Adsorbing material, method for producing the same, adsorbing sheet, separation membrane for artificial dialysis, and artificial dialysis apparatus

Abstract

Provided is an adsorbent material containing MXene, which has excellent adsorption properties for polar organic compounds. The adsorbent material contains particles of a layered material having one or more layers, the layers including: a layer main body represented by the formula: M m X n (n is 1 or more and 4 or less, and m is greater than n and 5 or less), a modification or a terminal T (T is at least one selected from the group consisting of a hydroxyl group, a fluorine atom, a chlorine atom, an oxygen atom, and a hydrogen atom) present on the surface of the layer main body, the average value of the thickness of the particles is 1 nm or more and 10 nm or less, and the Li content is 0.0001 mass% or more and 0.0020 mass% or less.

Description

TECHNICAL FIELD

[0001] The present application relates to an adsorbing material and a method for manufacturing the same, an adsorbing sheet, a separation membrane for artificial dialysis, and an artificial dialysis apparatus. BACKGROUND

[0002] In recent years, MXene has attracted attention as a new material. MXene is one of so-called two-dimensional materials, and as described later, is a layered material having a morphology of one or more layers. In general, MXene has a morphology of particles (also referred to as MXene particles. May include powder, flake, nanoplate, etc.) of such a layered material.

[0003] Currently, in view of the application of MXene to various uses such as electronic devices, medical devices, etc., various studies are being conducted. For example, in Non-Patent Literature 1, it is shown that MXene is used for removal of urea in dialysis, and it is pointed out that the MXene is obtained by etching with HF. In Non-Patent Literature 2, it is shown that in a suspension obtained by intercalation using Li, by adding hydrochloric acid or the like to adjust the pH value to about 2.9, it is possible to control the amount of Li between the layers of MXene. In Non-Patent Literature 3, it is shown that as a dispersant, by using TMAOH (tetramethylammonium hydroxide) instead of Li, interlayer peeling of multi-layer MXene is performed.

[0004] PRIOR ART DOCUMENTS

[0005] NON-PATENT LITERATURE

[0006] Non-Patent Literature 1: Fayan Meng et al., MXene Sorbents for Removal of Urea from Dialysate: A Step toward the Wearable Artificial Kidney ACS Nano 2018, 12, 10518-10528

[0007] Non-Patent Literature 2: Hongwu chen et al., Pristine Titanium Carbide MXene Films with Environmentally Stable Conductivity and Superior Mechanical Strength (Adv. Funct. Mater. 2020, 30, 1906996)

[0008] Non-Patent Literature 3: Mohamed Alhabeb et al., Guidelines for Synthesis and Processing of Two-Dimensional Titanium Carbide (Ti3C2Tx MXene) Chem. Mater. 2017, 29, 7633-7644 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] As described in Non-Patent Literature 1, it is pointed out that in recent years, for example, MXene is used for urea removal in artificial dialysis, but it is difficult to say that the adsorption performance of urea is sufficient in the prior art. The MXene disclosed in Non-Patent Literature 2 and Non-Patent Literature 3 is not intended for urea removal in dialysis, and when used for dialysis urea removal, it is desirable to suppress substances such as Li and TMAOH, which are harmful to patients with kidney disease.

[0011] MEANS FOR SOLVING THE PROBLEMS

[0012] According to one aspect of the present application, there is provided an adsorbent material, wherein,

[0013] particles including a layered material having one or more layers, and Li,

[0014] the layer includes:

[0015] a layer main body represented by the following formula: M m X n (M is at least one of Group 3, 4, 5, 6, 7 metals, X is a carbon atom, a nitrogen atom, or a combination thereof, n is 1 or more and 4 or less, and m is greater than n and 5 or less); a modification or a terminal T (T is at least one selected from the group consisting of a hydroxyl group, a fluorine atom, a chlorine atom, an oxygen atom, and a hydrogen atom) present on the surface of the layer main body,

[0016] an average value of the thickness of the particles is 1 nm or more and 10 nm or less,

[0017] the Li content is 0.0001 mass% or more and 0.0020 mass% or less.

[0018] According to another aspect of the present application, there is provided a method for producing an adsorbent material, wherein,

[0019] (a) preparing a layered material having one or more layers represented by the following formula: M m AX na precursor represented by the formula: MxAXn (wherein M is at least one metal of Groups 3 to 7, X is a carbon atom, a nitrogen atom, or a combination thereof, A is at least one element of Groups 12 to 16, n is 1 or more and 4 or less, and m is greater than n and 5 or less);

[0020] (b1) performing an etching treatment for removing at least a part of A atoms from the precursor using an etching solution;

[0021] (c1) performing a water washing of the etching treatment product obtained by the etching treatment;

[0022] (d1) performing a Li intercalation treatment including a step of mixing a water washing product obtained by the water washing with a Li-containing compound;

[0023] (e) performing a delamination treatment including a step of stirring a Li intercalation product obtained by the Li intercalation treatment;

[0024] (f) performing an acid treatment including a step of mixing a delamination product obtained by the delamination treatment with an acid solution; and

[0025] (g) performing a water washing of an acid treatment product obtained by the acid treatment to obtain an adsorbent material,

[0026] The Li content in the adsorbent material is 0.0001 mass% or more and 0.0020 mass% or less.

[0027] Effects of the Invention

[0028] According to the present application, the adsorbent material contains particles of a prescribed layered material (also referred to as "MXene" in the present specification) having an average value of the thickness of the particles of 1 nm or more and 10 nm or less and Li having a content of 0.0001 mass% or more and 0.0020 mass% or less, thereby providing an adsorbent material containing MXene, which has excellent adsorption performance.

[0029] Further, according to the present application, by (a) preparing a prescribed precursor; (bl) performing an etching treatment for removing at least a part of A atoms from the precursor using an etching solution; (cl) water washing an etching treatment product obtained through the etching treatment; (dl) performing a Li intercalation treatment, which includes a step of mixing a water washing treatment product obtained through the water washing with a Li-containing compound; (e) performing a delamination treatment, which includes a step of stirring a Li intercalation treatment product obtained through the Li intercalation treatment; (f) performing an acid treatment, which includes a step of mixing a delamination treatment product obtained through the delamination treatment with an acid solution; and (g) water washing an acid treatment product obtained through the acid treatment, it is possible to produce an adsorbing material containing the above-described particle and the above-described amount of Li, having the above-described shape, and having excellent adsorbing properties for, for example, polar organic compounds. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic cross-sectional view showing a layered material, i.e., MXene, which can be used for the adsorbing material of the present application, (a) shows a single-layer MXene, and (b) shows a multi-layer (illustrated as a double layer) MXene.

[0031] Figure 2 is a graph showing the interlayer distance of one form of the adsorbing material of the present application.

[0032] Figure 3 is a graph schematically illustrating an artificial dialysis apparatus using the adsorbing material of the present application.

[0033] Figure 4 is a graph showing the results of X-ray diffraction measurement of the examples. DETAILED DESCRIPTION

[0034] (Embodiment 1: Adsorbing material)

[0035] Hereinafter, the adsorbing material of one embodiment of the present application will be described in detail, but the present application is not limited to this embodiment.

[0036] The adsorbing material of the present embodiment,

[0037] contains a particle of a layered material having one or more layers and Li,

[0038] The layer includes:

[0039] MxXy m X na layer body represented by the formula (MnXm) (where M is at least one metal of Groups 3, 4, 5, 6, and 7, X is a carbon atom, a nitrogen atom, or a combination thereof, n is 1 or more and 4 or less, and m is greater than n and 5 or less); a modification or a terminal T (T is at least one selected from the group consisting of a hydroxyl group, a fluorine atom, a chlorine atom, an oxygen atom, and a hydrogen atom) present on the surface of the layer body,

[0040] The average value of the thickness of the particle is 1 nm or more and 10 nm or less,

[0041] The Li content is 0.0001 mass% or more and 0.0020 mass% or less.

[0042] The above-mentioned layered material can be understood as a layered compound, and is also represented as "M m X n T s " and s is an arbitrary number. In the past, x or z has sometimes been used instead of s. Typically, n can be 1, 2, 3, or 4, but is not limited thereto.

[0043] In the above formula of MXene, M is preferably at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and Mn, and is more preferably at least one selected from the group consisting of Ti, V, Cr, and Mo.

[0044] It is known that MXene can be represented by the above formula: M m X n is expressed as follows.

[0045] Sc2C, Ti2C, Ti2N, Zr2C, Zr2N, Hf2C, Hf2N, V2C, V2N, Nb2C, Ta2C, Cr2C, Cr2N, Mo2C, Mo 1.3 C, Cr 1.3 C, (Ti, V)2C, (Ti, Nb)2C, W2C, W 1.3 C, Mo2N, Nb 1.3 C, Mo 1.3 Y 0.6 C (in the above formula, "1.3" and "0.6" mean about 1.3 (= 4 / 3) and about 0.6 (= 2 / 3), respectively),

[0046] Ti3C2, Ti3N2, Ti3(CN), Zr3C2, (Ti, V)3C2, (Ti2Nb)C2, (Ti2Ta)C2, (Ti2Mn)C2, Hf3C2, (Hf2V)C2, (Hf2Mn)C2, (V2Ti)C2, (Cr2Ti)C2, (Cr2V)C2, (Cr2Nb)C2, (Cr2Ta)C2, (Mo2Sc)C2, (Mo2Ti)C2, (Mo2Zr)C2, (Mo2Hf)C2, (Mo2V)C2, (Mo2Nb)C2, (Mo2Ta)C2, (W2Ti)C2, (W2Zr)C2, (W2Hf)C2,

[0047] Ti4N3, V4C3, Nb4C3, Ta4C3, (Ti, Nb)4C3, (Nb, Zr)4C3, (Ti2Nb2)C3, (Ti2Ta2)C3, (V2Ti2)C3, (V2Nb2)C3, (V2Ta2)C3, (Nb2Ta2)C3, (Cr2Ti2)C3, (Cr2V2)C3, (Cr2Nb2)C3, (Cr2Ta2)C3, (Mo2Ti2)C3, (Mo2Zr2)C3, (Mo2Hf2)C3, (Mo2V2)C3, (Mo2Nb2)C3, (Mo2Ta2)C3, (W2Ti2)C3, (W2Zr2)C3, (W2Hf2)C3, (Mo 2.7 V 1.3 )C3 (in the above formula, "2.7" and "1.3" mean about 2.7 (= 8 / 3) and about 1.3 (= 4 / 3), respectively.)

[0048] Typically, in the above formula, M is titanium or vanadium, and X can be a carbon atom or a nitrogen atom. For example, the MAX phase is Ti3AlC2, and the MXene is Ti3C2T s (in other words, M is Ti, X is C, n is 2, and m is 3).

[0049] Also, in the present application, the MXene can contain a small amount of residual A atoms, for example, 10 mass% or less relative to the original A atoms. The residual amount of A atoms can be preferably 8 mass% or less, and more preferably 6 mass% or less. However, even if the residual amount of A atoms exceeds 10 mass%, depending on the use and use conditions of the adsorbent material, there are cases where there is no problem.

[0050] The adsorbent material of the present embodiment contains Li, but the content thereof is suppressed. The above Li can come from an intercalation agent for intercalation of Li. In the adsorbent material of the present embodiment, Li can be inserted into the interlayer of MXene as Li ions, and / or exist by being supported outside the layer, and the like. The adsorbent material of the present embodiment contains Li, but the content thereof is suppressed to 0.0001 mass% or more and 0.0020 mass% or less. Since the content of Li is suppressed to 0.0020 mass% or less, even if the adsorbent material of the present embodiment is used, for example, in artificial dialysis and the like, excellent biological compatibility can be achieved. Specifically, the safety factor with respect to the upper limit value of blood lithium concentration evaluated in the Examples described later is 27.2 times or more. The content of Li is measured by ICP-AES using inductively coupled plasma atomic emission spectrometry. The adsorbent material of the present embodiment, because the content of Li is suppressed as described above, can be used, for example, as an adsorbent material for a separation membrane for artificial dialysis, and the like. In addition, the adsorbable amount of urea and the like per unit volume of MXene is fixed, and the adsorbent material of the present embodiment, because the unnecessary intercalation agent (here, Li) is suppressed to an extremely small amount, can adsorb urea and the like in a large amount.

[0051] The adsorbent material of the present embodiment, as described above, contains Li, but the content thereof is sufficiently suppressed compared to the existing lithium-containing MXene. Therefore, in order to distinguish from the existing MXene, the MXene constituting the adsorbent material of the present embodiment is referred to as "Li-suppressed MXene".

[0052] Hereinafter, the MXene particle corresponding to the skeleton of the Li-suppressed MXene constituting the adsorbent material of the present embodiment will be described using Figure 1 The MXene particle corresponding to the skeleton of the Li-suppressed MXene constituting the adsorbent material of the present embodiment will be described using Figure 1 The MXene particle corresponding to the skeleton of the Li-suppressed MXene constituting the adsorbent material of the present embodiment will be described using

[0053] The adsorbent material of the present embodiment is Figure 1 (a) is a collection of MXene 10a (single-layer MXene) containing one layer, which is schematically illustrated. The MXene 10a, in more detail, is a MXene layer 7a having a layer main body (M m X n indicated by M m X n layer) 1a, and a modification or a terminal T3a, 5a present on the surface of the layer main body 1a (in more detail, at least one of the two surfaces opposed to each other in each layer). Therefore, the MXene layer 7a is also indicated as "M m X n T s ", and s is an arbitrary number.

[0054] The adsorbent material of the present embodiment can include one layer, and can include a plurality of layers. As the plurality of layers, a MXene (a multi-layer MXene) such as Figure 1 (b) schematically shows a MXene 10b of two layers, but is not limited to these examples. Figure 1 1b, 3b, 5b, 7b in (b) are the same as the aforementioned Figure 1 1a, 3a, 5a, 7a of (a). The adjoining two MXene layers of the multi-layer MXene (for example, 7a and 7b) are not necessarily completely separated, and can be partially in contact. The MXene 10a is the multi-layer MXene 10b each of which is separated as one layer, and sometimes the multi-layer MXene 10b remains as a mixture of the above-described single-layer MXene 10a and the multi-layer MXene 10b without being separated. Even when the above-described multi-layer MXene is contained, it is preferable that the multi-layer MXene subjected to interlayer peeling treatment be a MXene having a small number of layers. The so-called "small number of layers" means, for example, that the number of layers of the MXene is 10 layers or less. Hereinafter, this "multi-layer MXene having a small number of layers" is referred to as a "few-layer MXene". The thickness in the layer stacking direction of the few-layer MXene is preferably 10 nm or less. In addition, the single-layer MXene and the few-layer MXene are collectively referred to as a "single-layer / few-layer MXene".

[0055] The adsorbent material of the present embodiment preferably contains a large amount of the single-layer / few-layer MXene. By containing a large amount of the single-layer / few-layer MXene, the specific surface area of the MXene can be made larger than that of the multi-layer MXene, and as a result, the adsorption target substance can be adsorbed in a large amount, and the adsorption performance can be further improved. For example, in the adsorbent material of the present embodiment, the single-layer / few-layer MXene having a number of layers of 10 layers or less and a thickness of preferably 10 nm or less accounts for 80% by volume or more, more preferably 90% by volume or more, and further preferably 95% by volume or more, in terms of the proportion in the total MXene. In addition, it is more preferable that the volume of the single-layer MXene be larger than the volume of the few-layer MXene. It can be said that the true density of these MXenes does not greatly vary depending on the existing form, and therefore, it is more preferable that the mass of the single-layer MXene be larger than the mass of the few-layer MXene. If these relationships are satisfied, the specific surface area can be further increased, and the adsorption performance can be further improved. It is most preferable that the adsorbent material of the present embodiment be formed only of the single-layer MXene.

[0056] (Average value of particle thickness)

[0057] The average of the particle thickness is 1 nm or more and 10 nm or less. The thickness is preferably 7 nm or less, more preferably 5 nm or less. On the other hand, if the thickness of a single-layer MXene is taken into consideration, the lower limit of the particle thickness is 1 nm as described above. The thickness of the above-described particle, in the case of a single-layer MXene, corresponds to the thickness of the MXene layer 7a described above Figure 1 , as a multi-layer MXene (preferably a few-layer MXene), for example, like Figure 1 (b) When this is 2 layers, the sum of the thickness of the MXene layer 7a, the void Δd, and the thickness of the MXene layer 7b.

[0058] The average of the particle thickness is obtained as follows. That is, using an atomic force microscope (AFM), a photograph is taken as in the example described later, and the thickness of each MXene particle is obtained with 50 MXene particles arbitrarily selected in the photograph as the object, and the average is obtained.

[0059] (Average of the maximum dimension in the plane parallel to the layer of the particle)

[0060] The average of the maximum dimension in the plane parallel to the layer of the particle is preferably 0.1 μm or more and 20 μm or less. Since the average of the above-described maximum dimension is preferably 0.1 μm or more, the surface area of the adsorbent material becomes larger, and thus the adsorption performance for the adsorption target substance such as urea can be further improved. On the other hand, from the viewpoint of ensuring dispersibility in a solution such as a dialysate used in artificial dialysis, the average of the above-described maximum dimension is preferably 20 μm or less, more preferably 15 μm or less, and further preferably 10 μm or less.

[0061] The average of the maximum dimension in the plane parallel to the layer of the particle is obtained as follows. That is, using a scanning electron microscope (SEM), a photograph is taken as in the example described later, and the maximum dimension in the direction (plane) parallel to the developed surface of each MXene particle is obtained with 50 MXene particles arbitrarily selected in the photograph as the object, and the average of 50 is obtained.

[0062] (Interlayer distance of the flaky adsorbent material)

[0063] The adsorbent material of the present embodiment is such that the distance between the layers constituting the MXene is shorter than that of the MXene having a large number of Li ions, because there are almost no Li ions between the layers constituting the MXene. This can be determined from the XRD pattern obtained by performing X-ray diffraction measurement on the flaky adsorbent material as the adsorbent material of the present embodiment. For example, in the XRD pattern obtained by performing X-ray diffraction measurement on the flaky adsorbent material, the position of the low-angle peak corresponding to the (002) plane of the MXene at 10° (deg) or less can be determined. The higher the peak angle in the XRD pattern, the narrower the interlayer distance. The peak of the (002) plane obtained by performing X-ray diffraction measurement on the flaky adsorbent material is preferably 2θ = 8.0° or more in the adsorbent material of the present embodiment. The peak position is more preferably 8.5° or more. Also, the upper limit of the peak position is around 9.0°. The peak position refers to the peak top. The X-ray diffraction measurement can be performed under the conditions shown in the Examples described later.

[0064] The above-mentioned so-called "distance between the layers constituting the MXene" includes any one of the following:

[0065] • the distance between the single-layer MXenes in a structure in which two single-layer MXenes are overlaid together;

[0066] • the distance between the single-layer MXene and the multi-layer MXene (preferably the few-layer MXene) in a structure in which the single-layer MXene and the multi-layer MXene (preferably the few-layer MXene) are overlaid together;

[0067] • the interlayer distance (or the void size, represented by Δd in (b) below) of one multi-layer MXene (preferably one few-layer MXene); Figure 1

[0068] • the distance between the multi-layer MXenes in a structure in which two multi-layer MXenes (preferably few-layer MXenes) are overlaid together.

[0069] Using Figure 2 Among the above-mentioned modes, the interlayer distance of one multi-layer MXene (preferably one few-layer MXene) is described. Figure 2 is an example of MXene, showing M m X n a diagram of the crystal structure of the case where Ti3C2O2 (O-term) represented by Ti3C2 is shown, Figure 2 In this case, 20 is a titanium atom, 21 is an oxygen atom, and other elements are not shown. Here Figure 2 In this case, the interlayer distance of one multi-layer MXene (preferably one few-layer MXene) refers to Figure 2 ​The distance indicated by the double-headed arrow.

[0070] Although not limiting the present embodiment, for example, the interlayer distance (or void size, indicated by Δd in (b) in the present embodiment) in each of the various layer stacks of the multilayer MXene (preferably, few-layer MXene) that can be included can be 0.8 nm or more and 10 nm or less, particularly 0.8 nm or more and 5 nm or less. Figure 1 (b) in the present embodiment) can be 0.8 nm or more and 10 nm or less, particularly 0.8 nm or more and 5 nm or less.

[0071] (Sorbent material formed of composite)

[0072] As the sorbent material of the present embodiment, one or more materials among a ceramic, a metal, and a resin material can be further included. As will be exemplified later, when the sorbent material of the present embodiment is used for urea sorption in artificial dialysis, the Li-suppressed MXene of the present embodiment forms a composite with one or more materials among a ceramic, a metal, and a resin material, and a sorbent material that can stably exhibit sorption performance, such as urea sorption performance, can be achieved.

[0073] As the above-described ceramic, metal oxides such as silicon dioxide, aluminum oxide, zirconium oxide, titanium oxide, magnesium oxide, cerium oxide, zinc oxide, barium titanate, hexaferrite, and mullite; and non-oxide ceramics such as silicon nitride, titanium nitride, aluminum nitride, silicon carbide, titanium carbide, tungsten carbide, boron carbide, and titanium boride can be exemplified. As the above-described metal, iron, titanium, magnesium, aluminum, and alloys based thereon can be exemplified.

[0074] In addition, as the above-described resin material (polymer), a cellulose-based synthetic high-molecular compound can be exemplified. As the above-described polymer, for example, a hydrophilic polymer (included in a hydrophobic polymer to which a hydrophilic aid is incorporated to exhibit hydrophilicity, a surface of a hydrophobic polymer or the like is subjected to a hydrophilization treatment) can be exemplified, and as the hydrophilic polymer, one or more polymers selected from the group consisting of polysulfone, cellulose acetate, regenerated cellulose, polyether sulfone, water-soluble polyurethane, polyvinyl alcohol, sodium alginate, an acrylic water-soluble polymer, polyacrylamide, polystyrene sulfonic acid, and nylon can be exemplified.

[0075] As the above-described hydrophilic polymer, for example, a hydrophilic polymer having a polar group is used, and a group that forms a hydrogen bond with the modification of the layer of the Li-suppressed MXene or the terminal T is preferably used. As the polymer, for example, one or more polymers selected from the group consisting of water-soluble polyurethane, polyvinyl alcohol, sodium alginate, an acrylic water-soluble polymer, polyacrylamide, polystyrene sulfonic acid, and nylon is preferably used. Among them, one or more polymers selected from the group consisting of water-soluble polyurethane, polyvinyl alcohol, and sodium alginate is more preferable, and water-soluble polyurethane is further preferable.

[0076] In addition, when the composite material is used as an adsorbent material for biological use, for example, a high-molecular polymer constituting a member of a device for hemofiltration can be exemplified. Specifically, polymethyl methacrylate, polyacrylonitrile, cellulose, cellulose acetate, polysulfone, polyvinyl alcohol, or a copolymer of polyvinyl alcohol and ethylene, and the like can be exemplified. One or more of polysulfone, polymethyl methacrylate, and cellulose acetate is preferable. Polysulfone and polymethyl methacrylate are more preferable.

[0077] The proportion of the polymer contained in the composite material can be appropriately set according to the use. For example, the proportion of the polymer can be higher than 0% by volume, for example, 80% by volume or less, further 50% by volume or less, more further 30% by volume or less, more further 10% by volume or less, and still further 5% by volume or less, based on the proportion in the adsorbent material (when dried).

[0078] The method for producing the adsorbent material formed of the composite material is not particularly limited. In the adsorbent material of the present embodiment, which is a polymer-containing adsorbent material having a sheet shape, for example, the Li- controlled MXene can be mixed with a polymer to form a coating film, as exemplified below.

[0079] First, the Li-controlled MXene particles formed of the Li-controlled MXene are mixed with a polymer in a Li-controlled MXene aqueous dispersion, a Li-controlled MXene organic solvent dispersion, or a Li-controlled MXene powder, which is present in a solvent. The solvent of the Li-controlled MXene aqueous dispersion is typically water, and other liquid substances other than water can be contained in a small amount (30% by mass or less, preferably 20% by mass or less, based on the total standard) as appropriate.

[0080] The Li-controlled MXene particles and the polymer can be stirred using a dispersing device such as a homogenizer, a push-type stirrer, a thin-film rotary stirrer, a planetary stirrer, a mechanical shaker, or a vortex mixer.

[0081] The mixture of the Li-controlled MXene particles and the polymer, that is, the slurry, can be coated on a substrate (for example, a substrate), and the coating method is not limited. For example, a method in which a nozzle such as a single-fluid nozzle, a double-fluid nozzle, or an airbrush is used for spraying; slit coating using a bench coater, a comma coater, or a bar coater; a method such as screen printing or metal mask printing; and a coating method based on spin coating, dipping, or dropping can be exemplified.

[0082] The coating and drying described above can be repeated as many times as necessary until a film of the desired thickness is obtained. The drying and hardening, for example, can be performed using a normal pressure oven or a vacuum oven at a temperature of 400 degrees C or lower.

[0083] When the adsorbent material of the present embodiment is a composite material containing a ceramic or a metal, as a method for producing the same, the following method can be cited: mixing a Li-attenuating MXene in the form of, for example, particles with a ceramic or a metal in the form of, for example, particles, and forming the adsorbent material by low-temperature heating to maintain the composition of the Li-attenuating MXene.

[0084] (Shape of adsorbent material)

[0085] The shape of the adsorbent material of the present embodiment is not limited. The shape of the adsorbent material can be a cuboid having a thickness, a sphere, a polygonal body, or the like, except in the case of a film or the like having a sheet-like shape.

[0086] (Adsorbent sheet)

[0087] As a preferred embodiment of the adsorbent material of the present embodiment, an adsorbent sheet can be cited. The adsorbent sheet can be one in which the adsorbent material of the present embodiment, i.e., a Li-attenuating MXene, or a composite material containing the same is formed on the surface of a substrate formed of one or more of a ceramic, a metal, and a resin material. The ceramic, the metal, and the resin material can use the materials cited in the aforementioned composite material description. Among them, a preferred adsorbent sheet is one in which the adsorbent material of the present embodiment is formed on a substrate formed of a resin material, preferably a polymer. The adsorbent material of the present embodiment on the substrate can be one in which the adsorbent material is formed on one face of the substrate, for example, by coating or the like, or can be one in which the adsorbent material is formed on at least a part of the substrate. As a method for forming the adsorbent material on the aforementioned substrate, for example, a coating method commonly used such as dipping, a brush, a roller, a roll coater, air spraying, airless spraying, curtain coating, roll curtain coating, slit coating, electrostatic coating, or the like can be used. The thickness of the adsorbent sheet and the thickness of the substrate can be appropriately set according to the use.

[0088] (Use of adsorbent material)

[0089] As one of the uses of the adsorbent material of the present embodiment, adsorption of a polar organic compound can be exemplified. The polar organic compound is a general term for organic compounds having polarity, and refers to a compound having a polar group such as an OH group, an NO2 group, an NH group, an NH2 group, a COOH group, or the like, which can form a hydrogen bond with a hydrogen atom in a water molecule if mixed with water. Among the polar organic compounds, as the adsorption target, a polar solvent such as an alcohol having a hydroxyl group, a compound having an amino group, ammonia, or the like can be exemplified. The adsorbent material of the present embodiment can be used for adsorbing one or more of these compounds having a hydroxyl group and an amino group, and ammonia. Among the one or more compounds having a hydroxyl group and an amino group, as the compound having a hydroxyl group, for example, a monohydric alcohol having a carbon number of 1 to 22; a polyhydric phenol; a polyhydric alcohol such as ethylene glycol, propylene glycol, glycerol; an alkanolamine such as triethanolamine; a sugar such as xylose, glucose; or the like can be exemplified. In addition, as the compound having an amino group, a monamine such as methylamine, dimethylamine; a diamine such as ethylenediamine; a polyamine such as diethylenetriamine; an aromatic amine such as aniline; an amino acid such as valine, leucine; urea, uric acid, urate, creatinine; or the like can be exemplified. As the compound having a hydroxyl group and an amino group, ethanolamine, diethanolamine can be exemplified.

[0090] The adsorbent material of the present embodiment is preferably used for adsorbing, for example, uremic toxins such as urea, uric acid, creatinine. The adsorbent material of the present embodiment is most suitable for adsorbing urea, in particular.

[0091] The adsorbent material of the present embodiment can be used for adsorption and removal of urea and the like among waste products in hemodialysis, hemofiltration, hemodiafiltration, peritoneal dialysis, and the like. In addition, the adsorbent material of the present embodiment can be used for an artificial dialysis apparatus for performing hemodialysis, hemofiltration, hemodiafiltration, peritoneal dialysis, and the like.

[0092] As the artificial dialysis apparatus, for example, a hemodialysis apparatus, a peritoneal dialysis apparatus, a hemodialysis apparatus can be classified into a single-pass type and a circulation type. In addition, in the circulation type, a REDY system (recirculating dialysate system) and other systems can be exemplified. The artificial dialysis apparatus can also be classified according to the following methods: a method in which blood from a patient and a dialysate are passed through a cross-flow, and urea is removed without contact with the blood; a method in which blood is directly subjected to filtration. In addition, the peritoneal dialysis apparatus is mainly of a single-pass type. The adsorbent material of the present embodiment can be used in both of these hemodialysis and peritoneal dialysis, and can be used as an adsorption membrane, a separation membrane, an adsorbent material cartridge, and the like in an artificial dialysis apparatus such as a hemodialysis apparatus, a peritoneal dialysis apparatus, and the like. It is preferable that the adsorbent material of the present embodiment be used for a separation membrane for artificial dialysis. In addition, for example, when used in a REDY system (recirculating dialysate system), the adsorbent material of the present embodiment can be used as an adsorbent material cartridge.

[0093] Figure 3 In the present embodiment, as an example of an artificial dialysis apparatus using the adsorbent material of the present embodiment, a single-pass type hemodialysis apparatus is schematically shown. In the present embodiment, the adsorbent material of the present embodiment is used in the blood purification apparatus 44. Figure 3 In the hemodialysis apparatus 40, the blood before treatment introduced from the blood inlet port 41 is sent to the blood purification apparatus 44 by the blood pump 43. On the other hand, the dialysate is sent to the blood purification apparatus 44 from the unused dialysate tank 48 by the dialysate pump 50. In the blood purification apparatus 44, the blood passing through the blood passage region 46 of the blood purification apparatus is subjected to hemodialysis, hemodiafiltration dialysis, or hemofiltration dialysis by the separation membrane 45, and the substances to be removed are moved to the dialysate passage region 47 of the blood purification apparatus by the separation membrane 45. The purified blood is sent to the blood outlet port 42. On the other hand, the dialysate containing the substances to be removed passing through the dialysate passage region 47 is sent to the used dialysate tank 49. Figure 3 In the present embodiment, a device including a path for supplementing a medicament, a protein, or the like into the blood can be provided as needed in the blood sending passage of the blood before and / or after treatment, but is not shown. In addition, a sensor for measuring the blood flow rate, the dialysate flow rate, and the protein concentration in the blood as needed can be provided. In addition, a switching valve that can switch the flow passage on and off can be provided as needed in the flow passage of the blood and / or the dialysate.

[0094] The separation membrane using the adsorbent material of the present embodiment is suitable for the above-described hemodialysis. As a material constituting the separation membrane together with the adsorbent material of the present embodiment, generally, a cellulose-based or a synthetic polymer-based material for hemodialysis or the like can be listed. Specifically, polymethyl methacrylate, polyacrylonitrile, cellulose, cellulose acetate, polysulfone, polyvinyl alcohol, or a copolymer of polyvinyl alcohol and ethylene, or the like can be listed. One or more selected from the group consisting of polysulfone, polymethyl methacrylate, and cellulose acetate is preferred, and one or more selected from among polysulfone and polymethyl methacrylate is more preferred. The form of the artificial dialysis separation membrane is not particularly limited, and, for example, a porous type, a hollow fiber type, or a flat membrane laminated type can be listed.

[0095] (Embodiment 2: Method for manufacturing adsorbent material)

[0096] Hereinafter, the method for manufacturing the adsorbent material of the present embodiment will be described in detail, but the present embodiment is not limited to such an embodiment.

[0097] The method for manufacturing one adsorbent material of the present embodiment (first manufacturing method) includes the following contents.

[0098] (a) preparing a material represented by the following formula: M m AX na precursor represented by the following formula: M

[0099] (b1) performing etching treatment for removing at least a part of A atoms from the precursor using an etching solution;

[0100] (c1) water washing an etching treatment product obtained through the etching treatment;

[0101] (d1) performing Li intercalation treatment including a step of mixing a water washing treatment product obtained through the water washing with a Li-containing compound;

[0102] (e) performing delamination treatment including a step of stirring a Li intercalation treatment product obtained through the Li intercalation treatment;

[0103] (f) performing acid treatment including a step of mixing a delamination treatment product obtained through the delamination treatment with an acid solution; and

[0104] (g) water washing an acid treatment product obtained through the acid treatment to obtain an adsorbent material. According to the production method, an adsorbent material having a Li content of 0.0001 mass% or more and 0.0020 mass% or less can be produced.

[0105] Another production method (second production method) of an adsorbent material according to the present embodiment includes the following:

[0106] (a) preparing a precursor represented by the following formula: M m AX n a precursor represented by the following formula: M

[0107] (b2) performing etching treatment for removing at least a part of A atoms from the precursor using an etching solution including a Li-containing compound, and performing Li intercalation treatment;

[0108] (c2) water washing a (etching + Li intercalation) treatment product obtained through the etching treatment and the Li intercalation treatment;

[0109] (e) performing delamination treatment including a step of stirring a water washing treatment product obtained through the water washing;

[0110] (f) performing acid treatment, wherein the acid treatment includes a step of mixing the delamination product with an acid solution; and

[0111] (g) washing the acid-treated product obtained by the acid treatment with water to obtain an adsorbent material. According to the production method, an adsorbent material having a Li content of 0.0001 mass% or more and 0.0020 mass% or less can be produced.

[0112] In order to achieve single-layering and few-layering, intercalation of Li of a certain amount or more is required, but in the production method of the present embodiment, after single-layering and few-layering of MXene is performed by Li intercalation, the Li used in the Li intercalation is removed, so that single-layered and few-layered MXene having a very small amount of Li can be produced. Hereinafter, each step of the first production method and the second production method will be described in detail. The steps (a) and (e) to (g) common to both production methods are described together.

[0113] • Step (a)

[0114] First, a prescribed precursor is prepared. The prescribed precursor that can be used in the present embodiment is a MAX phase that is a precursor of MXene, represented by the following formula: M m AX n (n is 1 or more and 4 or less, and m is greater than n and 5 or less) (in the formula, M is at least one metal of Groups 3, 4, 5, 6, and 7, X is a carbon atom, a nitrogen atom, or a combination thereof, A is at least one element of Groups 12, 13, 14, 15, and 16, and n is 1 or more and 4 or less).

[0115] The above M, X, n, and m are as described in MXene. A is at least one element of Groups 12, 13, 14, 15, and 16, and is typically an A group element, and is more typically Group IIIA and Group IVA, and more specifically can include at least one selected from the group consisting of Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As, S, and Cd, and is preferably Al.

[0116] The MAX phase has a crystal structure in which a layer composed of A atoms is located between two layers represented by M m X n (in the formula, M is at least one metal of Groups 3, 4, 5, 6, and 7, X is a carbon atom, a nitrogen atom, or a combination thereof, A is at least one element of Groups 12, 13, 14, 15, and 16, and n is 1 or more and 4 or less). Each X can have a lattice located in an octahedral array of M. m X n In the case where m = n + 1, a repeating unit in which a layer of X atoms is arranged one layer each between layers of n + 1 layers of M atoms (collectively referred to as "M m X n X layers") and a layer of A atoms ("layer of A atoms") is arranged as the next layer of the n + 1 layer of M atoms, but is not limited thereto.

[0117] The above MAX phase can be produced by a known method. For example, TiC powder, Ti powder, and Al powder are mixed by a ball mill, and the resulting mixed powder is fired in an Ar atmosphere to obtain a fired body (bulk MAX phase). Thereafter, the resulting fired body is pulverized by an end mill to obtain a powdered MAX phase for use in the next step.

[0118] • Step (b1)

[0119] In the first production method, an etching treatment is performed to remove at least a part of A atoms from the precursor using an etching solution. The conditions of the etching treatment are not particularly limited and known conditions can be employed. The etching can be performed using an etching solution containing F － , for example, a method using hydrofluoric acid, a method using a mixed solution of hydrofluoric acid and hydrochloric acid, a method using a mixed solution of lithium fluoride and hydrochloric acid, and the like. The etching solution can also contain phosphoric acid or the like. In these methods, as a solvent with the above acid or the like, for example, a mixed solution with pure water can be mentioned. As the etching treatment product obtained by the above etching treatment, for example, a slurry can be mentioned.

[0120] • Step (c1)

[0121] The etching treatment product obtained by the etching treatment is washed with water. By performing the washing with water, the acid or the like used in the etching treatment can be sufficiently removed. The amount of water mixed with the etching treatment product and the washing method are not particularly limited. For example, water can be added and stirred, and centrifugal separation or the like can be performed. As the stirring method, stirring using a hand shaker, an automatic shaker, a shear mixer, a jar mill, or the like can be mentioned. The degree of stirring such as the stirring speed and the stirring time can be adjusted according to the amount and the depth of the etching treatment product as the treatment target. The washing with water can be performed once or more. It is preferable to perform the washing with water a plurality of times. For example, specifically, in a range of two or more times, for example, 15 times or less, the following steps (i) to (iii) can be performed: (i) water is added and stirred (in the etching treatment product or the remaining precipitate obtained in the following (iii)); (ii) the stirred product is subjected to centrifugal separation; and (iii) the supernatant is discarded after the centrifugal separation.

[0122] • Step (d1)

[0123] A Li intercalation treatment is performed, which includes a step of mixing the washing treatment product obtained by the washing with water with a Li-containing compound.

[0124] As the Li-containing compound, a metal compound containing a Li ion can be mentioned. As the metal compound containing a Li ion, an ionic compound in which a Li ion is combined with a cation can be used. For example, halides such as iodides, chlorides, and fluorides of the Li ion, sulfide salts containing phosphates and sulfates, nitrate salts, acetate salts, carboxylate salts can be mentioned.

[0125] The content ratio of the Li-containing compound in the intercalation treatment complex is preferably 0.001 mass% or more. The content ratio is more preferably 0.01 mass% or more, and further preferably 0.1 mass% or more. On the other hand, from the viewpoint of dispersibility in a solution, the content ratio of the Li-containing compound is preferably 10 mass% or less, and more preferably 1 mass% or less.

[0126] The specific method of the intercalation treatment is not particularly limited, and, for example, for the water medium clay of the MXene described above, the Li-containing compound can be mixed, and stirring can be performed or the mixture can be left to stand. For example, stirring at room temperature can be mentioned. The method of the stirring described above can be, for example, a method using a stirrer or the like, a method using a stirring blade, a method using a mixer, and a method using a centrifugal device, and the stirring time can be set according to the manufacturing scale of the adsorbent material, and for example, a time of 12 to 24 hours can be mentioned.

[0127] In the second manufacturing method, the etching treatment and the Li intercalation treatment of the precursor are performed together in step (b2).

[0128] • Step (b2)

[0129] In the second manufacturing method, an etching liquid including a Li-containing compound is used to etch (remove and, if appropriate, delaminate) at least a part of the A atoms (and, if appropriate, a part of the M atoms) from the precursor, and the Li intercalation treatment is performed.

[0130] In the present embodiment, the Li intercalation treatment is performed, that is, at least a part of the A atoms (and, if appropriate, a part of the M atoms) are etched (removed and, if appropriate, delaminated) from the MAX phase, and Li ions are interposed between the layers of the M m X n the layers.

[0131] As the Li-containing compound, the ionic compound described in step (d1) of the first manufacturing method can be used. The content ratio of the Li-containing compound in the etching liquid is preferably 0.001 mass% or more. The content ratio is more preferably 0.01 mass% or more, and further preferably 0.1 mass% or more. On the other hand, from the viewpoint of dispersibility in a solution, the content ratio of the Li-containing compound in the etching liquid is preferably 10 mass% or less, and more preferably 1 mass% or less.

[0132] The etching liquid in step (b2) can include only the Li-containing compound, and the other components of the etching liquid are not particularly limited, and known conditions can be used. For example, as described in step (b1) described above, an F －As the etching solution, for example, a method using hydrofluoric acid can be mentioned. A method using a mixture of hydrofluoric acid and hydrochloric acid, a method using a mixture of lithium fluoride and hydrochloric acid, and the like can be mentioned. Phosphoric acid or the like can also be contained in the etching solution. In these methods, as a solvent with the above-described acid or the like, for example, a mixture with pure water can be mentioned. As the etching treatment product obtained by the above-described etching treatment, for example, a slurry can be mentioned.

[0133] • Step (c2)

[0134] The (etching + Li intercalation) treatment product is washed with water. By washing with water, the acid or the like used in the above-described (etching + Li intercalation) treatment can be sufficiently removed. The amount of water mixed with the (etching + Li intercalation) treatment product and the washing method are not particularly limited. For example, stirring with water, performing centrifugal separation, and the like can be mentioned. As the stirring method, stirring using a manual shaker, an automatic shaker, a shear mixer, a pot mill, or the like can be mentioned. The degree of stirring such as the stirring speed and the stirring time can be adjusted according to the amount and the concentration of the treatment product as the treatment target. The washing with water can be performed once or more. Washing with water is preferably performed a plurality of times. For example, specifically, in a range of two times or more, for example, 15 times or less, the following steps (i) to (iii) can be performed: (i) stirring with water (in the (etching + Li intercalation) treatment product or the remaining precipitate obtained in the following (ii i)); (ii) centrifugal separation of the stirred product; and (iii) discarding the supernatant after the centrifugal separation.

[0135] Among the first manufacturing method and the second manufacturing method, as the first manufacturing method, the manufacturing method in which the process of the etching treatment in step (b1) and the process of the Li intercalation treatment in step (d1) are separated is preferable because it is easy to further single the MXene.

[0136] • Step (e)

[0137] The layer separation treatment includes a step of stirring the Li intercalation product obtained in the first production method after the step (d1) or the water washing product obtained by the water washing in the step (c2) in the second production method. By this layer separation treatment, the single-layer and few-layer MXene can be obtained. The conditions of the layer separation treatment are not particularly limited and can be performed by a known method. For example, as the stirring method, stirring using a hand shaker, an automatic shaker, or the like can be exemplified. The degree of stirring such as the stirring speed and the stirring time can be adjusted according to the amount and the concentration of the product to be treated. For example, after the slurry after the intercalation is subjected to centrifugal separation and the supernatant is discarded, pure water is added to the remaining precipitate, and then stirring is performed using a hand shaker or an automatic shaker, for example, to perform layer separation. As the step of removing the unpeeled product, a step of performing centrifugal separation and discarding the supernatant, and then washing the remaining precipitate with water can be exemplified. For example, (i) pure water is added to the remaining precipitate after the supernatant is discarded and stirred, (ii) centrifugal separation is performed, and (iii) the supernatant is recovered. The operations of (i) to (iii) are repeated one or more times, preferably two or more times and ten times or less, and as the layer separation product, the supernatant containing the single-layer and few-layer MXene before the acid treatment is obtained. Alternatively, the supernatant can be subjected to centrifugal separation, and the supernatant after the centrifugal separation is discarded, and as the layer separation product, the clay containing the single-layer and few-layer MXene before the acid treatment is obtained.

[0138] In the production method of the present embodiment, the layer separation is not performed with ultrasonic treatment. As described above, since the ultrasonic treatment is not performed, particle breakage is less likely to occur, and an adsorbent material containing the single-layer and few-layer MXene having a large two-dimensional surface parallel to the layer of the particle can be obtained.

[0139] • Step (f)

[0140] The acid treatment (also referred to as "acid washing") includes a step of mixing the layer separation product (the supernatant containing the single-layer and few-layer MXene or the clay containing the single-layer and few-layer MXene) obtained by the layer separation treatment and an acid solution. By this acid treatment, the amount of Li in the adsorbent material can be reduced. For example, in artificial dialysis, the adsorption of urea by MXene is synonymous with the insertion of urea, and the amount of urea that can be inserted per unit volume of MXene is determined. By removing the excess intercalation agent (Li at this time) remaining after the Li intercalation in this acid treatment, the amount of urea adsorbed in the artificial dialysis described above can be increased.

[0141] The acid used for the above acid treatment is not limited, and for example, an inorganic acid such as a mineral acid, and / or an organic acid can be used. The acid is preferably only an inorganic acid, or a mixed acid of an inorganic acid and an organic acid. The acid is more preferably only an inorganic acid. As the above inorganic acid, for example, one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, hydroiodic acid, hydrobromic acid, and hydrofluoric acid can be used. One or more of hydrochloric acid and sulfuric acid is preferable. As the above organic acid, for example, acetic acid, citric acid, oxalic acid, benzoic acid, sorbic acid, and the like can be listed. The concentration of the acid solution mixed with the delamination treatment product can be adjusted as appropriate in accordance with the amount and concentration of the delamination treatment product as the treatment target, and the like.

[0142] The above delamination treatment product and the acid solution are mixed. The above delamination treatment product and the acid solution can also be mixed while being stirred. As the stirring method, stirring using a manual shaker, an automatic shaker, a shear mixer, a jar mill, or the like can be listed. The degree of stirring, such as the stirring speed and the stirring time, can be adjusted as appropriate in accordance with the amount and concentration of the delamination treatment product as the treatment target, and the like.

[0143] Whether or not heating is performed is not critical when the above acid solution is mixed and stirred. The acid solution can be mixed and stirred without heating, or can be mixed and stirred while being heated in a range of 80°C or lower.

[0144] After the above mixing, or after the above mixing and stirring, for example, centrifugal separation can be performed, and the supernatant can be removed to obtain an acid-treated product as a slurry. The operation of mixing and stirring with the above acid solution can be performed one or more times. From the viewpoint of further reducing the Li content in the MXene particles, it is preferable that the operation of mixing and stirring with a fresh acid solution (an acid solution that has not been used in acid treatment) be performed two or more times, for example, in a range of ten times or less. As a method of performing the above operation multiple times, a method in which the following processes (i) to (iii) are performed two or more times, for example, in a range of ten times or less, can be listed: (i) mixing and stirring (the delamination treatment product or the remaining precipitate obtained in the following (ii)) with a fresh acid solution; (ii) performing centrifugal separation on the stirred product; and (iii) discarding the supernatant after the centrifugal separation.

[0145] The pH of the acid-treated product obtained through the above acid treatment is preferably 2.5 or lower. The pH is more preferably 2.0 or lower, further preferably 1.5 or lower, and more further preferably 1.2 or lower. Also, the lower limit of the pH is not particularly limited, but is approximately 1.0 or so. If the pH of the acid-treated product is sufficiently low like this, the dispersibility of the MXene particles decreases, and the MXene particles are difficult to handle in the subsequent processes, but according to the present embodiment, unlike Non-Patent Literature 1, by performing water washing in the next process, this problem can be eliminated.

[0146] In the present application, unlike the above-described non-patent literature 1, since Li is actively removed by acid treatment as described above, it is possible to further reduce the Li content in the MXene particles.

[0147] • Step (g)

[0148] The acid-treated product obtained by the acid treatment is washed with water to obtain an adsorbent material. By this water washing, it is possible to raise the pH value lowered in the acid treatment. After the acid-treated product is washed with water, the pH value is 4 or higher, and for example, it is preferably 7 or lower. According to the present embodiment, it is considered that, after the acid treatment of the step (f), by this water washing, for example, the pH value is raised to 4 or higher, and thereby, on the surface of the MXene, for example, OH groups, which are easily adsorbed urea and the like, are reconstructed, the activity of the adsorption performance is improved, and the adsorption amount of urea is increased. The amount of water mixed with the acid-treated product and the washing method are not particularly limited. For example, water can be added and stirred, and centrifugal separation and the like can be performed. As the stirring method, stirring using a manual shaker, an automatic shaker, a shear mixer, a jar mill, and the like can be used. The degree of stirring, such as the stirring speed and the stirring time, can be adjusted according to the amount and the concentration of the acid-treated product as the treatment target. The water washing can be performed once or more. It is preferable to perform water washing a plurality of times. For example, specifically, in a range of two or more times, for example, ten or less times, the following steps (i) to (iii) can be performed: (i) water is added and stirred (in the acid-treated product or the remaining precipitate obtained in the following (iii)); (ii) the stirred product is subjected to centrifugal separation; and (iii) the supernatant is discarded after the centrifugal separation.

[0149] The above-described adsorbent material of the present embodiment and the manufacturing method thereof, the adsorption sheet, the separation membrane for artificial dialysis, and the artificial dialysis apparatus have been described in detail, but various changes can be made. Also, the adsorbent material of the present application can be manufactured by a method different from the manufacturing method of the above-described embodiment, and in addition, it should be noted that the manufacturing method of the adsorbent material of the present application is not limited only to the provision of the adsorbent material of the above-described embodiment.

[0150] Examples

[0151] Preparation of MXene-containing material

[0152] [Examples 1 to 4]

[0153] In Examples 1 to 4, the following (1) preparation of a precursor (MAX), (2) etching of the precursor, (3) water washing after etching, (4) intercalation of Li, (5) delamination, (6) acid treatment, and (7) water washing described in detail below were sequentially performed, and a single-layer and few-layer MXene clay-containing material was obtained as a MXene-containing material.

[0154] (1) Preparation of a precursor (MAX)

[0155] TiC powder, Ti powder, and Al powder (all manufactured by Takasago Pure Chemical Industries, Ltd.) were mixed in a ball mill with zirconia balls added thereto for 24 hours at a molar ratio of 2:1:1. The resulting mixed powder was fired at 1350°C for 2 hours under an Ar atmosphere. The fired body (bulk MAX) thus obtained was pulverized to a maximum size of 40 μm or less using an end mill. Thus, Ti3AlC2 particles were obtained as a precursor (powdered MAX).

[0156] (2) Etching of the precursor

[0157] Using the Ti3AlC2 particles (powder) prepared by the above method, etching was performed under the following etching conditions to obtain a solid-liquid mixture (slurry) containing a solid component from the Ti3AlC2 powder.

[0158] (etching conditions)

[0159] • Precursor: Ti3AlC2 (passed through a 45-μm mesh sieve)

[0160] • Etching liquid composition: 49% HF 6 mL

[0161] H2O 18 mL

[0162] HCl (12 M) 36 mL

[0163] • Precursor amount: 3.0 g

[0164] • Etching container: 100-mL bottle container

[0165] • Etching temperature: 35°C

[0166] • Etching time: 24 h

[0167] • Agitator rotation speed: 400 rpm

[0168] (3) Water washing after etching

[0169] The above slurry was divided into two portions, which were inserted into two 50-mL centrifuge tubes, respectively. After centrifugation was performed using a centrifuge at 3500 G, the supernatant was discarded. Next, (i) 40 mL of pure water was added to the remaining precipitate in each centrifuge tube, (ii) centrifugation was performed again at 3500 G, and (iii) the supernatant was separated and removed. This (i) to (iii) was repeated 11 times. After the final centrifugation, the supernatant was discarded, and Ti3C2T s - water medium clay.

[0170] (4) Intercalation of Li

[0171] For the Ti3C2Ts - Water medium clay, intercalation of Li was performed by stirring for 10 hours at 20°C or higher and 25°C or lower using Li as an intercalating agent. The detailed conditions of the intercalation of Li were as follows.

[0172] (Li intercalation conditions)

[0173] • Ti3C2T s - Water medium clay (after water washing MXene): solid content 0.75 g

[0174] • LiCl: 0.75 g

[0175] • Intercalation container: 100 mL bottle container

[0176] • Temperature: 20°C or higher and 25°C or lower (room temperature)

[0177] • Time: 10 h

[0178] • Agitator rotation speed: 800 rpm

[0179] (5) Layer separation

[0180] The slurry obtained by the intercalation of Li was put into a 50 mL centrifuge tube, and after centrifugation was performed using a centrifuge at 3500G, the supernatant was discarded. Next, (i) after 40 mL of pure water was added to the remaining precipitate in the centrifuge tube, stirring was performed using a shaker for 15 minutes, (ii) centrifugation was performed at 3500G, (iii) the supernatant was recovered as a single-layer and few-layer MXene-containing liquid. This (i) to (iii) was repeated a total of 4 times, and a supernatant containing single-layer and few-layer MXene was obtained. The supernatant was further centrifuged using a centrifuge at 4300G for 2 hours, and the supernatant was discarded, and a clay containing single-layer and few-layer MXene was obtained.

[0181] (6) Acid treatment

[0182] In the clay containing single-layer and few-layer MXene described above, (i) after 35 mL of 1.8M hydrochloric acid was added, stirring was performed using a shaker for 5 minutes, (ii) centrifugation was performed at 3500G, (iii) the supernatant was discarded. This (i) to (iii) was repeated a total of 5 times.

[0183] (7) Water washing

[0184] In the clay containing single-layer and few-layer MXene after the above acid treatment, (i) after 35 mL of water was added, it was stirred with a shaker for 5 minutes, (ii) centrifugal separation was performed at 3500G, and (iii) the supernatant was discarded. The above (i) to (iii) were repeated a total of 5 times to obtain a clay containing single-layer and few-layer MXene as a MXene-containing sample. The pH of the above supernatant was finally confirmed to be 4 or more.

[0185] [Comparative Example 1]

[0186] In Comparative Example 1, (1) after the preparation of the precursor (MAX) was performed in the same manner as in Examples 1 to 4, (2) and (3) described below were sequentially performed with reference to the method described in Non-Patent Literature 1 to obtain a MXene-containing sample.

[0187] (1) Preparation of precursor (MAX): same as in Examples 1 to 4

[0188] (2) Etching of precursor

[0189] Using the Ti3AlC2 particles (powder) prepared by the process of (1) above, etching was performed under the following etching conditions to obtain a solid-liquid mixture (slurry) containing solid components from the Ti3AlC2 powder.

[0190] • Precursor: Ti3AlC2 (passed through a 37-μm mesh sieve)

[0191] • Etching solution composition: 50% HF 5 mL,

[0192] H2O 45 mL

[0193] • Precursor input amount: 5.0 g

[0194] • Etching container: 100-mL bottle container

[0195] • Etching temperature: 35°C

[0196] • Etching time: 24 h

[0197] • Stirrer rotation speed: 400 rpm

[0198] (3) Washing after etching

[0199] The slurry was divided into two portions, and each was inserted into a 50 mL centrifuge tube. After centrifugation at 3500 G using a centrifuge, the supernatant was discarded. (i) To the remaining precipitate in each centrifuge tube, 40 mL of pure water was added, and (ii) centrifugation was performed again at 3500 G. The supernatant was removed. This (i) to (ii) was repeated a total of 10 times. After the final centrifugation, the pH of the supernatant of the 10th time was confirmed to be higher than 5, and the supernatant was discarded. Then, Ti3C2T s - Multilayer MXene clay as a MXene-containing sample.

[0200] [Comparative Example 2]

[0201] In Comparative Example 2, after (1) preparation of the precursor (MAX) was performed in the same manner as in Examples 1 to 4, (2) to (5) described below were sequentially performed with reference to the method described in Non-Patent Literature 2, to obtain a MXene-containing sample.

[0202] (1) Preparation of the precursor (MAX): same as in Examples 1 to 4

[0203] (2) Etching of the precursor and Li intercalation

[0204] Using the Ti3AlC2 particles (powder) prepared by the procedure of (1) above, etching was performed under the etching conditions described below, and Li intercalation was performed, to obtain a solid-liquid mixture (slurry) containing a solid component from the Ti3AlC2 powder.

[0205] • Precursor: Ti3AlC2 (passed through a 45-μm mesh sieve)

[0206] • Etching solution composition: LiF 2.4 g

[0207] HCl (9M) 30 mL

[0208] • Precursor amount: 1.5 g

[0209] • Etching container: 100-mL bottle container

[0210] • Etching temperature: 25°C

[0211] • Etching time: 36 h

[0212] • Stirrer rotation speed: 400 rpm

[0213] (3) Water washing after etching

[0214] The slurry was inserted into a 50 mL centrifuge tube, and after centrifugation at 3500 G using a centrifuge, the supernatant was discarded. (i) 40 mL of pure water was added to the remaining precipitate in the centrifuge tube, (ii) centrifugation was performed again at 3500 G, and (iii) the supernatant was separated and removed. This (i) to (iii) was repeated a total of 10 times, and the supernatant at the 10th time was confirmed to have a pH of 5 or higher, and the supernatant was discarded, to obtain Ti3C2T s - moisture medium clay.

[0215] (4) Layer separation

[0216] In the Ti3C2T s 200 mL of pure water was added to the moisture medium clay, and ultrasonic treatment was performed for 15 minutes at 10°C or lower using an ultrasonic bath (ultrasonic cleaner (ASU series), product number 1-2160-03). Thereafter, after centrifugation at 2000 G for 20 minutes using a centrifuge, the supernatant was recovered, and a slurry of single-layer and few-layer MXene was recovered.

[0217] (5) pH adjustment

[0218] To 59.0 mL of the slurry of single-layer and few-layer MXene, 1 mL of 6.0 M hydrochloric acid was added dropwise. Thereafter, ultrasonic treatment was performed for 10 minutes at 10°C or lower using an ultrasonic bath, as in the layer separation in (4) above, to obtain a slurry containing single-layer and few-layer MXene as a MXene-containing material.

[0219] [Comparative Example 3]

[0220] In Comparative Example 3, after (1) preparation of the precursor (MAX) was performed as in Examples 1 to 4, the following (2) to (5) were sequentially performed as a reference to the method described in Non-Patent Literature 3, to obtain a MXene-containing material.

[0221] (1) Preparation of the precursor (MAX): same as in Examples 1 to 4

[0222] (2) Etching of the precursor

[0223] Using the Ti3AlC2 particles (powder) prepared in the process of (1) above, etching was performed under the following etching conditions to obtain a solid-liquid mixture (slurry) containing a solid component from the Ti3AlC2 powder.

[0224] (Etching conditions)

[0225] • Precursor: Ti3AlC2 (passed through a sieve with a mesh size of 45 μm)

[0226] • Etching solution composition: 49% HF 6 mL

[0227] H2O 54 mL

[0228] • Precursor charge: 3.0 g

[0229] • Etching container: 100 mL bottle container

[0230] • Etching temperature: 20°C or higher and 25°C or lower (room temperature)

[0231] • Etching time: 24 h

[0232] • Agitator rotation speed: 400 rpm

[0233] (3) Washing with water after etching

[0234] The above slurry was divided into two portions, and each was inserted into a 50 mL centrifuge tube. After centrifugation at 3500G using a centrifuge, the supernatant was discarded. (i) 40 mL of pure water was added to the remaining precipitate in each centrifuge tube, (ii) centrifugation was performed again at 3500G, and (iii) the supernatant was separated and removed. This (i) to (iii) was repeated a total of 11 times. After the final centrifugation, the supernatant was discarded, and Ti3C2T s - moisture medium clay.

[0235] (4) Intercalation of TMAOH

[0236] For Ti3C2T s - moisture medium clay, TMAOH was used as an intercalating agent under the following conditions, stirring at 20°C or higher and 25°C or lower for 12 hours, to perform intercalation of TMAOH.

[0237] (Conditions for intercalation of TMAOH)

[0238] • Ti3C2T s - moisture medium clay (MXene after washing with water): solid content 1.0 g

[0239] • TMAOH·5H2O: 1.98 g

[0240] • Pure water: 100 mL

[0241] • Intercalation container: 250 mL bottle container

[0242] • Temperature: 20°C or higher and 25°C or lower (room temperature)

[0243] • Time: 12 h

[0244] • Agitator rotation speed: 800 rpm

[0245] (5) Layer separation

[0246] The slurry obtained by the intercalation of TMAOH was divided into two, and each was inserted into a 50 mL centrifuge tube. Centrifugal separation was performed at 3500 G using a centrifuge, and the supernatant was recovered. (i) To the remaining precipitate in each centrifuge tube, 40 mL of pure water was added, (ii) centrifugal separation was performed again at 3500 G, and the supernatant was recovered. This (i) to (ii) was repeated a total of 2 times, and a slurry of single-layer and few-layer MXene was obtained as a MXene-containing sample.

[0247] [Comparative Example 4]

[0248] In Comparative Example 4, after (1) the preparation of the precursor (MAX) was performed in the same manner as in Examples 1 to 4, the following (2) and (3) were sequentially performed, and a MXene-containing sample was obtained.

[0249] (1) Preparation of the precursor (MAX): same as in Examples 1 to 4

[0250] (2) Etching of the precursor

[0251] Using the Ti3AlC2 particles (powder) prepared by the procedure of (1) above, etching was performed under the following etching conditions, and a solid-liquid mixture (slurry) containing solid components from the Ti3AlC2 powder was obtained.

[0252] • Precursor: Ti3AlC2 (passed through a 45-μm mesh sieve)

[0253] • Etching solution composition: 49% HF 6 mL

[0254] HCl (9M) 45 mL

[0255] H2O 9 mL

[0256] • Precursor amount: 3.0 g

[0257] • Etching container: 100-mL bottle container

[0258] • Etching temperature: 35°C

[0259] • Etching time: 24 h

[0260] • Stirrer speed: 400 rpm

[0261] (3) Water washing after etching

[0262] The slurry was divided into two portions, and each was inserted into a 50 mL centrifuge tube. After centrifugation at 3500 G using a centrifuge, the supernatant was discarded. (i) To the remaining precipitate in each centrifuge tube, 40 mL of pure water was added, (ii) centrifugation was performed again at 3500 G (iii) the supernatant was removed. This (i) to (iii) was repeated a total of 10 times. After the final centrifugation, the pH of the supernatant of the 10th time was confirmed to be higher than 5, and the supernatant was discarded. Then, as a MXene-containing sample, Ti3C2T s - Clay of multilayer MXene.

[0263] [Comparative Example 5]

[0264] In Comparative Example 5, after (1) preparation of the precursor (MAX) was performed in the same manner as in Examples 1 to 4, the following (2) to (5) were sequentially performed to obtain a MXene-containing sample.

[0265] (1) Preparation of the precursor (MAX): same as in Examples 1 to 4

[0266] (2) Etching of the precursor

[0267] Using the Ti3AlC2 particles (powder) prepared by the procedure of (1) above, etching was performed under the following etching conditions to obtain a solid-liquid mixture (slurry) containing solid components from the Ti3AlC2 powder.

[0268] • Precursor: Ti3AlC2 (passed through a 45-μm mesh sieve)

[0269] • Etching solution composition: 49% HF 6 mL

[0270] HCl (9M) 45 mL

[0271] H2O 9 mL

[0272] • Precursor amount: 3.0 g

[0273] • Etching container: 100-mL bottle container

[0274] • Etching temperature: 35°C

[0275] • Etching time: 24 h

[0276] • Stirrer rotation speed: 400 rpm

[0277] (3) Water washing after etching

[0278] The slurry was divided into two portions, and each was inserted into a 50 mL centrifuge tube. After centrifugation at 3500 G using a centrifugal separator, the supernatant was discarded. (i) To the remaining precipitate in each centrifuge tube, 40 mL of pure water was added, (ii) centrifugation was performed again at 3500 G, and (iii) the supernatant was recovered as an MXene-containing liquid. This (i) to (iii) was repeated a total of 10 times. After the final centrifugation, the supernatant of the 10th time was confirmed to have a pH of 5 or higher, and the supernatant was discarded to obtain Ti3C2T s - moisture medium clay.

[0279] (4) intercalation of Li

[0280] For the Ti3C2T s - moisture medium clay, intercalation of Li was performed using Li as an intercalating agent, with stirring for 10 hours at 20°C or higher and 25°C or lower. The detailed conditions for the intercalation of Li were as follows.

[0281] (conditions for intercalation of Li)

[0282] • Ti3C2T s - moisture medium clay (MXene after water washing): solid content 0.75 g

[0283] • LiCl: 0.75 g

[0284] • intercalation container: 100 mL bottle container

[0285] • temperature: 20°C or higher and 25°C or lower (room temperature)

[0286] • time: 10 h

[0287] • stirrer rotation speed: 800 rpm

[0288] (5) delamination

[0289] The slurry obtained by the intercalation of Li was inserted into a 50 mL centrifuge tube, and centrifugation was performed at 3500 G using a centrifugal separator, and the supernatant was discarded. Subsequently, (i) after 40 mL of pure water was added to the remaining precipitate in the centrifuge tube, the mixture was stirred with a shaker for 15 minutes, (ii) centrifugation was performed at 3500 G, and (iii) the supernatant was recovered as an MXene-containing liquid. This (i) to (iii) was repeated a total of 4 times to obtain an MXene-containing supernatant liquid. For this supernatant liquid, centrifugation was performed at 4300 G for 2 hours using a centrifugal separator, and the supernatant was discarded to obtain a single-layer and few-layer MXene clay as an MXene-containing material.

[0290] 〔Evaluation of MXene-containing material〕

[0291] [Measurement of Li content in MXene]

[0292] The MXene solution was solubilized by an alkali fusion method, and the Li content (amount of intercalating agent remaining) in the MXene-containing sample was measured using ICP-AES (iCAP7400 manufactured by Thermo Fisher Scientific) using an inductively coupled plasma atomic emission spectrometry method. Also, in Table 1, the amount of Li for the comparative examples in which the sample was not prepared using a Li-containing compound is “-” and is considered to be less than 0.0001 mass%.

[0293] [Measurement of average value of particle thickness]

[0294] One or more photographs were taken with an atomic force microscope (AFM) with a field size of 50 μm x 50 μm, and the thickness of each MXene particle was obtained by selecting 50 MXene particles at random in the photograph, and the average value of the 50 particles was obtained.

[0295] As a result, the values for Examples 1 to 4 were 2.8 nm, 3.2 nm, 5.2 nm, and 2.5 nm, respectively.

[0296] [Measurement of average value of maximum length in plane of particle]

[0297] One or more photographs were taken with a scanning electron microscope (SEM) at a magnification of 5000x, and the maximum dimension in the direction parallel to the developed surface (plane) of each MXene particle was obtained by selecting 50 MXene particles at random in the photograph, and the average value of the 50 particles was obtained.

[0298] As a result, the values for Examples 1 to 4 were 10.4 μm, 7.1 μm, 13.5 μm, and 6.3 μm, respectively.

[0299] [Evaluation of adsorption performance]

[0300] The MXene-containing samples of Examples 1 to 4 and Comparative Examples 1 to 5 described above were used to measure the amount of adsorbed substance (urea) and evaluate the adsorption performance of the MXene-containing samples for urea.

[0301] (1) Preparation of urea solution

[0302] Urea 0.5 g was weighed and added to 100 mL of pure water, and the solution was diluted 100-fold to adjust the concentration to 5 mg / dL of urea solution.

[0303] (2) Preparation of detection kit solution

[0304] The reagent kit solution was prepared by mixing the A and B solutions of a biological reagent kit (product name: DIUR-100) manufactured by Funakoshi Co., Ltd. in equal volumes.

[0305] (3) Preparation of a solution containing an adsorption target substance (urea solution)

[0306] In a 500 mL beaker, 250 mL of the urea solution prepared in Step (1) above was placed, and warmed and stirred at a rotation speed of 400 rpm and a liquid temperature of 37°C using a hot stirrer to prepare a solution containing urea as an adsorption target substance. Nine of these urea solutions were prepared for each example.

[0307] (4) Urea adsorption and sample collection

[0308] As the MXene-containing samples of Examples 1 to 4 and Comparative Examples 1 to 5 above, 0.1 g of solid (powdered) MXene or MXene clay was placed in the urea solution prepared in Step (3) in an amount of 0.1 g of the solid component of MXene, and stirred for 30 minutes using a hot stirrer. Thereafter, after allowing it to stand, 10 mL of the solution was extracted using a dropper, and centrifuged at 20,000 rpm for 10 minutes using a centrifugal separator to separate the floated MXene-containing sample, and 250 μL of the supernatant was collected as a sample.

[0309] (5) Dropping of the reagent kit solution

[0310] In the supernatant above, 1250 μL of the reagent kit solution prepared in Step (2) was placed, and allowed to stand for 50 minutes to obtain a sample for absorbance measurement.

[0311] (6) Absorbance measurement

[0312] First, in order to set the calibration line, a urea solution into which no MXene-containing sample was placed, and a solution in which the urea solution into which no MXene-containing sample was placed was diluted 2-fold were prepared. Then, the absorbance of each solution was measured, and the calibration line was set. Next, the absorbance of the sample prepared in Step (5) was measured, and the concentration of the residual urea in the solution that was not adsorbed was obtained by comparing the respective absorbances with the calibration line. Then, based on the concentration of the urea, the amount of urea adsorbed (mg of urea adsorbed per 1 g of MXene-containing sample) was calculated. The results are shown in Table 1.

[0313] [Calculation of safety factor]

[0314] Since the amount of urea removed by 1 dialysis is about 6 g on average, the amount of adsorbent material (containing MXene sample, indicated as "adsorbent material required amount" in Table 1) required to remove 6 g of urea was calculated using the value of the urea adsorption amount of the sample. In addition, the amount of Li (g) contained in the adsorbent material required amount was calculated, assuming that the Li in this MXene was eluted in all the blood (the average amount of blood of an adult male (body weight 60 kg) is 5 L), and the Li concentration in blood (mmol / L) was calculated. On the other hand, the upper limit of the amount of Li in blood is considered to be 1.5 mmol / L. Therefore, the safety factor was calculated by subtracting the Li concentration in blood calculated above from the upper limit of the amount of Li in blood.

[0315] Regarding the adsorption performance, urea adsorption amount of 30 mg / g or more was judged as O (good), 10 mg / g or more and less than 30 mg / g was judged as Δ (conventional level), and less than 10 mg / g was judged as X (poor). Regarding the biological adaptability, a safety factor of 5.0 (times) or more was judged as O (good), 3.0 (times) or more and less than 5.0 (times) was judged as Δ (conventional level), and less than 3.0 (times) was judged as X (poor). Then, when both the adsorption performance and the biological adaptability were O, the comprehensive evaluation was O (good), and if not, the comprehensive evaluation was judged as X (poor). The results are shown in Table 1.

[0316] [Table 1]

[0317]

[0318] [Evaluation of interlayer distance]

[0319] Using the MXene-containing samples of Example 1, Comparative Example 3, and Comparative Example 5, XRD measurement was performed to obtain the interlayer distance of MXene in the MXene-containing sample. In performing the XRD measurement, a filter membrane (MXene membrane) of each example was prepared. The filter membrane (MXene membrane) was obtained by suction filtration using the clay containing MXene or the slurry containing MXene obtained in each example. After filtration, vacuum drying was performed at 80°C for 24 hours to produce the MXene membrane. The filter for suction filtration used a membrane filter (manufactured by Merck Corporation, Durapore, pore size 0.45 μm).

[0320] The XRD measurement was performed under the following conditions to obtain a two-dimensional X-ray diffraction image of the MXene membrane. The results are shown in Figure 4 .

[0321] (XRD measurement conditions)

[0322] • Apparatus used: MiniFlex600 manufactured by Rigaku Corporation

[0323] • Conditions

[0324] Light source: Cu tube sphere

[0325] Characteristic X-ray:

[0326] Measurement range: 3 degrees - 20 degrees

[0327] Step: 50 steps / degree

[0328] Sample: Filter membrane

[0329] In Figure 4 , the peak is on the low angle side, i.e., the left side of the x-axis of Figure 4 , the wider the interlayer distance. From Figure 4 , it is known that the interlayer distance of Example 1 is the smallest, and the interlayer distances of Comparative Example 3 and Comparative Example 5 are larger than that of Example 1. Although Comparative Example 3 does not contain Li, it contains TMA (organic dispersant) from TMAOH, and thus it is considered that the interlayer distance becomes large. In addition, in Comparative Example 5, the amount of Li is not suppressed, and Li exists between the layers of MXene, and thus it is considered that the interlayer distance becomes large.

[0330] From the above measurement results, it is considered that, according to the present embodiment, Li intercalation is performed, and then delamination is performed to promote monolayerization, and thus the MXene constituting the adsorbent material is a single-layer or few-layer MXene having a sufficiently large surface area. As a result, in artificial dialysis, for example, urea can be sufficiently adsorbed and removed using an adsorbent material in which the MXene has a very large surface area, compared to Comparative Example 1 and Comparative Example 4 in which a multi-layer MXene is used.

[0331] In addition, it is considered that, in the manufacturing process of the adsorbent material, by performing acid treatment after Li intercalation, the intercalating agent (Li in this case) remaining after Li intercalation can be sufficiently removed, and the urea adsorption amount in the above artificial dialysis can be increased. In addition, by making the Li content 0.0020 mass% or less, the safety factor with respect to the upper limit value of blood lithium concentration is 27.2 times or more, and the Li, which is harmful to the human body, particularly to patients with kidney disease, is sufficiently suppressed compared to Non-Patent Literature 2 (Comparative Example 2) and Comparative Example 5. In addition, because TMAOH, which is harmful to the human body and hinders urea adsorption, as shown in Non-Patent Literature 3 (Comparative Example 3), is not included, an adsorbent material having, for example, high urea adsorption performance and excellent biocompatibility can be provided.

[0332] In addition, it is considered that, in the manufacturing process of the adsorbent material, by performing acid treatment and subsequent water washing, the OH group, which easily adsorbs urea, is reconstructed on the surface of the MXene, the activity of the adsorption performance is improved, and the urea adsorption amount is increased.

[0333] This application claims priority based on Japanese Patent Application No. 2021-013645. Japanese Patent Application No. 2021-013645 is hereby incorporated by reference into the present specification.

[0334] Industrial applicability

[0335] The adsorbing material of the present application can be used for any suitable purpose, for example, can be preferably used as a separation membrane or the like in an artificial dialysis apparatus.

[0336] Explanation of symbols

[0337] 1a, 1b Layer main body (M m X n Layer)

[0338] 3a, 5a, 3b, 5b Modification or terminal T

[0339] 7a, 7b MXene layer

[0340] 10a, 10b MXene particle (particle of layered material)

[0341] 20 Titanium atom

[0342] 21 Oxygen atom

[0343] 40 Hemodialysis apparatus

[0344] 41 Blood introduction port

[0345] 42 Blood discharge port

[0346] 43 Blood pump

[0347] 44 Blood purification apparatus

[0348] 45 Separation membrane

[0349] 46 Blood passage area of blood purification apparatus

[0350] 47 Dialysate passage area of blood purification apparatus

[0351] 48 Unused dialysate tank

[0352] 49 Used dialysate tank

[0353] 50 Dialysate pump

Claims

1. An adsorbent material comprising particles of a layered material having one or more layers, and Li, the layer includes: from the formula: M m X n layer body represented by the formula, in the formula, M is at least one of a Group 3, 4, 5, 6, 7 metal, X is a carbon atom, a nitrogen atom, or a combination of a carbon atom and a nitrogen atom, n is 1 or more and 4 or less, m is greater than n and 5 or less; a modification or a terminal T present on a surface of the layer main body, T is at least one selected from the group consisting of a hydroxyl group, a fluorine atom, a chlorine atom, an oxygen atom, and a hydrogen atom, an average value of the thickness of the particles is 1 nm or more and 10 nm or less, the Li content is 0.0001 mass% or more and 0.0020 mass% or less.

2. The adsorbent material of claim 1, wherein, In a line shape obtained by performing X-ray diffraction measurement on the adsorbent material in a sheet shape, a peak of a (002) plane is present at 2Θ = 8° or more.

3. The adsorbent material of claim 1 or 2, wherein, An average value of the largest dimension in a plane parallel to the layer of the particles is 0.1 μm or more and 20 μm or less.

4. The adsorbent material of claim 1 or 2, wherein, Further comprising one or more materials among ceramic, metal, and resin materials.

5. The adsorbent material of claim 1 or 2, wherein, Has a morphology in a sheet shape.

6. The adsorbent material of claim 1 or 2, wherein, For adsorbing a polar organic compound.

7. The adsorbent material of claim 1 or 2, wherein, For adsorbing a compound having one or more among a hydroxyl group and an amino group and ammonia.

8. The adsorbent material of claim 1 or 2, wherein, For adsorbing a uremic toxin.

9. The adsorbent material of claim 1 or 2, wherein, For adsorbing urea.

10. An adsorption sheet using the adsorbent material according to any one of claims 1 to 9.

11. A separation membrane for artificial dialysis using the adsorbent material according to any one of claims 1 to 9.

12. An artificial dialysis apparatus using the adsorbent material according to any one of claims 1 to 9.

13. A method for producing an adsorbent material, wherein, includes: (a) preparing a precursor represented by the formula: M m AX n ​ in the formula, M is at least one of a Group 3, 4, 5, 6, 7 metal, X is a carbon atom, a nitrogen atom, or a combination of a carbon atom and a nitrogen atom, A is at least one of a Group 12, 13, 14, 15, 16 element, n is 1 or more and 4 or less, m is greater than n and 5 or less; (b1) performing etching treatment for removing at least a part of A atoms from the precursor using an etching solution; (c1) performing water washing on an etching treatment product obtained by the etching treatment; (d1) performing Li intercalation treatment, which includes a step of mixing a water washing product obtained by the water washing with a Li-containing compound; (e) performing delamination treatment, which includes a step of stirring a Li intercalation product obtained by the Li intercalation treatment; (f) performing acid treatment, which includes a step of mixing a delamination product obtained by the delamination treatment with an acid solution; and (g) performing water washing on an acid treatment product obtained by the acid treatment to obtain an adsorbent material, the Li content in the adsorbent material is 0.0001 mass% or more and 0.0020 mass% or less.

14. A method for producing an adsorbent material, wherein, includes: (a) preparing a precursor represented by the formula: M m AX n ​ in the formula, M is at least one of a Group 3, 4, 5, 6, 7 metal, X is a carbon atom, a nitrogen atom, or a combination of a carbon atom and a nitrogen atom, A is at least one of a Group 12, 13, 14, 15, 16 element, n is 1 or more and 4 or less, m is greater than n and 5 or less; (b2) performing etching treatment for removing at least a part of A atoms from the precursor using an etching solution including a Li-containing compound, and performing Li intercalation treatment; (c2) water-washing an etching and Li intercalation treatment product obtained by the etching treatment and the Li intercalation treatment; (e) performing a delamination treatment, which includes a step of stirring a water-washing treatment product obtained by the water-washing; (f) performing an acid treatment, which includes a step of mixing a delamination treatment product obtained by the delamination treatment with an acid solution; and (g) washing an acid treatment product obtained by the acid treatment with water to obtain an adsorbent material, The Li content in the adsorbent material is 0.0001 mass% or more and 0.0020 mass% or less.

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