An Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater

Abstract

The application belongs to the technical field of SERS detection, and particularly relates to an Ag-CuCo 0.5 Al 1.5 O4 composite SERS substrate in detecting 4-mercaptobenzoic acid in wastewater. First, CuCo 0.5 Al 1.5 O4 nanoparticles are prepared by high-temperature calcination process, then silver nanoparticles are loaded by in-situ growth mode to obtain an Ag-CuCo 0.5 Al 1.5 O4 composite SERS substrate, and the substrate is fixed on a glass sheet substrate to complete the detection system construction. The composite substrate can greatly improve the separation and transmission rate of photo-generated carriers. Meanwhile, the cobalt and aluminum bimetallic synergistic effect can effectively introduce rich structural defect sites, realize the precise regulation of material electronic structure, build an efficient transmission channel for interface charge transfer, and improve the Raman scattering signal enhancement effect of the detected molecules, so that the precise detection of trace 4-mercaptobenzoic acid pollutants in wastewater is realized.

Description

Technical Field

[0001] This invention belongs to the field of SERS detection technology, specifically relating to an Ag-CuCo... 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater. Background Technology

[0002] Industrial production activities discharge large quantities of complex and harmful wastewater, among which 4-mercaptobenzoic acid (4-MBA) is a widely used organic chemical raw material and also a typical organic pollutant in the aquatic environment. 4-MBA exhibits strong biotoxicity and bioaccumulation, allowing it to persist in aquatic environments and organisms for extended periods. Therefore, developing an efficient and sensitive method for detecting trace amounts of 4-MBA in water is a critical technical challenge that urgently needs to be addressed in the fields of environmental monitoring and water pollution control.

[0003] Surface-enhanced Raman scattering (SERS) technology, with its unique advantages such as fast detection rate, simple sample pretreatment process, and outstanding ability to identify ultra-trace substances, has extremely high application value in the rapid screening and accurate detection of organic pollutants in water. The preparation and construction of high-performance SERS active substrates is the core key to achieving highly sensitive pollutant detection. The composite substrate constructed in this invention fully combines the localized surface plasmon resonance effect of silver nanoparticles and CuCo... 0.5 Al 1.5 The cation rearrangement and lattice distortion characteristics of O4 materials work synergistically to effectively promote the separation and rapid transport of photogenerated charge carriers. Simultaneously, the synergistic regulation of cobalt and aluminum bimetals in the material can construct abundant structural defect sites, enabling flexible control of the electronic structure, establishing efficient interfacial charge transfer pathways, and significantly improving Raman signal enhancement, thus meeting the practical application requirements for the rapid detection of 4-MBA trace amounts in industrial wastewater. Summary of the Invention

[0004] To address the problems of existing technologies, this invention provides an Ag-CuCo... 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater.

[0005] The technical solution of the present invention is as follows: an Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater.

[0006] The above-mentioned Ag-CuCo 0.5 Al 1.5The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is as follows: Ag-CuCo 0.5 Al 1.5 The O4 composite SERS substrate was immersed in a solution containing 4-mercaptobenzoic acid for 1 hour, then removed and dried in air. The dried Ag-CuCo substrate was then... 0.5 Al 1.5 Raman scattering spectroscopy was performed on the O4 composite SERS substrate.

[0007] The above-mentioned Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater, wherein the concentration of 4-mercaptobenzoic acid is 10. -3 M-10 -7 M.

[0008] The above-mentioned Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater, wherein Ag-CuCo 0.5 Al 1.5 The preparation method of O4 composite SERS substrate includes the following steps.

[0009] 1) Disperse copper nitrate trihydrate, cobalt nitrate hexahydrate, aluminum nitrate nonahydrate, and citric acid monohydrate in deionized water and stir to obtain a mixed solution.

[0010] 2) Dry the mixed solution obtained in step 1) until completely dry, grind and calcine thoroughly, allow it to cool naturally, wash several times and dry again to obtain CuCo. 0.5 Al 1.5 O4 nanoparticles.

[0011] 3) CuCo 0.5 Al 1.5 O4 nanoparticles were dispersed in deionized water, ultrasonically dispersed, and then silver nitrate solution was added and stirred.

[0012] 4) Add ascorbic acid solution to the mixed solution obtained in step 3), stir, and grow silver nanoparticles using in-situ reduction method.

[0013] 5) The mixed solution obtained in step 4) is washed, dried, and ground to obtain the target product Ag-CuCo. 0.5 Al 1.5 O 4。

[0014] 6) Take the Ag-CuCo obtained in step 5) 0.5 Al 1.5O4 was prepared into a solution, drop-coated onto a clean glass slide, and dried to obtain Ag-CuCo. 0.5 Al 1.5 O4 composite SERS substrate.

[0015] The above-mentioned Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in detection of 4-mercaptobenzoic acid in wastewater, in step 1), copper nitrate trihydrate: cobalt nitrate hexahydrate: aluminum nitrate nonahydrate: citric acid monohydrate = 2.416g±0.128g: 1.455g±0.072g: 5.627g±0.281g: 7.565g±0.378g.

[0016] The above-mentioned Ag-CuCo 0.5 Al 1.5 In the application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater, step 2) involves calcination at a temperature of 500-600℃, a heating rate of 5℃ / min, and a time of 3-4h.

[0017] The above-mentioned Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater, in steps 3) and 4), the CuCo 0.5 Al 1.5 O4 nanoparticles: silver nitrate solution: ascorbic acid solution = 50mg: 2mL: 6mL.

[0018] The above-mentioned Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater, in steps 3) and 4), the CuCo 0.5 Al 1.5 The concentration of O4 nanoparticles was 2.5 ± 0.125 mg / mL, the concentration of silver nitrate solution was 50 mM, and the concentration of ascorbic acid solution was 50 mM.

[0019] The above-mentioned Ag-CuCo 0.5 Al 1.5 In the application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater, step 4) describes the in-situ reduction method, which involves reacting at 20-25°C for 1-1.5 hours.

[0020] The above-mentioned Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater, step 6), Ag-CuCo0.5 Al 1.5 The concentration of the O4 solution is 1 mg / mL.

[0021] The Ag-CuCo of this invention 0.5 Al 1.5 The O4 composite SERS substrate integrates the excellent localized surface plasmon resonance properties of silver nanoparticles, while relying on CuCo... 0.5 Al 1.5 The inherent cation rearrangement and lattice distortion characteristics of O4 material significantly enhance the separation and transport rate of photogenerated carriers. Simultaneously, the synergistic effect of the cobalt-aluminum bimetallic composition effectively introduces abundant structural defect sites, enabling precise control of the material's electronic structure. This constructs an efficient transport channel for interfacial charge transfer, enhancing the Raman scattering signal of the analyte molecules and ultimately achieving precise detection of trace 4-mercaptobenzoic acid pollutants in wastewater.

[0022] The beneficial effects of this invention are as follows.

[0023] 1. This invention prepares an Ag-CuCo 0.5 Al 1.5 The O4 composite SERS substrate can sample analytes in industrial wastewater, enabling trace detection of 4-mercaptobenzoic acid.

[0024] 2. The Ag-CuCo prepared by this invention 0.5 Al 1.5 The O4 composite SERS substrate possesses excellent chemical stability and anti-interference capabilities. The localized surface plasmon resonance (LSPR) effect of Ag nanoparticles, combined with the rich defect states brought about by Co / Al synergistic regulation, can rapidly capture the Raman signal of 4-mercaptobenzoic acid molecules. The single detection time is short, enabling rapid batch detection of 4-mercaptobenzoic acid in industrial wastewater, which is suitable for the actual needs of on-site detection and real-time control of industrial wastewater discharge.

[0025] 3. The Ag-CuCo prepared by this invention 0.5 Al 1.5 The O4 composite SERS substrate combines strong SERS enhancement effect, efficient targeted adsorption capacity for 4-mercaptobenzoic acid molecules, excellent structural stability, and simple operation performance, effectively solving the shortcomings of existing 4-mercaptobenzoic acid detection methods and substrates, and providing a reliable technical solution for the efficient, sensitive, and rapid detection of 4-mercaptobenzoic acid in industrial wastewater. Attached Figure Description

[0026] Figure 1 CuCo prepared in Example 1 0.5 Al 1.5 O4 and Ag-CuCo prepared in Example 2 0.5Al 1.5 X-ray diffraction pattern of O4-2.

[0027] Figure 2 Ag-CuCo 0.5 Al 1.5 O4-1, Ag-CuCo 0.5 Al 1.5 O4-2, Ag-CuCo 0.5 Al 1.5 O4-3 composite SERS substrate detection 4-MBA solution (10 -3 Comparison of SERS spectra of M).

[0028] Figure 3 CuCo 0.5 Al 1.5 O4 composite SERS substrate and Ag-CuCo 0.5 Al 1.5 O4-2 composite SERS substrate detection 4-MBA solution (10 -3 Comparison of SERS spectra of M).

[0029] Figure 4 Ag-CuCo prepared in Example 2 0.5 Al 1.5 SERS spectra of 4-MBA solutions of different concentrations were obtained by detecting the SERS spectrum on the O4-2 composite SERS substrate.

[0030] Figure 5 Ag-CuCo prepared in Example 2 0.5 Al 1.5 O4-2 composite SERS substrate was immersed in 4-MBA solution (10) -3 After 1 hour, the sample was removed and dried. After one month at room temperature, 4-MBA solutions (10 μL) were obtained from 6 randomly selected points on the substrate. - 3 M) Raman spectrum.

[0031] Figure 6 Ag-CuCo prepared in Example 2 0.5 Al 1.5 Six test points were randomly selected from the O4-2 composite SERS substrate at the 4-MBA characteristic Raman peak at 1584 cm⁻¹. -1 A bar chart showing the intensity values ​​at a given location. Detailed Implementation

[0032] Example 1.

[0033] CuCo 0.5 Al 1.5 The preparation method of O4 is as follows.

[0034] 2.416 g of copper nitrate trihydrate, 5.627 g of aluminum nitrate nonahydrate, 1.455 g of cobalt nitrate hexahydrate, and 7.565 g of citric acid monohydrate were dispersed in 20 mL of deionized water. After magnetic stirring for 30 min, the mixture was transferred to an oven at 80 °C and dried completely. After thorough grinding, the mixture was transferred to a muffle furnace and calcined at 500 °C at a heating rate of 5 °C / min for 3-4 h. After natural cooling, the mixture was washed three times with deionized water and dried to obtain CuCo. 0.5 Al 1.5 O4 nanoparticles.

[0035] Example 2.

[0036] Ag-CuCo 0.5 Al 1.5 The preparation method of O4 composite SERS substrate is as follows.

[0037] Take 50 mg of CuCo prepared in Example 1 0.5 Al 1.5 O4 nanoparticles were dispersed in a beaker containing 20 mL of deionized water and ultrasonically dispersed for 30 min. Then, 2 mL of 50 mM silver nitrate solution was added, and the mixture was magnetically stirred for 10 min. Next, 6 mL of 50 mM ascorbic acid was added to the solution, and the mixture was magnetically stirred for another 50 min. Silver nanoparticles were grown using an in-situ reduction method and reacted at 25 °C for 1 h. Finally, the mixture was centrifuged and washed three times (centrifugation rate 8000 r / min, centrifugation time 10 min) and dried at 60 °C for 8 h to obtain the target product Ag-CuCo. 0.5 Al 1.5 O4; Take 20 μL of Ag-CuCo 0.5 Al 1.5 O4 solution (1 mg / mL) was dropped onto a clean 25 × 76 mm glass slide and dried to obtain Ag-CuCo. 0.5 Al 1.5 O4 composite SERS substrate, labeled Ag-CuCo 0.5 Al 1.5 O4-2.

[0038] Figure 1 CuCo prepared in Example 1 0.5 Al 1.5 X-ray diffraction pattern of O4 and Ag-CuCo prepared in Example 2 0.5 Al 1.5 X-ray diffraction pattern of O4-2. Figure 1 In the middle, CuCo 0.5 Al 1.5O4 exhibits characteristic peaks at 2θ = 35.7°, 37.1°, 59.5°, and 64.6°; Ag-CuCo 0.5 Al 1.5 The characteristic diffraction peaks of O₄⁻² at 2θ = 38.2°, 44.4°, 64.5°, and 77.5° correspond to the characteristic peaks of Ag. Ag-CuCo 0.5 Al 1.5 CuCo can be observed simultaneously in O4. 0.5 Al 1.5 The characteristic peaks of O4 and Ag indicate that Ag-CuCo 0.5 Al 1.5 O4 composite SERS substrate was successfully prepared.

[0039] Example 3.

[0040] Ag-CuCo 0.5 Al 1.5 The preparation method of the O4 composite SERS substrate contrast sample is as follows.

[0041] According to the preparation method of Example 2, CuCo 0.5 Al 1.5 The amount of O4 nanoparticles remained constant at 50 mg, while the amount of silver nitrate solution was changed to 1 mL and 4 mL, respectively. After magnetic stirring until homogeneous, 3 mL and 8 mL of ascorbic acid solution were added to the above solution, and the mixture was magnetically stirred for 50 min. Finally, the mixed solution was centrifuged and washed three times (centrifugation rate 8000 r / min, centrifugation time 10 min) and dried at 60 °C for 8 h to obtain the target product. 20 μL of the target product solution (1 mg / mL) was dropped onto a clean glass slide of 25 × 76 mm to obtain Ag-CuCo. 0.5 Al 1.5 O4 composite SERS substrate comparison samples, labeled Ag-CuCo, respectively 0.5 Al 1.5 O4-1 and Ag-CuCo 0.5 Al 1.5 O4-3.

[0042] Ag-CuCo 0.5 Al 1.5 O4-1, Ag-CuCo 0.5 Al 1.5 O4-2, Ag-CuCo 0.5 Al 1.5 O4-3 composite SERS substrates were immersed in a concentration of 10... -3 The substrate was immersed in 4-MBA solution of M for 1 hour, then removed and dried in air. The dried composite SERS substrate was then subjected to Raman scattering spectroscopy.

[0043] Figure 2 Ag-CuCo 0.5 Al 1.5 O4-1, Ag-CuCo 0.5 Al 1.5 O4-2, Ag-CuCo 0.5 Al 1.5 O4-3 composite SERS substrate detection 4-MBA solution (10 -3 Comparison of SERS spectra of M). (From...) Figure 2 It can be seen that the characteristic Raman peaks of 4-MBA can be detected in all three substrates, among which Ag-CuCo 0.5 Al 1.5 The O4-2 sample exhibits the highest signal intensity across all characteristic peaks, demonstrating the best SERS enhancement effect.

[0044] Example 4.

[0045] CuCo 0.5 Al 1.5 The preparation method of O4 composite SERS substrate is as follows.

[0046] Take 20 μL of CuCo 0.5 Al 1.5 O4 solution (1 mg / mL) was dropped onto a clean glass slide (25 × 76 mm) to obtain CuCo. 0.5 Al 1.5 O4 composite SERS substrate.

[0047] CuCo 0.5 Al 1.5 O4 composite SERS substrate was immersed in a concentration of 10 -3 The substrate was immersed in 4-MBA solution of M for 1 hour, then removed and dried in air. The dried composite SERS substrate was then subjected to Raman scattering spectroscopy.

[0048] Figure 3 CuCo 0.5 Al 1.5 O4 composite SERS substrate and Ag-CuCo 0.5 Al 1.5 O4-2 composite SERS substrate detection 4-MBA solution (10 -3 Comparison of SERS spectra of M). (From...) Figure 3 It can be seen that Ag-CuCo loaded with silver 0.5 Al 1.5 The O4-2 substrate exhibits significantly higher Raman signal intensity, and its SERS enhancement performance is far superior to that of unsilver-loaded CuCo. 0.5 Al 1.5 O4 substrate.

[0049] Example 5.

[0050] Ag-CuCo 0.5 Al 1.5 Application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater.

[0051] Ag-CuCo 0.5 Al 1.5 O4-2 composite SERS substrate was immersed in different concentrations (10) -3 M-10 -7 The substrate was immersed in 4-MBA solution (M) for 1 hour, then removed and dried in air. The dried composite SERS substrate was then subjected to Raman scattering spectroscopy.

[0052] Figure 4 For this Ag-CuCo 0.5 Al 1.5 O4-2 composite SERS substrate detection 4-MBA solution (10 -3 M-10 -7 SERS spectrum of M). Figure 4 As shown, the intensity of the characteristic peak SERS increases significantly with increasing 4-MBA solution concentration, even at concentrations as low as 10. -7 M, 1584cm can still be clearly observed. -1 The characteristic peaks of the SERS spectrum at that location.

[0053] Figure 5 Ag-CuCo prepared in Example 2 0.5 Al 1.5 O4-2 composite SERS substrate was immersed in 4-MBA solution (10) -3 After 1 hour, the sample was removed and dried. After one month at room temperature, 4-MBA solutions (10 M) were obtained by randomly selecting 6 points on the composite SERS substrate. -3 M) Raman spectrum. It can be seen from the figure that the intensity of its Raman characteristic peaks has not decreased significantly compared with a month ago, and the peak position and peak height of the 6 spectral curves are consistent, indicating that the signal response of the composite SERS substrate at different sites has good consistency. Figure 6 Therefore, the six test points were located at 1584 cm on the 4-MBA characteristic Raman peak. -1 The histogram of intensity values ​​at the specified location shows an RSD of 5.95%, indicating that the composite SERS substrate maintains good signal reproducibility even after being placed at room temperature for one month. These results demonstrate that Ag-CuCo... 0.5 Al 1.5 The O4-2 composite SERS substrate exhibits good sensitivity, stability, and uniformity, making it a reliable SERS substrate for detection.

Claims

1. An Ag-CuCo 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... The Ag-CuCo 0.5 Al 1.5 The preparation method of O4 composite SERS substrate includes the following steps: 1) Disperse copper nitrate trihydrate, cobalt nitrate hexahydrate, aluminum nitrate nonahydrate, and citric acid monohydrate in deionized water and stir to obtain a mixed solution; 2) Dry the mixed solution obtained in step 1) until completely dry, grind and calcine thoroughly, allow it to cool naturally, wash several times and dry again to obtain CuCo. 0.5 Al 1.5 O4 nanoparticles; 3) CuCo 0.5 Al 1.5 O4 nanoparticles were dispersed in deionized water and ultrasonically dispersed. Then, silver nitrate solution was added and stirred. 4) Add ascorbic acid solution to the mixed solution obtained in step 3), stir, and grow silver nanoparticles using in-situ reduction method; 5) The mixed solution obtained in step 4) is washed, dried, and ground to obtain the target product Ag-CuCo. 0.5 Al 1.5 O4; 6) Take the Ag-CuCo obtained in step 5) 0.5 Al 1.5 O4 was prepared into a solution, drop-coated onto a clean glass slide, and dried to obtain Ag-CuCo. 0.5 Al 1.5 O4 composite SERS substrate.

2. An Ag-CuCo according to claim 1 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... The method is as follows: Add Ag-CuCo 0.5 Al 1.5 The O4 composite SERS substrate was immersed in 4-mercaptobenzoic acid solution for 1 hour, then removed and dried in air. The dried Ag-CuCo substrate was then... 0.5 Al 1.5 Raman scattering spectroscopy was performed on the O4 composite SERS substrate.

3. An Ag-CuCo according to claim 2 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... The concentration of the 4-mercaptobenzoic acid solution is 10. -3 M-10 -7 M.

4. An Ag-CuCo according to claim 1 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... In step 1), the ratios of copper nitrate trihydrate, cobalt nitrate hexahydrate, aluminum nitrate nonahydrate, and citric acid monohydrate are 2.416g ± 0.128g, 1.455g ± 0.072g, 5.627g ± 0.281g, and 7.565g ± 0.378g, respectively.

5. An Ag-CuCo according to claim 1 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... In step 2), the calcination temperature is 500-600℃, the heating rate is 5℃ / min, and the time is 3-4h.

6. An Ag-CuCo according to claim 1 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... In steps 3) and 4), the CuCo 0.5 Al 1.5 O4 nanoparticles: silver nitrate solution: ascorbic acid solution = 50mg: 2mL: 6mL.

7. An Ag-CuCo according to claim 6 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... In steps 3) and 4), the CuCo 0.5 Al 1.5 The concentration of O4 nanoparticles was 2.5 ± 0.125 mg / mL, the concentration of silver nitrate solution was 50 mM, and the concentration of ascorbic acid solution was 50 mM.

8. An Ag-CuCo according to claim 1 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... In step 4), the in-situ reduction method involves reacting at 20-25°C for 1-1.5 hours.

9. An Ag-CuCo according to claim 1 0.5 Al 1.5 The application of O4 composite SERS substrate in the detection of 4-mercaptobenzoic acid in wastewater is characterized by... In step 6), Ag-CuCo 0.5 Al 1.5 The concentration of the O4 solution is 1 mg / mL.

Images