Two-dimensional nanosheet membrane materials, methods of making the same, and osmotic energy power generation membrane materials and applications thereof

Abstract

The application provides a two-dimensional nanosheet film material, a preparation method thereof, a permeation energy power generation film material and an application thereof. The preparation method comprises the following steps: preparing an intermediate film material by suction filtration through two-dimensional nanosheets, and performing plasma treatment on the intermediate film material to obtain the two-dimensional nanosheet film material; wherein the ionized gas used in the plasma treatment comprises at least one of air, oxygen and carbon tetrafluoride; in the plasma treatment, the flow rate of the ionized gas is 0.5-30 slm, and the ionization power is 10-500 W. The application further provides the two-dimensional nanosheet film material obtained by the above preparation method, a permeation energy power generation film material comprising the two-dimensional nanosheet film material or prepared from the two-dimensional nanosheet film material, and an application of the permeation energy power generation film material. The above preparation method is simple in process, safe and reliable, and high in operability; the two-dimensional film material prepared has high output power, and has wide industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of inorganic non-metallic materials and new energy technology, and particularly relates to a two-dimensional nanosheet membrane material, a preparation method thereof, and a permeation energy power generation membrane material and application thereof. BACKGROUND

[0002] The development and utilization of energy is the basis for human survival and development. The survival environment of human beings has also been damaged to a considerable extent due to the extensive use of fossil energy. Energy and environmental crisis has become the most urgent problem to be solved by human beings. The chemical energy contained in ocean salinity is a kind of renewable clean energy with abundant reserves and easy access. It is necessary to have a high-efficiency energy conversion technology to capture the osmotic energy from the salinity gradient. In recent years, two-dimensional nanofluidic channel membrane materials prepared by inspiration from the ion channel protein of electric eel show excellent energy conversion performance.

[0003] In order to realize an output power density close to 5.0 W / m 2 , people mainly increase the charge density in the channel to improve the selectivity of two-dimensional nanofluidic channel membrane materials to counterions. Common methods mainly include introducing oxygen-containing groups in the channel, modifying ion groups in the channel, compounding charged polymers in the channel, and adjusting the acidity and alkalinity of the electrolyte. Based on the improvement of charge density, the output power density that can be achieved by the prior art is basically maintained between 5.0-5.2 W / m 2 . Although the output power density obtained by using the above-mentioned methods can meet the industrial development needs of river-sea water systems, it is difficult to obtain further substantial improvement.

[0004] Therefore, developing a new method that can effectively increase the charge density and ion selectivity of two-dimensional nanofluidic channel membrane materials is one of the future development directions of river-sea osmotic energy collection. SUMMARY

[0005] In order to solve the above-mentioned problems, the purpose of the present application is to provide a two-dimensional nanosheet membrane material, a preparation method thereof, and a permeation energy power generation membrane material and application thereof. The preparation method is simple, safe and reliable, and has strong operability. The output power of the two-dimensional membrane material prepared by the method is high, and the industrial application prospect is broad.

[0006] In order to achieve the above-mentioned purpose, the present application provides a preparation method of a two-dimensional nanosheet membrane material, which comprises the following steps:

[0007] The two-dimensional nanosheet is prepared into an intermediate membrane material by suction filtration, and the intermediate membrane material is subjected to plasma treatment to obtain the two-dimensional nanosheet membrane material;

[0008] The ionized gas used in the plasma treatment includes one or a combination of two or more of air, oxygen, and carbon tetrafluoride; and the ionized gas flow used in the plasma treatment is 0.5-30 slm.

[0009] The ionized power used in the plasma treatment is 10-500 W.

[0010] The two-dimensional nanosheet includes one or a combination of two or more of MXenes, two-dimensional nanosheets of metal oxides, two-dimensional nanosheets of transition metal sulfides, graphene, graphene oxide (GO), two-dimensional nanosheets of elemental phosphorus, and two-dimensional nanosheets of clay.

[0011] When the two-dimensional nanosheet includes one or a combination of two or more of MXenes, graphene, graphene oxide, and two-dimensional nanosheets of elemental phosphorus, the treatment time of the plasma treatment is 0.5 min-5 min.

[0012] When the two-dimensional nanosheet is one or a combination of two or more of two-dimensional nanosheets of metal oxides, two-dimensional nanosheets of transition metal sulfides, and two-dimensional nanosheets of clay, the treatment time of the plasma treatment is 10 min-30 min.

[0013] In the above preparation method, the MXenes are typically at least one of a nitride of a transition metal, a carbide of a transition metal, a boride of a transition metal, etc., and specifically can include one or a combination of two or more of Ti3C2T x , Ti2C, Ti2N, Nb2C, V2C, Mo2C, MnB, Fe2B2, MoB, and Cr2B2.

[0014] In the above preparation method, the metal oxide can include MnO2 and / or MoO3.

[0015] In the above preparation method, the transition metal sulfide can include WS2 and MoS2.

[0016] In the above preparation method, the clay can include one or a combination of two or more of montmorillonite, mica, zeolite, kaolin, vermiculite, and hydrotalcite.

[0017] In the above preparation method, the elemental phosphorus can include black phosphorus and / or purple phosphorus, etc.

[0018] In some embodiments, the two-dimensional nanosheet can include one or a combination of two or more of two-dimensional nanosheets of hydrotalcite, Ti2C, Ti3C2T x , graphene oxide, montmorillonite, black phosphorus, manganese dioxide, and molybdenum disulfide. Further, the two-dimensional nanosheet can include one or a combination of two or more of two-dimensional nanosheets of hydrotalcite, Ti2C, Ti3C2Tx one or more of graphene oxide and a combination of two or more of two-dimensional nanosheets such as graphene and montmorillonite.

[0019] In the above preparation method, the two-dimensional nanosheet can have 1-3 layers, and specifically can be a single layer (1 layer), a few layers (2 layers, 3 layers), etc.

[0020] In the above preparation method, the thickness of the two-dimensional nanosheet film material can be controlled to be 1-10 μm, for example, 1-8 μm. In some specific embodiments, the thickness of the two-dimensional nanosheet film material can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc. specific value and the range with any two of the above specific values as the end point. In the above preparation method, the two-dimensional nanosheet as a raw material is assembled layer by layer after being filtered by suction to form an intermediate film material with a sheet layer structure, which has a two-dimensional nanofluid channel for ion migration.

[0021] In the above preparation method, by using air or oxygen and other ionized gases with strong oxidation ability to treat the intermediate film material by plasma, oxygen-containing functional groups can be formed in the film material; and by using ionized gases containing high electronegative ions such as carbon tetrafluoride to treat the intermediate film material by plasma, fluorine ions can be modified in the film material to increase the negative charge of the film material. In the process of plasma treatment, air, oxygen, carbon tetrafluoride can be introduced to improve the charge density and ion selectivity of the film material.

[0022] In the above preparation method, by controlling the ionization power, time of plasma treatment and the type of ionized gas introduced, the interlayer spacing and ion channel height of the film material can be regulated. The present application research found that by controlling the ionization power of the plasma treatment and the time of the plasma treatment, the interlayer spacing and ion channel height of the film material can be increased, thereby increasing the ion migration rate and effectively improving the power generation performance of the film material.

[0023] In some specific embodiments, the ionization power is generally controlled to be 10 W-500 W, for example, it can be 50 W-500 W, 100 W-500 W, specifically it can be 10 W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 450 W, 500 W, etc. specific value and the range with any two of the above specific values as the end point.

[0024] In some embodiments, the treatment time of the plasma treatment can be adjusted according to the type of two-dimensional nanosheets, for example, when the two-dimensional nanosheets comprise one or more than two combinations of MXenes, elemental phosphorus, graphene, graphene oxide, etc., the treatment time can be controlled to be 0.5-5 min, and further controlled to be 1-5 min; when the two-dimensional nanosheets are one or more than two combinations of clay, metal oxide, transition metal sulfide, the treatment time can be 10-30 min, wherein when the two-dimensional nanosheets are clay, the treatment time can be further controlled to be 20-30 min.

[0025] In the above preparation method, the gas flow used in the plasma treatment is generally 0.5-30 slm, and can be specifically 0.5 slm, 1 slm, 5 slm, 10 slm, 15 slm, 20 slm, 25 slm, 30 slm, etc. and a range with any two of the above specific values as the end points. By controlling the ionization gas flow, the amount of plasma can be controlled, and thus the ion selectivity and ion migration rate of the film material can be controlled. In some embodiments, the gas flow can be adjusted according to the type of two-dimensional nanosheets, for example, when the two-dimensional nanosheets comprise MXenes, the gas flow can be 0.5-20 slm, and further controlled to be 1-20 slm; when the two-dimensional nanosheets comprise graphene and / or graphene oxide (and do not comprise MXenes), the gas flow can be 10-20 slm; when the two-dimensional nanosheets are clay, the gas flow can be 10-30 slm, 20-30 slm; when the two-dimensional nanosheets are one or more than two combinations of metal oxide, transition metal sulfide, elemental phosphorus, the gas flow can be 10-20 slm.

[0026] In the above preparation method, the vacuum degree used in the plasma treatment is 0.1-0.9 mbar, for example, greater than 0.3 mbar and less than or equal to 0.9 mbar, 0.3 mbar-0.7 mbar, etc. By controlling the vacuum degree, the purity of the plasma can be controlled, and thus the ion selectivity and ion migration rate of the film material can be controlled. In some embodiments, the vacuum degree used in the plasma treatment can be specifically controlled to be 0.1 mbar, 0.2 mbar, 0.3 mbar, 0.4 mbar, 0.5 mbar, 0.6 mbar, 0.7 mbar, 0.8 mbar, 0.9 mbar, etc. and a range with any two of the above specific values as the end points.

[0027] In some embodiments, the plasma treatment can be carried out in a plasma cleaning machine.

[0028] According to a specific embodiment of the present application, the process parameters of the plasma treatment can be adjusted according to the specific type of two-dimensional nanosheets as raw materials, for example:

[0029] When the two-dimensional nanosheets comprise MXenes (such as Ti3C2T x ), the ionization power can be controlled to be 100-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar, the ionization gas can use oxygen, the gas flow can be controlled to be 1-20 slm, and the processing time can be controlled to be 1-5 min;

[0030] When the two-dimensional nanosheets are clays such as montmorillonite, hydrotalcite, etc., the ionization power can be controlled to be 50-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar; the ionization gas can use one or a combination of two or more of air, oxygen, carbon tetrafluoride, etc., for example, for montmorillonite, carbon tetrafluoride can also be used as the ionization gas; the gas flow can be controlled to be 20-30 slm, and the processing time can be controlled to be 10-30 min;

[0031] When the two-dimensional nanosheets are a combination of MXenes and clays (such as a combination of hydrotalcite and Ti2C), the ionization power can be controlled to be 100 W-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar, the ionization gas can use oxygen, the gas flow can be controlled to be 0.5-20 slm, further can be 1-20 slm, and the processing time can be controlled to be 1-5 min;

[0032] When the two-dimensional nanosheets are graphene oxide, the ionization power can be controlled to be 100-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar, the ionization gas can use air and / or oxygen, the gas flow can be controlled to be 10-20 slm, and the processing time can be controlled to be 1-5 min;

[0033] When the two-dimensional nanosheets are graphene, the ionization power can be controlled to be 100-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar, the ionization gas can use air and / or oxygen, the gas flow can be controlled to be 10-20 slm, and the processing time can be controlled to be 1-5 min;

[0034] When the two-dimensional nanosheets are phosphorus monomer such as black phosphorus, the ionization power can be controlled to be 100-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar, the ionization gas can use air and / or oxygen, the gas flow can be controlled to be 10-20 slm, and the processing time can be controlled to be 1-5 min;

[0035] When the two-dimensional nanosheet is a metal oxide such as manganese dioxide, the ionization power can be controlled to be 100-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar, the ionized gas can be oxygen, or a combination of oxygen and nitrogen, the gas flow rate can be controlled to be 10-20 slm, and the processing time can be controlled to be 10-30 min.

[0036] When the two-dimensional nanosheet is a transition metal sulfide such as molybdenum disulfide, the ionization power can be controlled to be 100-500 W, the vacuum degree can be controlled to be 0.3-0.7 mbar, the ionized gas can be oxygen, or a combination of oxygen and hydrogen, the gas flow rate can be controlled to be 10-20 slm, and the processing time can be controlled to be 10-30 min.

[0037] According to a specific embodiment of the present application, the process of suction filtration in the above preparation method can specifically include: uniformly dispersing the two-dimensional nanosheet in water to form a suspension, suction filtering the suspension into a film on a filter membrane, drying to obtain the intermediate film material.

[0038] In the above suction filtration process, the concentration of the suspension is generally 0.2-10 g / L. In some specific embodiments, the concentration of the suspension can be adjusted according to the type of two-dimensional nanosheet, and can be specifically 0.2 g / L, 0.5 g / L, 1 g / L, 5 g / L, 10 g / L, and the like, and a range with any two of the above specific values as the end points.

[0039] In the above suction filtration process, an operation of ultrasonic treatment of the suspension can be included, and the ultrasonic treatment can promote the uniform dispersion of the two-dimensional nanosheet in the suspension. In some specific embodiments, the ultrasonic treatment time is generally controlled to be 10 min or more, for example, 10 min-60 min. In some specific embodiments, the ultrasonic treatment time can be controlled to be 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, and the like, and a range with any two of the above specific values as the end points.

[0040] The power of the ultrasonic treatment can be controlled to be 100-500 W, for example, 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 450 W, 500 W, and the like, and a range with any two of the above specific values as the end points. In some specific embodiments, the power of the ultrasonic treatment can be controlled to be 240 W.

[0041] In the above filtration process, an operation of adjusting the pH value of the suspension can be included to increase the amount of negative charge on the surface of the two-dimensional nanosheets: for example, under alkaline conditions, the content of hydroxyl groups and carboxyl groups on the surface of the two-dimensional nanosheets is higher, and the two-dimensional nanosheets have higher negative charge. The pH value of the suspension is generally 1-13. The pH value of the suspension can be further adjusted according to the specific type of the two-dimensional nanosheets. For example, when the two-dimensional nanosheets include hydrotalcite, the pH value of the suspension can be 1-1.5; for other types of two-dimensional nanosheets (such as two-dimensional nanosheets not containing hydrotalcite), the pH value of the suspension can be 11-13.

[0042] In some specific embodiments, a pH value adjusting agent can be used to adjust the pH value of the suspension. The pH value adjusting agent can include one or more than two combinations of an acid, a base, and a salt. The acid can include one or more than two combinations of hydrochloric acid (HCl), sulfuric acid (H2SO4), nitric acid (HNO3), carbonic acid (H2CO3), acetic acid (CH3COOH), and citric acid (C6H8O7), etc., for example, hydrochloric acid and / or sulfuric acid can be used. The base can include one or more than two combinations of sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), magnesium hydroxide (Mg(OH)2), and ammonia (NH3), etc., for example, sodium hydroxide and / or potassium hydroxide can be used. The salt can include one or more than two combinations of sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), and calcium carbonate (CaCO3), etc., for example, sodium carbonate can be used.

[0043] The above filtration process can remove excess water from the intermediate film material by drying. In some specific embodiments, the temperature of the drying can be 25-80°C, and the time of the drying can be 30-120 min.

[0044] In the above preparation method, the ionized gas used in the plasma treatment also includes one or more than two combinations of nitrogen (N2), argon (Ar), hydrogen (H2), ammonia (NH3), and carbon dioxide (CO2). The above types of ionized gas can assist air, oxygen, carbon tetrafluoride, etc. to modify the film material with functional groups (oxygen-containing functional groups) or ions (fluoride ions). For example, hydrogen can be introduced together with air or oxygen during the plasma treatment to modify the hydroxyl groups in the film material, thereby increasing the charge density and ion selectivity of the film material.

[0045] The application further provides a two-dimensional nanosheet membrane material prepared by the above method. The two-dimensional nanosheet membrane material has moderate interlamellar spacing, high ion migration rate and ion selectivity, and thus has high power generation capacity. In addition, the two-dimensional nanosheet membrane material has increased oxygen content and / or fluorine content, improved ion selectivity, higher average electric potential and better power generation performance. In some specific embodiments, the thickness of the two-dimensional nanosheet membrane material is generally 1-10 μm, for example, 1-8 μm.

[0046] The application further provides a permeation energy power generation membrane material comprising the above two-dimensional nanosheet membrane material or prepared from the above two-dimensional nanosheet membrane material. In some specific embodiments, the output power of the permeation energy power generation membrane material can be greater than or equal to 5.5 W / m 2 , for example, 5.5-6 W / m 2 .

[0047] The application further provides application of the above permeation energy power generation membrane material in permeation energy collection in river-sea systems (for example, river water-high salt lake, river water-fresh water lake, etc.). For example, the above permeation energy power generation membrane material can be used as a reverse ion exchange membrane for permeation energy collection at the river water outlet.

[0048] The application has the following advantages:

[0049] The preparation method of the two-dimensional nanosheet membrane material provided by the application is simple, safe and reliable, and has high operability and is easy to industrialize. The two-dimensional nanosheet membrane material prepared by the method can be used as a permeation energy power generation membrane material and has an output power density of 5.5 W / m 2 , which breaks through the bottleneck of collecting permeation energy by two-dimensional nanofluid channel membrane materials. The two-dimensional nanosheet membrane material can be used as a reverse electrodialysis ion exchange membrane and applied to permeation energy collection at the river water outlet. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 The cross-sectional micrograph of the Ti3C2T x x nanosheet membrane material prepared in Example 1.

[0051] Figure 2 The surface potential distribution graph of the Ti3C2T x x nanosheet membrane material prepared in Example 1.

[0052] Figure 3 The surface potential curve graph of the Ti3C2T x x nanosheet membrane material prepared in Example 1 before and after plasma treatment.

[0053] Figure 4 Ti3C2T x The interlayer spacing curve of the two-dimensional nanosheet film material before and after plasma treatment.

[0054] Figure 5 Ti3C2T x The infrared spectrum of the two-dimensional nanosheet film material before and after plasma treatment.

[0055] Figure 6 Ti3C2T x The contact angle diagram of the two-dimensional nanosheet film material before and after plasma treatment.

[0056] Figure 7 Ti3C2T x The conductance diagram of the two-dimensional nanosheet film material before and after plasma treatment.

[0057] Figure 8 Ti3C2T x The I-V curve diagram of the two-dimensional nanosheet film material before and after plasma treatment.

[0058] Figure 9 Ti3C2T x The output power density curve of the two-dimensional nanosheet film material. DETAILED DESCRIPTION

[0059] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present application, the technical solutions of the present application will be described in detail below, but it cannot be understood as limiting the implementable scope of the present application.

[0060] The two-dimensional Ti3C2T x The two-dimensional Ti3C2 nanosheet can be a commercially available nanosheet, or can be prepared in the following manner: 1g of LiF is slowly dissolved in 20mL of 9M HCl solution to obtain an etching solution. Then, 1g of Ti3AlC2 MAX powder is added to the etching solution, and etched under magnetic stirring at ambient temperature for 24 hours. Subsequently, the obtained acidic slurry is centrifuged several times with ultrapure water at 3500rpm until the pH is higher than 6.0. Under the protection of ice water bath and argon flow, the sediment of the above slurry is ultrasonically dispersed in ultrapure water for 0.5 hours, and then centrifuged at 5000rpm for 0.5 hours to obtain Ti3C2T x The upper layer of the MXenes dispersion.

[0061] The characterization methods and instruments used in the examples are described as follows:

[0062] Micro-morphology characterization: SU8200 type scanning electron microscope, Hitachi. Preparation process: quenching in liquid nitrogen.

[0063] Surface potential distribution test: Cypher ES type atomic force microscope, Asylum Research. Test mode: point contact, probe: NSC18 / Pt.

[0064] Output power density test: 600E type electrochemical workstation, China Chenhua. Test area: 0.03mm 2 , test temperature: 25℃, electrolyte: 0.01M / 0.5M NaCl solution.

[0065] Example 1

[0066] This example provides a two-dimensional nanosheet film material, and a preparation method thereof comprises the following steps:

[0067] 1. Preparation of intermediate film material: take a certain mass of few-layer (2-layer) two-dimensional Ti3C2T x nanosheets, adjust them into a suspension with a concentration of 10g / L in deionized water, and ultrasonically treat them in an ultrasonic cleaning instrument for 60 minutes until the nanosheets are uniformly dispersed; adjust the pH of the suspension to 11.0 with NaOH, and then use a circulating water vacuum pump to filter the suspension into a film on a filter membrane; dry the film in a vacuum oven at 80℃ for half an hour to remove excess water, thereby obtaining the intermediate film material.

[0068] 2. Plasma treatment: place the intermediate film material obtained in step 1 in a plasma cleaning machine with an ionization power of 500W, a vacuum degree of 0.5mbar, a gas flow of 1slm, and O2 as the ionization gas, and treat it for 1 minute, thereby obtaining a Ti3C2T x two-dimensional nanosheet film material.

[0069] Characterize the Ti3C2T x two-dimensional nanosheet film material prepared in this example, and the results are as follows:

[0070] Figure 1 The figure is a cross-sectional micro-morphology diagram of the Ti3C2T x two-dimensional nanosheet film material prepared in this example. From the figure, it can be observed that the Ti3C2T x nanosheets are assembled into a Ti3C2T x permeation power generation film material stacked layer by layer after vacuum filtration. The thickness of the film material is about 2.02μm, and it has a dense (i.e. a large number) of two-dimensional nanofluid channels.

[0071] Figure 2 The figure is a cross-sectional micro-morphology diagram of the Ti3C2Tx The surface potential distribution of the two-dimensional nanosheet film material is shown in the figure. The prepared Ti3C2T can be observed from this figure. x The base permeation energy-generating membrane material has a uniformly distributed potential, with an average potential of approximately 387mV.

[0072] Figure 3 In this embodiment, Ti3C2T x The surface potential curves of the two-dimensional nanosheet film material before and after plasma treatment are shown. The film material without plasma treatment is "Ti3C2T". x The membrane material after plasma treatment is Plasma-treated Ti3C2T. x membrane Figures 4-9 Same). By Figure 3 It can be observed that after plasma treatment, Ti3C2T x The average surface potential of the permeation energy-generating membrane material was significantly improved, from 205mV to 387mV.

[0073] Figure 4 In this embodiment, Ti3C2T x Interlayer spacing curves of a two-dimensional nanosheet film material before and after plasma treatment. Figure 4 It can be observed that after plasma treatment, Ti3C2T x The characteristic peak angle of the plasma-treated permeation energy-generating membrane material becomes smaller. According to calculations, the interlayer spacing of the material after plasma treatment is increased by 0.032 nm, that is, the channel height is increased by 0.032 nm.

[0074] Figure 5 The images show the infrared spectra of the Ti3C2-based two-dimensional nanosheet film material in this embodiment before and after plasma treatment (normalized, with peak values ​​representing the content of each functional group). Figure 5 It can be observed that after plasma treatment, Ti3C2T x The peak values ​​and contents of Ti-OH, TiO2, C=O, CO and Ti-O functional groups in the permeation energy-generating membrane material are larger.

[0075] Figure 6 In this embodiment, Ti3C2T x Contact angle diagrams of a two-dimensional nanosheet film material before and after plasma treatment. Figure 6 It can be observed that after plasma treatment, Ti3C2T x The contact angle of the hydrophilic membrane material is significantly reduced, indicating improved hydrophilicity.

[0076] Figure 7 In this embodiment, Ti3C2Tx Conductivity diagrams of two-dimensional nanosheet film materials before and after plasma treatment.

[0077] The testing method was as follows: data was collected using a 600E electrochemical workstation (CHI, China). The electrode pair was Ag / AgCl, the electrolyte was KCl solution of different concentrations, and the permeation membrane was Ti3C2T as used in this embodiment. x Two-dimensional nanosheet film material with an area of ​​0.03 mm² 2 The above tests were conducted using an H-type electrochemical cell. The effects of moisture evaporation and air absorption were minimized during testing. Test conditions were: -0.2 to 0.2 V, scan rate: 0.01 V / s. Ion transport behavior and osmotic energy conversion were analyzed, and output power performance was evaluated using a variable external resistor. Figure 7 The horizontal axis represents the concentration of the KCl solution, and the vertical axis represents the conductivity (the reciprocal of the resistance) of the membrane material, in units of S (Ω). -1 ).

[0078] Depend on Figure 7 It can be observed that after plasma treatment, Ti3C2T x The conductivity of the permeation energy-generating membrane material was significantly improved at different concentrations, indicating a substantial enhancement in ion selectivity.

[0079] Figure 8 In this embodiment, Ti3C2T x IV curves of a two-dimensional nanosheet film material before and after plasma treatment. Figure 8 It can be observed that after plasma treatment, the internal resistance of the Ti3C2-based permeation energy-generating membrane material decreased from approximately 20kΩ to 18kΩ, indicating an increase in ion mobility.

[0080] Figure 9 The Ti3C2T prepared in this embodiment x Output power density curves of two-dimensional nanosheet film materials. Figure 9 The prepared Ti3C2-based permeation energy-generating membrane material exhibited a high permeation voltage of 120 mV and a high permeation current of 5.0 μA in a 50-fold gradient NaCl electrolyte (0.01 M / 0.5 M NaCl), indicating that the charge density and ion selectivity of the two-dimensional nanofluidic channels in this membrane material were effectively increased. The output power density, calculated using an external resistor, reached 5.95 W / m². 2 .

[0081] Example 2

[0082] This embodiment provides a two-dimensional nanosheet film material, the preparation method of which includes:

[0083] 1. Preparation of osmotic power generation membrane material: Take a certain mass of few-layer (3 layers) two-dimensional GO nanosheet, adjust it into a suspension with a concentration of 5 g / L in deionized water, and ultrasonically treat it in an ultrasonic cleaning instrument for 30 minutes until the nanosheet is uniformly dispersed; adjust the pH of the suspension to 12.0 with Na2CO3, and then use a circulating water vacuum pump to filter the suspension into a membrane on a filter membrane; dry the membrane in a vacuum oven at 80°C for half an hour to remove excess water, and prepare an intermediate membrane material.

[0084] 2. Plasma treatment: place the intermediate membrane material obtained in step 1 in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.5 mbar, a gas flow of 10 slm, and air as the ionization gas, and treat it for 5 minutes to prepare a two-dimensional nanosheet membrane material.

[0085] The plasma-treated GO-based two-dimensional nanosheet membrane material prepared in this example was characterized. The results showed that the GO nanosheet was assembled into a GO-based two-dimensional nanosheet membrane material with layer-by-layer stacking after vacuum filtration, and the membrane material had a dense two-dimensional nanofluid channel; the prepared GO-based two-dimensional nanosheet membrane material had a uniformly distributed electric potential, and the average electric potential was about 360 mV; after plasma treatment, the channel height of the GO-based two-dimensional nanosheet membrane material increased, the content of oxygen-containing functional groups increased, the hydrophilicity improved, the ion selectivity improved, and the ion mobility increased; the output power density of the prepared GO-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 5.89 W / m 2 .

[0086] Example 3

[0087] This example provides a two-dimensional nanosheet membrane material, and a preparation method thereof comprises:

[0088] 1. Preparation of intermediate membrane material: take a certain mass of single-layer two-dimensional montmorillonite nanosheet, adjust it into a suspension with a concentration of 0.2 g / L in deionized water, and ultrasonically treat it in an ultrasonic cleaning instrument for 10 minutes until the nanosheet is uniformly dispersed; adjust the pH of the suspension to 13.0 with KOH, and then use a circulating water vacuum pump to filter the suspension into a membrane on a filter membrane; dry the membrane in a vacuum oven at 80°C for half an hour to remove excess water, and prepare an intermediate membrane material.

[0089] 2. Plasma treatment: place the intermediate membrane material obtained in step 1 in a plasma cleaning machine with an ionization power of 50 W, a vacuum degree of 0.7 mbar, a gas flow of 30 slm, and CF4 as the ionization gas, and treat it for 10 minutes to prepare a two-dimensional nanosheet membrane material.

[0090] The prepared plasma-treated montmorillonite-based two-dimensional nanosheet membrane material of this example was characterized. The results show that the montmorillonite nanosheets are assembled into a layer-by-layer stacked montmorillonite-based two-dimensional nanosheet membrane material after vacuum filtration, and the membrane material has a dense two-dimensional nanofluid channel; the prepared montmorillonite-based two-dimensional nanosheet membrane material has a uniform distribution of electric potential, and the average electric potential is about 390 mV; the channel height of the plasma-treated montmorillonite-based two-dimensional nanosheet membrane material increases, the F-C bond content increases, the hydrophilicity decreases, the ion selectivity improves, and the ion mobility increases; the output power density of the prepared montmorillonite-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 5.50 W / m 2 .

[0091] Example 4

[0092] This example provides a two-dimensional nanosheet membrane material, and a preparation method thereof comprises:

[0093] 1. Preparation of intermediate membrane material: take a certain mass of single-layer two-dimensional hydrotalcite nanosheets, adjust them into a suspension with a concentration of 1 g / L in deionized water, and ultrasonically treat them in an ultrasonic cleaning instrument for 20 minutes until the nanosheets are uniformly dispersed; adjust the pH of the suspension to 1.0 with hydrochloric acid, and then use a circulating water vacuum pump to filter the suspension into a membrane on a filter membrane; dry the membrane in a vacuum oven at 80°C for half an hour to remove excess water, and obtain the intermediate membrane material.

[0094] 2. Plasma treatment: place the intermediate membrane material obtained in step 1 in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.7 mbar, a gas flow of 20 slm, and O2 as the ionization gas, and treat it for 30 minutes to obtain a two-dimensional nanosheet membrane material.

[0095] The prepared plasma-treated hydrotalcite-based two-dimensional nanosheet membrane material of this example was characterized. The results show that the hydrotalcite nanosheets are assembled into a layer-by-layer stacked hydrotalcite-based two-dimensional nanosheet membrane material after vacuum filtration, and the membrane material has a dense two-dimensional nanofluid channel; the prepared hydrotalcite-based two-dimensional nanosheet membrane material has a uniform distribution of electric potential, and the average electric potential is about 384 mV; the channel height of the plasma-treated hydrotalcite-based two-dimensional nanosheet membrane material increases, the oxygen-containing functional group content increases, the hydrophilicity improves, the ion selectivity improves, and the ion mobility increases; the output power density of the prepared hydrotalcite-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 5.60 W / m 2 .

[0096] Example 5

[0097] This example provides a two-dimensional nanosheet membrane material, and a preparation method thereof comprises:

[0098] 1. Preparation of intermediate film material: Take a certain mass of few-layer (2-layer) two-dimensional black phosphorus (BP) nanosheet, adjust it into a suspension with a concentration of 2 g / L in deionized water, and ultrasonically treat it in an ultrasonic cleaner for 15 minutes until the nanosheet is uniformly dispersed; adjust the pH of the suspension to 11.0 with NH3, and then use a circulating water vacuum pump to filter the suspension into a film on a filter membrane; dry the film in a vacuum oven at 80°C for half an hour to remove excess water, and prepare the intermediate film material.

[0099] 2. Plasma treatment: place the intermediate film material obtained in step 1 in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.7 mbar, a gas flow of 20 slm, and an ionization gas of air / O2 mixed gas (air to oxygen volume ratio of 1:1) for 5 minutes to prepare the two-dimensional nanosheet film material.

[0100] The plasma-treated BP-based two-dimensional nanosheet film material prepared in this example was characterized. The results showed that the BP-based nanosheet was assembled into a BP-based two-dimensional nanosheet film material with layer-by-layer stacking after vacuum filtration, and the film material had a dense two-dimensional nanofluid channel; the prepared BP-based two-dimensional nanosheet film material had a uniformly distributed electric potential, and the average electric potential was about 397 mV; after plasma treatment, the channel height of the BP-based two-dimensional nanosheet film material increased, the content of oxygen-containing functional groups increased, the hydrophilicity improved, the ion selectivity improved, and the ion mobility increased; the output power density of the prepared BP-based two-dimensional nanosheet film material in a 50-fold gradient NaCl electrolyte could reach 5.92 W / m 2 .

[0101] Example 6

[0102] This example provides a two-dimensional nanosheet film material, and a preparation method thereof comprises:

[0103] 1. Preparation of intermediate film material: take a certain mass of few-layer (3-layer) two-dimensional MnO2 nanosheet, adjust it into a suspension with a concentration of 0.5 g / L in deionized water, and ultrasonically treat it in an ultrasonic cleaner for 30 minutes until the nanosheet is uniformly dispersed; adjust the pH of the suspension to 11.0 with KOH, and then use a circulating water vacuum pump to filter the suspension into a film on a filter membrane; dry the film in a vacuum oven at 80°C for half an hour to remove excess water, and prepare the intermediate film material.

[0104] 2. Plasma treatment: place the intermediate film material obtained in step 1 in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.7 mbar, a gas flow of 20 slm, and an ionization gas of N2 / O2 mixed gas (nitrogen to oxygen volume ratio of 1:1) for 10 minutes to prepare the two-dimensional nanosheet film material.

[0105] The plasma treated MnO2-based two-dimensional nanosheet membrane material prepared in this example was characterized. The results show that the MnO2 nanosheets are assembled into a layer-by-layer stacked MnO2-based two-dimensional nanosheet membrane material after vacuum suction filtration, and the membrane material has a dense two-dimensional nanofluid channel; the prepared MnO2-based two-dimensional nanosheet membrane material has a uniform distribution of electric potential, and the average electric potential is about 390 mV; the channel height of the plasma treated MnO2-based two-dimensional nanosheet membrane material increases, the content of oxygen-containing functional groups increases, the hydrophilicity improves, the ion selectivity improves, and the ion transference rate improves; the output power density of the prepared MnO2-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 5.80 W / m 2 .

[0106] Example 7

[0107] This example provides a two-dimensional nanosheet membrane material, and a preparation method thereof comprises:

[0108] 1. Preparation of intermediate membrane material: take a certain mass of few-layer (2-layer) two-dimensional MoS2 nanosheets, adjust them into a suspension with a concentration of 0.5 g / L in deionized water, and ultrasonically treat them in an ultrasonic cleaning instrument for 30 minutes until the nanosheets are uniformly dispersed; adjust the pH of the suspension to 11.0 with KOH, and then use a circulating water vacuum pump to suction filter the suspension into a membrane on a filter membrane; dry the membrane in a vacuum oven at 80°C for half an hour to remove excess water, and obtain the intermediate membrane material.

[0109] 2. Plasma treatment: place the intermediate membrane material obtained in step 1 in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.7 mbar, a gas flow of 20 slm, and H2 / O2 mixed gas as the ionization gas, and treat it for 10 minutes to obtain a two-dimensional nanosheet membrane material.

[0110] The plasma treated MoS2-based two-dimensional nanosheet membrane material prepared in this example was characterized. The results show that the MoS2 nanosheets are assembled into a layer-by-layer stacked MoS2-based two-dimensional nanosheet membrane material after vacuum suction filtration, and the membrane material has a dense two-dimensional nanofluid channel; the prepared MoS2-based two-dimensional nanosheet membrane material has a uniform distribution of electric potential, and the average electric potential is about 393 mV; the channel height of the plasma treated MoS2-based two-dimensional nanosheet membrane material increases, the content of oxygen-containing functional groups increases, the hydrophilicity improves, the ion selectivity improves, and the ion transference rate improves; the output power density of the prepared MoS2-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 5.72 W / m 2 .

[0111] Example 8

[0112] The embodiment provides a two-dimensional nanosheet membrane material, and a preparation method thereof.

[0113] 1. Preparation of an intermediate membrane material: taking monolayer two-dimensional hydrotalcite and monolayer Ti2C nanosheets with a mass ratio of 1:1, preparing a suspension with a concentration of 0.5 g / L in deionized water, and ultrasonically treating the suspension in an ultrasonic cleaning instrument for 30 minutes until the nanosheets are uniformly dispersed; adjusting the pH of the suspension to 1.5 by using H2SO4, and then using a circulating water vacuum pump to filter the suspension into a membrane on a filter membrane; and drying the membrane in a vacuum oven at 80 DEG C for half an hour to remove excess water, thereby obtaining the intermediate membrane material.

[0114] 2. Plasma treatment: placing the intermediate membrane material obtained in step 1 in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.7 mbar, a gas flow of 20 slm, and O2 gas as the ionization gas, and treating the intermediate membrane material for 5 minutes, thereby obtaining the two-dimensional nanosheet membrane material.

[0115] The hydrotalcite / Ti2C-based two-dimensional nanosheet membrane material prepared in the embodiment is characterized. The results show that the hydrotalcite / Ti2C nanosheets are assembled into a MoS2-based two-dimensional nanosheet membrane material after vacuum filtration, and the membrane material has a dense two-dimensional nanofluid channel; the prepared hydrotalcite / Ti2C-based two-dimensional nanosheet membrane material has a uniform distribution of electric potential, and the average electric potential is about 399 mV; after the plasma treatment, the channel height of the hydrotalcite / Ti2C-based two-dimensional nanosheet membrane material increases, the content of oxygen-containing functional groups increases, the hydrophilicity is improved, the ion selectivity is improved, and the ion transference rate is improved; the output power density of the prepared hydrotalcite / Ti2C-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 5.94 W / m 2 .

[0116] Embodiment 9

[0117] The embodiment provides a two-dimensional nanosheet membrane material, and a preparation method thereof.

[0118] 1. Preparation of an intermediate membrane material: taking a certain amount of few-layer (3 layers) two-dimensional graphene nanosheets, preparing a suspension with a concentration of 0.5 g / L in deionized water, and ultrasonically treating the suspension in an ultrasonic cleaning instrument for 30 minutes until the nanosheets are uniformly dispersed; adjusting the pH of the suspension to 11.0 by using KOH, and then using a circulating water vacuum pump to filter the suspension into a membrane on a filter membrane; and drying the membrane in a vacuum oven at 80 DEG C for half an hour to remove excess water, thereby obtaining the intermediate membrane material.

[0119] 2. Plasma treatment: the intermediate film material obtained in step 1 was placed in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.7 mbar, a gas flow of 20 slm, and O2 gas as the ionization gas, and treated for 5 minutes to obtain a graphene-based two-dimensional nanosheet film material.

[0120] The graphene-based two-dimensional nanosheet film material prepared in this example was characterized. The results showed that the graphene nanosheets were assembled into a graphene-based two-dimensional nanosheet film material with layer-by-layer stacking after vacuum filtration, and the film material had a dense two-dimensional nanofluid channel; the graphene-based two-dimensional nanosheet film material prepared had a uniform distribution of electric potential, and the average electric potential was about 380 mV; after plasma treatment, the channel height of the graphene-based two-dimensional nanosheet film material increased, the content of oxygen-containing functional groups increased, the hydrophilicity improved, the ion selectivity improved, and the ion mobility increased; the output power density of the graphene-based two-dimensional nanosheet film material prepared could reach 5.52 W / m 2 .

[0121] Comparative Example 1

[0122] This comparative example provides a two-dimensional nanosheet film material, and the preparation method thereof comprises:

[0123] 1. Preparation of intermediate film material: a certain amount of few-layer (2-layer) two-dimensional Ti3C2 nanosheets were taken, and a suspension with a concentration of 10 g / L was prepared in deionized water, and the nanosheets were ultrasonically treated in an ultrasonic cleaning instrument for 60 minutes until they were uniformly dispersed; the pH of the suspension was adjusted to 11.0 with NaOH, and then the suspension was filtered into a film on a filter membrane using a circulating water vacuum pump; the film was dried in a vacuum oven at 80°C for half an hour to remove excess water, and an intermediate film material was prepared.

[0124] 2. Plasma treatment: the intermediate film material obtained in step 1 was placed in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.5 mbar, a gas flow of 10 slm, and O2 as the ionization gas, and treated for 20 minutes to obtain a Ti3C2-based two-dimensional nanosheet film material.

[0125] The plasma-treated Ti3C2-based two-dimensional nanosheet membrane material prepared in this comparative example was characterized. The results show that the Ti3C2nanosheets are assembled into a layer-by-layer stacked Ti3C2-based two-dimensional nanosheet membrane material after vacuum suction filtration, and the membrane material has a dense two-dimensional nanofluid channel; the prepared Ti3C2-based two-dimensional nanosheet membrane material has a uniform distribution of electric potential, and the average electric potential is about 300 mV; the channel height of the plasma-treated Ti3C2-based two-dimensional nanosheet membrane material increases, the content of oxygen-containing functional groups increases, the hydrophilicity improves, the ion selectivity improves, and the ion mobility improves; the output power density of the prepared Ti3C2-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 3.1 W / m 2 .

[0126] Comparative Example 2

[0127] This comparative example provides a two-dimensional nanosheet membrane material, and the preparation method thereof comprises:

[0128] 1. Preparation of intermediate membrane material: take a certain mass of few-layer (3 layers) two-dimensional graphene nanosheets, adjust them into a suspension with a concentration of 0.5 g / L in deionized water, and ultrasonically treat them in an ultrasonic cleaning instrument for 40 minutes until the nanosheets are uniformly dispersed; adjust the pH of the suspension to 11.0 with KOH, and then use a circulating water vacuum pump to suction filter the suspension into a membrane on a filter membrane; dry the membrane in a vacuum oven at 60°C for half an hour to remove excess water, and obtain the intermediate membrane material.

[0129] 2. Plasma treatment: place the intermediate membrane material obtained in step 1 in a plasma cleaning machine with an ionization power of 100 W, a vacuum degree of 0.5 mbar, a gas flow of 10 slm, and O2 gas as the ionization gas, and treat it for 20 minutes to obtain a two-dimensional nanosheet membrane material.

[0130] The plasma-treated graphene-based two-dimensional nanosheet membrane material prepared in this comparative example was characterized. The results show that the graphene nanosheets are assembled into a layer-by-layer stacked graphene-based two-dimensional nanosheet membrane material after vacuum suction filtration, and the membrane material has a dense two-dimensional nanofluid channel; the prepared graphene-based two-dimensional nanosheet membrane material has a uniform distribution of electric potential, and the average electric potential is about 280 mV; the channel height of the plasma-treated graphene-based two-dimensional nanosheet membrane material increases, the content of oxygen-containing functional groups increases, the hydrophilicity improves, the ion selectivity improves, and the ion mobility improves; the output power density of the prepared graphene-based two-dimensional nanosheet membrane material in a 50-fold gradient NaCl electrolyte can reach 2.82 W / m 2 .

[0131] Comparative Example 3

[0132] This comparative example provides a two-dimensional nanosheet film material, the preparation method of which includes:

[0133] 1. Preparation of intermediate membrane material: A certain mass of single-layer two-dimensional montmorillonite nanosheets was prepared into a suspension with a concentration of 0.5 g / L in deionized water, and ultrasonically treated in an ultrasonic cleaner for 30 minutes until the nanosheets were evenly dispersed; the pH of the suspension was adjusted to 11.0 with KOH, and then the suspension was filtered onto a filter membrane using a circulating water vacuum pump to form a membrane; the membrane was dried in a vacuum oven at 40℃ for half an hour to remove excess water, thus obtaining the intermediate membrane material.

[0134] 2. Plasma treatment: The intermediate membrane material obtained in step 1 is placed in a plasma cleaner with an ionization power of 200W, a vacuum degree of 0.7mbar, a gas flow rate of 20slm, and an ionization gas of CF4 for 2 minutes to obtain a two-dimensional nanosheet membrane material.

[0135] The plasma-treated montmorillonite-based two-dimensional nanosheet film material prepared in this comparative example was characterized. The results showed that montmorillonite nanosheets, after vacuum filtration, assembled into a stacked montmorillonite-based two-dimensional nanosheet film material with dense two-dimensional nanofluid channels. The prepared montmorillonite-based two-dimensional nanosheet film material exhibited a uniformly distributed potential with an average potential of approximately 173 mV. The plasma-treated montmorillonite-based two-dimensional nanosheet film material showed increased channel height, increased FC bond content, decreased hydrophilicity, almost unchanged ion selectivity, and decreased ion mobility. The prepared montmorillonite-based two-dimensional nanosheet film material achieved a power density of 1.54 W / m³ in a NaCl electrolyte with a 50-fold gradient. 2 .

[0136] Other experimental parameters for the above embodiments and comparative examples are shown in Table 1.

[0137] Table 1

[0138]

[0139] As can be seen from Table 1, the thickness of the two-dimensional nanosheet film material in the embodiment is slightly greater than that of the intermediate film material. This is because plasma treatment can increase the interlayer spacing between the two-dimensional structures, which is macroscopically manifested as an increase in the thickness of the film material.

[0140] Table 2 summarizes the performance test results of the two-dimensional nanosheet film materials of Examples 1 to 9.

[0141] Table 2

[0142]

[0143]

[0144] As shown in Table 2, the two-dimensional nanosheet films prepared in Examples 1-8 exhibit high average potential and output power. Specifically, by controlling parameters such as ionization power, ionization time, and gas flow rate during plasma treatment, the average potential of the two-dimensional nanosheet films obtained in Examples 1-8 is above 360 ​​mV, and the output power is above 5.5 W / m. 2 The above figures can reach a maximum of 5.94-5.95 W / m. 2 .

[0145] For example, by comparing Comparative Example 1 with Example 1, Comparative Example 2 with Example 9, and Comparative Example 3 with Example 3, it can be seen that by controlling the ionization power and processing time of plasma treatment, the intensity of plasma treatment can be controlled, thereby improving the average potential and output power of the two-dimensional nanosheet film material.

[0146] In summary, through microstructure characterization, surface potential distribution testing, and output power density testing, it was demonstrated that this embodiment successfully utilized plasma treatment to improve the charge density and ion selectivity of the two-dimensional nanofluidic channel, and produced an output power density of 5.5 W / m². 2 The above-mentioned two-dimensional nanosheet film materials, especially the Ti3C2-based two-dimensional nanosheet film materials, achieved an output power of 5.95 W / m. 2 The power density of the two-dimensional nanosheet membrane material provided by this invention is significantly higher than the industrial benchmark for river-sea water system development and also exceeds the output power density of most advanced permeable energy power generation membrane materials. These results demonstrate that the two-dimensional nanosheet membrane material provided by this invention can be used as a permeable energy power generation membrane material, exhibiting excellent power generation capabilities. Furthermore, its simple and safe preparation process makes it suitable for industrial production and has broad application prospects.

Claims

1. A method for preparing a two-dimensional nanosheet film material, the method comprising: Two-dimensional nanosheets are filtered to form an intermediate membrane material, and the intermediate membrane material is subjected to plasma treatment to obtain the two-dimensional nanosheet membrane material. The ionizing gas used in the plasma treatment includes one or more combinations of air, oxygen, and carbon tetrafluoride; the flow rate of the ionizing gas used in the plasma treatment is 0.5 slm - 30 slm. The plasma treatment uses an ionization power of 10W-500W; The two-dimensional nanosheets include one or more of the following: MXenes, two-dimensional nanosheets of metal oxides, two-dimensional nanosheets of transition metal sulfides, graphene, graphene oxide, two-dimensional nanosheets of elemental phosphorus, and two-dimensional nanosheets of clay. When the two-dimensional nanosheets include one or more of MXenes, graphene, graphene oxide, and phosphorus, the plasma treatment time is 0.5 min to 5 min. When the two-dimensional nanosheets are one or more of the following: two-dimensional nanosheets of metal oxides, two-dimensional nanosheets of transition metal sulfides, and two-dimensional nanosheets of clay, the plasma treatment time is 10 min to 30 min.

2. The preparation method according to claim 1, wherein, The MXenes include Ti3C2T x One or more of Ti2C, Ti2N, Nb2C, V2C, Mo2C, MnB, Fe2B2, MoB and Cr2B2; The metal oxides include MnO2 and / or MoO3; The transition metal sulfides include WS2 and MoS2; The clay includes one or more of montmorillonite, mica, zeolite, kaolinite, vermiculite and hydrotalcite; The phosphorus element includes black phosphorus and / or purple phosphorus.

3. The preparation method according to claim 2, wherein, The two-dimensional nanosheets include hydrotalcite, Ti2C, and Ti3C2T. x One or more of two-dimensional nanosheets of graphene oxide and montmorillonite.

4. The preparation method according to any one of claims 1-3, wherein, The two-dimensional nanosheets have 1-3 layers.

5. The preparation method according to claim 1, wherein, The plasma treatment uses a vacuum level of 0.1-0.9 mbar; And / or, the plasma treatment uses an ionization gas flow rate of 0.5 slm-20 slm or 20 slm-30 slm; And / or, the plasma treatment uses an ionization power of 100W-500W.

6. The preparation method according to claim 5, wherein, The plasma treatment uses a vacuum level greater than 0.3 mbar and less than or equal to 0.9 mbar.

7. The preparation method according to claim 5, wherein, The plasma treatment uses a vacuum level of 0.3 mbar to 0.7 mbar.

8. The preparation method according to claim 1, wherein, The filtration process includes: uniformly dispersing two-dimensional nanosheets in water to form a suspension, filtering the suspension onto a filter membrane to form a membrane, and drying to obtain the intermediate membrane material.

9. The preparation method according to claim 8, wherein, The concentration of the suspension is 0.2-10 g / L.

10. The preparation method according to claim 1, wherein, The ionized gas used in the plasma treatment also includes one or more combinations of nitrogen, argon, hydrogen, ammonia, and carbon dioxide.

11. A two-dimensional nanosheet film material, which is obtained by the preparation method according to any one of claims 1-10.

12. The two-dimensional nanosheet film material according to claim 11, wherein, The thickness of the two-dimensional nanosheet film material is 1-10 μm.

13. The two-dimensional nanosheet film material according to claim 11, wherein, The thickness of the two-dimensional nanosheet film material is 1-8 μm.

14. A permeation energy generating membrane material, comprising or made of the two-dimensional nanosheet membrane material according to any one of claims 11-13.

15. The permeation energy generation membrane material according to claim 14, wherein, The output power of this permeation energy-generating membrane material is greater than or equal to 5.5 W / m. 2 .

16. The application of the permeation energy power generation membrane material according to claim 14 or 15 in permeation energy harvesting in river-sea systems.

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