A catalytic material and its preparation method

Abstract

This invention relates to a catalytic material and its preparation method, addressing the problems of low design freedom in existing catalytic material preparation methods and competitive ultraviolet energy absorption between the catalyst and photosensitive resin during photopolymerization 3D printing. The preparation method of the catalytic material in this invention includes the following steps: S1, preparing a calcium oxide sacrificial mold using photopolymerization 3D printing; S2, preparing a catalyst-epoxy resin slurry; S3, gel casting: adding a curing agent to the catalyst-epoxy resin slurry, then injecting it into the calcium oxide sacrificial mold, and heating to cure to obtain a gelled wet preform; S4, demolding and drying the gelled wet preform to obtain a catalyst blank; S5, debinding and sintering the catalyst blank to obtain the catalytic material. This preparation method possesses high design freedom and realizes the preparation of catalytic materials with artificially designed ordered pore structures using catalyst slurries with high solid content.

Description

Technical Field

[0001] This invention relates to the field of photopolymer 3D printing catalytic materials, and more particularly to a catalytic material and its preparation method. Background Technology

[0002] To address environmental problems such as organic dye pollution, antibiotic pollution, and bacterial contamination in water bodies, catalytic materials such as TiO2 and ZnO have played a crucial role in photocatalytic water purification due to their high catalytic efficiency and low cost. However, the application of powdered catalytic materials presents challenges such as difficulty in recycling and long-term utilization, and the potential for nanoparticles to penetrate filters and cause secondary pollution. Therefore, bulk catalytic materials with integrated structure and function have become a research hotspot in the field of photocatalytic materials.

[0003] The creation of bulk catalytic materials with integrated structure and function requires the design of artificially ordered porous structures to achieve high catalytic performance under rapid mass transfer. The main preparation methods include pen-and-ink 3D printing and photopolymerization 3D printing. However, pen-and-ink 3D printing is limited to producing simple configurations such as grid patterns and arrays, making it difficult to increase the contact area between reactants and catalytic materials and thus failing to fully leverage the design advantages of 3D printing.

[0004] Compared to pen-and-ink direct-write 3D printing, photopolymerization 3D printing offers higher precision and greater design freedom. Photopolymerization 3D printing of catalytic materials often utilizes a catalyst slurry containing both catalyst and photosensitive resin to directly form a catalytic material with both catalyst and photosensitive resin. However, this method is not suitable for catalyst slurries with high solid content. Specifically, there is a competitive issue of UV energy absorption between the catalyst and the photosensitive resin. When the catalyst constitutes too high a percentage of the catalyst slurry by mass, UV energy is absorbed by the catalyst, making it difficult for the photosensitive resin to cure, resulting in an unformed final sample. Conversely, when the catalyst constitutes a low percentage of the catalyst slurry by mass, the photocatalytic performance of the catalytic material is limited by the total amount of catalyst and cannot reach its optimal value. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a catalytic material and its preparation method to solve at least one of the following technical problems in the prior art: low design freedom of the preparation method of catalytic materials; competitive ultraviolet energy absorption problem between catalyst and photosensitive resin in the photocuring 3D printing process of high solid content catalyst slurry; difficulty in curing photosensitive resin leading to failure of final sample molding; and the photocatalytic performance of catalytic materials being limited by the total amount of catalyst in the material, which cannot reach the optimal value.

[0006] On one hand, the present invention provides a method for preparing a catalytic material, comprising the following steps: S1. Photopolymerization 3D printing to prepare calcium oxide sacrificial molds; S2. Preparation of catalyst-epoxy resin slurry; S3. Gel injection molding: Add a curing agent to the catalyst-epoxy resin slurry, then inject it into the calcium oxide sacrificial mold, and heat and cure to obtain a gelled wet blank; S4. Demold and dry the gelled wet preform to obtain the catalyst preform; S5. The catalyst blank is degreased and sintered to obtain the catalyst material.

[0007] Furthermore, the process of preparing the catalyst-epoxy resin slurry in S2 includes: S21. Mix the epoxy resin, dispersant, and solvent evenly to obtain the second premixed liquid; S22. Then, catalyst powder is added to the second premixed liquid, and the mixture is ball-milled to obtain the catalyst-epoxy resin slurry.

[0008] Furthermore, the mass percentage of catalyst powder in the catalyst-epoxy resin slurry in S22 is 65%~75%.

[0009] Furthermore, the catalyst powder in S22 includes titanium dioxide and / or zinc oxide.

[0010] Furthermore, the process of preparing the calcium oxide sacrificial mold by photopolymerization 3D printing in S1 includes: S11. Preparation of calcium hydroxide photocurable 3D printing slurry; S12. Using the calcium hydroxide photocurable 3D printing slurry, prepare calcium hydroxide green blanks by photocurable 3D printing; S13. The calcium hydroxide green body is degreased and sintered to obtain the calcium oxide sacrificial mold.

[0011] Furthermore, the process of degreasing and sintering the calcium hydroxide green in step S13 includes: S131. Heat from room temperature to 200-300℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S132. Heat to 400-600℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S133, Heat to 700-800℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S134. Cool to room temperature in the furnace; S135. Heat from room temperature to 600-800℃ at a heating rate of 1-2℃ / min, and hold for 5-8 hours. S136. Cool to room temperature in the furnace; S137. Heat from room temperature to 1000-1200℃ at a heating rate of 3-5℃ / min, and hold for 2-4 hours; S138. Cool to room temperature with the furnace; S131 to S134 are performed in an argon atmosphere or a vacuum environment below 10 Pa, while S135 to S138 are performed in an air atmosphere.

[0012] Furthermore, the process of preparing the calcium hydroxide photocurable 3D printing slurry in S11 includes: S111. Mix the acrylic resin, dispersant, and photoinitiator evenly to obtain the first premixed liquid; S112. Then, calcium hydroxide powder is added to the first premixed liquid, and ball milling and vacuum defoaming are performed to obtain the calcium hydroxide photocurable 3D printing slurry.

[0013] Furthermore, the mass percentage of calcium hydroxide powder in the calcium hydroxide photocurable 3D printing slurry in S112 is 60%~65%.

[0014] Furthermore, the process of debinding and sintering the catalyst preform in S5 includes the following steps: S51. Increase the temperature from room temperature to 200-300℃ at a rate of 1-2℃ / min, and hold for 2-4 hours; S52. Heat to 400-600℃ at a heating rate of 1-2℃ / min, and hold for 2-6 hours; S53. Cool to room temperature in the furnace; S54. Raise the temperature from room temperature to 800-1100℃ at a heating rate of 3-5℃ / min, and hold for 4-6 hours; S55, cool to room temperature in the furnace; S51 to S55 were all conducted in an air atmosphere.

[0015] On the other hand, the present invention provides a catalytic material prepared using the above-described method for preparing catalytic materials.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. This invention uses photopolymerization 3D printing of calcium oxide sacrificial molds and uses a catalyst slurry without photosensitive resin for gel casting, avoiding direct printing of catalyst slurry containing photosensitive resin. This solves the problem of conflict between the high catalytic activity of the catalyst and the high curability of the photosensitive resin in the photopolymerization 3D printing process of high solid content catalyst slurry, and realizes the preparation of catalytic materials with artificially designed ordered pore structures using catalyst slurry with high solid content.

[0017] 2. The catalyst mass percentage in the high solid content catalyst slurry prepared by the method of the present invention can reach 65%~75% (compared to less than 10% in the prior art), which improves the structural strength of the catalytic material and provides more catalytic active sites, thereby enhancing the catalytic performance of the catalytic material.

[0018] 3. The preparation method of the present invention replaces the synchronous operation of mold removal and degreasing sintering in the prior art with the asynchronous operation of water immersion demolding followed by degreasing sintering. This reduces the stress concentration caused by the release of a large amount of gas, which leads to defects in the artificial ordered pore structure and inhibits the cracking of the catalytic material.

[0019] 4. The preparation method of the present invention has a wide range of applications and can be used in a variety of metal oxide catalytic materials.

[0020] 5. The preparation method of the present invention has the characteristics of high design freedom, and can realize the preparation of catalytic materials with different artificially designed ordered pore structures such as simple "grid" structure and complex structure of three-period minimal curved surface.

[0021] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0022] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0023] Figure 1 This is a schematic flowchart of the catalytic material preparation process in Example 1 of the present invention; Figure 2 This is a physical image of the calcium oxide sacrificial mold of Embodiment 1 of the present invention; Figure 3 This is a photograph of the catalytic material in Example 1 of the present invention; Figure 4 This is a physical image of the calcium oxide sacrificial mold of Embodiment 6 of the present invention; Figure 5 Here is a physical image of the catalytic material of Example 6 of the present invention; Figure 6 This is a photograph of the catalyst green body of Comparative Example 2 of the present invention; Figure 7 The graph shows the degradation rate of Rhodamine B by the catalytic material in Examples 1 and 6 of this invention over time. Figure 8This is a graph showing the change in the degradation rate of tetracycline by the catalytic material over time in Example 7 of the present invention. Detailed Implementation

[0024] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0025] To address the competitive ultraviolet energy absorption problem between the catalyst and photosensitive resin in existing catalyst slurries, the current technology employs photopolymerization 3D printing to first print a photosensitive resin mold, then uses gel casting to solidify the catalyst slurry (which does not contain photosensitive resin), and finally removes the photosensitive resin mold to obtain the catalyst material. However, the photosensitive resin mold has poor stability and is prone to softening and deformation during gel casting. Furthermore, the mold removal and debinding / sintering of the catalyst material must be carried out simultaneously, releasing a large amount of gas that causes the catalyst material to crack, resulting in the inability to form the catalyst material.

[0026] Based on this, a specific embodiment of the present invention discloses a method for preparing a catalytic material, comprising the following steps: S1. Photopolymerization 3D printing to prepare calcium oxide sacrificial molds; S2. Preparation of catalyst-epoxy resin slurry; S3. Gel injection molding: Add curing agent to catalyst-epoxy resin slurry, then inject into calcium oxide sacrificial mold, heat and cure to obtain gelled wet blank; S4. Demold and dry the gelled wet preform to obtain the catalyst preform; S5. The catalyst blank is degreased and sintered to obtain the catalyst material.

[0027] This invention uses calcium oxide as a sacrificial mold, injecting a catalyst-epoxy resin slurry (i.e., catalyst slurry) into the calcium oxide sacrificial mold. After demolding, debinding, and sintering, a catalytic material (or catalytic reactor) with integrated structure and function is obtained. Compared with the prior art, this invention avoids the direct photocuring 3D printing of catalyst slurry containing photosensitive resin and catalyst, thus avoiding the problem of competitive ultraviolet energy absorption between the catalyst and photosensitive resin, which leads to the difficulty in curing the photosensitive resin. Furthermore, by demolding, debinding, and sintering, organic matter such as epoxy resin in the calcium oxide sacrificial mold and the catalyst preform is removed, realizing the preparation of catalytic materials with artificially designed ordered pore structures using catalyst slurry with high solid content.

[0028] The catalyst slurry prepared by the method of the present invention has a high mass percentage of catalyst, which improves the structural strength of the catalytic material and provides more catalytic active sites, thus effectively improving the catalytic performance of the catalytic material.

[0029] The calcium oxide sacrificial mold in this invention can be demolded by immersing in water and disintegrating at room temperature. The asynchronous operation of demolding followed by degreasing and sintering replaces the simultaneous operation of mold burning and degreasing sintering in the prior art, which reduces the stress concentration caused by the release of a large amount of gas during sintering and the defects caused by the artificially ordered pore structure of the catalytic material, thus inhibiting the cracking of the catalytic material.

[0030] Furthermore, the preparation method of this invention has a wide range of applications and can be used for various metal oxide catalytic materials. The preparation method of this invention also features a high degree of design freedom, enabling the preparation of catalytic materials with different artificially designed ordered pore structures, such as simple "grid" structures and complex three-period minimal curved surfaces.

[0031] In some embodiments, the calcium oxide sacrificial mold includes a calcium oxide sacrificial mold having an internal through-hole structure that complements a simple "grid" solid (e.g., Figure 2 (as shown) and / or calcium oxide sacrificial molds with internally curved facet structures complementary to the three-period minimal surface solid (such as...) Figure 4 (As shown).

[0032] Furthermore, the process of preparing the calcium oxide sacrificial mold by photopolymerization 3D printing in S1 includes: S11. Preparation of calcium hydroxide photocurable 3D printing slurry; S12. Calcium hydroxide green blanks were prepared by photopolymerization 3D printing using calcium hydroxide photopolymerization slurry. S13. Degrease and sinter the calcium hydroxide green to obtain a calcium oxide sacrificial mold.

[0033] Furthermore, the process of preparing calcium hydroxide photocurable 3D printing slurry in S11 includes: S111. Mix the acrylic resin, dispersant, and photoinitiator evenly to obtain the first premixed liquid; S112. Then, calcium hydroxide powder is added to the first premixed liquid, and ball milling and vacuum defoaming are performed to obtain calcium hydroxide photocurable 3D printing slurry.

[0034] Furthermore, the acrylic resin in S111 includes one or more of 1,6-hexanediol diacrylate, polyurethane acrylate, and trimethylolpropane triacrylate. The acrylic resin is a crosslinking monomer that forms a photocurable crosslinking network during the preparation of the calcium oxide sacrificial mold. This is beneficial for the calcium hydroxide green body to have both good strength and toughness, and facilitates the clamping and transfer of the calcium hydroxide green body during the preparation of the calcium oxide sacrificial mold, thus avoiding breakage due to insufficient strength and toughness.

[0035] Furthermore, the mass percentage of acrylic resin in the first premix in S111 is 85%~98%, for example, 85%, 88%, 90%, 93%, 95%, 98% or any combination thereof, to ensure that the calcium hydroxide photocurable 3D printing slurry has good fluidity while giving the calcium hydroxide green body good strength and toughness.

[0036] Furthermore, the dispersant in S111 includes one or more of KOS110, KH560 and BYK111, which is beneficial to the dispersion of calcium hydroxide powder, so that it can be stably suspended in the calcium hydroxide photocurable 3D printing slurry, and thus improve the uniformity of the calcium hydroxide photocurable 3D printing slurry and the calcium hydroxide green body.

[0037] Furthermore, the mass percentage of dispersant in the first premixed liquid in S111 is 1% to 10%, for example, 1%, 3%, 5%, 8%, 10% or any combination thereof, to avoid the calcium hydroxide powder from agglomerating and settling due to excessively low or high dispersant content, which would lead to uneven calcium hydroxide green body.

[0038] Furthermore, the photoinitiator in S111 includes 1-hydroxycyclohexylphenyl ketone and / or 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, which is beneficial for inducing photocuring crosslinking reaction with ultraviolet laser in the subsequent preparation of calcium hydroxide green blank, so that the liquid calcium hydroxide photocuring 3D printing slurry becomes solid calcium hydroxide green blank.

[0039] Furthermore, the mass percentage of photoinitiator in the first premixed liquid in S111 is 1% to 5%, for example, 1%, 2%, 3%, 4%, 5% or any combination thereof. This is beneficial for the rapid curing of calcium hydroxide photocurable 3D printing slurry while avoiding excessive curing and shrinkage of the calcium hydroxide photocurable 3D printing slurry, which would prevent the successful preparation of calcium hydroxide green blanks.

[0040] Furthermore, the average particle size of the calcium hydroxide powder in S112 is 1~10μm, for example, 1μm, 3μm, 5μm, 8μm, 10μm or any combination thereof, which is beneficial to improve the uniformity of the calcium oxide sacrificial mold. If the particle size of the calcium hydroxide powder is too small, it will scatter the ultraviolet laser, causing the calcium hydroxide green body printing to fail. If the particle size of the calcium hydroxide powder is too large, it cannot be stably suspended in the calcium hydroxide photocuring 3D printing slurry, resulting in uneven printing of the calcium hydroxide green body.

[0041] Furthermore, the mass percentage of calcium hydroxide powder in the S112 photocurable 3D printing slurry is 60%~65%, for example, 60%, 61%, 62%, 63%, 64%, 65%, or any combination thereof. This is beneficial for the formation of the calcium oxide sacrificial mold. If the mass percentage of calcium hydroxide powder in the photocurable 3D printing slurry is too high, it is easy for the slurry to fail to level, thus preventing the formation of the calcium hydroxide green body. If the mass percentage of calcium hydroxide powder in the photocurable 3D printing slurry is too low, it is easy for the calcium oxide sacrificial mold to crack.

[0042] Furthermore, the ball milling in S112 can be carried out by a planetary ball mill with a ball milling speed of 300~400 rpm (e.g., 300 rpm, 330 rpm, 350 rpm, 380 rpm, 400 rpm or any combination thereof) and a ball milling time of 4~8 h (e.g., 4 h, 5 h, 6 h, 7 h, 8 h or any combination thereof) until the resulting slurry is uniform and free of particles, which is beneficial to improving the uniformity of calcium hydroxide photocurable 3D printing slurry.

[0043] Furthermore, vacuum defoaming in S112 can be performed in a vacuum pumping system with a vacuum degree less than or equal to 10 Pa (e.g., less than or equal to 10 Pa, less than or equal to 9 Pa, less than or equal to 8 Pa, less than or equal to 7 Pa, less than or equal to 6 Pa, less than or equal to 5 Pa, or any combination thereof). The holding time for vacuum defoaming is 10 to 30 minutes (e.g., 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, or any combination thereof), until the resulting slurry has no visible bubbles. This helps to reduce the number of pores formed in the calcium hydroxide photocuring 3D printing slurry during the photocuring 3D printing process and inhibits cracking of the calcium hydroxide green body during the debinding and sintering process.

[0044] Furthermore, the process in S12 of preparing calcium hydroxide green bodies using photocurable 3D printing slurry via photocurable 3D printing includes: S121. Use modeling software to create a model and import the resulting model into a photopolymer 3D printer; S122. Using calcium hydroxide photocurable 3D printing slurry as raw material, prepare calcium hydroxide green blanks using a photocurable 3D printer.

[0045] Furthermore, the ultraviolet laser wavelength of the photopolymer 3D printer in S122 is 355nm~405nm, such as 355nm, 370nm, 400nm, 405nm or any combination thereof, which is beneficial for inducing the curing and shaping of calcium hydroxide green bodies.

[0046] Furthermore, the process of debinding and sintering the calcium hydroxide green in S13 includes: S131. Heat from room temperature to 200-300℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S132. Heat to 400-600℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S133, Heat to 700-800℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S134. Cool to room temperature in the furnace; S135. Heat from room temperature to 600-800℃ at a heating rate of 1-2℃ / min, and hold for 5-8 hours. S136. Cool to room temperature in the furnace; S137. Heat from room temperature to 1000-1200℃ at a heating rate of 3-5℃ / min, and hold for 2-4 hours; S138. Cool to room temperature with the furnace; Among them, S131~S134 are carried out in an argon atmosphere or a vacuum environment below 10 Pa, and S135~138 are carried out in an air atmosphere.

[0047] Specifically, S131, S132, S133, and S134 are performed in an argon atmosphere or a vacuum environment below 10 Pa (e.g., below 10 Pa, below 9 Pa, below 8 Pa, below 7 Pa, below 6 Pa, below 5 Pa, or any combination thereof), causing the organic matter (such as acrylic resin) in the calcium hydroxide photocuring 3D printing slurry to undergo pyrolysis and carbonization; S135, S136, S137, and S138 are performed in an air atmosphere, causing the organic matter generated by the pyrolysis and carbonization of the organic matter in S131~S134 to oxidize into gas. By sintering in different environments sequentially, the organic matter is carbonized first and then oxidized, which helps to slow down the release of gas during the debinding and sintering process and inhibit the cracking of the calcium oxide sacrificial mold.

[0048] In the above system, S131, S132, S133, S135, and S137 all have a degreasing and heat-preserving platform. Specifically, the degreasing and heat-preserving platform in S131 allows moisture and small organic molecules (such as dispersants) in the calcium hydroxide photocuring 3D printing slurry to evaporate. The purpose of the degreasing and heat-preserving platform in S132 is to pyrolyze and carbonize organic materials with low cross-linking degrees (such as acrylic resin) in the calcium hydroxide green body. The purpose of the degreasing and heat-preserving platform in S133 is to pyrolyze and carbonize organic materials with high cross-linking degrees in the calcium hydroxide green body. Controlling the heating rate, temperature, and holding time in S131, S132, and S133 within the above-mentioned ranges is beneficial for the slow release of moisture, small organic molecules, and gases generated during the pyrolysis and carbonization of organic materials, and reduces... The degreasing and heat preservation platform in S135 aims to oxidize the pyrolytic carbon produced by the pyrolysis of organic matter into gas, thoroughly removing organic matter. Controlling the heating rate, temperature, and holding time within the above range helps to slow down the gas release process and inhibit the cracking of the calcium oxide sacrificial mold. The degreasing and heat preservation platform in S137 aims to densify and sinter the calcium oxide sacrificial mold. Controlling the temperature, holding time, and heating rate within the above range helps to densify and sinter the calcium oxide sacrificial mold, while also improving the strength and production efficiency of the calcium oxide sacrificial mold.

[0049] Specifically, in S131, the temperature is increased from room temperature to 200-300°C (e.g., 200°C, 230°C, 250°C, 280°C, 300°C, or any two of these) at a heating rate of 1-2°C / min (e.g., 1°C / min, 1.3°C / min, 1.5°C / min, 1.8°C / min, 2°C / min, or any two of these) and held at that temperature for 2-4 hours (e.g., 2 hours, 3 hours, 4 hours, or any two of these).

[0050] Specifically, in S132, the temperature is increased to 400-600℃ (e.g., 400℃, 450℃, 500℃, 550℃, 600℃ or any two of these) at a heating rate of 1-2℃ / min (e.g., 1℃ / min, 1.3℃ / min, 1.5℃ / min, 1.8℃ / min, 2℃ / min or any two of these) and held at that temperature for 2-4 hours (e.g., 2 hours, 3 hours, 4 hours or any two of these).

[0051] Specifically, in S133, the temperature is increased to 700-800℃ (e.g., 700℃, 730℃, 750℃, 780℃, 800℃ or any two of these) at a heating rate of 1-2℃ / min (e.g., 1℃ / min, 1.3℃ / min, 1.5℃ / min, 1.8℃ / min, 2℃ / min or any two of these) and held at that temperature for 2-4 hours (e.g., 2 hours, 3 hours, 4 hours or any two of these).

[0052] Specifically, in S135, the temperature is increased from room temperature to 600-800°C (e.g., 600°C, 650°C, 700°C, 750°C, 800°C, or any two of these) at a heating rate of 1-2°C / min (e.g., 1°C / min, 1.3°C / min, 1.5°C / min, 1.8°C / min, 2°C / min, or any two of these) and held at that temperature for 5-8 hours (e.g., 5 hours, 6 hours, 7 hours, 8 hours, or any two of these).

[0053] Specifically, in S137, the temperature is increased from room temperature to 1000-1200℃ (e.g., 1000℃, 1050℃, 1100℃, 1150℃, 1200℃ or any two of these) at a heating rate of 3-5℃ / min (e.g., 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, or any two of these) and held at that temperature for 2-4 hours (e.g., 2 hours, 3 hours, 4 hours or any two of these).

[0054] Furthermore, the process for preparing the catalyst-epoxy resin slurry in S2 includes: S21. Mix the epoxy resin, dispersant, and solvent evenly to obtain the second premixed liquid; S22. Then, catalyst powder is added to the second premixed liquid, and the mixture is ball-milled to obtain catalyst-epoxy resin slurry.

[0055] Furthermore, the epoxy resin in S21 includes one or more of ethylene glycol diglycidyl ether, glycerol diglycidyl ether, and 1,4-butanediol diglycidyl ether. The catalyst-epoxy resin slurry (i.e., catalyst slurry) in this invention does not contain photosensitive resin, thus avoiding the problem of UV absorption competition in 3D photopolymerization printing of catalyst slurries containing photosensitive resin. Using the above-mentioned epoxy resin as the crosslinking monomer to form the gel-curing crosslinking network is beneficial to promoting the curing of the catalyst-epoxy resin slurry, improving the strength of the gelled wet preform, facilitating clamping and transfer, avoiding its insufficient strength and breakage, and also helps to make the catalyst-epoxy resin slurry have a lower viscosity, which is convenient for injection into the cavity of the calcium oxide sacrificial mold.

[0056] Furthermore, the epoxy resin content in the second premix in S21 is 16% to 40% by mass, for example, 16%, 20%, 25%, 30%, 35%, 40% or any combination thereof, which is beneficial to improving the fluidity of the catalyst-epoxy resin slurry. This facilitates filling the cavity of the calcium oxide sacrificial mold while also improving the strength of the gelled wet preform and making it easier to clamp and transfer.

[0057] Furthermore, the dispersant in S21 includes one of KOS110, KH560 and BYK111, which helps to stably suspend the catalyst powder in the catalyst-epoxy resin slurry and improve the uniformity of the gelled wet preform.

[0058] Furthermore, the mass percentage of dispersant in the second premix in S21 is 2% to 17%, for example, 2%, 5%, 8%, 10%, 13%, 15%, 17% or any combination thereof. This is beneficial to improve the uniformity of the gelled wet preform and avoid the catalyst powder in the catalyst-epoxy resin slurry from agglomerating and settling due to too low or too high dispersant content, which would result in uneven gelled wet preform.

[0059] Furthermore, the solvent in S21 includes benzyl alcohol and / or cyclohexanone. The solvent is used as a diluent for the epoxy resin, which helps to reduce the viscosity of the catalyst-epoxy resin slurry, thereby facilitating the flow of the catalyst-epoxy resin slurry to fill the cavity of the calcium oxide sacrificial mold and suppressing the cracking of the catalyst material.

[0060] Furthermore, the solvent content in the second premix in S21 is 49% to 78% by mass, for example, 49%, 50%, 55%, 60%, 65%, 70%, 75%, 78%, or any combination thereof. This is beneficial to ensure that the gelled wet preform has a certain strength and is not easily broken, while reducing the viscosity of the catalyst-epoxy resin slurry, thereby facilitating the flow of the catalyst-epoxy resin slurry to fill the cavity of the calcium oxide sacrificial mold.

[0061] Furthermore, the catalyst powder in S22 includes titanium dioxide and / or zinc oxide. Preparing catalytic materials with the above-mentioned catalyst powder is beneficial to reducing the production cost of catalytic materials and making the catalytic materials both environmentally friendly and have good catalytic activity.

[0062] Furthermore, in S22, the mass percentage of catalyst powder in the catalyst-epoxy resin slurry is 65%~75%, for example, 65%, 68%, 70%, 72%, 75%, or any combination thereof. Compared with the prior art, the mass percentage of catalyst powder in the high solid content catalyst-epoxy resin slurry prepared by the present invention can reach 65%~75% (the prior art is usually less than 10%), which belongs to the high solid content catalyst slurry. While improving the structural strength of the catalytic material, it is beneficial to provide more catalytic active sites and improve the catalytic performance of the catalytic material.

[0063] Furthermore, the ball milling in S22 can be carried out using a planetary ball mill with a milling speed of 300~400 rpm (e.g., 300 rpm, 330 rpm, 350 rpm, 380 rpm, 400 rpm or any combination thereof) and a milling time of 4~8 h (e.g., 4 h, 5 h, 6 h, 7 h, 8 h or any combination thereof) until the resulting slurry is uniform and free of particles, which is beneficial to improving the uniformity of the catalyst-epoxy resin slurry.

[0064] Furthermore, the gel injection molding process in S3 includes: S31. Add curing agent to catalyst-epoxy resin slurry, mix evenly to obtain mixed slurry; S32. Inject the mixed slurry into the calcium oxide sacrificial mold; S33. Vacuum defoaming and heating curing are performed to obtain gelled wet blank.

[0065] Furthermore, the curing agent in S31 includes one or more of diethylenetriamine, triethylenetetramine, and polyethyleneimine, which facilitates the cross-linking and curing of the catalyst-epoxy resin slurry to form a gelled wet blank.

[0066] Furthermore, the ratio of the mass of the curing agent to the mass of the catalyst-epoxy resin slurry in S31 is 0.5% to 4%, for example, 0.5%, 1%, 2%, 3%, 4%, or any combination thereof. This is beneficial for the rapid curing of the catalyst-epoxy resin slurry while ensuring that the catalyst-epoxy resin slurry can be completely cured without excessive curing shrinkage causing mismatch between the gelled wet blank and the calcium oxide sacrificial mold, resulting in cracking.

[0067] Furthermore, the process of injecting the mixed slurry into the calcium oxide sacrificial mold in S32 includes: injecting the mixed slurry into the calcium oxide sacrificial mold at an injection rate of 1~5 mL / min (e.g., 1 mL / min, 2 mL / min, 3 mL / min, 4 mL / min, 5 mL / min) until the cavity of the calcium oxide sacrificial mold is filled. Controlling the injection rate within the above range for slow injection helps to reduce the bubbles generated during the injection process while improving the production efficiency of the catalytic material.

[0068] Furthermore, vacuum defoaming in S33 can be carried out in a vacuum pumping system with a vacuum degree of less than 10 Pa (e.g., less than 10 Pa, less than 9 Pa, less than 8 Pa, less than 7 Pa, less than 6 Pa, less than 5 Pa, or any combination thereof). The holding time for vacuum defoaming is 10 to 30 minutes (e.g., 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, or any combination thereof), until there are no visible bubbles in the mixed slurry injected into the calcium oxide sacrificial mold. This helps to reduce the number of pores formed during the solidification of the mixed slurry into a gelled wet blank and inhibits the cracking of the catalyst blank during debinding and sintering.

[0069] Furthermore, the heating and curing process in S33 includes sealed heating inside a drying oven to prevent cracking caused by thermal shrinkage mismatch between the gelled wet blank and the calcium oxide sacrificial mold due to excessive solvent evaporation.

[0070] Furthermore, the curing temperature in S33 is 60~80℃ (e.g., 60℃, 65℃, 70℃, 75℃, 80℃ or any combination thereof), and the curing time is 20~24h (e.g., 20h, 21h, 22h, 23h, 24h or any combination thereof). This is beneficial to ensure that the catalyst-epoxy resin slurry is fully cured while avoiding cracking caused by thermal shrinkage mismatch between the gelled wet blank and the calcium oxide sacrificial mold due to excessive solvent evaporation.

[0071] Furthermore, the process of demolding the gelled wet preform in S4 includes: S41. Soak the gelled wet blank in water to cause the calcium oxide sacrificial mold to collapse. S42. Rinse the gelled wet preform with water to remove the residue of the sacrificial mold of calcium oxide on the surface, and obtain the catalyst gel green preform.

[0072] In the above system, the gelled wet blank is attached to the calcium oxide sacrificial mold. When the gelled wet blank is immersed in water, the calcium oxide sacrificial mold on which it is attached collapses, thereby completing the demolding of the gelled wet blank.

[0073] Specifically, the immersion treatment in S41 can be carried out at room temperature.

[0074] Specifically, the soaking time in S41 is 12 to 24 hours (e.g., 12 hours, 15 hours, 18 hours, 20 hours, 24 hours or any two of these), which is conducive to the full reaction of the calcium oxide sacrificial mold and water to generate calcium hydroxide, causing the calcium oxide sacrificial mold to collapse.

[0075] Furthermore, the drying conditions in S4 are as follows: the drying temperature is 60~80℃ (e.g., a range of 60℃, 65℃, 70℃, 75℃, 80℃ or any combination thereof), the drying time is 20~24h (e.g., 20h, 21h, 22h, 23h, 24h or any combination thereof), and drying is carried out until constant weight is achieved to remove the solvent from the catalyst gel green body and obtain the catalyst preform.

[0076] Furthermore, the process of debinding and sintering the catalyst preform in S5 includes the following steps: S51. Increase the temperature from room temperature to 200-300℃ at a rate of 1-2℃ / min, and hold for 2-4 hours; S52. Heat to 400-600℃ at a heating rate of 1-2℃ / min, and hold for 2-6 hours; S53. Cool to room temperature in the furnace; S54. Raise the temperature from room temperature to 800-1100℃ at a heating rate of 3-5℃ / min, and hold for 4-6 hours; S55, cool to room temperature in the furnace; Among them, S51 to S55 are all carried out in an air atmosphere, which is beneficial to the decomposition of organic matter (such as epoxy resin) in the catalyst preform and improves the compactness and structural strength of the catalyst material.

[0077] In the above system, S51, S52, and S54 in S5 all have degreasing and heat preservation platforms. The degreasing and heat preservation platform in S51 is conducive to the volatilization of moisture and small organic molecules (such as dispersants) in the catalyst-epoxy resin slurry. The degreasing and heat preservation platform in S52 is conducive to removing cross-linked organic matter such as cured epoxy resin, preventing moisture, small organic molecules, and cross-linked organic matter from concentrated pyrolysis in one temperature range, which would release a large amount of gas and cause cracking of the catalyst preform. The degreasing and heat preservation platform in S54 is conducive to achieving rapid densification and sintering of the catalyst preform, improving the structural strength and production efficiency of the catalyst material.

[0078] Specifically, in S51, the temperature is increased from room temperature to 200-300°C (e.g., 200°C, 230°C, 250°C, 280°C, 300°C, or any two of these) at a heating rate of 1-2°C / min (e.g., 1°C / min, 1.3°C / min, 1.5°C / min, 1.8°C / min, 2°C / min, or any two of these) and held at that temperature for 2-4 hours (e.g., 2 hours, 3 hours, 4 hours, or any two of these).

[0079] Specifically, in S52, the temperature is increased to 400-600℃ (e.g., 400℃, 450℃, 500℃, 550℃, 600℃, or any two of these) at a heating rate of 1-2℃ / min (e.g., 1℃ / min, 1.3℃ / min, 1.5℃ / min, 1.8℃ / min, 2℃ / min, or any two of these) and held for 2-6h (e.g., 2h, 3h, 4h, 5h, 6h, or any two of these).

[0080] Specifically, in S54, the temperature is increased from room temperature to 800-1100℃ (e.g., 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃, 1100℃ or any two of these) at a heating rate of 3-5℃ / min (e.g., 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, 5℃ / min, or any two of these) and held at that temperature for 4-6 hours (e.g., 4 hours, 5 hours, 6 hours or any two of these).

[0081] This invention also provides a catalytic material prepared using the above-described method.

[0082] Furthermore, the catalytic materials include catalytic materials with a simple "grid" structure and / or catalytic materials with a three-period minimal surface structure. The catalytic materials have an artificially designed ordered pore structure, which combines high structural strength and high specific surface area, and have a large number of catalytic active sites and good catalytic performance.

[0083] The preparation method of the catalytic material in this invention has a high degree of design freedom, and the obtained catalytic material has good structural strength and catalytic performance. Specifically, the compressive strength of the catalytic material in this invention is ≥12 MPa, for example, 12.7~16.5 MPa, the pollutant degradation rate is ≥64% with a degradation time of 240 min, for example, the degradation rate of Rhodamine B with a degradation time of 240 min is 64.3%~89.9%, and the kinetic constant is 0.00417~0.00965 min. -1 .

[0084] The present invention will be further described below through specific embodiments.

[0085] Example 1 This embodiment provides a catalytic material and its preparation method, the preparation process is as follows: Figure 1 As shown, the specific operation steps are as follows: S11. 1,6-Hexanediol diacrylate, trimethylolpropane triacrylate, KOS110, and 1-hydroxycyclohexylphenyl ketone are stirred and mixed to prepare a first premix. Then, calcium hydroxide powder with an average particle size of 7.5 μm is added to the first premix. The mixture is ball-milled at 400 rpm for 4 hours using a planetary ball mill until the resulting slurry is uniform and free of particles. Then, the vacuum system is used to evacuate to a vacuum degree of 10 Pa and hold the pressure for 15 minutes to perform vacuum defoaming, thereby obtaining calcium hydroxide photocurable 3D printing slurry.

[0086] In the calcium hydroxide photocurable 3D printing slurry, the mass percentage of calcium hydroxide powder is 62%, and the mass percentage of the first premix is ​​38%. The mass percentages of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, KOS110, and 1-hydroxycyclohexylphenyl ketone in the first premix are 75%, 21%, 3%, and 1%, respectively.

[0087] S12. Model the model using modeling software and import the resulting model into a photopolymer 3D printer. Use calcium hydroxide photopolymer 3D printing slurry as raw material and control the ultraviolet laser wavelength of the photopolymer 3D printer to 355nm. Use the photopolymer 3D printer to prepare calcium hydroxide green blanks.

[0088] S13. The calcium hydroxide green billet is transferred to an electric furnace for debinding and sintering. First, under an argon atmosphere, the temperature is increased from room temperature to 260°C at a rate of 1°C / min and held for 2 hours. Then, the temperature is increased to 450°C at a rate of 1°C / min and held for 2 hours. Next, the temperature is increased to 800°C at a rate of 1°C / min and held for 2 hours, followed by furnace cooling to room temperature. Then, under an air atmosphere, the temperature is increased from room temperature to 600°C at a rate of 1°C / min and held for 6 hours, followed by furnace cooling to room temperature. Finally, the temperature is increased from room temperature to 1000°C at a rate of 5°C / min and held for 4 hours, followed by furnace cooling to room temperature. This yields a calcium oxide sacrificial mold with an internal straight-through channel structure that complements the simple "grid" solid structure. Figure 2 As shown.

[0089] S2. Ethylene glycol diglycidyl ether, KOS110, and benzyl alcohol are stirred and mixed to prepare a second premix. Then, titanium dioxide powder is added to the second premix. The mixture is ball-milled at 400 rpm for 4 hours using a planetary ball mill until the resulting slurry is uniform and free of particles, thus obtaining the catalyst-epoxy resin slurry.

[0090] The catalyst-epoxy resin slurry contains 69% titanium dioxide catalyst powder by mass and 31% premixed liquid by mass. The second premixed liquid contains 19% ethylene glycol diglycidyl ether, 5% KOS110, and 76% benzyl alcohol by mass, respectively.

[0091] S3. Add polyethyleneimine (the mass ratio of polyethyleneimine to catalyst-epoxy resin slurry is 1.5%) to the above catalyst-epoxy resin slurry and stir evenly to obtain a mixed slurry; then slowly inject the mixed slurry into the calcium oxide sacrificial mold at a pouring speed of 2 mL / min until the cavity of the calcium oxide sacrificial mold is completely filled, then evacuate to a vacuum degree of 10 Pa in the vacuum pumping system and hold the pressure for 15 min to perform vacuum defoaming, and then seal and heat curing in a drying oven at a temperature of 80℃ for 24 h to obtain a gelled wet blank.

[0092] S4. Soak the gelled wet preform in water at room temperature for 12 hours to disintegrate the calcium oxide sacrificial mold. Rinse the gelled wet preform with water to remove the residue of the calcium oxide sacrificial mold on the surface, and obtain the catalyst gel green preform. Dry it in a drying oven at a constant temperature of 80°C for 24 hours to obtain the catalyst initial preform.

[0093] S5. The catalyst preform is transferred to an electric furnace for degreasing and sintering. Under air atmosphere, the temperature is increased from room temperature to 250°C at a rate of 1°C / min, held for 2 hours, then increased to 500°C at a rate of 1°C / min, held for 6 hours, and cooled to room temperature in the furnace. Then, the temperature is increased from room temperature to 1000°C at a rate of 5°C / min, held for 4 hours, and cooled to room temperature in the furnace to obtain the desired product. Figure 3 The catalytic material shown has a simple "grid" structure and integrates structural and functional functions.

[0094] Example 2 The difference from Example 1 is that the mass percentage of titanium dioxide catalyst powder in the catalyst-epoxy resin slurry is 75%, the mass percentage of the second premixed liquid is 25%, and the remaining steps and conditions are the same as in Example 1.

[0095] Example 3 The difference from Example 1 is that the mass percentage of titanium dioxide catalyst powder in the catalyst-epoxy resin slurry is 65%, the mass percentage of the second premixed liquid is 35%, and the remaining steps and conditions are the same as in Example 1.

[0096] Example 4 The difference from Example 1 is that the mass percentage of calcium hydroxide powder in the calcium hydroxide photocurable 3D printing slurry is 60%, the mass percentage of the first premixed liquid is 40%, and the remaining steps and conditions are the same as in Example 1.

[0097] Example 5 The difference from Example 1 is that the mass percentage of calcium hydroxide powder in the calcium hydroxide photocuring 3D printing slurry is 65%, the mass percentage of the first premixed liquid is 35%, and the remaining steps and conditions are the same as in Example 1.

[0098] Example 6 The difference from Example 1 is that the model structure is adjusted to obtain a calcium oxide sacrificial mold with an internal curved pore channel structure that complements the three-period minimal surface solid (e.g., Figure 4 (as shown), and the cavity volume of the calcium oxide sacrificial mold was controlled to be consistent with that of the calcium oxide sacrificial mold in Example 1, while the remaining steps and conditions were consistent with those in Example 1. The resulting catalytic material has a three-period minimal surface structure, as shown. Figure 5 As shown.

[0099] Example 7 The difference from Example 6 is that zinc oxide powder is used instead of titanium dioxide powder, while the remaining steps and conditions are the same as in Example 6.

[0100] Comparative Example 1 Modeling software was used to create a model, and the resulting model (consistent with Example 1) was imported into a photopolymer 3D printer. A photosensitive resin resistant to 100°C (Dongguan Aisheng Synthetic Materials Technology Co., Ltd., product brand 1670-150) was used as the raw material. The ultraviolet laser wavelength of the photopolymer 3D printer was controlled to be 355nm. The photosensitive resin sacrificial mold was prepared using the photopolymer 3D printer.

[0101] Ethylene glycol diglycidyl ether, KOS110, and benzyl alcohol were stirred and mixed to prepare a second premix. Titanium dioxide powder was then added to the second premix, and the mixture was ball-milled at 400 rpm for 4 hours until the resulting slurry was homogeneous and free of particles, yielding a catalyst-epoxy resin slurry. The catalyst-epoxy resin slurry contained 69% titanium dioxide catalyst powder by mass, and the second premix contained 31% by mass. The second premix contained 19% ethylene glycol diglycidyl ether, 5% KOS110, and 76% by mass, respectively.

[0102] S3. Add polyethyleneimine (the mass ratio of polyethyleneimine to catalyst-epoxy resin slurry is 1.5%) to the above catalyst-epoxy resin slurry and stir evenly to obtain a mixed slurry. Then, slowly inject the mixed slurry into the photosensitive resin sacrificial mold at a pouring rate of 2 mL / min until the cavity of the photosensitive resin sacrificial mold is completely filled. Then, evacuate to a vacuum degree of 10 Pa in a vacuum pumping system and hold the pressure for 15 min to perform vacuum defoaming. Then, seal and heat-cur in a drying oven at a temperature of 80℃ for 24 h. During the above preparation process, the photosensitive resin sacrificial mold softens and deforms, making it impossible to prepare a complete gelled wet preform, thus preventing the subsequent preparation of catalytic materials.

[0103] Comparative Example 2 A premix was prepared by mixing 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, KOS110, and 1-hydroxycyclohexylphenyl ketone. Titanium dioxide catalyst powder was then added to the premix, and the mixture was ball-milled at 400 rpm for 4 hours using a planetary ball mill until the resulting slurry was homogeneous and free of particles. The mixture was then evacuated to a vacuum of 10 Pa and held for 15 minutes to defoam until no visible bubbles remained, yielding a titanium dioxide photocurable 3D printing slurry. The titanium dioxide photocurable 3D printing slurry contained 69% titanium dioxide by mass, and the premix contained 31% titanium dioxide by mass. The premix contained 75% 1,6-hexanediol diacrylate, 20% trimethylolpropane triacrylate, 4% KOS110, and 1% 1% 1% hydroxycyclohexylphenyl ketone by mass.

[0104] A simple "grid" structure model was created using modeling software and imported into a 355nm UV laser photopolymerization 3D printer. Titanium dioxide photopolymerization 3D printing slurry was used as raw material to prepare a titanium dioxide catalyst green body. Figure 6 As shown, due to the competitive ultraviolet energy absorption problem between the catalyst (titanium dioxide powder) and the photosensitive resin, the interlayer bonding of the titanium dioxide catalyst green body is weak, resulting in complete structural breakage and inability to form.

[0105] The catalytic materials in the above embodiments were tested using the following process, and the results are shown in Table 1: 1. Pollutant degradation rate test: Rhodamine B and tetracycline were used as the catalytic materials in the examples to test the photocatalytic degradation performance at different degradation times to obtain the pollutant degradation rate.

[0106] (1) Photocatalytic degradation performance test when the pollutant is Rhodamine B The catalytic materials prepared in Examples 1-6 were added to 50 mL of Rhodamine B solution (concentration 10 mg / L), and magnetically stirred in the dark for 30 min. A full-spectrum xenon lamp was turned on, and photocatalytic degradation was carried out at room temperature with the distance between the light source and the Rhodamine B solution being 25 cm. 4 mL of Rhodamine B solution was taken sequentially at degradation times of 0 min, 30 min, 60 min, 120 min, and 240 min, centrifuged, and the supernatant was collected for later use. The absorbance was measured using a UV spectrophotometer, and the absorbance value corresponding to the absorption peak at a wavelength of 554 nm was recorded. The degradation rate of Rhodamine B at different degradation times was calculated according to Formula 1.

[0107] Formula 1 Among them, A t1 A0 is the absorbance of Rhodamine B at degradation time t1, and A0 is the absorbance of Rhodamine B at degradation time 0 (i.e., t1 is 0).

[0108] and -ln(A t1 Using / A0) as the ordinate and the degradation time t1 of Rhodamine B solution as the abscissa, a linear fit was performed, and the slope was recorded as the kinetic constant k1.

[0109] (2) Photocatalytic degradation performance test when the pollutant is tetracycline The catalytic material from Example 7 was added to 50 mL of tetracycline solution (concentration 10 mg / L), and magnetically stirred for 30 min in the dark. A full-spectrum xenon lamp was turned on, and photocatalytic degradation was carried out at room temperature with the distance between the light source and the tetracycline solution being 25 cm. 4 mL of tetracycline solution was taken sequentially at degradation times of 0 min, 30 min, 60 min, 120 min, and 240 min, centrifuged, and the supernatant was collected for later use. The absorbance was measured using a UV spectrophotometer, and the absorbance value corresponding to the absorption peak at a wavelength of 358 nm was recorded. The tetracycline degradation rate was calculated according to Formula 2.

[0110] Formula 2 Among them, A t2 A is the absorbance at a tetracycline degradation time of t2, and A′ is the absorbance at a tetracycline degradation time of 0 (i.e., t2 is 0).

[0111] and -ln(A t2 Using / A′) as the ordinate and the tetracycline solution degradation time t2 as the abscissa, a linear fit was performed, and the slope was recorded as the kinetic constant k2.

[0112] 2. Compression strength test The catalytic materials prepared in each embodiment were subjected to a uniform unidirectional compressive load using an electronic universal testing machine, and their compressive strength was calculated. The specific steps are as follows: The catalyst material in each embodiment was ground flat on both sides and placed between the centers of the upper and lower pressure plates of a flat cemented carbide block. The upper pressure plate was gradually moved closer to the lower pressure plate at a displacement rate of 0.5 mm / min. A uniform unidirectional compressive load was continuously applied until the catalyst material broke or the compressive load dropped significantly. The compressive load at this point was recorded as the maximum compressive load. The compressive strength was calculated using the stress calculation formula σ=P / A.

[0113] In the formula, σ is the compressive strength, in MPa. P—Maximum compressive load, in N; A—Cross-sectional area of ​​the catalyst material, in mm 2 .

[0114] Table 1

[0115] Compared to the method of preparing catalytic materials using photosensitive resin molds and catalyst slurry gel casting in Comparative Example 1, and the direct 3D photopolymerization printing of catalyst slurry containing photosensitive resin in Comparative Example 2, Examples 1-7 utilize photopolymerization 3D printing to prepare calcium oxide sacrificial molds. A catalyst-epoxy resin slurry without photosensitive resin is then gel-cast into the calcium oxide sacrificial mold. After demolding, debinding, and sintering, a catalytic material with integrated structure and function is successfully obtained. Furthermore, the preparation method of the catalytic materials in these embodiments of the invention has a high degree of design freedom. For example, the method in these embodiments can prepare catalytic materials with a simple "grid structure" (as in Example 1) and a three-period minimal surface structure (as in Example 7), as shown in Table 1. Figure 7 , Figure 8 It can be seen that the catalytic materials in Examples 1-7 have good structural strength and catalytic performance. The compressive strength of the catalytic materials in Examples 1-7 is ≥12MPa, for example, 12.7~16.5MPa. The degradation rate of pollutants with a degradation time of 240min is ≥64%. For example, the degradation rate of Rhodamine B with a degradation time of 240min is 64.3%~89.9%, and the kinetic constant is 0.00417~0.00965min. -1 .

[0116] Furthermore, such as Figure 7 As shown, compared to Example 1, the catalytic material in Example 6 has a three-period minimal surface structure, which further improves the catalytic performance of the catalytic material and results in a higher degradation rate of Rhodamine B for the same degradation time.

[0117] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a catalytic material, characterized in that, Includes the following steps: S1. Photopolymerization 3D printing to prepare calcium oxide sacrificial molds; S2. Preparation of catalyst-epoxy resin slurry; S3. Gel injection molding: Add a curing agent to the catalyst-epoxy resin slurry, then inject it into the calcium oxide sacrificial mold, and heat and cure to obtain a gelled wet blank; S4. Demold and dry the gelled wet preform to obtain the catalyst preform; S5. The catalyst blank is degreased and sintered to obtain the catalyst material.

2. The method for preparing the catalytic material according to claim 1, characterized in that, The process of preparing the catalyst-epoxy resin slurry in S2 includes: S21. Mix the epoxy resin, dispersant, and solvent evenly to obtain the second premixed liquid; S22. Then, catalyst powder is added to the second premixed liquid, and the mixture is ball-milled to obtain the catalyst-epoxy resin slurry.

3. The method for preparing the catalytic material according to claim 2, characterized in that, The catalyst powder content in the catalyst-epoxy resin slurry in S22 is 65%~75% by mass.

4. The method for preparing the catalytic material according to claim 2, characterized in that, The catalyst powder in S22 includes titanium dioxide and / or zinc oxide.

5. The method for preparing the catalytic material according to claim 1, characterized in that, The process of preparing the calcium oxide sacrificial mold by photopolymerization 3D printing in S1 includes: S11. Preparation of calcium hydroxide photocurable 3D printing slurry; S12. Using the calcium hydroxide photocurable 3D printing slurry, prepare calcium hydroxide green blanks by photocurable 3D printing; S13. The calcium hydroxide green body is degreased and sintered to obtain the calcium oxide sacrificial mold.

6. The method for preparing the catalytic material according to claim 5, characterized in that, The process of degreasing and sintering the calcium hydroxide green in S13 includes: S131. Heat from room temperature to 200-300℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S132. Heat to 400-600℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S133, Heat to 700-800℃ at a heating rate of 1-2℃ / min, and hold for 2-4 hours; S134. Cool to room temperature in the furnace; S135. Heat from room temperature to 600-800℃ at a heating rate of 1-2℃ / min, and hold for 5-8 hours. S136. Cool to room temperature in the furnace; S137. Heat from room temperature to 1000-1200℃ at a heating rate of 3-5℃ / min, and hold for 2-4 hours; S138. Cool to room temperature with the furnace; S131 to S134 are performed in an argon atmosphere or a vacuum environment below 10 Pa, while S135 to S138 are performed in an air atmosphere.

7. The method for preparing the catalytic material according to claim 5, characterized in that, The process of preparing calcium hydroxide photocurable 3D printing paste in S11 includes: S111. Mix the acrylic resin, dispersant, and photoinitiator evenly to obtain the first premixed liquid; S112. Then, calcium hydroxide powder is added to the first premixed liquid, and ball milling and vacuum defoaming are performed to obtain the calcium hydroxide photocurable 3D printing slurry.

8. The method for preparing the catalytic material according to claim 7, characterized in that, The calcium hydroxide powder in the S112 photocurable 3D printing slurry has a mass percentage content of 60%~65%.

9. The method for preparing the catalytic material according to claim 1, characterized in that, The process of debinding and sintering the catalyst preform in S5 includes the following steps: S51. Increase the temperature from room temperature to 200-300℃ at a rate of 1-2℃ / min, and hold for 2-4 hours; S52. Heat to 400-600℃ at a heating rate of 1-2℃ / min, and hold for 2-6 hours; S53. Cool to room temperature in the furnace; S54. Raise the temperature from room temperature to 800-1100℃ at a heating rate of 3-5℃ / min, and hold for 4-6 hours; S55, cool to room temperature in the furnace; S51 to S55 were all conducted in an air atmosphere.

10. A catalytic material, characterized in that, The catalytic material was prepared using the method described in any one of claims 1-9.

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