A molybdenum disulfide / copper sulfide / molybdenum trioxide ternary composite material and application thereof in hydrogen evolution and trace detection

Abstract

The application discloses a MoS2 / Cu2S / MoO3 ternary composite material, wherein MoS2 nanoflowers are uniformly distributed on snowflake-shaped Cu2S, and MoO3 is distributed on the surface of the MoS2 nanoflowers. The application further discloses a preparation method of the MoS2 / Cu2S / MoO3 ternary composite material, which comprises the following steps: uniformly mixing a copper source, a solvent, a sulfur source and MoS2, and then performing reaction to obtain the MoS2 / Cu2S / MoO3 ternary composite material. The application discloses application of the MoS2 / Cu2S / MoO3 ternary composite material in electrocatalysis, photocatalytic degradation and surface enhanced Raman spectrum detection. The application can not only perform electrocatalytic hydrogen evolution in an alkaline environment, but also realize high-sensitivity SERS detection and high-efficiency photocatalytic degradation on various dyes in actual water bodies.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a MoS2 / Cu2S / MoO3 ternary composite material and its application in hydrogen evolution and trace detection. Background Technology

[0002] In the energy sector, industrialization and globalization have accelerated population growth and financial development. The massive consumption of fossil fuels has led to various social and environmental problems. Hydrogen (H2) energy, as a sustainable, efficient, and clean green energy source, has received widespread attention for addressing environmental issues. Hydrogen evolution by electrolysis (HER) has garnered significant attention due to its cleanliness, environmental friendliness, and sustainable development. Currently, most catalysts limit their application in practical water electrolysis due to insufficient active sites or low conductivity. To date, noble metals such as platinum (Pt), ruthenium (Ru), and iridium (Ir) are widely recognized as robust electrocatalysts due to the balance of adsorption and desorption energies of their intermediates. However, these metals are very expensive and scarce, limiting their widespread use. Furthermore, since the active sites of MoS2 are mainly concentrated at its edges, its matrix is ​​inert to the electrocatalytic hydrogen evolution process, severely affecting both its conductivity and active sites. Simply altering its morphology is insufficient to improve its HER performance.

[0003] In terms of the environment, water resources are suffering from industrial pollution, with dye wastewater becoming a major environmental threat. Therefore, achieving trace detection and effective degradation of various dyes in actual water bodies is crucial. Although several methods for dye detection and degradation have been proposed, these methods still have some inherent drawbacks, such as low specificity, low sensitivity, high instrument costs, long cycles, and complex pretreatment steps. Therefore, there is an urgent need to develop simple, sensitive, specific, and rapid methods for detecting and degrading dyes in actual water bodies. Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique widely used in environmental monitoring, food safety, and biomedicine. Meanwhile, photocatalysis has also become an efficient and economical water purification technology. However, due to the weak interaction between organic molecules and MoS2, simply changing the internal structure is insufficient to improve SERS and photocatalytic degradation performance, which limits its application in practical environmental monitoring.

[0004] The aforementioned technical bottlenecks severely restrict the application of MoS2 in electrocatalytic hydrogen production, water body detection, and photocatalytic degradation. Summary of the Invention

[0005] Based on the technical problems existing in the background technology, this invention proposes a MoS2 / Cu2S / MoO3 ternary composite material and its application in hydrogen evolution and trace detection. The MoS2 / Cu2S / MoO3 ternary composite material of this invention can achieve effective ternary composite, and its morphology and structure have a large specific surface area and reactive active sites, which can exhibit excellent photoelectrocatalysis and enhanced SERS performance. It can not only perform electrocatalytic hydrogen evolution in alkaline environment, but also achieve highly sensitive SERS detection and efficient photocatalytic degradation of various dyes in actual water bodies.

[0006] This invention proposes a MoS2 / Cu2S / MoO3 ternary composite material, in which MoS2 nanoflowers are uniformly distributed on snowflake-shaped Cu2S, and MoO3 is distributed on the surface of the MoS2 nanoflowers.

[0007] MoO3 can be distributed in whole or in part on the surface of MoS2 nanoflowers.

[0008] Preferably, in the MoS2 / Cu2S / MoO3 ternary composite material, MoS2 exists in the form of metallic 1T phase and 2H phase.

[0009] The present invention also proposes a method for preparing the above-mentioned MoS2 / Cu2S / MoO3 ternary composite material, comprising the following steps: mixing copper source, solvent, sulfur source and MoS2, and then reacting to obtain the MoS2 / Cu2S / MoO3 ternary composite material.

[0010] Preferably, the copper source is an inorganic copper salt.

[0011] Preferably, the copper source is at least one of copper chloride and copper chloride dihydrate.

[0012] Preferably, the sulfur source is thiourea.

[0013] Preferably, the solvent is ethylenediamine.

[0014] Preferably, the molar ratio of copper in the copper source to sulfur in the sulfur source is 1:2.8-3.2.

[0015] Preferably, the molar ratio of copper to MoS2 in the copper source is 1:0.1-0.15.

[0016] Preferably, the molar ratio of copper to ethylenediamine in the copper source is 1:450-470.

[0017] Preferably, the reaction temperature is 75-85℃.

[0018] Preferably, the reaction time is 7.5-8 hours.

[0019] Preferably, after the reaction is complete, the mixture is washed and dried to obtain the MoS2 / Cu2S / MoO3 ternary composite material.

[0020] Preferably, in the preparation of MoS2, an aqueous solution containing a molybdenum source and a sulfur source is taken and subjected to a hydrothermal reaction to obtain MoS2.

[0021] Preferably, in the preparation of MoS2, the molybdenum source is at least one of ammonium molybdate and ammonium molybdate tetrahydrate.

[0022] Preferably, the sulfur source in the preparation of MoS2 is thiourea.

[0023] Preferably, in the preparation of MoS2, the molar ratio of molybdenum in the molybdenum source to sulfur in the sulfur source is 1:30-36.

[0024] Preferably, in the preparation of MoS2, the hydrothermal reaction temperature is 220-240℃ and the hydrothermal reaction time is 17-19h.

[0025] Preferably, in the preparation of MoS2, after the hydrothermal reaction is completed, the product is washed and dried to obtain MoS2.

[0026] This invention also proposes the application of the above-mentioned MoS2 / Cu2S / MoO3 ternary composite material in electrocatalysis, photocatalytic degradation, and surface-enhanced Raman spectroscopy detection.

[0027] Preferably, it is used in the photocatalytic degradation of crystal violet, methylene blue, malachite green, and rhodamine 6G.

[0028] Preferably, it is used in surface-enhanced Raman spectroscopy for the detection of crystal violet, methylene blue, malachite green, and rhodamine 6G.

[0029] The present invention also proposes an electrode on which a thin film is attached to the electrode surface, the thin film containing the above-mentioned MoS2 / Cu2S / MoO3 ternary composite material.

[0030] The aforementioned film can be a perfluorosulfonic acid polymer containing the above-mentioned MoS2 / Cu2S / MoO3 ternary composite material.

[0031] The present invention also proposes a method for electrocatalytic hydrogen production, comprising the following steps: using the above-mentioned electrode as a cathode, electrolyzing an alkaline electrolyte, and collecting hydrogen gas.

[0032] Preferably, the electrolyte in the alkaline electrolyte is an inorganic alkali. The inorganic alkali can be potassium hydroxide, sodium hydroxide, etc.

[0033] The above-mentioned electrocatalytic hydrogen production method uses a three-electrode system for electrolysis.

[0034] The present invention also proposes a method to enhance the detection sensitivity of SERS, comprising the following steps: adding the above-mentioned MoS2 / Cu2S / MoO3 ternary composite material to the test solution, and then performing SERS detection.

[0035] Beneficial effects:

[0036] (1) By regulating the physicochemical properties of MoS2, this invention has developed a multifunctional MoS2 / Cu2S / MoO3 ternary composite material, which can achieve effective ternary composite. Its morphology and structure have a large specific surface area and a large number of reactive sites, which is more conducive to internal charge transfer, can improve conductivity, and suppress internal electron-hole recombination. It can exhibit excellent photoelectrocatalytic degradation and SERS detection performance. It can not only perform electrocatalytic hydrogen evolution in alkaline environment, but also achieve highly sensitive SERS detection and efficient photocatalytic degradation of various dyes in actual water bodies. It has important application prospects in the fields of electrocatalytic hydrogen production, water body detection and photocatalytic degradation technology, and is an unprecedented new technology. The MoS2 / Cu2S / MoO3 ternary composite material exhibits high sensitivity in water body detection and excellent stability, efficiency and recyclability in catalysis.

[0037] (2) The raw materials of this invention are cheap and readily available, and the cost is low. There is no need to use other toxic and harmful organic surfactants and additives. The preparation process is simple, the reaction conditions are mild, and it conforms to the preparation concept of green synthesis. It is safe, environmentally friendly and suitable for large-scale industrial production.

[0038] (3) The MoS2 / Cu2S / MoO3 ternary composite material can achieve efficient hydrogen production in alkaline electrolytes at 10 mA / cm². 2 The lowest hydrogen evolution reaction overpotential is 59mV, which significantly improves the conductivity and stability of MoS2. It solves the shortcomings of insufficient active sites and poor conductivity of MoS2 due to its inert basal plane, broadens the application range of the material, and provides an effective way to produce hydrogen by electrolysis of water and thus alleviate the energy crisis.

[0039] (4) The MoS2 / Cu2S / MoO3 ternary composite material exhibits significant SERS enhancement and low detection limits for four dyes (methylene blue, malachite green, rhodamine 6G, and crystal violet); among them, the enhancement factor of the MoS2 / Cu2S / MoO3 ternary composite material for methylene blue can reach 1.4 × 10⁻⁶. 6 Detection limit as low as 10 -12 M;MoS2 / Cu2S / MoO3 ternary composite materials can improve the sensitivity of SERS detection, simplify pretreatment, and enable rapid detection, solving the problems of complex pretreatment steps and inconvenient instrument operation in traditional detection methods.

[0040] (5) The MoS2 / Cu2S / MoO3 ternary composite material has a good photocatalytic degradation effect on four dyes (methylene blue, malachite green, rhodamine 6G and crystal violet). Among them, the degradation rate of malachite green under visible light irradiation within 24 minutes can reach 99%, which solves the difficulties encountered by traditional dye treatment, such as high cost and the need for additional plans to remove by-products.

[0041] (6) The MoS2 / Cu2S / MoO3 ternary composite material described in this invention not only solves the problem of resource scarcity in the energy sector, but also addresses the challenges of accurate detection and effective degradation of pollutants in the environment. Furthermore, its performance in these aspects far surpasses that of most reported semiconductor materials, demonstrating excellent application prospects. The design strategy of this material can provide new ideas for the preparation of other high-performance ternary heterojunctions and will guide scientists in utilizing wastewater to produce clean energy. Attached Figure Description

[0042] Figure 1 The images show the SEM and TEM images of the MoS2 / Cu2S / MoO3 ternary composite material, where a is the SEM image and b is the TEM image.

[0043] Figure 2 XRD and Raman intrinsic spectra of the MoS2 / Cu2S / MoO3 ternary composite material are shown, where CSM 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3. a is the XRD pattern and b is the Raman pattern.

[0044] Figure 3 EDX elemental mapping and XPS spectra of O1s in the MoS2 / Cu2S / MoO3 ternary composite material are shown, where a is the EDX elemental mapping and b is the XPS spectra of O1s. 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3.

[0045] Figure 4 The graph shows the electrocatalytic hydrogen evolution performance of the electrode prepared in Example 4, where CSM... 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3. a is the LSV curve, b is the current density at 10mA / cm². 2 The overpotential histogram is shown at time a, c is the Tafel plot corresponding to a, d is the EIS spectrum, e is the electrochemical double layer capacitance value, f is the LSV curve after 16 h, and the inset shows the current density change over 16 h.

[0046] Figure 5The graph shows the SERS detection results of methylene blue by the MoS2 / Cu2S / MoO3 ternary composite material. In the graph, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of methylene blue. (CSM) 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3, and MB is methylene blue; b is the SERS detection graph of different concentrations of methylene blue using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c is the linear relationship graph corresponding to b; d is the SERS detection result of methylene blue after the MoS2 / Cu2S / MoO3 ternary composite material is used 5 times; e is the SERS detection result of methylene blue using the MoS2 / Cu2S / MoO3 ternary composite material after 1, 2, 3, and 4 months; f is the uniformity result of the SERS detection of methylene blue using the MoS2 / Cu2S / MoO3 ternary composite material.

[0047] Figure 6 The image shows the SERS detection results of Rhodamine 6G on the MoS2 / Cu2S / MoO3 ternary composite material. In the image, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of Rhodamine 6G. (CSM) 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3, and R6G is Rhodamine 6G; b is the SERS detection graph of different concentrations of Rhodamine 6G using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c is the linear relationship graph corresponding to b; d is the SERS detection result of Rhodamine 6G after the MoS2 / Cu2S / MoO3 ternary composite material is used 5 times; e is the SERS detection result of Rhodamine 6G after the MoS2 / Cu2S / MoO3 ternary composite material is placed for 1, 2, 3, and 4 months; f is the SERS detection uniformity result of Rhodamine 6G using the MoS2 / Cu2S / MoO3 ternary composite material.

[0048] Figure 7 The graph shows the SERS detection results of the MoS2 / Cu2S / MoO3 ternary composite material for crystal violet. In the graph, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of crystal violet. (CSM) 0.02- MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3, and CV represents crystal violet; b shows the SERS detection results of different concentrations of crystal violet using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c shows the linear relationship corresponding to b; d shows the SERS detection results of crystal violet after 5 cycles of the MoS2 / Cu2S / MoO3 ternary composite material; e shows the SERS detection results of crystal violet after the MoS2 / Cu2S / MoO3 ternary composite material has been stored for 1, 2, 3, and 4 months; f shows the uniformity of the SERS detection results of crystal violet using the MoS2 / Cu2S / MoO3 ternary composite material.

[0049] Figure 8 The graph shows the SERS results of the MoS2 / Cu2S / MoO3 ternary composite material on malachite green. In the graph, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of malachite green. (CSM) 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3, and MG represents malachite green; b shows the SERS detection results of malachite green at different concentrations using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c shows the linear relationship corresponding to b; d shows the SERS detection results of malachite green after each of the five cycles of the MoS2 / Cu2S / MoO3 ternary composite material; e shows the SERS detection results of malachite green using the MoS2 / Cu2S / MoO3 ternary composite material after 1, 2, 3, and 4 months of storage; f shows the uniformity of the SERS detection results of malachite green using the MoS2 / Cu2S / MoO3 ternary composite material.

[0050] Figure 9 Figure 1 shows the photocatalytic degradation results of malachite green by the MoS2 / Cu2S / MoO3 ternary composite material. In this figure, a represents the absorbance of the MoS2 / Cu2S / MoO3 ternary composite material at different time points during photocatalytic degradation of malachite green; b represents the absorbance of MoS2 at different time points during photocatalytic degradation of malachite green; c represents the absorbance of Cu2S at different time points during photocatalytic degradation of malachite green; and d represents the degradation rate of malachite green by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, respectively. (CSM) 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the kinetic modeling results of the photocatalytic degradation of malachite green by the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S; f represents the degradation rate of malachite green by the ternary composite material of MoS2 / Cu2S / MoO3 after 5 cycles.

[0051] Figure 10The graph shows the photocatalytic degradation results of crystal violet by the MoS2 / Cu2S / MoO3 ternary composite material. In the graph: a) absorbance of the MoS2 / Cu2S / MoO3 ternary composite material at different time points during photocatalytic degradation of crystal violet; b) absorbance of MoS2 at different time points during photocatalytic degradation of crystal violet; c) absorbance of Cu2S at different time points during photocatalytic degradation of crystal violet; d) degradation rate of crystal violet by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, according to CSM. 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the results of the photocatalytic degradation kinetic modeling study of crystal violet by the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S; f represents the degradation rate of crystal violet by the ternary composite material of MoS2 / Cu2S / MoO3 after 5 cycles.

[0052] Figure 11 Figure 1 shows the photocatalytic degradation results of Rhodamine 6G by the MoS2 / Cu2S / MoO3 ternary composite material. In this figure, a represents the absorbance of Rhodamine 6G at different time points during photocatalytic degradation by the MoS2 / Cu2S / MoO3 ternary composite material; b represents the absorbance of Rhodamine 6G at different time points during photocatalytic degradation by MoS2; c represents the absorbance of Rhodamine 6G at different time points during photocatalytic degradation by Cu2S; and d represents the degradation rate of Rhodamine 6G by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, respectively. 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the photocatalytic degradation kinetics modeling results of the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S on Rhodamine 6G; f represents the degradation rate of Rhodamine 6G after 5 cycles of the ternary composite material of MoS2 / Cu2S / MoO3.

[0053] Figure 12 The graph shows the photocatalytic degradation results of methylene blue by the MoS2 / Cu2S / MoO3 ternary composite material, where: a) is the absorbance of the MoS2 / Cu2S / MoO3 ternary composite material at different time points during photocatalytic degradation of methylene blue; b) is the absorbance of MoS2 at different time points during photocatalytic degradation of methylene blue; c) is the absorbance of Cu2S at different time points during photocatalytic degradation of methylene blue; and d) is the degradation rate of methylene blue by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, according to CSM. 0.02-MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the kinetic modeling results of the photocatalytic degradation of methylene blue by the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S; f represents the degradation rate of methylene blue after each of the five cycles of the ternary composite material of MoS2 / Cu2S / MoO3. Detailed Implementation

[0054] The technical solution of the present invention will now be described in detail through specific embodiments.

[0055] Reagents and materials:

[0056] Ammonium molybdate tetrahydrate ([(NH4)6Mo7O) 24 [·4H2O] (Shanghai Maclean Biochemical Technology Co., Ltd.) was analytical grade; thiourea (NH2CSNH2, Shanghai Maclean Biochemical Technology Co., Ltd.) was analytical grade; copper chloride dihydrate (CuCl2·2H2O, Shenyang Guoyao Group Chemical Reagent Co., Ltd.) was ≥99% concentration; ethylenediamine (C2H8N2, Shenyang Guoyao Group Chemical Reagent Co., Ltd.) was ≥98% concentration; anhydrous ethanol (CH3CH2OH, Shenyang Guoyao Group Chemical Reagent Co., Ltd.) was analytical grade; isopropanol (C3H8O, Shanghai Maclean Biochemical Technology Co., Ltd.) was analytical grade; perfluorosulfonic acid polymer solution (Nafion, Beijing Cool Chemical Technology Co., Ltd.) was 5% concentration; potassium hydroxide (KOH, Shanghai Maclean Biochemical Technology Co., Ltd.) was analytical grade; crystal violet (C4H2O) was analytical grade. 25 H 30 N3Cl (Shanghai Maclean Biochemical Technology Co., Ltd.) concentration ≥98%; Methylene Blue (C 16 H 18 ClN3S (Shanghai Maclean Biochemical Technology Co., Ltd.) has a concentration of ≥70%; Malachite Green (C 23 H 25 N2·C 2H O4·0.5C2H2O (Shanghai Maclean Biochemical Technology Co., Ltd.) has a concentration of ≥95%; Rhodamine 6G (C 28 H 31 ClN2O3 (Shanghai Maclean Biochemical Technology Co., Ltd.) was of analytical grade.

[0057] Example 1

[0058] A method for preparing a MoS2 / Cu2S / MoO3 ternary composite material includes the following steps:

[0059] 1.23 g (1 mmol) of ammonium molybdate tetrahydrate and 2.512 g (33 mmol) of thiourea were dissolved in 60 mL of deionized water. The mixture was stirred with a magnetic stirrer for 0.5 h until completely dissolved. The solution was then transferred to a 100 mL Teflon-lined stainless steel autoclave and placed in a drying oven at 220 °C for hydrothermal reaction for 18 h. The black precipitate was then collected, washed three times with deionized water and alcohol, and dried in a drying oven at 60 °C for 6 h to obtain a black solid powder, MoS2.

[0060] 0.228 g (3 mmol) of thiourea and 0.170 g (1 mmol) of copper chloride dihydrate were dissolved in 30 mL (450 mmol) of ethylenediamine to obtain a transparent solution. Then, 0.02 g (0.12 mmol) of MoS2 powder was added and stirred for 2 h to mix. The mixture was then transferred to a stainless steel autoclave lined with polytetrafluoroethylene and heated in an electric oven at 80 °C for 8 h. After cooling, the black precipitate was collected, washed with distilled water and ethanol, and dried in a drying oven at 60 °C for 24 h. The resulting black powder was the MoS2 / Cu2S / MoO3 ternary composite material.

[0061] The MoS2 / Cu2S / MoO3 ternary composite material prepared in Example 1 was tested, and the results are as follows: Figure 1-3 As shown.

[0062] Figure 1 The images show the SEM and TEM images of the MoS2 / Cu2S / MoO3 ternary composite material, where a is the SEM image and b is the TEM image.

[0063] Depend on Figure 1 It can be seen that MoS2 is in the form of nanoflowers, uniformly distributed on the snowflake-shaped Cu2S.

[0064] Figure 2 XRD and Raman intrinsic spectra of the MoS2 / Cu2S / MoO3 ternary composite material are shown, where CSM 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3. a is the XRD pattern and b is the Raman pattern.

[0065] Depend on Figure 2 It can be seen that the MoS2 / Cu2S / MoO3 ternary composite material simultaneously possesses the characteristic peaks of both MoS2 and Cu2S; Figure 2 b shows that MoS2 in the MoS2 / Cu2S / MoO3 ternary composite material has a metallic 1T phase and a 2H phase.

[0066] Figure 3EDX elemental mapping and XPS spectra of O1s in the MoS2 / Cu2S / MoO3 ternary composite material are shown, where a is the EDX elemental mapping and b is the XPS spectra of O1s. 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3.

[0067] Depend on Figure 3 It can be seen that MoO3 was detected in the MoS2 / Cu2S / MoO3 ternary composite material. MoO3 has a high adsorption capacity for water molecules. At the same time, the presence of a large number of octahedral and tetrahedral interstices in the MoO3 lattice provides a convenient channel for the transition of certain charge carriers and also provides an ideal position for ions in catalytic reactions.

[0068] Example 2

[0069] A method for preparing a MoS2 / Cu2S / MoO3 ternary composite material includes the following steps:

[0070] 1.2358 g (1 mmol) of ammonium molybdate tetrahydrate and 2.7445 g (36 mmol) of thiourea were dissolved in 60 mL of deionized water. The mixture was stirred with a magnetic stirrer for 0.5 h until completely dissolved. The solution was then transferred to a 100 mL Teflon-lined stainless steel autoclave and placed in a drying oven at 240 °C for hydrothermal reaction for 17 h. The black precipitate was then collected, washed three times with deionized water and alcohol, and dried in a drying oven at 60 °C for 6 h to obtain a black solid powder, MoS2.

[0071] 0.2430 g (3.2 mmol) of thiourea and 0.170 g (1 mmol) of copper chloride dihydrate were dissolved in 30 mL (450 mmol) of ethylenediamine to obtain a transparent solution. Then, 0.0241 g (0.15 mmol) of MoS2 powder was added and stirred for 2 h to mix. The mixture was then transferred to a stainless steel autoclave lined with polytetrafluoroethylene and heated in an electric oven at 75 °C for 7.8 h. After cooling, the black precipitate was collected, washed with distilled water and ethanol, and dried in a drying oven at 60 °C for 24 h. The resulting black powder was the MoS2 / Cu2S / MoO3 ternary composite material.

[0072] Example 3

[0073] A method for preparing a MoS2 / Cu2S / MoO3 ternary composite material includes the following steps:

[0074] 1.2358 g (1 mmol) of ammonium molybdate tetrahydrate and 2.3004 g (30 mmol) of thiourea were dissolved in 60 mL of deionized water. The mixture was stirred with a magnetic stirrer for 0.5 h until completely dissolved. The solution was then transferred to a 100 mL Teflon-lined stainless steel autoclave and placed in a drying oven at 230 °C for hydrothermal reaction for 19 h. The black precipitate was then collected, washed three times with deionized water and alcohol, and dried in a drying oven at 60 °C for 6 h to obtain a black solid powder, MoS2.

[0075] 0.2138 g (2.8 mmol) of thiourea and 0.170 g (1 mmol) of copper chloride dihydrate were dissolved in 30 mL (450 mmol) of ethylenediamine to obtain a transparent solution. Then, 0.0165 g (0.1 mmol) of MoS2 powder was added and stirred for 2 h to mix well. The mixture was then transferred to a stainless steel autoclave lined with polytetrafluoroethylene and heated in an electric oven at 85 °C for 7.5 h. After cooling, the black precipitate was collected, washed with distilled water and ethanol, and dried in a drying oven at 60 °C for 24 h. The resulting black powder was the MoS2 / Cu2S / MoO3 ternary composite material.

[0076] Example 4

[0077] An electrode is prepared as follows: 2 mg of the MoS2 / Cu2S / MoO3 ternary composite material prepared in Example 1 is weighed and added to isopropanol (the isopropanol contains 0.5% Nafion solution), and ultrasonically dispersed in an ultrasonic machine to obtain a dispersion; 2 μL of the dispersion is pipetted and dropped onto a glassy carbon electrode with a diameter of 3 mm, and naturally dried at room temperature for 10 min to obtain the electrode, with a perfluorosulfonic acid polymer film containing the MoS2 / Cu2S / MoO3 ternary composite material attached to the electrode surface.

[0078] A standard three-electrode system was constructed using the aforementioned electrode as the cathode (i.e., working electrode), a carbon rod as the anode (i.e., counter electrode), and an Hg / HgO electrode as the reference electrode. A 1 mol / L potassium hydroxide aqueous solution was used as the electrolyte, and the electrolyte was purged with nitrogen for 0.5 h to remove dissolved oxygen. Several cyclic voltammetry tests were performed between -0.19 and -0.29 V to remove organic matter and other impurities from the cathode surface, converting all potentials to the potential relative to the reversible hydrogen electrode. Electrocatalytic hydrogen evolution performance was tested and compared with electrodes prepared from MoS2 and Cu2S as cathodes. The results are as follows: Figure 4 As shown.

[0079] Figure 4 The graph shows the electrocatalytic hydrogen evolution performance of the electrode prepared in Example 4, where CSM... 0.02-MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3. a is the LSV curve, b is the current density at 10mA / cm². 2 The overpotential histogram is shown at time a, c is the Tafel plot corresponding to a, d is the EIS spectrum, e is the electrochemical double layer capacitance value, f is the LSV curve after 16 h, and the inset shows the current density change over 16 h.

[0080] Depend on Figure 4 It can be seen that the MoS2 / Cu2S / MoO3 ternary composite material has good electrocatalytic hydrogen evolution performance and long-term stability. Compared with MoS2 and Cu2S, the MoS2 / Cu2S / MoO3 ternary composite material not only improves the conductivity, but also increases the number of active sites required for the reaction.

[0081] Example 5

[0082] Select a concentration of 10 -3 Methylene blue (MB), rhodamine 6G (R6G), crystal violet (CV), and malachite green (MG) were used as substrates. MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material described in Example 1 were added as substrates, respectively. The substrates were shaken for 2 hours to ensure sufficient contact between the substrates and each substrate. SERS detection was then performed to verify the optimal SERS activity of each substrate. The results are as follows: Figure 5-7 As shown.

[0083] Figure 5 The graph shows the SERS detection results of the MoS2 / Cu2S / MoO3 ternary composite material for methylene blue. In the graph, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of methylene blue. (CSM) 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3, and MB is methylene blue; b is the SERS detection graph of different concentrations of methylene blue using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c is the linear relationship graph corresponding to b; d is the SERS detection result of methylene blue after the MoS2 / Cu2S / MoO3 ternary composite material is used 5 times; e is the SERS detection result of methylene blue using the MoS2 / Cu2S / MoO3 ternary composite material after 1, 2, 3, and 4 months; f is the uniformity result of the SERS detection of methylene blue using the MoS2 / Cu2S / MoO3 ternary composite material.

[0084] Figure 6The image shows the SERS detection results of Rhodamine 6G on the MoS2 / Cu2S / MoO3 ternary composite material. In the image, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of Rhodamine 6G. (CSM) 0.02 -MoO3 is a ternary composite material of MoS2 / Cu2S / MoO3, and R6G is Rhodamine 6G; b is the SERS detection graph of different concentrations of Rhodamine 6G using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c is the linear relationship graph corresponding to b; d is the SERS detection result of Rhodamine 6G after the MoS2 / Cu2S / MoO3 ternary composite material is used 5 times; e is the SERS detection result of Rhodamine 6G after the MoS2 / Cu2S / MoO3 ternary composite material is placed for 1, 2, 3, and 4 months; f is the SERS detection uniformity result of Rhodamine 6G using the MoS2 / Cu2S / MoO3 ternary composite material.

[0085] Figure 7 The graph shows the SERS detection results of crystal violet by the MoS2 / Cu2S / MoO3 ternary composite material. In the graph, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of crystal violet. (CSM) 0.02 - MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3, and CV represents crystal violet; b shows the SERS detection results of different concentrations of crystal violet using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c shows the linear relationship corresponding to b; d shows the SERS detection results of crystal violet after 5 cycles of the MoS2 / Cu2S / MoO3 ternary composite material; e shows the SERS detection results of crystal violet after the MoS2 / Cu2S / MoO3 ternary composite material has been stored for 1, 2, 3, and 4 months; f shows the uniformity of the SERS detection results of crystal violet using the MoS2 / Cu2S / MoO3 ternary composite material.

[0086] Figure 8 The graph shows the SERS results of the MoS2 / Cu2S / MoO3 ternary composite material on malachite green. In the graph, 'a' represents the influence of MoS2, Cu2S, and the MoS2 / Cu2S / MoO3 ternary composite material on the SERS detection of malachite green. (CSM) 0.02-MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3, and MG represents malachite green; b shows the SERS detection results of malachite green at different concentrations using the MoS2 / Cu2S / MoO3 ternary composite material as a substrate; c shows the linear relationship corresponding to b; d shows the SERS detection results of malachite green after each of the five cycles of the MoS2 / Cu2S / MoO3 ternary composite material; e shows the SERS detection results of malachite green using the MoS2 / Cu2S / MoO3 ternary composite material after 1, 2, 3, and 4 months of storage; f shows the uniformity of the SERS detection results of malachite green using the MoS2 / Cu2S / MoO3 ternary composite material.

[0087] Depend on Figure 5-8 (a) It can be seen that the MoS2 / Cu2S / MoO3 ternary composite material can improve the SERS detection sensitivity of methylene blue, rhodamine 6G, crystal violet, and malachite green, with an enhancement factor of 1.4 × 10⁻⁶ for methylene blue. 6 Furthermore, the effect of the MoS2 / Cu2S / MoO3 ternary composite material on improving the SERS detection sensitivity is significantly better than that of MoS2 and Cu2S.

[0088] Depend on Figure 5-8 (bc) It can be seen that the addition of the MoS2 / Cu2S / MoO3 ternary composite material can make the four dyes exhibit a linear relationship in a low concentration range, and the detection limits of the four dyes are very low, with the detection limit of methylene blue as low as 10. -12 M.

[0089] Depend on Figure 5-8 (df) shows that the MoS2 / Cu2S / MoO3 ternary composite material has good cycleability, stability and uniformity.

[0090] The MoS2 / Cu2S / MoO3 ternary composite material described in this invention not only has extremely high SERS detection performance for a variety of dyes, but also has good versatility.

[0091] Example 6

[0092] The MoS2 / Cu2S / MoO3 ternary composite material was used in photocatalytic degradation tests of various dyes, including the following steps:

[0093] Weigh 10 mg of the MoS2 / Cu2S / MoO3 ternary composite material described in Example 1, and add 25 mL of each material with a concentration of 10. -3In a solution of methylene blue, rhodamine 6G, crystal violet, and malachite green, the MoS2 / Cu2S / MoO3 ternary composite material was magnetically stirred for 30 min at room temperature in the dark to establish adsorption-desorption equilibrium. The solution was then transferred to a 300W xenon arc lamp (the light from the xenon arc lamp was filtered through a 420nm cutoff filter) for photodegradation. At regular intervals, 1 mL of the solution was taken, centrifuged to remove the MoS2 / Cu2S / MoO3 ternary composite material, and the concentration of the corresponding dye in the solution was determined using a UV-Vis spectrometer. The results are as follows: Figure 9-11 .

[0094] Figure 9 Figure 1 shows the photocatalytic degradation results of malachite green by the MoS2 / Cu2S / MoO3 ternary composite material. In this figure, a represents the absorbance of the MoS2 / Cu2S / MoO3 ternary composite material at different time points during photocatalytic degradation of malachite green; b represents the absorbance of MoS2 at different time points during photocatalytic degradation of malachite green; c represents the absorbance of Cu2S at different time points during photocatalytic degradation of malachite green; and d represents the degradation rate of malachite green by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, respectively. (CSM) 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the kinetic modeling results of the photocatalytic degradation of malachite green by the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S; f represents the degradation rate of malachite green by the ternary composite material of MoS2 / Cu2S / MoO3 after 5 cycles.

[0095] Figure 10 The graph shows the photocatalytic degradation results of crystal violet by the MoS2 / Cu2S / MoO3 ternary composite material. In the graph: a) absorbance of the MoS2 / Cu2S / MoO3 ternary composite material at different time points during photocatalytic degradation of crystal violet; b) absorbance of MoS2 at different time points during photocatalytic degradation of crystal violet; c) absorbance of Cu2S at different time points during photocatalytic degradation of crystal violet; d) degradation rate of crystal violet by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, according to CSM. 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the results of the photocatalytic degradation kinetic modeling study of crystal violet by the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S; f represents the degradation rate of crystal violet by the ternary composite material of MoS2 / Cu2S / MoO3 after 5 cycles.

[0096] Figure 11Figure 1 shows the photocatalytic degradation results of Rhodamine 6G by the MoS2 / Cu2S / MoO3 ternary composite material. In this figure, a represents the absorbance of Rhodamine 6G at different time points during photocatalytic degradation by the MoS2 / Cu2S / MoO3 ternary composite material; b represents the absorbance of Rhodamine 6G at different time points during photocatalytic degradation by MoS2; c represents the absorbance of Rhodamine 6G at different time points during photocatalytic degradation by Cu2S; and d represents the degradation rate of Rhodamine 6G by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, respectively. 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the photocatalytic degradation kinetics modeling results of the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S on Rhodamine 6G; f represents the degradation rate of Rhodamine 6G after 5 cycles of the ternary composite material of MoS2 / Cu2S / MoO3.

[0097] Figure 12 The graph shows the photocatalytic degradation results of methylene blue by the MoS2 / Cu2S / MoO3 ternary composite material, where: a) is the absorbance of the MoS2 / Cu2S / MoO3 ternary composite material at different time points during photocatalytic degradation of methylene blue; b) is the absorbance of MoS2 at different time points during photocatalytic degradation of methylene blue; c) is the absorbance of Cu2S at different time points during photocatalytic degradation of methylene blue; and d) is the degradation rate of methylene blue by the MoS2 / Cu2S / MoO3 ternary composite material, MoS2, and Cu2S, according to CSM. 0.02 -MoO3 represents the ternary composite material of MoS2 / Cu2S / MoO3; e represents the kinetic modeling results of the photocatalytic degradation of methylene blue by the ternary composite material of MoS2 / Cu2S / MoO3, MoS2, and Cu2S; f represents the degradation rate of methylene blue after each of the five cycles of the ternary composite material of MoS2 / Cu2S / MoO3.

[0098] Depend on Figure 9-12 (ae) It can be seen that the MoS2 / Cu2S / MoO3 ternary composite material achieves almost complete degradation of the four dyes; the time required for the photocatalytic degradation of the four dyes by the MoS2 / Cu2S / MoO3 ternary composite material is much shorter than that of MoS2 and Cu2S; the degradation rate of the dye malachite green by the MoS2 / Cu2S / MoO3 ternary composite material can reach 99% within 24 minutes under visible light irradiation.

[0099] Depend on Figure 9-12 (f) It can be seen that the MoS2 / Cu2S / MoO3 ternary composite material has good recyclability and can be reused.

[0100] The MoS2 / Cu2S / MoO3 ternary composite material of the present invention has extremely high photocatalytic degradation ability for a variety of dyes.

[0101] In summary, the MoS2 / Cu2S / MoO3 ternary composite material of this invention can be used simultaneously for electrocatalytic hydrogen evolution under alkaline conditions, and can achieve highly sensitive SERS detection and efficient photocatalytic degradation of various dyes in actual water bodies. As a multifunctional material, the MoS2 / Cu2S / MoO3 ternary composite material has promising applications in both the energy and environmental fields.

[0102] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A MoS2 / Cu2S / MoO3 ternary composite material, characterized in that, In the MoS2 / Cu2S / MoO3 ternary composite material, MoS2 nanoflowers are uniformly distributed on snowflake-shaped Cu2S, and MoO3 is distributed on the surface of the MoS2 nanoflowers. In the MoS2 / Cu2S / MoO3 ternary composite material, MoS2 exists in the form of metallic 1T phase and 2H phase; The preparation method of the above-mentioned MoS2 / Cu2S / MoO3 ternary composite material includes the following steps: mixing copper source, solvent, sulfur source and MoS2, and then reacting to obtain MoS2 / Cu2S / MoO3 ternary composite material; The reaction temperature is 75-85℃; the reaction time is 7.5-8 h. The solvent is ethylenediamine; The molar ratio of copper to MoS2 in the copper source is 1:0.1-0.15; The molar ratio of copper to ethylenediamine in the copper source is 1:450-470; In the preparation of MoS2, an aqueous solution containing a molybdenum source and a sulfur source is taken and subjected to a hydrothermal reaction to obtain MoS2. In the preparation of MoS2, the molar ratio of molybdenum in the molybdenum source to sulfur in the sulfur source is 1:30-36. In the preparation of MoS2, the hydrothermal reaction temperature is 220-240℃ and the hydrothermal reaction time is 17-19 h.

2. A method for preparing the MoS2 / Cu2S / MoO3 ternary composite material as described in claim 1, characterized in that, The process includes the following steps: mixing copper source, solvent, sulfur source and MoS2, and then reacting to obtain MoS2 / Cu2S / MoO3 ternary composite material.

3. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, The copper source is an inorganic copper salt.

4. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, The copper source is at least one of copper chloride and copper chloride dihydrate.

5. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, The sulfur source is thiourea.

6. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, The molar ratio of copper in the copper source to sulfur in the sulfur source is 1:2.8-3.

2.

7. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, After the reaction was complete, the mixture was washed and dried to obtain the MoS2 / Cu2S / MoO3 ternary composite material.

8. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, In the preparation of MoS2, the molybdenum source is at least one of ammonium molybdate and ammonium molybdate tetrahydrate.

9. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, In the preparation of MoS2, the sulfur source is thiourea.

10. The method for preparing the MoS2 / Cu2S / MoO3 ternary composite material according to claim 2, characterized in that, In the preparation of MoS2, after the hydrothermal reaction is completed, the product is washed and dried to obtain MoS2.

11. The application of the MoS2 / Cu2S / MoO3 ternary composite material as described in claim 1 in electrocatalysis, photocatalytic degradation, and surface-enhanced Raman spectroscopy detection.

12. An electrode, characterized in that, A thin film is attached to the electrode surface, and the thin film contains the MoS2 / Cu2S / MoO3 ternary composite material as described in claim 1.

13. A method for electrocatalytic hydrogen production, characterized in that, The method includes the following steps: using the electrode described in claim 12 as the cathode, electrolyzing the alkaline electrolyte, and collecting hydrogen gas.

14. The method for electrocatalytic hydrogen production according to claim 13, characterized in that, The electrolyte in an alkaline electrolyte solution is an inorganic base.

15. A method for enhancing the detection sensitivity of SERS, characterized in that, The procedure includes the following steps: adding the MoS2 / Cu2S / MoO3 ternary composite material as described in claim 1 to the solution to be tested, and then performing SERS detection.

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