Preparation method of coating of fixed photocatalyst and fixed photocatalyst

Abstract

The invention relates to the technical field of photocatalysts, in particular to a preparation method of a coating of a fixed photocatalyst and the fixed photocatalyst. Wherein in the hydrothermal reaction process, Zn < 2 + >, In < 3 + > and hydrolyzed thioacetamide form a ZnIn2S4 crystal nucleus, then the ZnIn2S4 crystal nucleus is continuously produced, and a petal-shaped surface structure is generated according to the crystal orientation, so that the ZnIn2S4 crystal nucleus has a relatively high specific surface area and becomes a porous nanosphere material; pt and Co elements are anchored by the surface of the porous ZnIn2S4 to form stable active sites. Therefore, the ZnIn2S4-Pt-Co flower-like nanosphere structure is loaded with high-activity Pt and Co catalysts, so that the specific surface area and active sites of the catalyst can be effectively increased, and meanwhile, the dosage of a noble metal catalyst can be effectively reduced. Meanwhile, a coating of the prepared fixed photocatalyst can be coated on substrates such as plastic and metal, has excellent stability in an aqueous solution, and can be used as a reaction substrate to be applied to photocatalytic hydrogen evolution and oxygen evolution reaction.

Description

Technical Field

[0001] The present invention relates to the technical field of photocatalysts, and in particular to a method for preparing a coating of a fixed photocatalyst and the fixed photocatalyst. Background Art

[0002] In the related art, methods for depositing photocatalysts on substrates mainly include hydrothermal reaction and melting, however, these methods have low preparation efficiency. Summary of the invention

[0003] The embodiments of the present invention provide a method for preparing a coating of a fixed photocatalyst and a fixed photocatalyst, which can improve the preparation efficiency of the photocatalyst.

[0004] In a first aspect, an embodiment of the present invention provides a method for preparing a fixed photocatalyst coating, comprising:

[0005] Step S11: ZnCl 2 、InCl 3 ·4H 2 O and glycerol are added to deionized water and stirred until clear, and then thioacetamide is added and stirred until clear to obtain a first mixed solution;

[0006] Step S12, placing the first mixed solution in a hydrothermal reactor for hydrothermal reaction, cooling to room temperature after the reaction is completed, and washing and drying the collected reaction product to obtain an intermediate reaction product;

[0007] Step S13: dispersing the intermediate reaction product in a mixture containing H 2 PtCl 6 6H 2 O and Co(NO 3 ) 2 The solution is then continuously irradiated with a light source, the solution is continuously stirred during the irradiation, and the collected reaction products are washed and dried to obtain ZnIn 2 S 4 -Pt-Co nanosphere photocatalyst;

[0008] Step S14: ethylene glycol and the obtained ZnIn 2 S 4 -Pt-Co nanosphere photocatalyst is added to deionized water and stirred, then hydroxyethyl methacrylate is added, and the solution is continuously irradiated with a light source, and the solution is continuously stirred during the irradiation period to obtain a second mixed solution;

[0009] Step S15: adding anhydrous citric acid to the second mixed solution and stirring until it is completely dissolved to obtain a mixture containing ZnIn 2 S 4-Target mixed solution of Pt-Co nanosphere photocatalyst;

[0010] Step S16, coating the target mixed solution on a substrate and drying it to obtain a fixed photocatalyst coating; wherein the fixed photocatalyst includes the substrate and the coating fixed on the substrate.

[0011] In a second aspect, an embodiment of the present invention provides a fixed photocatalyst, comprising a substrate and a coating fixed on the substrate, wherein the coating is prepared by the method described in the above embodiment.

[0012] The embodiment of the present invention provides a method for preparing a fixed photocatalyst coating and a fixed photocatalyst. In the hydrothermal reaction process, Zn 2+ 、In 3+ and hydrolyzed thioacetamide to form ZnIn 2 S 4 Nucleus, then ZnIn 2 S 4 The crystal nuclei are continuously produced and a petal-shaped surface structure is generated according to the crystal orientation, which makes it have a higher specific surface area and becomes a porous nanosphere material; Pt and Co elements are porous ZnIn 2 S 4 The surface is anchored to form a stable active site. 2 S 4 -Pt-Co flower-like nanospheres are loaded with highly active Pt and Co catalysts, which can effectively increase the specific surface area and active sites of the catalyst, and can also effectively reduce the amount of precious metal catalysts. At the same time, the prepared fixed photocatalyst coating can be coated on plastic, metal and other substrates, and has excellent stability in aqueous solution, and can be used as a reaction substrate in photocatalytic hydrogen and oxygen evolution reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 is a flow chart of a method for preparing a coating of a fixed photocatalyst provided in an embodiment of the present invention;

[0015] Figure 2 is a physical picture of a substrate in a fixed photocatalyst provided in an embodiment of the present invention;

[0016] Figure 3yes Figure 2 SEM images of the substrate shown. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] Please refer to Figure 1 The embodiment of the present invention provides a method for preparing a fixed photocatalyst coating, comprising:

[0019] Step S11: ZnCl 2 、InCl 3 ·4H 2 O and glycerol are added to deionized water and stirred until clear, and then thioacetamide is added and stirred until clear to obtain a first mixed solution;

[0020] Step S12, placing the first mixed solution in a hydrothermal reactor for hydrothermal reaction, cooling to room temperature after the reaction is completed, and washing and drying the collected reaction product to obtain an intermediate reaction product;

[0021] Step S13: Disperse the intermediate reaction product in a mixture containing H 2 PtCl 6 6H 2 O and Co(NO 3 ) 2 The solution is then continuously irradiated with a light source, the solution is continuously stirred during the irradiation, and the collected reaction products are washed and dried to obtain ZnIn 2 S 4 -Pt-Co nanosphere photocatalyst;

[0022] Step S14: ethylene glycol and the obtained ZnIn 2 S 4 -Pt-Co nanosphere photocatalyst is added to deionized water and stirred, then hydroxyethyl methacrylate is added, and the solution is continuously irradiated with a light source, and the solution is continuously stirred during the irradiation period to obtain a second mixed solution;

[0023] Step S15: adding anhydrous citric acid to the second mixed solution and stirring until completely dissolved to obtain a solution containing ZnIn 2 S 4 -Target mixed solution of Pt-Co nanosphere photocatalyst;

[0024] Step S16, coating the target mixed solution on the substrate and drying it to obtain a fixed photocatalyst coating; wherein the fixed photocatalyst includes a substrate and a coating fixed on the substrate.

[0025] In this embodiment, during the hydrothermal reaction, Zn 2+ 、In 3+ and hydrolyzed thioacetamide to form ZnIn 2 S 4 Nucleus, then ZnIn 2 S 4 The crystal nuclei are continuously produced and a petal-shaped surface structure is generated according to the crystal orientation, which makes it have a higher specific surface area and becomes a porous nanosphere material; Pt and Co elements are porous ZnIn 2 S 4 The surface is anchored to form a stable active site. 2 S 4 -Pt-Co flower-like nanospheres are loaded with highly active Pt and Co catalysts, which can effectively increase the specific surface area and active sites of the catalyst, and can also effectively reduce the amount of precious metal catalysts. At the same time, the prepared fixed photocatalyst coating can be coated on plastic, metal and other substrates, and has excellent stability in aqueous solution, and can be used as a reaction substrate in photocatalytic hydrogen and oxygen evolution reactions.

[0026] As a member of the metal chalcogenide family, the ternary sulfide ZnIn 2 S 4 ZnIn has attracted extensive attention due to its chemical and optical stability, appropriate band gap (2.3-2.6 eV) and non-toxicity. 2 S 4 The low photoactivity of the photocatalysts remains a challenge due to the heavy carrier recombination. The co-catalysts supported on the photocatalysts, including noble metals (such as Rh and Pd), can serve as reaction sites and carrier capture sites, thereby promoting the directional migration of charges with the help of strong electronic interactions at the interface and improving the photocatalytic hydrogen evolution rate.

[0027] In one embodiment of the present invention, in step S11, thioacetamide, InCl 3 ·4H 2 O and ZnCl 2 The molar ratio of is 8-15:2-2.5:1, and the volume ratio of deionized water and glycerol is 10-15:1.

[0028] In one embodiment of the present invention, in step S12, the temperature of the hydrothermal reaction is 160-200° C., the time is 24-36 hours, and the pressure is 3-8 MPa.

[0029] In one embodiment of the present invention, the drying temperature is 70-90° C. and the drying time is 10-12 hours.

[0030] In one embodiment of the present invention, H 2 PtCl 6 6H 2 O and Co(NO 3 ) 2 The ratio of the added amount is 1:1.

[0031] In one embodiment of the present invention, the drying temperature is 70-90° C. and the drying time is 10-12 hours.

[0032] In one embodiment of the present invention, in step S14, the volume ratio of deionized water to ethylene glycol is 1-1.5:1, and the amount of hydroxyethyl methacrylate added is 1-2.5 mmol / ml.

[0033] In one embodiment of the present invention, in step S15, the amount of anhydrous citric acid added is 1-2 μmol / ml.

[0034] In one embodiment of the present invention, in step S16, the drying temperature is 100-120° C. and the drying time is 1-2 hours.

[0035] It should be noted that the purpose of steps S14 to S16 is to prepare ZnIn 2 S 4 -Pt-Co nanosphere photocatalyst target mixed solution, and further obtain a coating fixed on the substrate, thereby improving the preparation efficiency of the photocatalyst.

[0036] In addition, an embodiment of the present invention further provides a fixed photocatalyst, comprising a substrate and a coating fixed on the substrate, wherein the coating is prepared by any of the methods mentioned in the above embodiments. Figure 2 Tablet in.

[0037] In the related art, a common method for photocatalytic hydrogen experiments is to suspend powdered photocatalysts in aqueous solution, but the photocatalytic efficiency of this method is low.

[0038] In order to solve this technical problem, it is possible to consider improving the substrate.

[0039] In one embodiment of the present invention, the substrate of the fixed photocatalyst can be prepared by the following method:

[0040] Step S21, mixing and stirring hydroxyethyl methacrylate, tetraethylene glycol diacrylate, phenoxyethanol, and 2,2-dimethoxy-2-phenylacetophenone to obtain a light-curable ink;

[0041] Step S22, designing surface microstructure units on the modeling software, and arraying the surface microstructure units to obtain a substrate model;

[0042] Step S23, importing the substrate model into a photocurable 3D printer, using photocurable ink to print out a substrate to be dried with a surface microstructure array, and placing the substrate to be dried in a vacuum drying oven for a first drying to obtain a target substrate; wherein the surface of the target substrate is used to fix the coating, and the coating is obtained by second drying a target mixed solution containing a photocatalyst material.

[0043] In this embodiment, since the target substrate has a surface microstructure array, the contact area between the photocatalyst and the aqueous solution can be effectively increased. At the same time, the target mixed solution containing the photocatalyst material can be coated on the substrate. The coating obtained by drying can ensure good stability in the aqueous solution. In addition, the 3D printing method is used to prepare a substrate with a surface microstructure array, which can expand the specific surface area of ​​the photocatalyst, increase the contact area with the reaction medium, and improve the photocatalytic efficiency.

[0044] In one embodiment of the present invention, in step S21, the volume ratio of hydroxyethyl methacrylate, tetraethylene glycol diacrylate and phenoxyethanol is 3-4:1-1.8:1.

[0045] In one embodiment of the present invention, in step S21, the amount of 2,2-dimethoxy-2-phenylacetophenone added is 0.1-0.25 mol / L.

[0046] In one embodiment of the present invention, in step S21, the stirring temperature is 15-35°C, the time is 0.5-2h, and the rotation speed is 800-1500r / min.

[0047] In one embodiment of the present invention, in step S22, the modeling software includes Solidworks and Pro / E, and the modeling file format is .stl file.

[0048] See also Figure 2 and Figure 3 In one embodiment of the present invention, in step S22, the shape of the surface microstructure unit includes a convex pyramid, a concave pyramid, a convex hemisphere, a concave hemisphere, a convex cylinder and a concave cylinder. That is, the outer convexity can be a convex pyramid (where Figure 2 The outer convex pyramid is shown), a convex hemisphere or a convex cylinder, and the inner concave pyramid can be a concave pyramid (where Figure 2 The ones shown are concave pyramids), concave hemispheres or concave cylinders; the flat plate is an ordinary substrate without any surface microstructure treatment. Figure 2It can be seen that by setting the surface microstructure unit, the specific surface area of ​​the substrate can be increased. Moreover, considering that the 3D printing process is interlayer printing, each layer has steps, so this can also increase the specific surface area of ​​the substrate to a certain extent. Figure 3 Shown from top to bottom are convex, concave and flat, and the coating thicknesses are 55.24μm, 252.3μm and 22.42μm respectively. It can be seen that the substrate with a concave configuration can attach more photocatalysts, that is, the photocatalytic efficiency of this type of substrate is the highest, followed by the substrate with a convex configuration, and finally the substrate with a flat configuration.

[0049] In one embodiment of the present invention, in step S22, the arrayed arrangement includes a rectangular array, a triangular array, a hexagonal array and a circular array.

[0050] In one embodiment of the present invention, in step S23, the wavelength of the light source of the light-curing 3D printer is 385 nm, and the printing time is 3 hours.

[0051] In one embodiment of the present invention, in step S23, the first drying temperature is 70-90° C., the time is 10-12 hours, and the second drying temperature is 100-120° C., the time is 1-2 hours.

[0052] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a fixed photocatalyst coating, characterized in that: include: Step S11, adding ZnCl2, InCl3·4H2O and glycerol to deionized water and stirring until the solution is clear, then adding thioacetamide and stirring until the solution is clear, to obtain a first mixed solution; Step S12, placing the first mixed solution in a hydrothermal reactor for hydrothermal reaction, cooling to room temperature after the reaction is completed, and washing and drying the collected reaction product to obtain an intermediate reaction product; Step S13, dispersing the intermediate reaction product in an aqueous solution containing H2PtCl6·6H2O and Co(NO3)2, and then continuously irradiating the solution with a light source, stirring the solution during the irradiation, and washing and drying the collected reaction product to obtain a ZnIn2S4-Pt-Co nanosphere photocatalyst; Step S14, adding ethylene glycol and the obtained ZnIn2S4-Pt-Co nanosphere photocatalyst into deionized water and stirring, then adding hydroxyethyl methacrylate, and continuously irradiating the solution with a light source, and keeping the solution continuously stirred during the irradiation period, to obtain a second mixed solution; Step S15, adding anhydrous citric acid to the second mixed solution and stirring until completely dissolved to obtain a target mixed solution containing ZnIn2S4-Pt-Co nanosphere photocatalyst; Step S16, coating the target mixed solution on a substrate and drying it to obtain a fixed photocatalyst coating; wherein the fixed photocatalyst includes the substrate and the coating fixed on the substrate.

2. The method according to claim 1, characterized in that In step S11, the molar ratio of thioacetamide, InCl3·4H2O and ZnCl2 is 8-15:2-2.5:1, and the volume ratio of deionized water and glycerol is 10-15:

1.

3. The method according to claim 1, characterized in that In step S12, the temperature of the hydrothermal reaction is 160-200°C, the time is 24-36 hours, and the pressure is 3-8 MPa.

4. The method according to claim 1, characterized in that: In step S12, the drying temperature is 70-90°C and the drying time is 10-12 hours.

5. The method according to claim 1, characterized in that In step S13, the ratio of the added amounts of H2PtCl6·6H2O and Co(NO3)2 is 1:

1.

6. The method according to claim 1, characterized in that In step S13, the drying temperature is 70-90°C and the drying time is 10-12 hours.

7. The method according to any one of claims 1 to 6, characterized in that In step S14, the volume ratio of deionized water to ethylene glycol is 1-1.5:1, and the amount of hydroxyethyl methacrylate added is 1-2.5 mmol / ml.

8. The method according to claim 7, characterized in that In step S15, the amount of anhydrous citric acid added is 1 to 2 μmol / ml.

9. The method according to claim 8, characterized in that In step S16, the drying temperature is 100-120°C and the drying time is 1-2 hours.

10. A fixed photocatalyst, characterized in that: The invention comprises a substrate and a coating fixed on the substrate, wherein the coating is prepared by the method according to any one of claims 1 to 9.

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