 2: Then, 300 μL of the mixture is dropped onto a glass surface coated with indium tin oxide (ITO) and dried in a vacuum oven at 60°C to form the working electrode of the photoelectrochemical detector.

[0053] Step 3: Take 100 μL each of 0.05 wt% chitosan (CS), 5 wt% glutaraldehyde (GA), 10 μg / mL bovine serum albumin (BSA), and 0.5-500 μg / mL polystyrene microspheres, and drop them layer by layer onto the electrode plate obtained in Step 2.

[0054] We used scanning electron microscopy (SEM) to demonstrate the successful binding of bovine serum albumin to microplastics (100 nm polystyrene microspheres). Figure 2 A) It exhibits a state of aggregation, while Figure 2Figure C shows polystyrene microspheres (100 nm) without bovine serum albumin (BSA) attachment; their surfaces are smooth and the particles are clearly defined. This phenomenon confirms that BSA and polystyrene microspheres undergo adsorption and aggregation. Figure 2 B, 2D, and 2E are morphology images of polystyrene microspheres at 50-60 nm, 140 nm, and 200 nm, respectively.

[0055] After preparing the Cu3SnS4 electrode plate, chitosan, glutaraldehyde, bovine serum albumin, and polystyrene microspheres were added dropwise layer by layer onto the Cu3SnS4 electrode plate. Figure 3 As shown in Figure A, the photocurrent of the electrode plate gradually decreases (when added to the bovine serum albumin layer), indicating that the sensor has been successfully constructed. However, the addition of polystyrene microspheres increases the photocurrent of the electrode plate. This is because the polystyrene microspheres form a protein crown with the bovine serum albumin and aggregate, causing the protein crown to detach from the electrode plate, thus increasing the photocurrent. Impedance diagram ( Figure 3 B) confirmed this change: the greater the impedance, the smaller the photocurrent.

[0056] like Figure 4 As shown in Figure A, 100 nm polystyrene microspheres of different concentrations were dropped onto an electrode plate. The concentrations of the polystyrene microspheres were 0.5 μg / mL, 1 μg / mL, 5 μg / mL, 10 μg / mL, 50 μg / mL, 100 μg / mL, and 500 μg / mL. As the concentration of polystyrene microspheres increased, the photocurrent of the electrode plate gradually increased, and the magnitude of the photocurrent showed a good linear relationship with the concentration of polystyrene microspheres. Figure 4 B) The photocurrent increases with increasing polyethylene microsphere concentration, and its regression equation is I(μA) = 3.698logC. PS The correlation coefficient was +9.271, the limit of detection was 0.989, and the detection limit was 0.29 μg / mL. The same test was performed using polystyrene microspheres of 50-60 nm, 140 nm, and 200 nm respectively, replacing the 100 nm polystyrene microspheres. Figure 4 As shown in C to 4E, where... Figure 4 The photocurrent of polystyrene microspheres with C of 50-60 nanometers and logC PS Linear fitting plot; Figure 4 The photocurrent of polystyrene microspheres with a wavelength of D of 140 nm and logC PS Linear fitting plot; Figure 4 The photocurrent of polystyrene microspheres with E = 200 nm and logC PSThe linear fitting plots all showed a good linear relationship between the concentration of polystyrene microspheres and the photocurrent, with detection limits of 1.14 μg / mL, 1.13 μg / mL, and 1.15 μg / mL, respectively, indicating that the method has a certain degree of universality in detecting microplastics.

[0057] The modified electrode underwent a 400-second stability test. Figure 5 As can be seen from A, the photocurrent of the modified electrode remains essentially constant, demonstrating good stability. Long-term stability tests were conducted on the same modified electrode, such as... Figure 5 As shown in Figure B, the decrease in photocurrent of the modified electrode on day 9 was still within an acceptable range. Six modified electrodes were tested, as shown... Figure 5 As shown in Figure C, the photocurrents of the six currents are not significantly different, with a relative standard deviation of 1.66%, indicating that the modified electrode has good repeatability.

[0058] Figure 6 B shows the real-time detection setup, which includes an electrochemical workstation, a lighting source, a three-electrode system, a digital multimeter, and a smartphone. During testing, the digital multimeter measures the photocurrent of the modified electrode and transmits the data to the smartphone via Bluetooth, enabling real-time monitoring of microplastics. The data received on the smartphone after real-time detection is as follows: Figure 6 As shown in Figure A, the photocurrent increases with increasing polystyrene microsphere concentration (0.5 μg / mL, 1 μg / mL, 5 μg / mL, and 50 μg / mL, respectively). Simultaneously, a good linear relationship is observed between the two, with a correlation coefficient of 0.978. Figure 6 C).

Claims

1. A method for detecting microplastics, characterized in that: Microplastics are detected using a photoelectrochemical sensor; the steps for constructing the photoelectrochemical sensor are as follows: 1) Disperse Cu3SnS4 nanomaterials in a dimethylformamide solution containing polyvinylidene fluoride to obtain a mixed solution containing Cu3SnS4 nanomaterials; 2) A mixture containing Cu3SnS4 nanomaterials was dropped onto a glass surface containing indium tin oxide, and the working electrode was obtained after drying. 3) Chitosan solution, glutaraldehyde solution, bovine serum albumin solution, and polystyrene microsphere solution are sequentially added dropwise to the working electrode; The preparation method of the Cu3SnS4 nanomaterial is as follows: CuSn(OH)6 nanomaterial, thioacetamide, ethylenediaminetetraacetic acid and water are mixed and subjected to hydrothermal reaction to obtain the nanomaterial. The molar ratio of CuSn(OH)6 nanomaterial to thioacetamide and ethylenediaminetetraacetic acid is 1:1~8:1~6.

2. The microplastic detection method according to claim 1, characterized in that: The solid-liquid ratio of the Cu3SnS4 nanomaterial to the dimethylformamide solution containing polyvinylidene fluoride is 1.5~7.5 mg:1 mL; The chitosan solution has a mass concentration of 0.005 wt% to 0.05 wt%. The mass concentration of the glutaraldehyde solution is 0.1 wt% to 5 wt%. The mass-volume concentration of the bovine serum albumin solution is 10~500 μg / mL; The mass ratio of the polystyrene microsphere solution is 0.5~500 μg / mL; The volume ratio of the chitosan solution, glutaraldehyde solution, bovine serum albumin solution, and polystyrene microsphere solution is 1:1~2:1~3:1~5.

3. The microplastic detection method according to claim 1, characterized in that: The conditions for the hydrothermal reaction are: temperature 150~200℃, time 2~9h.

4. The microplastic detection method according to claim 1, characterized in that: The CuSn(OH)6 nanomaterial was obtained by reacting tin chloride with alkali and copper chloride in sequence.

5. The microplastic detection method according to claim 4, characterized in that: The molar amount of the alkali is 6 to 6.5 times that of tin chloride; The molar amount of copper chloride is 1 to 1.2 times that of tin chloride.

Images