Zero-valent cobalt / CoFe2O4 / molybdenum disulfide heterojunction composite material and application thereof in water treatment

Abstract

The invention provides a zero-valent cobalt / CoFe2O4 / molybdenum disulfide heterojunction composite material and application thereof in water treatment, and belongs to the technical field of photocatalysis and advanced oxidation water treatment. The spinel type cobalt ferrite in the composite material provides high-density active sites; rich molybdenum ions exposed on the edge of molybdenum disulfide are utilized to promote in-situ dynamic reconstruction of a Co / Fe bimetallic active center, a heterojunction is formed by the molybdenum disulfide and the Co / Fe bimetallic active center, photon-generated carriers are effectively separated, reducing electrons are provided, and PMS activation efficiency and degradation kinetics of organic pollutants are synergistically enhanced; co ions in cobalt ferrite are reduced into zero-valent cobalt nanoclusters rich in electrons in situ by introducing light-induced in-situ reduction, so that the separation efficiency of photon-generated carriers is remarkably improved, and the in-situ regeneration of multi-metal active sites and the activation efficiency of PMS are enhanced.

Description

Technical Field

[0001] This invention belongs to the field of photocatalysis and advanced oxidation water treatment technology, specifically relating to a Co 0 / CoFe2O4 / MoS2 heterojunction composite materials and their application in water treatment. Background Technology

[0002] With rapid industrialization and urbanization, a large number of recalcitrant emerging pollutants have entered the aquatic environment, posing a serious threat to ecosystems and public health. These pollutants have wide sources and complex compositions, making their treatment a major challenge in the environmental field. For example, mineral processing wastewater is rich in high concentrations of heavy metal ions and flotation reagents, exhibiting characteristics of high alkalinity, high calcium ion content, and organic-inorganic complex pollution. Antibiotic wastewater discharged from medical and aquaculture industries has attracted much attention due to its bioinhibitory properties and the ease with which it induces the spread of resistance genes. Despite their diverse sources, these emerging pollutants generally share common challenges such as high concentration, high toxicity, stable chemical structure, and poor biodegradability. Traditional physical, chemical, and biological treatment methods often suffer from insufficient adaptability, low degradation efficiency, and the potential for secondary pollution, especially for residual flotation reagents, antibiotics, and their stable complexes with heavy metals, where conventional processes struggle to achieve deep purification and efficient removal. Therefore, developing efficient, broad-spectrum, and environmentally friendly deep treatment technologies and theories has become an urgent need and a cutting-edge direction in the field of water pollution control.

[0003] Advanced oxidation processes (AOPs) are widely used for treating recalcitrant organic wastewater due to their ability to generate strong oxidizing free radicals, high degradation efficiency, and wide applicability. Among them, persulfate activation technology is based on sulfate free radicals (·SO4). - Due to its strong oxidizing properties and long half-life, persulfate exhibits excellent degradation performance against a variety of organic pollutants. However, traditional homogeneous persulfate activation systems suffer from problems such as difficulty in recovering metal ions and the potential for secondary pollution.

[0004] To address the aforementioned issues, heterogeneous catalytic materials have been extensively developed. Among them, spinel-type cobalt ferrite (CoFe2O4) has become an ideal heterogeneous catalyst due to its stable crystal structure and the ability to be externally magnetically recovered. However, the catalytic activity of CoFe2O4 is heavily dependent on its surface metal ions (Co... 2+ / Fe 2+ The valence cycle of Co 3+ / Fe 3+ To Co 2+ / Fe 2+The slow kinetics of the reduction process of molybdenum disulfide (MoS2) is a key bottleneck limiting its catalytic efficiency. On the other hand, the two-dimensional layered material MoS2 shows potential in the field of catalysis due to its unique semiconductor properties and abundant active sites at its edges. However, single MoS2 has weak direct activation ability for PMS, and its inherent 2H phase has poor conductivity, resulting in low photogenerated carrier separation efficiency, making it difficult to effectively drive advanced oxidation reactions when used alone. In addition, MoS2 nanosheets tend to stack and aggregate between layers, leading to a reduction in active sites, and its instability in complex aquatic environments limits its direct application. Therefore, there is an urgent need to develop a novel material with efficient synergistic catalytic performance, good magnetic separation characteristics, and strong resistance to inorganic ions and pH interference. This has important theoretical and practical significance for achieving efficient treatment and resource recycling of organic wastewater. Summary of the Invention

[0005] The purpose of this invention is to provide a Co 0 / CoFe2O4 / MoS2 heterojunction composite material and its application in water treatment. This invention provides Co... 0 / CoFe2O4 / MoS2 heterojunction composite materials have the advantages of easy magnetic separation, good stability, wide adaptability and excellent ability to degrade organic pollutants.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a Co 0 The / CoFe2O4 / MoS2 heterojunction composite material includes MoS2 nanosheets and CoFe2O4 nanoparticles supported on the surface of the MoS2 nanosheets, as well as CoFe2O4 nanoparticles generated by photoinduced in-situ reduction of the CoFe2O4 nanoparticles. 0 .

[0007] The present invention also provides the Co described in the above technical solution. 0 The preparation method of / CoFe2O4 / MoS2 heterojunction composite material includes the following steps: (1) A cobalt source, an iron source, water and an alkaline solution are mixed and a co-precipitation reaction is carried out to obtain a precursor; the precursor is annealed to obtain nano-CoFe2O4; (2) (NH4)6Mo7O 24 • A hydrothermal reaction is carried out by mixing 4H2O, CH4N2S and ammonia water to obtain flower-shaped MoS2; (3) The nano-CoFe2O4 obtained in step (1) is mixed with the flower-shaped MoS2 obtained in step (2) and a solvent, and a solvothermal reaction is carried out to obtain a CoFe2O4 / MoS2 heterojunction; (4) The CoFe2O4 / MoS2 heterojunction obtained in step (3) is subjected to photoinduced in-situ reduction to obtain Co 0 / CoFe2O4 / MoS2 heterojunction composite material; The steps (1) and (2) are not in any particular order.

[0008] Preferably, the temperature of the coprecipitation reaction in step (1) is 60~90℃, and the time of the coprecipitation reaction is 1~3h.

[0009] Preferably, the annealing temperature in step (1) is 500~600℃ and the annealing time is 1~3h.

[0010] Preferably, in step (2), (NH4)6Mo7O 24 The molar ratio of 4H2O to CH4N2S is 1:(5~30).

[0011] Preferably, the temperature of the hydrothermal reaction in step (2) is 180~220℃ and the time of the hydrothermal reaction is 12~20h.

[0012] Preferably, in step (3), the mass ratio of nano-CoFe2O4 to flower-like MoS2 is 1:(2~4).

[0013] Preferably, the temperature of the solvothermal reaction in step (3) is 160~220℃, and the time of the solvothermal reaction is 4~20h.

[0014] Preferably, the photoinduced in-situ reduction in step (4) is performed under xenon lamp irradiation; the photoinduced in-situ reduction time is 2-5 min.

[0015] The present invention also provides the Co described in the above technical solution. 0 / CoFe2O4 / MoS2 heterojunction composite material or Co prepared by the preparation method described in the above technical solution. 0 Application of / CoFe2O4 / MoS2 heterojunction composite material in the degradation of organic pollutants in a photocatalytic-Fenton-like synergistic system.

[0016] This invention provides a Co 0 The / CoFe2O4 / MoS2 heterojunction composite material includes MoS2 nanosheets and CoFe2O4 nanoparticles supported on the surface of the MoS2 nanosheets, as well as CoFe2O4 nanoparticles generated by photoinduced in-situ reduction of the CoFe2O4 nanoparticles. 0 In the composite material provided by this invention, spinel-type CoFe2O4 serves as an excellent magnetic persulfate activating component, providing a high density of active sites; MoS2 acts as a co-catalyst, utilizing its exposed edges to generate abundant Mo. 4+This invention promotes the in-situ dynamic reconstruction of the Co / Fe bimetallic active centers. Simultaneously, the formation of a heterojunction between MoS2 and CoFe2O4 effectively separates photogenerated carriers and provides reducing electrons, synergistically enhancing the activation efficiency of peroxymonosulfate (PMS) and the degradation kinetics of organic pollutants. Furthermore, this invention introduces a photoinduced in-situ reduction strategy, where the surface of CoFe2O4 in the heterojunction can accumulate photogenerated electrons. These electrons can continuously reduce the Co content in CoFe2O4. 2+ In-situ reduction to electron-rich zero-valent cobalt (Co) 0 The nanoclusters significantly improve the separation efficiency of photogenerated carriers, enhance the in-situ regeneration of multi-metal active sites, and improve the activation efficiency of PMS. The composite material provided by this invention has the advantages of easy magnetic separation, good stability, wide adaptability, and excellent degradation performance of organic pollutants. Attached Figure Description

[0017] Figure 1 Flower-like MoS2, CoFe2O4 nanoparticles and Co prepared in Example 1 0 SEM image of the / CoFe2O4 / MoS2 heterojunction composite material; Figure 2 Co prepared in Example 1 0 Energy dispersive X-ray spectroscopy results of / CoFe2O4 / MoS2 heterojunction composite material; Figure 3 TEM image of the CoFe2O4 / MoS2 heterojunction prepared in Example 1; Figure 4 Co prepared in Example 1 0 TEM image of the / CoFe2O4 / MoS2 heterojunction composite material; Figure 5 Co prepared in Example 1 0 DRS spectrum of / CoFe2O4 / MoS2 heterojunction composite material; Figure 6 Flower-like MoS2, CoFe2O4 nanoparticles and Co prepared in Example 1 0 Photocurrent density-time spectrum of / CoFe2O4 / MoS2 heterojunction composite material; Figure 7 The CoFe2O4 / MoS2 heterojunction and Co prepared in Example 1 0 TRPL spectrum of / CoFe2O4 / MoS2 heterojunction composite material; Figure 8 Co prepared in Example 1 0 Magnetic separation effect diagram of / CoFe2O4 / MoS2 heterojunction composite material; Figure 9A comparison graph showing the degradation effects of different systems on CBZ in Application Example 2 and Comparative Application Examples 1-6; Figure 10 Co prepared in Example 1 0 Figure 1. Free radical quenching experimental results of CBZ degradation by / CoFe2O4 / MoS2 heterojunction composite material; Figure 11 Co prepared using Example 1 0 Ecotoxicity comparison of CBZ simulated wastewater before and after degradation of / CoFe2O4 / MoS2 heterojunction composite material; Figure 12 Co prepared in Example 1 0 Comparison of CBZ degradation in / CoFe2O4 / MoS2 heterojunction composites at different pH values; Figure 13 Co prepared in Example 1 0 Comparison of the degradation solutions CBZ of / CoFe2O4 / MoS2 heterojunction composites under different inorganic anion / humic acid interferences; Figure 14 Co prepared in Example 1 0 Comparison of the degradation effects of / CoFe2O4 / MoS2 heterojunction composite materials on different organic pollutants. Detailed Implementation

[0018] This invention provides a Co 0 The / CoFe2O4 / MoS2 heterojunction composite material includes MoS2 nanosheets and CoFe2O4 nanoparticles supported on the surface of the MoS2 nanosheets, as well as CoFe2O4 nanoparticles generated by photoinduced in-situ reduction of the CoFe2O4 nanoparticles. 0 .

[0019] This invention constructs Co 0 The / CoFe2O4 / MoS2 heterojunction achieves efficient separation of photogenerated electron-hole pairs under visible light excitation, and the MoS2 edge Mo 4+ Promote Co 3+ / Fe 3+ The reduction and regeneration process occurs. Under visible light excitation, electrons excited to the conduction band in MoS2 recombine with holes in the valence band of CoFe2O4. The large number of photogenerated electrons accumulated on the surface of CoFe2O4 can continuously reduce the Co content in CoFe2O4. 2+ Dynamically restored to Co 0 Thus achieving Co 0 In-situ green deposition of clusters; compared with traditional CoFe2O4 / MoS2 binary heterostructure composite materials, the Co provided by this invention... 0The / CoFe2O4 / MoS2 ternary composite material exhibits significant advantages in intrinsic catalytic mechanism, pollutant removal efficiency, anti-interference ability, and recyclability. (1) Photoinduced in-situ generation of electron-rich Co 0 Nanoclusters can directly convert low-activity Co in Fenton-like catalytic systems 3+ In-situ reduction to highly reactive Co 2+ Simultaneously accelerating the redox cycle kinetics of Fe and Mo dual active centers; on the other hand, the metal Co 0 It can act as an "electron trap," thus significantly promoting the separation and migration of photogenerated carriers. The synergistic effect of these mechanisms enables the ternary system to not only have a faster initial reaction rate, but also to maintain efficient and stable degradation performance over a wider range of pollutant concentrations and pH levels, providing a highly efficient catalytic solution with practical application prospects for treating recalcitrant organic wastewater.

[0020] (2) Metal Co 0 As an electron-rich center, it can physically block some inorganic anions (such as Cl-) through electrostatic repulsion. - NO3 - The poisoning effect on active sites; simultaneously, the system drives... 1 The O2-dominated oxidation pathway itself has strong anti-interference capabilities. This dual physical-chemical shielding mechanism ensures that the material maintains high efficiency and stable catalytic activity in complex water environments, breaking through the application limitations of traditional free radical-driven catalysts in practical scenarios.

[0021] (3) Co 0 The high intrinsic saturation magnetization further enhances the magnetic properties of the composite material, enabling rapid recovery and multiple recycling through an external magnetic field. It also maintains high catalytic activity and structural stability when treating various organic wastewaters.

[0022] The present invention also provides the Co described in the above technical solution. 0 The preparation method of / CoFe2O4 / MoS2 heterojunction composite material includes the following steps: (1) A cobalt source, an iron source, water and an alkaline solution are mixed and a co-precipitation reaction is carried out to obtain a precursor; the precursor is annealed to obtain nano-CoFe2O4; (2) (NH4)6Mo7O 24 • A hydrothermal reaction is carried out by mixing 4H2O, CH4N2S and ammonia water to obtain flower-shaped MoS2; (3) The nano-CoFe2O4 obtained in step (1) is mixed with the flower-shaped MoS2 obtained in step (2) and a solvent, and a solvothermal reaction is carried out to obtain a CoFe2O4 / MoS2 heterojunction; (4) The CoFe2O4 / MoS2 heterojunction obtained in step (3) is subjected to photoinduced in-situ reduction to obtain Co 0 / CoFe2O4 / MoS2 heterojunction composite material; The steps (1) and (2) are not in any particular order.

[0023] Unless otherwise specified, the present invention does not impose any special restrictions on the source of the raw materials, and commercially available products well known to those skilled in the art can be used.

[0024] This invention involves mixing a cobalt source, an iron source, water, and an alkaline solution to perform a co-precipitation reaction, thereby obtaining a precursor.

[0025] In this invention, the cobalt source preferably includes Co(NO3)2·6H2O, CoCl2·6H2O or CoSO4·7H2O.

[0026] In this invention, the iron source preferably includes Fe(NO3)3·9H2O, FeCl3·6H2O, or Fe2(SO4)3 hydrate.

[0027] In this invention, the preferred molar ratio of the cobalt source to the iron source is 1:(1.8~2.2). As one embodiment, the molar ratio of the cobalt source to the iron source may specifically be 1:1.8, 1:1.9, 1:2.0, 1:2.1 or 1:2.2.

[0028] In this invention, the water is preferably deionized water.

[0029] In this invention, the alkaline solution preferably comprises an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide; the concentration of the alkaline solution is preferably 4-8 mol / L. As one embodiment, the concentration of the alkaline solution can specifically be 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, or 8 mol / L.

[0030] In this invention, the preferred method for mixing the cobalt source, iron source, water, and alkaline solution is to: mix the cobalt source with a portion of the water to obtain a cobalt source solution; mix the iron source with the remaining water to obtain an iron source solution; mix the cobalt source solution and the iron source solution to obtain a mixed solution; and add the mixed solution dropwise to an alkaline solution at 60-90°C.

[0031] In this invention, the concentration of cobalt ions in the cobalt source solution is preferably 0.1~0.3 mol / L, more preferably 0.2 mol / L; the concentration of iron ions in the iron source solution is preferably 0.18~0.66 mol / L, more preferably 0.36~0.44 mol / L; and the volume ratio of the alkali solution to the mixed solution is preferably (1~3):10.

[0032] The present invention does not have a special limitation on the amount of water used and the remaining water, as long as the concentration of cobalt ions in the cobalt source solution and the concentration of iron ions in the iron source solution are within the required range.

[0033] The present invention does not impose any special limitation on the specific rate of dripping; any dripping technique known to those skilled in the art can be used.

[0034] In this invention, the temperature of the coprecipitation reaction is preferably 60~90℃; the time of the coprecipitation reaction is preferably 1~3h. As one embodiment, the temperature of the coprecipitation reaction can be specifically 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃; the time of the coprecipitation reaction can be specifically 1h, 1.5h, 2h, 2.5h or 3h.

[0035] The present invention controls the amount of each raw material, the reaction temperature and time within the above range, so that the raw materials can react fully.

[0036] After the coprecipitation reaction is completed, the product of the coprecipitation reaction is preferably subjected to cooling, solid-liquid separation, washing and drying in sequence.

[0037] The present invention does not impose any special limitations on the cooling operation; any technical solution known to those skilled in the art can be used to cool to room temperature.

[0038] The present invention does not impose any particular limitation on the operation of the solid-liquid separation; any technical solution well known to those skilled in the art can be used to obtain the solid. As one embodiment, the solid-liquid separation is centrifugation.

[0039] The present invention does not impose any special limitations on the washing operation; washing to neutrality can be performed using technical solutions well known to those skilled in the art.

[0040] The present invention does not impose any special limitations on the drying operation; drying to constant weight can be achieved using technical solutions well known to those skilled in the art.

[0041] After obtaining the precursor, the present invention performs annealing treatment on the precursor to obtain nano-CoFe2O4.

[0042] In this invention, the annealing temperature is preferably 500-600℃; the annealing time is preferably 1-3 hours. As one embodiment, the annealing temperature can specifically be 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, 560℃, 570℃, 580℃, 590℃, or 600℃; the annealing time can specifically be 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours. By controlling the annealing temperature and time within the above ranges, this invention enables the precursor to react fully to obtain nano-CoFe2O4.

[0043] After the annealing process is completed, the product of the annealing process is preferably cooled to obtain nano-CoFe2O4.

[0044] The present invention does not impose any special limitations on the cooling operation; any technical solution known to those skilled in the art can be used to cool to room temperature.

[0045] This invention uses (NH4)6Mo7O 24 • 4H2O, CH4N2S and ammonia water are mixed and subjected to a hydrothermal reaction to obtain flower-shaped MoS2.

[0046] In this invention, the (NH4)6Mo7O 24 The preferred molar ratio of 4H₂O to CH₄N₂S is 1:(5~30). As one embodiment, the (NH₄)₆Mo₇O₇ 24 The molar ratio of 4H2O and CH4N2S can be 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, 1:20, 1:22, 1:25, 1:28 or 1:30.

[0047] In this invention, the mass concentration of the ammonia water is preferably 28%.

[0048] In this invention, the (NH4)6Mo7O 24 The concentration of molybdenum ions in the mixed solution obtained by mixing ·4H2O, CH4N2S and ammonia is preferably 0.05~0.15mol / L, more preferably 0.1mol / L.

[0049] This invention relates to the (NH4)6Mo7O 24 There are no particular limitations on the method of mixing 4H2O, CH4N2S and ammonia water. A technical solution well-known to those skilled in the art can be used to mix (NH4)6Mo7O. 24 • Simply dissolve 4H2O and CH4N2S completely and mix thoroughly.

[0050] In this invention, the preferred temperature for the hydrothermal reaction is 180~220℃; the preferred reaction time is 12~20h. As one embodiment, the specific temperature for the hydrothermal reaction can be 180℃, 190℃, 200℃, 210℃, or 220℃; the specific reaction time can be 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, or 20h.

[0051] This invention controls the amount of each raw material, the reaction temperature, and the time within the above-mentioned range, which enables the raw materials to react fully and obtain flower-shaped MoS2.

[0052] After the hydrothermal reaction is completed, the present invention preferably cools, separates solids and liquids, washes and dries the products of the hydrothermal reaction in sequence.

[0053] The present invention does not impose any special limitations on the cooling operation; any technical solution known to those skilled in the art can be used to cool to room temperature.

[0054] The present invention does not impose any particular limitation on the operation of the solid-liquid separation; any technical solution well known to those skilled in the art can be used to obtain the solid. As one embodiment, the solid-liquid separation is centrifugation.

[0055] The present invention does not impose any special limitations on the washing operation; washing to neutrality can be performed using technical solutions well known to those skilled in the art.

[0056] The present invention does not impose any special limitations on the drying operation; drying to constant weight can be achieved using technical solutions well known to those skilled in the art.

[0057] After obtaining nano-CoFe2O4 and flower-like MoS2, the present invention mixes the nano-CoFe2O4 and flower-like MoS2 with a solvent and carries out a solvothermal reaction to obtain a CoFe2O4 / MoS2 heterojunction.

[0058] In this invention, the preferred mass ratio of nano-CoFe2O4 to flower-like MoS2 is 1:(2~4). As one embodiment, the mass ratio of nano-CoFe2O4 to flower-like MoS2 can be specifically 1:2, 1:2.5, 1:3, 1:3.5 or 1:4.

[0059] In this invention, the solvent preferably includes anhydrous ethanol, water, or an ethanol-water solution. When the solvent is an ethanol-water solution, the volume ratio of ethanol to water is preferably (0.3~3):1.

[0060] In this invention, the preferred mass ratio of the nano-CoFe2O4 to the volume ratio of the solvent is (0.5~1.5) mg:1 mL.

[0061] In this invention, the preferred method for mixing the nano-CoFe2O4 with the flower-like MoS2 and the solvent is to mix the nano-CoFe2O4 with the flower-like MoS2 and the solvent, and then sonicate for 20-40 minutes.

[0062] In this invention, the temperature of the solvothermal reaction is preferably 160~220℃; the time of the solvothermal reaction is preferably 4~20h. As one embodiment, the temperature of the solvothermal reaction can specifically be 160℃, 170℃, 180℃, 190℃, 200℃, 210℃ or 220℃; the time of the solvothermal reaction can specifically be 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 15h, 18h or 20h.

[0063] This invention controls the amount of each raw material and the reaction temperature and time within the above-mentioned range, which enables the two to react fully and form a heterojunction structure.

[0064] After the solvothermal reaction is completed, the products of the solvothermal reaction are preferably cooled, separated into solid and liquid phases, washed, and dried in sequence.

[0065] The present invention does not impose any special limitations on the cooling operation; any technical solution known to those skilled in the art can be used to cool to room temperature.

[0066] The present invention does not impose any particular limitation on the operation of the solid-liquid separation; any technical solution well known to those skilled in the art can be used to obtain the solid. As one embodiment, the solid-liquid separation is centrifugation.

[0067] The present invention does not impose any special limitations on the washing operation; washing to neutrality can be performed using technical solutions well known to those skilled in the art.

[0068] The present invention does not impose any special limitations on the drying operation; drying to constant weight can be achieved using technical solutions well known to those skilled in the art.

[0069] After obtaining the CoFe2O4 / MoS2 heterojunction, this invention performs photoinduced in-situ reduction on the CoFe2O4 / MoS2 heterojunction to obtain Co 0 / CoFe2O4 / MoS2 heterojunction composite material.

[0070] In this invention, the photoinduced in-situ reduction is preferably performed under xenon lamp irradiation; the power of the xenon lamp irradiation is preferably ≥300W; and the photoinduced in-situ reduction time is preferably 2-5 minutes. As one embodiment, the photoinduced in-situ reduction time can specifically be 2 minutes, 3 minutes, 4 minutes, or 5 minutes. By controlling the photoinduced in-situ reduction time and other parameters within the above ranges, this invention enables the composite material to contain an appropriate amount of Co. 0 This further improves the photocatalytic degradation effect of composite materials on organic pollutants.

[0071] This invention prepares a heterojunction composite material by electrostatic self-assembly and hydrothermal composite of flower-shaped MoS2 nanosheets and spinel-type CoFe2O4 nanoparticles. The CoFe2O4 nanoparticles are uniformly anchored on the surface of the MoS2 nanosheets, forming a heterojunction structure with a built-in electric field, which significantly promotes the separation and migration of photogenerated carriers. Furthermore, under xenon lamp irradiation, Co… 0 Nanoclusters are dynamically generated in situ on the surface of CoFe2O4, which further regulates the dynamic reconstruction and utilization of multi-metal active sites. The preparation method provided by this invention has low raw material cost and does not require complex high-temperature treatment or external reducing agents, which greatly simplifies the process flow. At the same time, it effectively avoids the agglomeration or destruction of material structure that may be caused by high temperature, and provides a novel and controllable synthesis route for the precise construction of metal-semiconductor multi-interface composite materials.

[0072] The present invention also provides the Co described in the above technical solution. 0 / CoFe2O4 / MoS2 heterojunction composite material or Co prepared by the preparation method described in the above technical solution. 0 Application of / CoFe2O4 / MoS2 heterojunction composite material in the degradation of organic pollutants in a photocatalytic-Fenton-like synergistic system.

[0073] The present invention preferably uses the Co 0 A mixture of / CoFe2O4 / MoS2 heterojunction composite material, peroxymonosulfate, and wastewater containing organic pollutants is subjected to a photocatalytic reaction to obtain treated wastewater.

[0074] In this invention, the Co 0 The preferred mass ratio of the / CoFe2O4 / MoS2 heterojunction composite material to the volume ratio of wastewater containing organic pollutants is (0.05~1) g:1L; the preferred mass ratio of the peroxymonosulfate to the volume ratio of wastewater containing organic pollutants is (0.1~1) mmol:1L.

[0075] This invention addresses the problems of low treatment efficiency, difficulty in recovering powdered catalysts, easy deactivation of active sites, and poor cycle stability in existing technologies for treating high-hardness, recalcitrant organic wastewater. It innovatively provides a Co... 0 CoFe2O4 / MoS2 heterojunction photocatalytic materials, their preparation methods, and application strategies. This material effectively integrates the co-catalytic properties of MoS2 with the Fenton-like catalytic activity of magnetic CoFe2O4 by constructing a heterojunction interface co-mediated by multiple metal active sites. Compared to traditional CoFe2O4 / MoS2 binary heterojunction composites, the photo-induced in-situ generation of metallic Co... 0Clusters can act as efficient electron donors and transport channels, greatly accelerating the redox cycle kinetics between multi-metal active sites and the separation efficiency of photogenerated carriers, inducing the use of non-radical pathways (singlet oxygen) 1 This composite material utilizes an efficient and stable oxidation pathway centered on O2. When applied to a photocatalytic-Fenton-like synergistic degradation system, it achieves efficient degradation of various organic pollutants in organic wastewater, exhibiting excellent magnetic separation performance and cycle stability.

[0076] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0077] Example 1 A Co 0 The / CoFe2O4 / MoS2 heterojunction composite material consists of MoS2 nanosheets, CoFe2O4 nanoparticles supported on the surface of the MoS2 nanosheets, and CoFe2O4 nanoparticles generated by photoinduced in-situ reduction of the CoFe2O4 nanoparticles. 0 composition; The Co 0 The preparation method of the / CoFe2O4 / MoS2 heterojunction composite material is as follows: (1) Mix 10 mmol Co(NO3)2·6H2O and 50 mL deionized water to obtain a cobalt nitrate solution (cobalt ion concentration is 0.2 mol / L), mix 20 mmol Fe(NO3)3·9H2O and 50 mL deionized water to obtain an iron nitrate solution (iron ion concentration is 0.4 mol / L), mix the cobalt nitrate solution and the iron nitrate solution to obtain a mixed solution (in the mixed solution, the molar ratio of cobalt nitrate to iron nitrate is 1:2), add the mixed solution dropwise to 20 mL of 5 mol / L sodium hydroxide aqueous solution at 80 °C (the volume ratio of sodium hydroxide aqueous solution to mixed solution is 2:10), and carry out a co-precipitation reaction at 80 °C for 2 h. After the reaction is completed, cool to room temperature, centrifuge to obtain a solid, wash the solid with water until neutral, and then vacuum dry at 60 °C for 12 h to obtain a precursor; (2) The precursor obtained in step (1) was annealed at 500℃ for 3h and cooled to room temperature to obtain CoFe2O4 nanoparticles; (3) (NH4)6Mo7O 24 Mix 4H2O, CH4N2S, and 60mL of ammonia solution (the mass concentration of ammonia solution is 28%), (NH4)6Mo7O 24The concentration of molybdenum ions in the mixed solution obtained by ·4H2O, CH4N2S and ammonia water is 0.1 mol / L, (NH4)6Mo7O 24 The molar ratio of 4H2O to CH4N2S was 1:20. The reaction was carried out at 200℃ for 18h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged to obtain a solid, washed three times each with anhydrous ethanol and deionized water, and dried under vacuum at 60℃ for 12h to obtain flower-shaped MoS2 microspheres. (4) Disperse 50 mg of CoFe2O4 nanoparticles obtained in step (2) and 100 mg of flower-shaped MoS2 microspheres obtained in step (3) in 50 mL of anhydrous ethanol (the mass ratio of CoFe2O4 nanoparticles to flower-shaped MoS2 microspheres is 1:2, and the mass ratio of CoFe2O4 nanoparticles to anhydrous ethanol is 1 mg:1 mL). Sonicate for 30 min, and carry out a solvothermal reaction at 200 °C for 8 h. After the reaction is completed, cool to room temperature, centrifuge to obtain solid, wash with anhydrous ethanol and deionized water three times alternately, and vacuum dry at 60 °C for 12 h to obtain CoFe2O4 / MoS2 heterojunction. (5) The CoFe2O4 / MoS2 heterojunction obtained in step (4) was photo-induced in-situ reduced by irradiation under a xenon lamp (power 300W) for 5 min to obtain Co 0 / CoFe2O4 / MoS2 heterojunction composite material.

[0078] SEM image of the nanoflower-like MoS2 microspheres prepared in Example 1 is shown below. Figure 1 As shown in (a), the SEM image of CoFe2O4 nanoparticles is as follows. Figure 1 As shown in (b), Co 0 SEM image of the / CoFe2O4 / MoS2 heterojunction composite material is shown below. Figure 1 As shown in (c). From Figure 1 As can be seen, pure MoS2 exhibits a typical flower-like microsphere structure, composed of countless 2D nanosheets self-assembled, with an overall size of approximately 2-3 μm; CoFe2O4 consists of irregular nanoparticles with a particle size distribution of 30-60 nm. Figure 1 (c) It can be clearly observed that CoFe2O4 nanoparticles are uniformly anchored on the surface of MoS2 nanosheets, indicating that the two have been successfully composited.

[0079] The Co prepared in Example 1 was subjected to spot scanning mode. 0 Energy dispersive X-ray spectroscopy (EDS) analysis was performed on the / CoFe2O4 / MoS2 heterojunction composite material, and the results are as follows: Figure 2 As shown. From Figure 2 The typical characteristic peaks corresponding to the five elements Mo, S, Co, Fe and O can be clearly observed, confirming the successful synthesis of the composite material.

[0080] The MoS2 / CoFe2O4 heterostructure prepared in Example 1 was compared with that of Co by TEM. 0 The microstructure elemental distribution of the / MoS2 / CoFe2O4 heterojunction composite material is shown in the following figures. Figure 3 and Figure 4 As shown. Figure 3 This paper presents high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images of the MoS2 / CoFe2O4 heterostructure and the corresponding elemental distribution energy dispersive spectroscopy mapping results. The HAADF images clearly demonstrate the nanoscale microstructure of the heterostructure, revealing structures with granular or aggregate characteristics, reflecting the microscopic aggregation state of the material. The coexistence and composite distribution of Mo, S, Co, Fe, and O elements at the nanoscale directly demonstrate the successful composite of MoS2 and CoFe2O4. In contrast, the TEM elemental mapping analysis results show that in Co... 0 In the / MoS2 / CoFe2O4 heterostructure, the enrichment region of Co is significantly larger than that of Fe. Figure 4 This phenomenon confirms that Co oxidative stress occurred on the surface of the composite material under visible light irradiation. 0 In-situ generation of clusters.

[0081] Figure 5 MoS2, CoFe2O4 and Co prepared in Example 1 0 The UV-Vis diffuse reflectance (UV-Vis DRS) spectra of the / MoS2 / CoFe2O4 heterojunction composite material reflect the absorption characteristics of different materials in the UV-Vis light range. CoFe2O4 exhibits strong light absorption in the 200–800 nm wavelength range, especially in the visible light region where it has high absorbance and a wide response range. The absorbance of MoS2 gradually increases with increasing wavelength, showing significant absorption in the UV to near-visible light region, demonstrating its response to UV and part of the visible light. The absorbance of the composite material lies between that of the two individual components. The synergistic light absorption of MoS2 and CoFe2O4 optimizes the light response range and absorption capacity, providing favorable optical conditions for photocatalytic degradation.

[0082] MoS2, CoFe2O4 and Co prepared in Example 1 0 The photocurrent density-time spectrum of the / MoS2 / CoFe2O4 heterojunction composite material is as follows: Figure 6 As shown. From Figure 6 It can be seen that Co 0 The photocurrent density of the / MoS2 / CoFe2O4 heterojunction composite material is significantly higher than that of the two monomer catalysts, mainly due to the efficient carrier conduction pathway constructed at the heterojunction interface. Simultaneously, the Co deposited on the surface... 0Clusters, acting as “electron storage devices,” effectively suppress recombination of photogenerated carriers.

[0083] The MoS2 / CoFe2O4 heterojunction prepared in Example 1 and Co 0 The time-resolved fluorescence lifetime (TRPL) spectrum of the / MoS2 / CoFe2O4 heterojunction composite material is shown below. Figure 7 As shown. From Figure 7 As can be seen from the data, the ratios of MoS2 / CoFe2O4 and Co can be calculated by combining the relevant parameters of the fitted line. 0 The photogenerated carrier lifetimes τ of the / MoS2 / CoFe2O4 heterojunction composite material are 0.659 ns and 0.725 ns, respectively, indicating that Co 0 Clustering effectively extends the lifetime of charge carriers.

[0084] Application Example 1 The Co prepared in Example 1 0 A suspension of the / MoS2 / CoFe2O4 heterojunction composite material was allowed to stand, and then a common neodymium iron boron magnet was placed on the outer wall of the container for separation. The results are as follows. Figure 8 As shown. From Figure 8 It can be seen from Co 0 The / MoS2 / CoFe2O4 heterojunction composite material was rapidly attracted to the right side of the container by the magnet, and the supernatant became clear and transparent, achieving rapid and efficient separation of the composite material from water. This phenomenon directly demonstrates the excellent magnetic response performance of the composite material, ensuring its convenient recovery and recycling in actual water treatment processes.

[0085] Application Example 2 6 mg of Co prepared in Example 1 0 The / MoS2 / CoFe2O4 heterojunction composite material was added to 50 mL of simulated wastewater containing 5 mg / L carbamazepine (CBZ) (initial pH = 6.6). The mixture was stirred in the dark for 30 min before the degradation reaction began to reach adsorption-desorption equilibrium. Then, 0.5 mmol / L PMS was added as an oxidant, and a xenon lamp (wavelength > 400 nm) was turned on. The reaction was stirred at 500 rpm at room temperature. Samples were taken at 0, 2, 4, 6, 8, and 10 min of the reaction. After filtration through a 0.22 μm filter membrane, the residual concentration of carbamazepine was determined by liquid chromatography and denoted as Co. 0 The degradation rate of CBZ reached 99.89% after reacting with / MoS2 / CoFe2O4+PMS+Vis for 10 min.

[0086] Comparative Application Example 1 Omit the PMS and xenon lamp light source from Application Example 2, and leave everything else the same as in Application Example 2, denoted as Co. 0 / MoS2 / CoFe2O4.

[0087] Comparative Application Example 2 Omit PMS in Application Example 2, otherwise remain the same as in Application Example 2, and denote it as Co. 0 / MoS2 / CoFe2O4+Vis.

[0088] Comparative Application Example 3 Omit the xenon lamp source in Application Example 2, and keep everything else the same as in Application Example 2, denoted as Co. 0 / MoS2 / CoFe2O4+PMS.

[0089] Comparative Application Example 4 Applying Co in Example 2 0 The / MoS2 / CoFe2O4 heterojunction composite material was replaced with the MoS2 / CoFe2O4 heterojunction prepared in Example 1, and everything else was the same as in Application Example 2, denoted as MoS2 / CoFe2O4+PMS+Vis.

[0090] Comparative Application Example 5 Applying Co in Example 2 0 The / MoS2 / CoFe2O4 heterojunction composite material was replaced with MoS2 prepared in Example 1, and everything else was the same as in Application Example 2, denoted as MoS2+PMS+Vis.

[0091] Comparative Application Example 6 Applying Co in Example 2 0 The / MoS2 / CoFe2O4 heterojunction composite material was replaced with CoFe2O4 prepared in Example 1, and everything else was the same as in Application Example 2, denoted as CoFe2O4+PMS+Vis.

[0092] The degradation curves of CBZ in different reaction systems in Application Example 2 and Comparative Application Examples 1-6 are shown below. Figure 9 As shown. From Figure 9 It can be seen from this that "Co" 0 The removal efficiency of CBZ in the " / MoS2 / CoFe2O4+PMS+Vis" synergistic system was significantly better than that in the "Co" system. 0 / MoS2 / CoFe2O4+PMS”, Co 0 The performance improvement is mainly attributed to the efficient migration of charge carriers at the heterojunction interface and the synergistic mechanism between photocatalysis and Fenton-like reactions. It is worth noting that the Co... 0The degradation performance of the "MoS2 / CoFe2O4+PMS+Vis" system is superior to that of the "MoS2 / CoFe2O4+PMS+Vis" system, indicating that nano-Co 0 The presence of clusters effectively improves the separation efficiency of photogenerated carriers and simultaneously promotes the activation of PMS.

[0093] The experimental procedure of Example 2 was repeated. Before the formal degradation reaction began, an appropriate amount of quencher was added to the carbamazepine solution to distinguish the contributions of different active species in the system. Tert-butanol (200 mmol / L) was used to quench hydroxyl radicals, methanol (200 mmol / L) was used to quench hydroxyl and sulfate radicals, p-benzoquinone (10 mmol / L) was used to quench superoxide radicals, and L-histidine (1 mmol / L) was used to quench singlet oxygen.

[0094] The experimental procedure of Example 2 was repeated, and water samples of carbamazepine solution before and after the degradation reaction were taken as test solutions. The degraded solution was subjected to solid-liquid separation to remove catalyst particles. Deionized water was used as a blank control. An equal volume of test solution was added to a petri dish for bean sprout growth experiments. The ecotoxicological changes of the solution before and after the degradation reaction were evaluated by comparing the growth status of bean sprouts under different test solution conditions.

[0095] Co prepared in Example 1 0 The free radical quenching experimental results of the / MoS2 / CoFe2O4 heterostructure composite material for the degradation of CBZ are as follows: Figure 10 As shown in the figure, the ecotoxicity comparison of CBZ solution before and after degradation is as follows: Figure 11 As shown. From Figure 10 As can be seen from the results of the free radical quenching experiment, the free radical and non-free radical pathways play a synergistic role in the degradation process, with singlet oxygen (…) 1 O2) is the main active species in this system. Meanwhile, from Figure 11 As can be seen from the results of the toxicity assessment experiment based on bean sprout cultivation, the ecotoxicity of CBZ was significantly reduced after the catalytic reaction.

[0096] Application Example 3 The experimental procedure of Example 2 was repeated, and the composite material after the reaction was recovered by centrifugation for the next degradation experiment. The results showed that the composite material could still maintain excellent catalytic performance after five consecutive cycles, and the degradation rate of CBZ was still higher than 90%, indicating that it has structural stability and durability.

[0097] Application Example 4 The pH of the simulated CBZ wastewater was adjusted to 3.0, 5.0, 7.0, and 9.0 respectively using 1 mol / L hydrochloric acid or sodium hydroxide solution. Degradation experiments were then conducted according to the method in Application Example 2, and the results are as follows: Figure 12 As shown, the unadjusted value represents application example 2 (pH=6.6). From Figure 12 It can be seen that when pH=3, 5, 7, 9, Co 0 The photo-Fenton-like synergistic catalytic system of the / MoS2 / CoFe2O4 heterojunction composite material exhibited high degradation performance for CBZ. After 10 min of catalytic reaction, the CBZ removal rate was 93.59% at pH 3, 99.69% at pH 5, 99.78% at pH 7, and 89.1% at pH 9.

[0098] Application Example 5 The experiment was conducted according to the method in Application Example 2, and 5 mmol / L of different types of inorganic anions (Cl) were added to the CBZ simulated wastewater. - HCO3 - NO3 - SO4 2- ) or 5 mg / L of humic acid (HA), the results are as follows Figure 13 As shown. From Figure 13 It can be seen from Co 0 The / MoS2 / CoFe2O4 / PMS / Vis system maintained a degradation rate of over 90% for CBZ in the presence of inorganic anions or humic acid, indicating that the catalytic system has excellent broad-spectrum anti-interference ability and stability in real complex aquatic environments.

[0099] Application Example 6 The experiment was conducted according to the method in Application Example 2, with CBZ replaced by other organic pollutants, including: Rhodamine B (RhB), Ciprofloxacin (CIP), Sulfamethoxazole (SMX), Bisphenol A (BPA), Tetracycline Hydrochloride (TC), Butyl Xanthate (BX), and Aniline Black Powder (DPT). The degradation effects were compared with those of CBZ as follows: Figure 14 As shown. From Figure 14 It can be seen from Co 0 The / MoS2 / CoFe2O4 / PMS / Vis system exhibited excellent broad-spectrum degradation performance for all tested organic pollutants, with degradation rates remaining above 96% within 10 minutes.

[0100] Example 2 A Co 0 The / CoFe2O4 / MoS2 heterojunction composite material consists of MoS2 nanosheets, CoFe2O4 nanoparticles supported on the surface of the MoS2 nanosheets, and CoFe2O4 nanoparticles generated by photoinduced in-situ reduction of the CoFe2O4 nanoparticles. 0 composition; The Co 0 The preparation method of the / CoFe2O4 / MoS2 heterojunction composite material is as follows: (1) Mix 10 mmol Co(NO3)2·6H2O and 50 mL deionized water to obtain a cobalt nitrate solution (cobalt ion concentration is 0.2 mol / L), mix 22 mmol Fe(NO3)3·9H2O and 50 mL deionized water to obtain an iron nitrate solution (iron ion concentration is 0.44 mol / L), mix the cobalt nitrate solution and the iron nitrate solution to obtain a mixed solution (in the mixed solution, the molar ratio of cobalt nitrate to iron nitrate is 1:2.2), add the mixed solution dropwise to 20 mL of 5 mol / L sodium hydroxide aqueous solution at 70 °C (the volume ratio of sodium hydroxide aqueous solution to mixed solution is 2:10), and carry out a co-precipitation reaction at 70 °C for 3 h. After the reaction is completed, cool to room temperature, centrifuge to obtain a solid, wash the solid with water until neutral, and then vacuum dry at 60 °C for 12 h to obtain a precursor; (2) The precursor obtained in step (1) was annealed at 550°C for 2 hours and cooled to room temperature to obtain CoFe2O4 nanoparticles. (3) (NH4)6Mo7O 24 Mix 4H2O, CH4N2S, and 70mL of ammonia solution (the mass concentration of ammonia solution is 28%), (NH4)6Mo7O 24 The concentration of molybdenum ions in the mixed solution obtained by ·4H2O, CH4N2S and ammonia water is 0.1 mol / L, (NH4)6Mo7O 24 The molar ratio of 4H2O to CH4N2S was 1:22. The hydrothermal reaction was carried out at 220℃ for 12h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged to obtain a solid, washed three times each with anhydrous ethanol and deionized water, and dried under vacuum at 60℃ for 12h to obtain flower-shaped MoS2 microspheres. (4) Disperse 50 mg of CoFe2O4 nanoparticles obtained in step (2) and 150 mg of flower-shaped MoS2 microspheres obtained in step (3) in 50 mL of ethanol-water solution (the mass ratio of CoFe2O4 nanoparticles to flower-shaped MoS2 microspheres is 1:3, the mass ratio of CoFe2O4 nanoparticles to the volume ratio of ethanol-water solution is 1 mg:1 mL, and the volume ratio of ethanol to water in the ethanol-water solution is 1:1). Sonicate for 20 min, and carry out a solvothermal reaction at 220 °C for 8 h. After the reaction is completed, cool to room temperature, centrifuge to obtain solid, wash with anhydrous ethanol and deionized water three times alternately, and vacuum dry at 60 °C for 12 h to obtain CoFe2O4 / MoS2 heterojunction. (5) The CoFe2O4 / MoS2 heterojunction obtained in step (4) was photo-induced in-situ reduced by irradiation under a xenon lamp (power 300W) for 3 min to obtain Co 0 / CoFe2O4 / MoS2 heterojunction composite material.

[0101] Example 3 A Co 0 The / CoFe2O4 / MoS2 heterojunction composite material consists of MoS2 nanosheets, CoFe2O4 nanoparticles supported on the surface of the MoS2 nanosheets, and CoFe2O4 nanoparticles generated by photoinduced in-situ reduction of the CoFe2O4 nanoparticles. 0 composition; The Co 0 The preparation method of the / CoFe2O4 / MoS2 heterojunction composite material is as follows: (1) Mix 10 mmol Co(NO3)2·6H2O and 50 mL deionized water to obtain a cobalt nitrate solution (cobalt ion concentration is 0.2 mol / L), mix 19 mmol Fe(NO3)3·9H2O and 50 mL deionized water to obtain an iron nitrate solution (iron ion concentration is 0.38 mol / L), mix the cobalt nitrate solution and the iron nitrate solution to obtain a mixed solution (in the mixed solution, the molar ratio of cobalt nitrate to iron nitrate is 1:1.9), add the mixed solution dropwise to 30 mL of 5 mol / L sodium hydroxide aqueous solution at 80 °C (the volume ratio of sodium hydroxide aqueous solution to mixed solution is 3:10), and carry out a co-precipitation reaction at 80 °C for 2 h. After the reaction is completed, cool to room temperature, centrifuge to obtain a solid, wash the solid with water until neutral, and then vacuum dry at 60 °C for 12 h to obtain a precursor; (2) The precursor obtained in step (1) was annealed at 500℃ for 3h and cooled to room temperature to obtain CoFe2O4 nanoparticles; (3) (NH4)6Mo7O 24 Mix 4H2O, CH4N2S, and 50mL of ammonia solution (the mass concentration of ammonia solution is 28%), (NH4)6Mo7O 24 The concentration of molybdenum ions in the mixed solution obtained by ·4H2O, CH4N2S and ammonia water is 0.1 mol / L, (NH4)6Mo7O 24 The molar ratio of 4H2O to CH4N2S was 1:17.5. The reaction was carried out hydrothermally at 220℃ for 14h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged to obtain a solid, washed three times each with anhydrous ethanol and deionized water, and dried under vacuum at 60℃ for 12h to obtain flower-shaped MoS2 microspheres. (4) Disperse 50 mg of CoFe2O4 nanoparticles obtained in step (2) and 125 mg of flower-shaped MoS2 microspheres obtained in step (3) in 50 mL of ethanol-water solution (the mass ratio of CoFe2O4 nanoparticles to flower-shaped MoS2 microspheres is 1:2.5, the mass ratio of CoFe2O4 nanoparticles to ethanol-water solution is 1 mg:1 mL, and the volume ratio of ethanol to water in ethanol-water solution is 2:1), sonicate for 30 min, and carry out a solvothermal reaction at 180 °C for 20 h. After the reaction is completed, cool to room temperature, centrifuge to obtain solid, wash with anhydrous ethanol and deionized water three times alternately, and vacuum dry at 60 °C for 12 h to obtain CoFe2O4 / MoS2 heterojunction; (5) The CoFe2O4 / MoS2 heterojunction obtained in step (4) was photo-induced in-situ reduced by irradiation under a xenon lamp (power 300W) for 4 min to obtain Co 0 / CoFe2O4 / MoS2 heterojunction composite material.

[0102] In summary, the Co provided by this invention 0 The / CoFe2O4 / MoS2 heterojunction composite material not only has a faster initial reaction rate, but also maintains efficient and stable degradation performance in complex water environments, over a wider range of pollutant concentrations and pH values, and has excellent recyclability.

[0103] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A Co 0 The / CoFe2O4 / MoS2 heterojunction composite material includes MoS2 nanosheets and CoFe2O4 nanoparticles supported on the surface of the MoS2 nanosheets, as well as CoFe2O4 nanoparticles generated by photoinduced in-situ reduction of the CoFe2O4 nanoparticles. 0 .

2. The Co as described in claim 1 0 The preparation method of / CoFe2O4 / MoS2 heterojunction composite material includes the following steps: (1) A cobalt source, an iron source, water and an alkaline solution are mixed and a co-precipitation reaction is carried out to obtain a precursor; the precursor is annealed to obtain nano-CoFe2O4; (2) (NH4)6Mo7O 24 • A hydrothermal reaction is carried out by mixing 4H2O, CH4N2S and ammonia water to obtain flower-shaped MoS2; (3) The nano-CoFe2O4 obtained in step (1) is mixed with the flower-shaped MoS2 obtained in step (2) and a solvent, and a solvothermal reaction is carried out to obtain a CoFe2O4 / MoS2 heterojunction; (4) The CoFe2O4 / MoS2 heterojunction obtained in step (3) is subjected to photoinduced in-situ reduction to obtain Co 0 / CoFe2O4 / MoS2 heterojunction composite material; The steps (1) and (2) are not in any particular order.

3. The preparation method according to claim 2, characterized in that, The temperature of the coprecipitation reaction in step (1) is 60~90℃, and the time of the coprecipitation reaction is 1~3h.

4. The preparation method according to claim 2, characterized in that, The annealing temperature in step (1) is 500~600℃ and the annealing time is 1~3h.

5. The preparation method according to claim 2, characterized in that, In step (2), (NH4)6Mo7O 24 The molar ratio of 4H2O to CH4N2S is 1:(5~30).

6. The preparation method according to claim 2, characterized in that, The temperature of the hydrothermal reaction in step (2) is 180~220℃, and the time of the hydrothermal reaction is 12~20h.

7. The preparation method according to claim 2, characterized in that, In step (3), the mass ratio of nano-CoFe2O4 to flower-like MoS2 is 1:(2~4).

8. The preparation method according to claim 2, characterized in that, The temperature of the solvothermal reaction in step (3) is 160~220℃, and the reaction time is 4~20h.

9. The preparation method according to claim 2, characterized in that, The photoinduced in-situ reduction in step (4) is carried out under xenon lamp irradiation; the photoinduced in-situ reduction time is 2~5 min.

10. The Co as described in claim 1 0 / CoFe2O4 / MoS2 heterojunction composite material or Co prepared by the preparation method according to any one of claims 2 to 9 0 Application of / CoFe2O4 / MoS2 heterojunction composite material in the degradation of organic pollutants in a photocatalytic-Fenton-like synergistic system.

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