A method for preparing aluminate / high entropy alloy composite photocatalyst

Abstract

The present invention proposes a method for preparing an aluminate / high entropy alloy composite photocatalyst, and belongs to the technical field of preparing inorganic metal and metal oxide composite photocatalysts. The present invention uses different metal salts as raw materials, synthesizes high entropy alloys by radiation reduction method, synthesizes aluminates with MAl2O4 type spinel structure by polyacrylamide gel method, and combines low-temperature sintering technology to synthesize aluminate / high entropy alloy composite photocatalysts. By controlling the experimental parameters and the ratio of aluminate / high entropy alloy, the photocatalytic activity of the aluminate / high entropy alloy composite photocatalyst can be adjusted. The method has low technical difficulty, low cost, does not require large equipment, has good repeatability, and overcomes the problem that aluminates are easily hydrolyzed when the surface of traditional precious metal particles is modified with aluminates and used as photocatalysts.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of inorganic composite metals and metal oxide materials, and relates to a method for preparing an aluminate / high entropy alloy composite photocatalyst. Background Art

[0002] Spinel-type MAl2O4 aluminates are difficult to respond to visible light due to their large band gap values, and their application in the field of photocatalysis is greatly limited. The methods commonly used by researchers are ion doping to reduce the band gap value of aluminates, constructing multi-heterojunction aluminate-based composite photocatalysts, and constructing surface defects under extreme preparation conditions to enhance its visible light photocatalytic activity. At the same time, since precious metal particles have high charge transfer capabilities, attempts have also been made to introduce precious metal particles on the surface of aluminates (especially MgAl2O4) for surface modification, but when used as photocatalysts, it is easy to cause aluminate hydrolysis. Patent ZL202010047639.0 uses a two-step polymerization method to obtain a cerium-manganese metal ion-modified aluminate photocatalyst with a core-shell structure, which solves the problem of aluminate hydrolysis. However, only some special metal ions can form such a core-shell structure, which greatly limits the application of aluminates in the field of photocatalysis.

[0003] High entropy alloys are a type of alloy formed by 5 or more approximately equal amounts of metals. They have the advantages of lattice distortion, "cocktail" effect, high thermal stability and strong visible light absorption capacity, and have been favored by researchers in the field of visible light photocatalysis. Ultrafine high entropy alloy particles also have the good charge transfer ability of traditional precious metal particles. Patent 202111519347.3 composites high entropy alloys with NiIn2S4 to obtain high entropy alloy / NiIn2S4 photocatalysts, which have high photocatalytic activity in degrading methylene blue under xenon lamp illumination. This method seems simple, but the content of high entropy alloy and NiIn2S4 is difficult to control. Therefore, the development of a novel preparation method to combine high entropy alloys with aluminates is expected to solve the problem of aluminate hydrolysis while enhancing the photocatalytic activity of aluminates. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing an aluminate / high entropy alloy composite photocatalyst, using metal salt as raw material, and adopting radiation reduction method, polyacrylamide gel method and low-temperature sintering technology to synthesize an aluminate / high entropy alloy composite photocatalyst that can effectively degrade dyes, medicines and persistent and difficult-to-degrade organic pollutants.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing an aluminate / high entropy alloy composite photocatalyst, comprising the following steps:

[0006] Step S1: weighing 5 or more metal precursor salts, a surfactant, and sodium borohydride, adding them into deionized water, and fully dissolving them under magnetic stirring conditions to form a high entropy alloy precursor solution;

[0007] Step S2: using a gamma ray irradiation method, transferring the high entropy alloy precursor solution prepared in step S1 into a wide-mouth sealed bottle, and irradiating it; after irradiation, pouring out the upper clear liquid, drying it in a drying oven, and obtaining ultrafine high entropy alloy powder;

[0008] Step S3: weighing M metal salt, aluminum salt, complexing agent, gel collapse prevention agent, acrylamide, and cross-linking agent, and preparing MAl2O4 aluminate by polyacrylamide gel method;

[0009] Step S4: The high entropy alloy prepared in step S2 and the MAl2O4 aluminate prepared in step S3 are fully mixed in a certain proportion in a mortar and ground for 1-5 hours, transferred to a porcelain boat for uniform dispersion, placed in a tubular furnace for low-temperature sintering treatment, and a high entropy alloy / aluminate composite photocatalyst is obtained.

[0010] Optionally, in step S1, the metal precursor salt can be any 5 or more metal alkoxides, halides, nitrates, sulfates, or carbonates of Co, Fe, Ni, Ti, Al, Cu, Mn, Zr, La, Ce, Cr, Au, Ag, In, Sn, Pt, Pd, Ir, or Rh.

[0011] Optionally, in step S1, the surfactant is one of carboxylic acid, sulfuric acid, sulfonic acid, amino or amine and salt series thereof, such as polyvinyl pyrrolidone.

[0012] Optionally, in step S2, the irradiation dose of the irradiation treatment is 10-60 kGy.

[0013] Optionally, in step S2, during the drying process, the drying temperature is 120° C. and the drying time is 24-60 hours.

[0014] Optionally, in step S3, the complexing agent is one of citric acid, ethylenediaminetetraacetic acid, oxalic acid, and salicylic acid; the agent to prevent gel collapse is one of glucose, sucrose, and maltose; and the cross-linking agent is methylenebisacrylamide.

[0015] Optionally, in step S3, the M metal salt is one of Mg, Ca, Sr, Ba, Mn, Fe, Co, Ni, Cu, Zn, Nb, Zr, Cd, Ga, Pd, Ru, Rh, and Pt metal salts.

[0016] Optionally, in step S4, the temperature of the low-temperature sintering treatment is 100-300° C., and the sintering time is 2 hours.

[0017] Optionally, the mass percentage of aluminate / high entropy alloy is 0.1%-50%.

[0018] The present invention synthesizes a high entropy alloy / aluminate composite photocatalyst by combining a radiation reduction method and a polyacrylamide gel method with a low-temperature sintering technology, which effectively solves the problem of easy hydrolysis when aluminate and noble metal are composited as photocatalysts.

[0019] The raw materials of the present invention have a wide range of choices, and the synthesis method is simple and easy to reproduce, thus realizing the economical use of resources. The morphology and photocatalytic activity of the sample can be controlled by adjusting the experimental parameters and the proportion of each component, and large-scale production with good repeatability can be realized. The method can be used to degrade dyes, medicines and persistent and difficult-to-degrade organic pollutants.

[0020] Other advantages, objectives, and physical features of the present invention may be realized and obtained through the description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 XRD patterns of NiAl2O4, FeCoNiCrTi and NiAl2O4 / 5wt%FeCoNiCrTi composite photocatalysts prepared by the present invention;

[0022] Figure 2 FTIR spectra of NiAl2O4, FeCoNiCrTi and NiAl2O4 / FeCoNiCrTi composite photocatalysts prepared by the present invention;

[0023] Figure 3 The UV-visible absorption spectra of NiAl2O4, FeCoNiCrTi and NiAl2O4 / FeCoNiCrTi composite photocatalysts prepared in the present invention are shown.

[0024] Figure 4 The degradation percentage of tetracycline hydrochloride by NiAl2O4, FeCoNiCrTi and NiAl2O4 / FeCoNiCrTi composite photocatalyst prepared by the present invention is shown in the figure. The drug concentration is 100 mg / L, the catalyst content is 1 g / L, and the irradiation time is 210 minutes. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0026] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0027] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0028] Embodiment 1

[0029] A method for preparing an aluminate / high entropy alloy composite photocatalyst comprises the following steps:

[0030] Step S1: weigh metal precursor salts containing Fe, Co, Ni, Cr, and Ti, polyvinyl pyrrolidone, and sodium borohydride, add them to 50 mL of deionized water, and fully dissolve them under magnetic stirring to form a FeCoNiCrTi high entropy alloy precursor solution.

[0031] Step S2: using a gamma ray irradiation method, the high entropy alloy precursor solution is transferred into a wide-mouth sealed bottle, and irradiated at a dose of 20 kGy; after irradiation, the upper clear liquid is poured out, and the solution is dried in a drying oven at 120° C. for 24 hours to obtain an ultrafine FeCoNiCrTi high entropy alloy powder.

[0032] Step S3: Weigh Ni metal salt, aluminum salt, citric acid, glucose, acrylamide, and methylenebisacrylamide, and prepare NiAl2O4 aluminate by polyacrylamide gel method, with total metal ions of 0.015 mol / L, nNi:nAl=1:2, the molar ratio of citric acid to metal ions of 1.5:1, 20 g of glucose, the molar ratio of acrylamide to metal ions of 9:1, and the mass ratio of acrylamide to methylenebisacrylamide of 5:1. The polymerization temperature is 90°C, the drying temperature is 120°C, and the sintering temperature is 1000°C, and finally NiAl2O4 is obtained.

[0033] Step S4: The FeCoNiCrTi high entropy alloy prepared in step S2 and the NiAl2O4 aluminate prepared in step S3 are fully mixed in a mortar at a mass percentage of high entropy alloy / aluminate of 5%, and ground for 2 hours, transferred to a porcelain boat for uniform dispersion, placed in a tubular furnace and sintered at 200°C for 2 hours to obtain a NiAl2O4 / 5wt% FeCoNiCrTi composite photocatalyst.

[0034] Step S5: A photocatalytic experiment of simulating sunlight illumination to degrade tetracycline hydrochloride was conducted on NiAl2O4 / 5wt%FeCoNiCrTi composite photocatalyst, the drug concentration was 50mg / L, the catalyst content was 1g / L, and the degradation percentage was 82.9% after 150 minutes of irradiation. Comparative experiments showed that the degradation percentage of NiAl2O4 was 72.3%, and the degradation percentage of FeCoNiCrTi was 18.5%.

[0035] Embodiment 2

[0036] The difference between this embodiment and embodiment 1 is that the mass percentage of the high entropy alloy / aluminate in step S4 is changed to 10%, and a NiAl2O4 / 10wt% FeCoNiCrTi composite photocatalyst is obtained after synthesis, the drug concentration is 50 mg / L, the catalyst content is 1 g / L, and the degradation percentage is 82.6% after 150 minutes of irradiation.

[0037] Embodiment 3

[0038] The difference between this embodiment and embodiment 1 is that the mass percentage of high entropy alloy / aluminate in step S4 is changed to 15%, and a NiAl2O4 / 15wt% FeCoNiCrTi composite photocatalyst is obtained after sintering, the drug concentration is 50 mg / L, the catalyst content is 1 g / L, and the degradation percentage is 82.4% after 150 minutes of irradiation.

[0039] Embodiment 4

[0040] The difference between this embodiment and embodiment 1 is that the mass percentage of high entropy alloy / aluminate in step S4 is changed to 20%, and a NiAl2O4 / 20wt% FeCoNiCrTi composite photocatalyst is obtained after sintering, the drug concentration is 50 mg / L, the catalyst content is 1 g / L, and the degradation percentage is 78.4% after 150 minutes of irradiation.

[0041] Embodiment 5

[0042] The difference between this embodiment and the first embodiment is that the concentration of the drug in step S5 is changed to 100 mg / L, and the degradation percentage of the NiAl2O4 / 10wt%FeCoNiCrTi composite photocatalyst is 79.5% after 210 minutes of irradiation. Comparative experiments show that the degradation percentage of NiAl2O4 is 59.8%, and the degradation percentage of FeCoNiCrTi is 15.6%.

[0043] Embodiment 6

[0044] The difference between this embodiment and the first embodiment is that the concentration of the drug in step S5 is changed to 20 mg / L, and the degradation percentage of the NiAl2O4 / 5wt%FeCoNiCrTi composite photocatalyst after 150 minutes of irradiation is 75.9%.

[0045] Embodiment 7

[0046] The difference between this embodiment and embodiment 1 is that the Ti salt in step S1 is changed to Mo salt, and the NiAl2O4 / 10wt% FeCoNiCrMo composite photocatalyst is obtained after synthesis according to the mass percentage of high entropy alloy / aluminate being 10%, the drug concentration is 100 mg / L, the catalyst content is 1 g / L, and the degradation percentage is 75.2% after 210 minutes of irradiation.

[0047] Embodiment 8

[0048] The difference between this embodiment and embodiment 1 is that the Ti salt in step S1 is changed to Mn salt, and the NiAl2O4 / 10wt% FeCoNiCrMn composite photocatalyst is obtained after synthesis according to the mass percentage of high entropy alloy / aluminate being 10%, the drug concentration is 100 mg / L, the catalyst content is 1 g / L, and the degradation percentage is 72.8% after 210 minutes of irradiation.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing an aluminate / high entropy alloy composite photocatalyst, characterized in that: The following steps are involved: Step S1: weighing 5 or more metal precursor salts, a surfactant, and sodium borohydride, adding them into deionized water, and fully dissolving them under magnetic stirring conditions to form a high entropy alloy precursor solution; Step S2: using a gamma ray irradiation method, transferring the high entropy alloy precursor solution prepared in step S1 into a wide-mouth sealed bottle, and irradiating it; after irradiation, pouring out the upper clear liquid, drying it in a drying oven, and obtaining ultrafine high entropy alloy powder; Step S3: weighing M metal salt, aluminum salt, complexing agent, gel collapse prevention agent, acrylamide, and cross-linking agent, and preparing MAl2O4 aluminate by polyacrylamide gel method; Step S4: The high entropy alloy prepared in step S2 and the MAl2O4 aluminate prepared in step S3 are fully mixed in a certain proportion in a mortar and ground for 1-5 hours, transferred to a porcelain boat for uniform dispersion, placed in a tubular furnace for low-temperature sintering treatment, and a high entropy alloy / aluminate composite photocatalyst is obtained.

2. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: In step S1, the metal precursor salt is an alkoxide, halide, nitrate, sulfate or carbonate of any five or more metals among Co, Fe, Ni, Ti, Al, Cu, Mn, Zr, La, Ce, Cr, Au, Ag, In, Sn, Pt, Pd, Ir and Rh.

3. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: In step S1, the surfactant is one of carboxylic acid, sulfuric acid, sulfonic acid, amino or amine and their salt series.

4. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: In step S2, the irradiation dose of the irradiation treatment is 10-60 kGy.

5. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: In step S2, during the drying process, the drying temperature is 120° C. and the drying time is 24-60 hours.

6. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: In step S3, the complexing agent is one of citric acid, ethylenediaminetetraacetic acid, oxalic acid, and salicylic acid; the gel-collapsing preventing agent is one of glucose, sucrose, and maltose; and the cross-linking agent is methylenebisacrylamide.

7. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: In step S3, the M metal salt is one of Mg, Ca, Sr, Ba, Mn, Fe, Co, Ni, Cu, Zn, Nb, Zr, Cd, Ga, Pd, Ru, Rh, and Pt metal salts.

8. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: In step S4, the temperature of the low temperature sintering treatment is 100-300°C, and the sintering time is 2 hours.

9. The method for preparing the aluminate / high entropy alloy composite photocatalyst as claimed in claim 1, characterized in that: The mass percentage of aluminate / high entropy alloy is 0.1%-50%.

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