NiCo2S4-MoS2 composite material with Raman enhancement effect as well as preparation method and application of NiCo2S4-MoS2 composite material

Abstract

The invention belongs to the technical field of surface enhanced Raman scattering (SERS) detection, and discloses a NiCo2S4-MoS2 composite material with a Raman enhancement effect as well as a preparation method and application of the NiCo2S4-MoS2 composite material. The NiCo2S4-MoS2 composite material is prepared by the following steps: adding a precursor of Mo, CH4N2S and a reducing agent into deionized water to obtain a mixed solution; and adding a precursor of Ni, a precursor of Co and a complexing agent into the mixed solution, performing ultrasonic treatment, performing hydrothermal reaction at 100-250 DEG C, centrifuging, cleaning and performing vacuum drying, thereby obtaining the Ni-Co composite material. The NiCo2S4-MoS2 composite material has a Raman enhancement effect, has rich sulfur vacancies, can be applied to analysis and detection of trace organic matters, has a relatively strong surface Raman enhancement effect on rhodamine 6G, has a detection range of 10 <-5 >-10 <-9 > mol / L, and has a relatively good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of surface Raman enhancement detection technology, and more specifically, relates to a NiCo2S4-MoS2 composite material with Raman enhancement effect, its preparation method and application. Background Technology

[0002] Raman spectroscopy, as an important analytical technique, can provide fingerprint information of molecular structure and chemical bonds. However, conventional Raman scattering signals are usually very weak, limiting its application in trace analysis and other fields. The emergence of surface-enhanced Raman scattering (SERS) technology has brought a breakthrough in solving this problem. Using SERS technology to prepare good conductor surfaces or sols of metals, such as silver, gold, or copper, the Raman scattering signal of adsorbed molecules is significantly enhanced compared to ordinary Raman scattering signals, with enhancement factors reaching up to 10. 3 ~10 6 The signal enhancement capability is several times higher, or even more. This powerful signal enhancement capability has enabled SERS technology to be widely used in many fields such as biochemical molecular detection, disease diagnosis, environmental monitoring, explosives detection, trace material analysis, food safety, and forensic examination. In the biomedical field, SERS technology can achieve highly sensitive detection of biomarkers, which is helpful for the early diagnosis and treatment of diseases; in environmental monitoring, it can quickly and accurately detect pollutants in the environment, promptly identify environmental problems, and protect the ecological environment.

[0003] In SERS technology, traditional noble metal materials such as silver and gold nanostructures, due to their surface plasmon resonance properties, can generate strong local electromagnetic field enhancement effects, making them commonly used Raman enhancement substrates. However, these noble metal materials have some limitations, such as high cost, which limits their large-scale application; poor chemical stability, making them susceptible to oxidation and other reactions caused by external environmental influences, leading to performance degradation; and poor biocompatibility, which may have adverse effects on organisms in biomedical applications. Developing novel, inexpensive materials with Raman enhancement effects that are easy to prepare and have good enhancement properties has become a research hotspot and important development direction in this field. Summary of the Invention

[0004] To address the aforementioned technical problems, the primary objective of this invention is to provide a NiCo2S4-MoS2 composite material with Raman enhancement. This composite material possesses abundant sulfur vacancies and a unique spherical structure, providing more adsorption sites and enhancing the interaction with the detected molecules, thereby achieving more efficient Raman signal enhancement. Furthermore, MoS2 and NiCo2S4 form a synergistic effect, promoting electron transport and improving the overall performance of the composite material. This results in the NiCo2S4-MoS2 non-noble metal composite material exhibiting higher SERS signal intensity, enabling faster and more accurate detection of trace organic compounds, and demonstrating good reproducibility and stability.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned NiCo2S4-MoS2 composite material with Raman enhancement effect. This method uses a hydrothermal method to prepare the NiCo2S4-MoS2 composite material, which is inexpensive.

[0006] Another object of the present invention is to provide the application of the above-mentioned NiCo2S4-MoS2 composite material with Raman enhancement effect.

[0007] The objective of this invention is achieved through the following technical solution: A NiCo2S4-MoS2 composite material with Raman enhancement effect is prepared by adding Mo precursor, CH4N2S and reducing agent to deionized water to obtain a mixed solution; adding Ni precursor, Co precursor and complexing agent to the mixed solution and sonicating, hydrothermally reacting at 100~250 °C, centrifuging, washing and vacuum drying.

[0008] Preferably, the mass ratio of the Mo precursor, CH4N2S and reducing agent to the volume ratio of deionized water is 1g:(1~50)g:(1~50)g:(10~50)mL; the mass ratio of the Ni precursor, Co precursor and complexing agent to the volume ratio of the mixed solution is (0.1~10)g:(0.1~10)g:(0.1~10)g:(10~50)mL.

[0009] Preferably, the Mo precursor is (NH4)6Mo7O 24 The reducing agent is one or more of 4H2O, Na2MoO4·2H2O, or MoO2; the reducing agent is one or more of oxalic acid, malonic acid, sodium citrate, or hexanediol; the precursor of Ni is one or more of NiCl2·6H2O, NiSO4·6H2O, or Ni(NO3)2·6H2O; the precursor of Co is one or more of CoCl2·6H2O, CoSO4·7H2O, or Co(NO3)2·6H2O; the complexing agent is one or more of urea, ethylenediaminetetraacetic acid, or ammonium chloride.

[0010] The preparation method of the NiCo2S4-MoS2 composite material with Raman enhancement effect includes the following specific steps: S1. Add the precursor of Mo, CH4N2S and reducing agent to deionized water to obtain a mixed solution; S2. Ni precursor, Co precursor and complexing agent are added to a mixed solution and sonicated. The mixture is then subjected to hydrothermal reaction at 100~250 ℃. After centrifugation, washing and vacuum drying, NiCo2S4-MoS2 composite material with Raman enhancement effect is obtained.

[0011] Preferably, in step S2, the ultrasonic time is 10-60 min, the hydrothermal reaction time is 5-40 h, the centrifugation speed is 8000-10000 rpm, the centrifugation time is 1-5 min, the vacuum drying temperature is 20-90℃, and the vacuum drying time is 8-20 h.

[0012] The application of the NiCo2S4-MoS2 composite material with Raman enhancement effect in the analysis and detection of trace organic compounds.

[0013] Preferably, the trace amount is at a concentration of 10. -5 ~10 -9 The organic compound is Rhodamine 6G, mol / L.

[0014] The application of the NiCo2S4-MoS2 composite material with Raman enhancement effect in surface-enhanced Raman scattering.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The NiCo2S4-MoS2 composite material of this invention exhibits Raman enhancement effect. It is obtained by compositing MoS2 with NiCo2S4, which has a nanosheet structure, to obtain a NiCo2S4-MoS2 composite material with a spherical structure. Compared with most commonly used noble metals (such as gold and silver), the NiCo2S4-MoS2 composite material has excellent SERS performance and is inexpensive, making it a functional material with great application potential. MoS2, with its unique layered crystal structure and excellent photoelectric properties, has become a highly promising reinforcing substrate material in the field of SERS. The electron transfer capability of its abundant active sites on the sheet surface can form strong interactions with the target analyte, effectively amplifying the Raman signal and exhibiting a good SERS enhancement effect. Due to the synergistic effect at the interface of MoS2 and NiCo2S4 composite, significant structural reconstruction is triggered, generating a large number of sulfur vacancies. These sulfur vacancies enhance the adsorption capacity for target molecules. Furthermore, sulfur vacancies can form defect levels and inhibit charge carrier recombination, which allows more photoinduced charge carriers to participate in the charge transfer process. This significantly improves the SERS performance of the NiCo2S4-MoS2 composite material, making it far superior to that of a single MoS2 substrate.

[0016] 2. The present invention uses a hydrothermal method to prepare NiCo2S4-MoS2 composite material, which is simple and low in cost.

[0017] 3. The NiCo2S4-MoS2 composite material prepared in this invention was used as a SERS substrate to detect Rhodamine 6G solutions of different concentrations. Experimental analysis showed that it exhibited a strong surface Raman enhancement effect on Rhodamine 6G, with a detection limit reaching 10. - 9 The concentration of mol / L showed good results, indicating that the NiCo2S4-MoS2 composite material has excellent SERS performance as a Raman substrate and can be used for Raman detection of organic matter. Attached Figure Description

[0018] Figure 1 The image shows a scanning electron microscope (SEM) image and elemental distribution map of the NiCo2S4-MoS2 composite material from Example 1.

[0019] Figure 2 The Raman spectrum characterizing sulfur vacancies is shown for the NiCo2S4-MoS2 composite material of Example 1.

[0020] Figure 3 The image shows the XRD spectrum of the NiCo2S4-MoS2 composite material from Example 1.

[0021] Figure 4 The Raman spectrum of the MoS2 material in Example 1 enhanced with Rhodamine 6G is shown.

[0022] Figure 5 The Raman spectrum of the NiCo2S4-MoS2 composite material in Example 1 for Rhodamine 6G enhancement is shown. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments, but these should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0024] Example 1 1. Take 1.236 g of (NH4)6Mo7O 24 • 4H2O, 3.24 g of CH4N2S and 0.75 g of sodium citrate were added to 30 mL of deionized water and sonicated for 20 min to obtain a mixed solution; 2. 1.19 g of NiCl2·6H2O, 1.19 g of CoCl2·6H2O and 2 g of urea were added to a mixed solution. After sonication for 30 min, the mixture was placed in a reaction vessel and hydrothermally reacted at 240 °C for 15 h. The mixture was then centrifuged at 10,000 rpm for 2 min, washed alternately with ultrapure water and ethanol, and vacuum dried at 60 °C for 12 h to obtain the NiCo2S4-MoS2 composite material.

[0025] The prepared NiCo2S4-MoS2 composite material was placed on a glass slide as a substrate, and a 10% concentration of [unspecified substance] was added. -5 ~10 - 9 Rhodamine 6G at mol / L was allowed to stand for 3 min to ensure that the droplets uniformly covered the effective area of ​​Rhodamine 6G, so that Rhodamine 6G was fully absorbed. Finally, Raman spectroscopy was performed using a 532 nm laser.

[0026] Figure 1 The images show scanning electron microscope (SEM) images and elemental distribution diagrams of the NiCo2S4-MoS2 composite material from Example 1. Figure 1 It can be seen that the prepared NiCo2S4-MoS2 composite material has a micron-sized spherical structure with a diameter of about 4 micrometers. The surface of the spheres is rough and is composed of NiCo2S4 nanosheets, which is beneficial to increasing the specific surface area of ​​the NiCo2S4-MoS2 composite material. Figure 2 The image shows the Raman spectrum characterizing the sulfur vacancies in the NiCo2S4-MoS2 composite material of Example 1. Figure 2 It can be seen that the E1 2g and A of MoS2 and NiCo2S4-MoS2 are different. 1g Peak position comparison: After NiCo2S4 composite, the redshift of the E1 2g peak and the A peak... 1gThe peak undergoes a blue shift, which is due to the large number of electron transfers generated by the recombination of MoS2 and NiCo2S4, resulting in sulfur vacancies. Figure 3 The image shows the XRD pattern of the NiCo2S4-MoS2 composite material from Example 1. The (002) plane diffraction peak corresponding to MoS2 shifts to a higher angle (18°), which may be due to the denser interlayer spacing of the MoS2. Figure 3 As can be seen, the NiCo2S4-MoS2 composite material retains the characteristic peaks of MoS2 and also shows the NiCo2S4 peak, indicating that the MoS2-NiCo2S4 composite material was successfully prepared. Figure 4 The Raman spectrum of Rhodamine 6G enhancement in MoS2 material. Figure 4 It can be seen that the limit of detection for MoS2 is 10. -7 mol / L. Figure 5 The image shows the Raman spectrum of the MoS2-NiCo2S4 composite material from Example 1 enhanced with Rhodamine 6G. Figure 5 It can be seen that the MoS2-NiCo2S4 composite material has excellent Raman reinforcement properties, with a detection limit as low as 10. -9 mol / L. From Figure 4-5 It can be seen that the SERS performance of NiCo2S4-MoS2 composite material is significantly improved, far superior to that of single MoS2.

[0027] Example 2 1. Add 1.53 g MoO2, 6.4 g CH4N2S and 0.75 g oxalic acid to 30 mL of deionized water and sonicate for 20 min to obtain a mixed solution; 2. 0.3 g of Ni(NO3)2·6H2O, 0.3 g of Co(NO3)2·6H2O and 4 g of ethylenediaminetetraacetic acid were added to a mixed solution. After sonication for 20 min, the mixture was placed in a reaction vessel and hydrothermally reacted at 120 °C for 12 h. The mixture was then centrifuged at 8000 rpm for 5 min, washed alternately with ultrapure water and ethanol, and vacuum dried at 60 °C for 10 h to obtain the NiCo2S4-MoS2 composite material.

[0028] The prepared NiCo2S4-MoS2 composite material was placed on a glass slide as a substrate, and a 10% concentration of [unspecified substance] was added. -5 ~10 - 9 Rhodamine 6G at a concentration of mol / L was allowed to stand for 3 min to ensure uniform coverage of the effective region of Rhodamine 6G, allowing for sufficient absorption. Finally, Raman spectroscopy was performed using a 532 nm laser. The results showed that the obtained NiCo2S4-MoS2 composite material exhibited excellent Raman enhancement performance, with a detection limit as low as 10 mol / L. -9mol / L.

[0029] Example 3 1. Add 2 g MoO2, 3.2 g CH4N2S and 0.75 g hexanediol to 50 mL of deionized water and sonicate for 40 min to obtain a mixed solution; 2. Add 0.5 g of NiSO4·6H2O, 0.5 g of CoSO4·7H2O and 3 g of ethylenediaminetetraacetic acid to a mixed solution, sonicate for 60 min and then place in a reaction vessel. React hydrothermally at 200 ℃ for 18 h. Centrifuge at 10000 rpm for 5 min, wash alternately with ultrapure water and ethanol, and vacuum dry at 80 ℃ for 10 h to obtain NiCo2S4-MoS2 composite material.

[0030] The prepared NiCo2S4-MoS2 composite material was placed on a glass slide as a substrate, and a 10% concentration of [unspecified substance] was added. -5 ~10 - 9 Rhodamine 6G at mol / L was allowed to stand for 3 min to ensure uniform coverage of the effective area of ​​Rhodamine 6G, allowing for sufficient absorption. Finally, Raman spectroscopy was performed using a 532 nm laser. The NiCo2S4-MoS2 composite material exhibited excellent Raman enhancement performance, with a detection limit as low as 10 mol / L. -8 mol / L.

[0031] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A NiCo2S4-MoS2 composite material with Raman enhancement effect, characterized in that, The composite material is prepared by adding a precursor of Mo, CH4N2S and a reducing agent to deionized water to obtain a mixed solution; adding a precursor of Ni, a precursor of Co and a complexing agent to the mixed solution and sonicating, then hydrothermally reacting at 100~250 °C, followed by centrifugation, washing and vacuum drying.

2. The NiCo2S4-MoS2 composite material with Raman enhancement effect according to claim 1, characterized in that, The mass ratio of the Mo precursor, CH4N2S and reducing agent to the volume ratio of deionized water is 1 g: (1~50) g: (1~50) g: (10~50) mL; the mass ratio of the Ni precursor, Co precursor and complexing agent to the volume ratio of the mixed solution is (0.1~10) g: (0.1~10) g: (0.1~10) g: (10~50) mL.

3. The NiCo2S4-MoS2 composite material with Raman enhancement effect according to claim 1, characterized in that, The Mo precursor is (NH4)6Mo7O 24 The reducing agent is one or more of 4H2O, Na2MoO4·2H2O, or MoO2; the reducing agent is one or more of oxalic acid, malonic acid, sodium citrate, or hexanediol; the precursor of Ni is one or more of NiCl2·6H2O, NiSO4·6H2O, or Ni(NO3)2·6H2O; the precursor of Co is one or more of CoCl2·6H2O, CoSO4·7H2O, or Co(NO3)2·6H2O; the complexing agent is one or more of urea, ethylenediaminetetraacetic acid, or ammonium chloride.

4. The method for preparing the NiCo2S4-MoS2 composite material with Raman enhancement effect according to any one of claims 1-3, characterized in that, The specific steps include the following: S1. Add the precursor of Mo, CH4N2S and reducing agent to deionized water to obtain a mixed solution; S2. Ni precursor, Co precursor and complexing agent are added to a mixed solution and sonicated. The mixture is then subjected to hydrothermal reaction at 100~250 ℃. After centrifugation, washing and vacuum drying, NiCo2S4-MoS2 composite material with Raman enhancement effect is obtained.

5. The method for preparing the NiCo2S4-MoS2 composite material with Raman enhancement effect according to claim 4, characterized in that, In step S2, the ultrasonic treatment time is 10-60 min, the hydrothermal reaction time is 5-40 h, the centrifugation speed is 8000-10000 rpm, the centrifugation time is 1-5 min, the vacuum drying temperature is 20-90 ℃, and the vacuum drying time is 8-20 h.

6. The application of the NiCo2S4-MoS2 composite material with Raman enhancement effect as described in any one of claims 1-3 in the analysis and detection of trace organic compounds.

7. The application according to claim 6, characterized in that, The trace amount is a concentration of 10. -5 ~10 -9 The organic compound is Rhodamine 6G, mol / L.

8. The application of the NiCo2S4-MoS2 composite material with Raman enhancement effect as described in any one of claims 1-3 in surface-enhanced Raman scattering.

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