Preparation method of nanoscale tungsten disulfide colloidal suspension

Abstract

The invention discloses a preparation method of a nanoscale tungsten disulfide colloidal suspension, which belongs to the field of tungsten disulfide preparation, and comprises the following steps: step 1, adding tungsten disulfide powder into a solvent, and adding a surfactant or a stabilizer to obtain a mixed solution; step 2, carrying out tungsten disulfide interlayer stripping treatment on the mixed solution to generate a suspension containing nanosheets or nanoparticles with the transverse size of less than 100nm and the thickness of less than 5nm; 3, the suspension liquid obtained after ultrasonic treatment is subjected to centrifugal treatment, and supernate serves as preliminarily purified nanometer tungsten disulfide dispersion liquid; step 4, adjusting the pH value of the nano tungsten disulfide dispersion liquid to 7-8, and adding a polymer stabilizer to enable the absolute value of the Zeta potential of the system to be greater than 30mV; step 5, performing impurity removal and filtration on the suspension to remove residual micron-sized impurities; 6, the obtained filtrate is the prepared stable nanoscale tungsten disulfide colloidal suspension, and the stable nanoscale tungsten disulfide colloidal suspension is packaged into a preset container to be stored.

Description

Technical Field

[0001] This invention relates to the field of tungsten disulfide preparation technology, and in particular to a method for preparing a nano-scale tungsten disulfide colloidal suspension. Background Technology

[0002] Tungsten disulfide (WS2) is a typical layered transition metal chalcogenide (TMD) compound. Its crystal structure consists of tungsten atoms sandwiched between two layers of sulfur atoms, forming SWS sandwich units, with the layers bonded by van der Waals forces. In recent years, with the development of nanotechnology, nano-WS2 with fullerene structures (such as nanotubes, nanocages, and rolled nanosheets) or two-dimensional exfoliated structures has shown great application potential in high-end lubricating additives, lithium / sodium-ion battery anode materials, photodetectors, and catalyst supports due to its excellent solid lubricity, high carrier mobility, good electrochemical activity, and photocatalytic performance.

[0003] Nano-WS2 with a fullerene-like structure was first discovered and systematically studied by R. Tenne's team at the Weizmann Institute of Science in Israel in the 1990s. Due to the absence of dangling bonds on its surface, its closed structure, and its extremely low coefficient of friction (as low as 0.01), this type of material is considered an ideal candidate for a new generation of high-performance solid lubricants. Since then, research institutions around the world have conducted extensive work on the large-scale preparation of IF-WS2, promoting the related industrialization process.

[0004] However, both fullerene-structured and two-dimensionally exfoliated nano-WS2 face a common challenge in practical applications: how to stably and uniformly disperse them in liquid media to form a colloidal suspension that can be stored for a long time and is easy to process and use. Bulk WS2 is highly hydrophobic and has high interlayer binding energy, making it prone to agglomeration and sedimentation in conventional solvents, leading to performance degradation or even failure. Therefore, developing a method that can efficiently exfoliate and stably disperse nano-WS2 over a long period has become a key technological bottleneck connecting material synthesis and end-use applications.

[0005] Chinese invention patent CN200810017530.1 discloses a solid-phase synthesis method for fullerene-structured nano-WS2, employing a two-step method to synthesize nano-WS2 powder with a fullerene structure: First, a sodium tungstate solution is treated with a cation exchange resin to obtain a tungstate sol, then polyethylene glycol or dimethyl sulfoxide is added as a dispersant, and after drying, it is reduced with hydrogen at 575–600℃ to obtain purple-black nano-low-valent tungsten oxide (WO3) 3-x (1≤x≤2); then the WO 3-xThe mixture is prepared by mixing elemental sulfur at a molar ratio of 1:2 to 20 and placing it in a sealed stainless steel reactor. The mixture undergoes a self-pressurized sulfurization reaction at 500–950°C for 1–2 hours, ultimately yielding fullerene-structured WS2 powder with a particle size of 5–100 nm, some of which are nanotube / rod-shaped (up to tens of micrometers in length). This method is simple, low-cost, and suitable for mass production, solving the problems of complex equipment and long reaction times associated with earlier gas-phase methods (such as fluidized beds). However, the solid-phase synthesis method only provides dry powder products and does not address the dispersion and stability issues in liquid media. Although the obtained fullerene-structured WS2 powder possesses excellent intrinsic properties, it still requires additional dispersion treatment if used directly in lubricants, coatings, or biological systems. This process often leads to structural damage or agglomeration, making it difficult to leverage the advantages of the nanoscale.

[0006] Currently, there is a lack of clear long-term stability indicators and validation data. Existing literature rarely provides stability test results for more than 6 months, let alone a reliable solution with no sedimentation for 24 months, which cannot support commercial applications.

[0007] In view of this, the present invention is hereby proposed. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing a nano-sized tungsten disulfide colloidal suspension, which can efficiently strip bulk tungsten disulfide and obtain a nano-sized tungsten disulfide colloidal suspension that can be stably stored for up to 24 months under normal or low temperature conditions. This breaks through the bottlenecks of existing technologies in terms of stability, universality and practicality, and solves the above-mentioned technical problems existing in the prior art.

[0009] The objective of this invention is achieved through the following technical solution: A method for preparing a nanoscale tungsten disulfide colloidal suspension, comprising: Step 1: Add the tungsten disulfide powder obtained by crushing the bulk material to the solvent, and then add a predetermined amount of surfactant or stabilizer to obtain a mixture; Step 2: Perform tungsten disulfide interlayer exfoliation on the mixture to generate a suspension containing nanosheets or nanoparticles with a lateral size of less than 100 nm and a thickness of less than 5 nm. Step 3: Centrifuge the suspension after the stripping process, and use the supernatant obtained by centrifugation as the preliminarily purified nano-tungsten disulfide dispersion. Step 4: Adjust the pH of the preliminarily purified nano-tungsten disulfide dispersion to 7-8, and add a polymeric stabilizer to make the absolute value of the Zeta potential of the system greater than 30mV. Step 5: The suspension obtained in step 4 is filtered to remove residual micron-sized impurities. Step 6: The filtrate obtained in step 5 is the prepared nano-sized tungsten disulfide colloidal suspension. The nano-sized tungsten disulfide colloidal suspension is packaged into a predetermined container for storage.

[0010] Compared with the prior art, the method for preparing nano-scale tungsten disulfide colloidal suspension provided by the present invention has the following beneficial effects: The method of this invention is simple to operate, cost-controllable, and environmentally friendly. The obtained nano-WS2 colloidal suspension can be stably stored for no less than 24 months under light-protected conditions at 4–10°C, during which time there is no significant precipitation, color change, or particle size increase, far exceeding the conventional stability period reported in the literature. Secondly, by optimizing the combination of solvent and stabilizer, efficient exfoliation and high dispersion are achieved, and the average particle size of the obtained product is less than 100 nm, with an absolute value of Zeta potential exceeding 30 mV, exhibiting excellent colloidal stability. Thirdly, the entire preparation process is simple to operate, energy-efficient, and cost-controllable, requiring no complex equipment or hazardous chemicals, and is easy to implement on a large scale. Fourthly, the solvent system and stabilizer type can be flexibly selected according to the end application scenario—for example, biocompatible materials such as Pluronic F127 or PEG can be used in the biomedical field, while a water and alcohol mixture system can be used in scenarios with high environmental protection requirements, thus balancing performance and safety. Fifthly, this method has good universality, and its core idea can be extended to the preparation of stable colloids of other two-dimensional transition metal chalcogenides such as MoS2, MoSe2, and WS2, possessing broad industrial application potential. The above effects collectively solve key problems in existing technologies such as poor stability, complex processes, and narrow applicability, significantly enhancing the practical value of WS2 nanomaterials. Detailed Implementation

[0011] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the specific content of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, which do not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0012] First, the following explanations are provided for the terms that may be used in this article: The term "and / or" means that either or both can be achieved simultaneously. For example, X and / or Y means that it includes both "X" or "Y" as well as the three cases of "X and Y".

[0013] The terms "comprising," "including," "containing," "having," or other similar semantic descriptions should be interpreted as non-exclusive inclusion. For example, including a technical feature element (such as raw material, component, ingredient, carrier, dosage form, material, size, part, component, mechanism, device, step, process, method, reaction conditions, processing conditions, parameter, algorithm, signal, data, product or article of manufacture, etc.) should be interpreted as including not only the expressly listed technical feature element, but also other technical feature elements that are not expressly listed and are well-known in the art.

[0014] The term "composed of" excludes any technical features not expressly listed. When used in a claim, it closes the claim to exclude all technical features other than those expressly listed, except for associated conventional impurities. If the term appears only in a clause of a claim, it limits the claim to the elements expressly listed in that clause; elements recited in other clauses are not excluded from the overall claim.

[0015] The term "parts by mass" indicates the mass ratio between multiple components. For example, if component X is described as x parts by mass and component Y as y parts by mass, then the mass ratio of component X to component Y is x:y. One part by mass can represent any mass; for example, one part by mass can be expressed as 1 kg or 3.1415926 kg, etc. The sum of the parts by mass of all components is not necessarily 100 parts; it can be greater than 100 parts, less than 100 parts, or equal to 100 parts. Unless otherwise stated, parts, proportions, and percentages mentioned herein are all measured by mass.

[0016] When concentration, temperature, pressure, size, or other parameters are expressed as numerical ranges, such ranges should be understood to specifically disclose all ranges formed by any pairing of upper limits, lower limits, or preferred values ​​within that range, regardless of whether the range is explicitly stated; for example, if the numerical range "2 to 8" is stated, then that range should be interpreted to include ranges such as "2 to 7", "2 to 6", "5 to 7", "3 to 4 and 6 to 7", "3 to 5 and 7", "2 and 5 to 7", etc. Unless otherwise stated, the numerical ranges described herein include both their endpoints and all integers and fractions within that range.

[0017] The solution provided by this invention will be described in detail below. Contents not described in detail in the embodiments of this invention are prior art known to those skilled in the art. Where specific conditions are not specified in the embodiments of this invention, they shall be performed according to conventional conditions in the art or conditions recommended by the manufacturer. Reagents or instruments used in the embodiments of this invention whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0018] This invention provides a method for preparing a nano-sized tungsten disulfide colloidal suspension, comprising: Step 1: Add the tungsten disulfide powder obtained by crushing the bulk material to the solvent, and then add a predetermined amount of surfactant or stabilizer to obtain a mixture; Step 2: Perform tungsten disulfide interlayer exfoliation on the mixture to generate a suspension containing nanosheets or nanoparticles with a lateral size of less than 100 nm and a thickness of less than 5 nm. Step 3: Centrifuge the suspension after the stripping process, and use the supernatant obtained by centrifugation as the preliminarily purified nano-tungsten disulfide dispersion. Step 4: Adjust the pH of the preliminarily purified nano-tungsten disulfide dispersion to 7-8, and add a polymeric stabilizer to make the absolute value of the Zeta potential of the system greater than 30mV. Step 5: The suspension obtained in step 4 is filtered to remove residual micron-sized impurities. Step 6: The filtrate obtained in step 5 is the prepared nano-sized tungsten disulfide colloidal suspension. The nano-sized tungsten disulfide colloidal suspension is packaged into a predetermined container for storage.

[0019] Preferably, in step 1 of the above method, the amount of tungsten disulfide powder added is 100 parts by weight. The amount of solvent used is 100 parts by weight; Based on the total weight of tungsten disulfide powder and solvent, the amount of surfactant or stabilizer added is 0.1 to 0.8 wt%.

[0020] Preferably, in the above method, the solvent is any one of N-methylpyrrolidone, a mixture of isopropanol and deionized water in a weight ratio of 1:1, ethanol, ethylene glycol, and pure water.

[0021] Preferably, in the above method, the surfactant or stabilizer is one or more of sodium dodecyl sulfate, polyvinylpyrrolidone, Pluronic F127, Triton X-100, and polyethylene glycol.

[0022] Preferably, in step 2 of the above method, the mixture is subjected to tungsten disulfide interlayer stripping treatment in the following manner: The resulting mixture was placed in an ice bath environment, and the cavitation effect formed by ultrasonic treatment was used to perform the stripping treatment between tungsten disulfide layers. Alternatively, the tungsten disulfide layers can be separated by ball milling-assisted stripping. Alternatively, electrochemical stripping can be used to remove the tungsten disulfide layers. Alternatively, microwave-assisted stripping can be used to remove the tungsten disulfide layers.

[0023] Preferably, in the above method, the ultrasonic treatment used is as follows: Ultrasonic treatment is performed for 3 to 9 hours using an ultrasonic probe; or ultrasonic treatment is performed for 12 to 24 hours using an ultrasonic bath. The ball milling-assisted peeling method used is: wet ball milling at 300-600 rpm for 2-12 hours under an inert atmosphere (such as argon). The electrochemical stripping method used is as follows: applying a current density of 1 to 5 mA / cm² in constant current mode, or applying a potential of +3.0 V to +6.0 V in constant potential mode (wherein the potential is measured with silver or silver chloride as a reference point set), and intercalating for 10 to 60 minutes. The microwave-assisted stripping method is as follows: irradiation with a microwave power of 300–800 W for 2–10 minutes in a nitrogen atmosphere, during which the system temperature is controlled not to exceed 120°C (achieved through built-in cooling or pulsed heating).

[0024] Preferably, in the above method, the power of the ultrasonic probe or ultrasonic bath is 200-500W.

[0025] Preferably, in step 3 of the above method, the suspension after the stripping treatment is performed by centrifugation in the following manner: Centrifuge the suspension at 3000-5000 rpm for 30 minutes; In step 4, the pH value of the preliminarily purified nano-tungsten disulfide dispersion is adjusted to 7-8 in the following manner: Add NaOH solution or HCl solution to the preliminarily purified nano-tungsten disulfide dispersion to adjust the pH value of the preliminarily purified nano-tungsten disulfide dispersion to 7-8. In step 4, the amount of polymeric stabilizer added is 0.01 to 0.1 wt%.

[0026] In step 5, the suspension obtained in step 4 is subjected to impurity removal filtration to remove residual micron-sized impurities, including: The suspension was filtered using an injection filter with a pore size of 0.22 μm or 0.45 μm to remove residual micron-sized impurities. In step 6, the filtrate obtained in step 5 is packaged into a predetermined container for storage as follows: The intended container is a brown glass bottle with a PTFE-lined, sealed cap.

[0027] Preferably, in the above method, the polymeric stabilizer added in step 4 is PEG or PVP.

[0028] Preferably, in the above method, step 6 further includes: filling the predetermined container with high-purity nitrogen or argon gas during sealing to replace the air inside the bottle; It also includes storing the encapsulated filtrate obtained in step 6 in a predetermined container in a light-protected environment at 4–10°C.

[0029] To more clearly demonstrate the technical solution and its effects provided by the present invention, the following detailed description of the solution provided by the embodiments of the present invention is provided with reference to specific examples.

[0030] Example 1 This embodiment provides a method for preparing a nano-scale tungsten disulfide colloidal suspension. It is an integrated process involving solvent-assisted ultrasonic exfoliation, centrifugal purification, dual stabilization control, and multi-protection storage, enabling the controllable preparation of highly stable nano-WS2 colloidal suspensions. The method includes the following steps: Step 1: First, add 100 mg of WS2 block powder to 100 mL of a selected solvent, which can be any one of N-methylpyrrolidone (NMP), a 1:1 mixture of isopropanol and deionized water, ethanol, ethylene glycol, or pure water; then add 0.1–0.8 wt% of a surfactant or stabilizer, such as one or more of sodium dodecyl sulfate (SDS), polyvinylpyrrolidone (PVP), Pluronic F127, Triton X-100, or polyethylene glycol (PEG); Step 2: Place the obtained mixture in an ice bath environment and use an ultrasonic probe (power 200-500 W) to perform ultrasonic treatment for 3-9 hours. Utilize the cavitation effect to achieve effective exfoliation of the WS2 interlayer, generating nanosheets or nanoparticles with a lateral size of less than 100 nm and a thickness of usually less than 5 nm. Alternatively, an ultrasonic bath can be used instead of a probe, but the treatment time needs to be extended to 12-24 hours to compensate for insufficient energy density. Step 3: After sonication, centrifuge the suspension at 3000-5000 rpm for 30 minutes, discard the large particles of precipitate that have not been separated at the bottom, and keep the supernatant as the preliminary purified nano WS2 dispersion. Step 4: To further improve stability, dilute NaOH or HCl solution is added to the supernatant to adjust the pH to 7-8, and 0.01-0.1 wt% of a polymeric stabilizer (such as PEG or PVP) is added to make the absolute value of the Zeta potential of the system greater than 30 mV, thereby constructing a stabilizing mechanism of electrostatic repulsion and steric hindrance synergistic effect. Step 5: Subsequently, the suspension is filtered using an injection filter with a pore size of 0.22 μm or 0.45 μm to remove any micron-sized impurities that may remain. Step 6: Finally, the filtrate is transferred to a brown glass bottle with a polytetrafluoroethylene (PTFE) liner and a sealed cap to obtain a nano-sized tungsten disulfide colloidal suspension. Alternatively, high-purity nitrogen or argon gas can be introduced to replace the air in the bottle and reduce the risk of oxidation.

[0031] Furthermore, the packaged samples should be stored in a light-protected environment at 4–10°C, and freezing is strictly prohibited.

[0032] The nano-sized tungsten disulfide colloidal suspension prepared above only requires slight shaking or short-term low-power sonication (<1 minute) before use to restore its uniform dispersion. This entire process does not require high temperature, high pressure, or highly corrosive reagents, has low equipment requirements, and is suitable for laboratory research and pilot-scale production.

[0033] While maintaining the core technical concept, this invention can be implemented through the following alternative solutions. Regarding solvent selection, NMP can be replaced by high-boiling-point polar aprotic solvents such as γ-butyrolactone (GBL) and dimethylformamide (DMF); the isopropanol and water system can also be replaced by other alcohol-water mixtures such as ethanol and water, or n-butanol and water. Regarding stabilizers, anionic SDS can be replaced by cationic cetyltrimethylammonium bromide (CTAB) or nonionic Tween series surfactants; PVP can also be replaced by natural or synthetic polymers such as polyacrylic acid (PAA) and chitosan; Pluronic F127 can be replaced by other PEO-PPO-PEO triblock copolymers (such as F68 and P123). Regarding the exfoliation method, ultrasonic treatment can be partially or completely replaced by ball milling-assisted exfoliation, electrochemical exfoliation, or microwave-assisted exfoliation, which is particularly suitable for large-scale continuous production. Regarding storage conditions, if the application scenario allows for short-term use, it can be stored at room temperature (25°C) in a dark and dry environment for no more than 6 months. Although inert gas protection can significantly extend stability, it can be omitted under non-critical conditions, in which case the stability period is approximately 12–18 months. Although the above alternatives differ slightly in efficiency, cost, or stability, they all achieve the basic inventive objective of preparing long-term stable nano-WS2 colloids.

[0034] The preparation method of this invention mainly focuses on three aspects: First, the synergistic effect mechanism of "solvent-stabilizer," where a specific solvent (such as NMP or a mixture of alcohol and water) and a surfactant (such as a combination of SDS and PVP) jointly promote WS2 exfoliation and provide dual stability through electrostatics and steric hindrance. Second, precise control of the zeta potential, achieved through pH adjustment and compounding with a polymeric stabilizer, ensures that the absolute value of the zeta potential of the suspension is greater than 30 mV, a key physical indicator for long-term colloidal stability. Third, a multi-protective storage strategy, employing brown glass bottles, low temperature (4–10°C), light protection, and an inert atmosphere to synergistically inhibit oxidation and aggregation kinetics. The product obtained by this invention and its applications in lubrication, catalysis, batteries, and bioimaging are also discussed.

[0035] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a nano-sized tungsten disulfide colloidal suspension, characterized in that, include: Step 1: Add the tungsten disulfide powder obtained by crushing the bulk material to the solvent, and then add a predetermined amount of surfactant or stabilizer to obtain a mixture; Step 2: Perform tungsten disulfide interlayer exfoliation on the mixture to generate a suspension containing nanosheets or nanoparticles with a lateral size of less than 100 nm and a thickness of less than 5 nm. Step 3: Centrifuge the suspension after the stripping process, and use the supernatant obtained by centrifugation as the preliminarily purified nano-tungsten disulfide dispersion. Step 4: Adjust the pH of the preliminarily purified nano-tungsten disulfide dispersion to 7-8, and add a polymeric stabilizer to make the absolute value of the Zeta potential of the system greater than 30mV. Step 5: The suspension obtained in step 4 is filtered to remove residual micron-sized impurities. Step 6: The filtrate obtained in step 5 is the prepared nano-sized tungsten disulfide colloidal suspension. The nano-sized tungsten disulfide colloidal suspension is packaged into a predetermined container for storage.

2. The method for preparing the nano-scale tungsten disulfide colloidal suspension according to claim 1, characterized in that, In step 1, the amount of tungsten disulfide powder added is 100 parts by weight. The amount of solvent used is 100 parts by weight; Based on the total weight of tungsten disulfide powder and solvent, the amount of surfactant or stabilizer added is 0.1 to 0.8 wt%.

3. The method for preparing the nano-scale tungsten disulfide colloidal suspension according to claim 2, characterized in that, The solvent is any one of deionized water, ethanol, N-methylpyrrolidone, isopropanol, and ethylene glycol.

4. The method for preparing the nano-scale tungsten disulfide colloidal suspension according to claim 2, characterized in that, The surfactant or stabilizer is one or more of sodium dodecyl sulfate, polyvinylpyrrolidone, Pluronic F127, Triton X-100, and polyethylene glycol.

5. The method for preparing the nano-sized tungsten disulfide colloidal suspension according to any one of claims 1-4, characterized in that, In step 2, the mixture is subjected to tungsten disulfide interlayer stripping treatment in the following manner: The resulting mixture was placed in an ice bath environment, and the cavitation effect formed by ultrasonic treatment was used to perform the stripping treatment between tungsten disulfide layers. Alternatively, the tungsten disulfide layers can be separated by ball milling-assisted stripping. Alternatively, electrochemical stripping can be used to remove the tungsten disulfide layers. Alternatively, microwave-assisted stripping can be used to remove the tungsten disulfide layers.

6. The method for preparing the nanoscale tungsten disulfide colloidal suspension according to claim 5, characterized in that, The ultrasonic treatment used is as follows: Ultrasonic treatment is performed for 3 to 9 hours using an ultrasonic probe; or ultrasonic treatment is performed for 12 to 24 hours using an ultrasonic bath. The ball milling-assisted peeling method used was: wet ball milling at 300-600 rpm for 2-12 hours under an inert atmosphere. The electrochemical stripping method used is as follows: applying a current density of 1 to 5 mA / cm² in constant current mode, or applying a potential of +3.0 V to +6.0 V in constant potential mode, wherein the potential is measured with silver or silver chloride as a reference point set, and the intercalation is continued for 10 to 60 minutes. The microwave-assisted stripping method involves irradiating the material with a microwave power of 300–800W for 2–10 minutes in a nitrogen atmosphere, during which the temperature is controlled to not exceed 120°C by a built-in cooling or pulsed heating system.

7. The method for preparing the nanoscale tungsten disulfide colloidal suspension according to claim 6, characterized in that, The power of the ultrasonic probe or ultrasonic bath is 200-500W.

8. The method for preparing the nanoscale tungsten disulfide colloidal suspension according to any one of claims 1-4, characterized in that, In step 3, the suspension after the stripping treatment is completed is centrifuged in the following manner: Centrifuge the suspension at 3000-5000 rpm for 30 minutes; In step 4, the pH value of the preliminarily purified nano-tungsten disulfide dispersion is adjusted to 7-8 in the following manner: Add NaOH solution or HCl solution to the preliminarily purified nano-tungsten disulfide dispersion to adjust the pH value of the preliminarily purified nano-tungsten disulfide dispersion to 7-8. In step 4, the amount of polymeric stabilizer added is 0.01–0.1 wt%. In step 5, the suspension obtained in step 4 is subjected to impurity removal filtration to remove residual micron-sized impurities, including: The suspension was filtered using an injection filter with a pore size of 0.22 μm or 0.45 μm to remove residual micron-sized impurities. In step 6, the filtrate obtained in step 5 is packaged into a predetermined container for storage as follows: The intended container is a brown glass bottle with a PTFE-lined, sealed cap.

9. The method for preparing the nanoscale tungsten disulfide colloidal suspension according to claim 8, characterized in that, The polymeric stabilizer added in step 4 is PEG or PVP.

10. The method for preparing the nanoscale tungsten disulfide colloidal suspension according to claim 8, characterized in that, Step 6 further includes: during sealing, filling the predetermined container with high-purity nitrogen or argon to replace the air inside the bottle; It also includes storing the encapsulated filtrate obtained in step 6 in a predetermined container in a light-protected environment at 4–10°C.