阅读说明：本技术 一种硫铟锌/铌酸钙钾二维异质结复合光催化材料的制备方法与用途 (Preparation method and application of sulfur-indium-zinc/calcium-potassium niobate two-dimensional heterojunction composite photocatalytic material ) 是由 姜德立 张乾晓 李娣 于 2020-07-07 设计创作，主要内容包括：本发明属于无机功能材料及其制备领域,具体说是一种硫铟锌/铌酸钙钾二维纳米片异质结复合光催化材料(ZnIn<Sub>2</Sub>S<Sub>4</Sub>/KCa<Sub>2</Sub>Nb<Sub>3</Sub>O<Sub>10</Sub>)的制备方法与用途。采用低温水热法制备具有紧密二维-二维界面的ZnIn<Sub>2</Sub>S<Sub>4</Sub>/KCa<Sub>2</Sub>Nb<Sub>3</Sub>O<Sub>10</Sub>异质结复合光催化剂。所开发材料展现出优异的可见光催化还原CO<Sub>2</Sub>活性,最佳比例产物即ZnIn<Sub>2</Sub>S<Sub>4</Sub>质量分数为20％,活性达4.69μmol·g<Sup>-1</Sup>·h<Sup>-1</Sup>,为纯相ZnIn<Sub>2</Sub>S<Sub>4</Sub>纳米片、KCa<Sub>2</Sub>Nb<Sub>3</Sub>O<Sub>10</Sub>纳米片的12.31倍和1.95倍。本方法简便可行,易于重复,所制备产物性能优异,在光催化还原CO<Sub>2</Sub>领域具有广阔的应用前景。(The invention belongs to the field of inorganic functional materials and preparation thereof, and particularly relates to a zinc indium sulfide/potassium calcium niobate two-dimensional nanosheet heterojunction composite photocatalytic material (ZnIn) 2 S 4 /KCa 2 Nb 3 O 10 ) The preparation method and the application thereof. Preparation of ZnIn with compact two-dimensional-two-dimensional interface by low-temperature hydrothermal method 2 S 4 /KCa 2 Nb 3 O 10 A heterojunction composite photocatalyst. The developed material shows excellent visible light catalytic reduction CO 2 Active, optimum ratio product namely ZnIn 2 S 4 20 percent of mass fraction and activity of 4.69 mu mol g ‑1 ·h ‑1 Is a pure phase ZnIn 2 S 4 Nanosheet, KCa 2 Nb 3 O 10 12.31 times and 1.95 times that of the nanoplatelets. The method is simple, convenient and feasible, is easy to repeat, and the prepared product has excellent performance and can be used for photocatalytic reactionCrude CO 2 The method has wide application prospect in the field.)

1. A preparation method of a sulfur indium zinc/potassium calcium niobate two-dimensional heterojunction composite photocatalytic material is characterized by comprising the following steps:

step 1, preparing potassium calcium niobate nanosheets (KCa)₂Nb₃O₁₀)：

Weighing a certain amount of dried K₂CO₃、CaCO₃And Nb₂O₅Grinding and mixing in mortar, placing in semi-closed crucible, transferring the crucible to automatic temperature-programmed tubular furnace, calcining, cooling to room temperature, taking out, grinding into powder, and adding into HNO₃Stirring the solution for several days to carry out protonation treatment; washing the white precipitate obtained by protonation with deionized water and absolute ethyl alcohol to remove HNO₃Centrifuging, and drying to obtain white solid HCa₂Nb₃O₁₀；

Weighing a certain amount of HCa₂Nb₃O₁₀Adding a certain amount of tetrabutylammonium hydroxide solution and a proper amount of deionized water, stirring for several days, and centrifuging to obtain an upper-layer colloid substance; then dropwise adding the colloidal substance into KCl solution to obtain white precipitate, washing the precipitate with deionized water and anhydrous ethanol, centrifuging, and drying in vacuum drying oven to obtain KCa₂Nb₃O₁₀Nanosheets;

step 2, preparation of ZnIn₂S₄/KCa₂Nb₃O₁₀Two-dimensional nanosheet heterojunction composite material:

take KCa₂Nb₃O₁₀Mixing the nanosheets in a certain amount of water and glycerol, stirring uniformly, and adding ZnCl₂，InCl₃·4H₂O and thioacetamide solid, putting the obtained mixed liquid into a round-bottom flask, performing oil bath reaction, centrifugally washing and drying in vacuum to obtain ZnIn₂S₄/KCa₂Nb₃O₁₀A two-dimensional nanosheet heterojunction composite material.

2. The process according to claim 1, wherein in step 1, the reaction material K is used as the starting material₂CO₃、CaCO₃And Nb₂O₅In, K⁺、Ca²⁺And Nb⁵⁺In a molar ratio of 1.1: 2: 3; the calcining temperature of the tubular furnace is 1100-1400 ℃, and the calcining time of the tubular furnace is 8-16 h.

3. The method according to claim 2, wherein in the step 1, the tube furnace calcination temperature is 1200 ℃.

4. The method according to claim 1, wherein in step 1, HNO is added₃The concentration of the solution was 5 mol. L^-1The protonation time is 3-5 days.

5. The preparation method according to claim 1, wherein in step 1, the mass fraction of the tetrabutylammonium hydroxide solution is 10%, and the protonation product is stirred in the tetrabutylammonium hydroxide solution for 5-10 days; the concentration of KCl solution is 2 mol.L^-1。

6. The method according to claim 1, wherein in step 2, KCa₂Nb₃O₁₀、ZnCl₂、InCl₃·4H₂The mass ratio of O to thioacetamide is 100: 6.41-25.62: 13.78-55.12: 7.11 to 28.42.

7. The method of claim 6, wherein KCa is used as the active ingredient₂Nb₃O₁₀、ZnCl₂、InCl₃·4H₂The mass ratio of O to thioacetamide is 100: 12.81: 27.56: 14.21.

8. the preparation method according to claim 1, wherein in the step 2, the oil bath reaction temperature is 60 to 100 ℃ and the oil bath reaction time is 1 to 3 hours.

9. The method according to claim 1, wherein the temperature of the vacuum in step 2 is 60 ℃ and the drying time is 24 hours.

10. ZnIn prepared by the preparation method of any one of claims 1 to 9₂S₄/KCa₂Nb₃O₁₀Two-dimensional heterojunction composite photocatalytic material for reducing CO₂Use for the preparation of CO.

Technical Field

The invention relates to a preparation method and application of a sulfur indium zinc/potassium calcium niobate two-dimensional heterojunction composite photocatalytic material, and belongs to the technical field of preparation of inorganic functional materials and photocatalysis.

Technical Field

With the continuous progress of industry, the problem of environmental pollution is increasingly highlighted, especially CO₂The emission of gas is increasing day by day, and the greenhouse effect caused by the gas continuously threatens the future development of human beings. Photocatalytic technology using solar energyIntroducing CO₂Conversion to high value-added chemicals is considered as an effective way to solve the above problems. Therefore, the development of high-efficiency photocatalysts is of great significance. In recent years, two-dimensional (2D) nanosheet semiconductor materials are believed to be building efficient CO due to their large specific surface area, abundant active sites and short carrier migration path₂Ideal materials for photocatalytic reduction systems. Wherein, as a typical Dion-Jacobson (DJ) phase perovskite oxide, KCa₂Nb₃O₁₀The nanosheet material has an energy band structure matched with the generation potential of the carbon-based compound, stronger photogenerated electron reduction capability and excellent stability, and has become a hotspot of research in the field of photocatalysis at present. However, pure phase KCa₂Nb₃O₁₀The nano-sheet has wider band gap energy (about 3.4eV), can only respond to ultraviolet light, and has high recombination rate of photon-generated carriers, thereby seriously limiting the photocatalytic activity. Thus, KCa is extended₂Nb₃O₁₀The nano-sheet-based photocatalyst has a photoresponse range, and simultaneously realizes high-efficiency carrier separation, thereby being a key problem for realizing high-efficiency catalysis.

In recent years, the photocatalytic material CO has been enhanced by building heterostructures₂The reducing activity has been studied extensively. Compared with other dimension heterojunction photocatalytic systems, the 2D-2D heterojunction has a larger contact area and a faster carrier separation and migration rate, and thus receives wide attention. Ternary chalcogenides ZnIn₂S₄The nano-sheet has good carrier separation capability and visible light absorption performance, but the photocatalytic stability is poor. Using it with KCa₂Nb₃O₁₀2D-2D heterojunction is constructed by nanosheets, and KCa can be effectively promoted₂Nb₃O₁₀While enhancing the light absorption capacity of ZnIn₂S₄The stability of the photocatalyst is more beneficial to promoting the separation of photon-generated carriers and improving the photocatalyst CO₂And (4) reducing activity.

However, there is currently a need for the successful preparation of 2D-2D ZnIn₂S₄/KCa₂Nb₃O₁₀Methods for heterojunction photocatalysts are still rarely reported.

Disclosure of Invention

The invention aims to provide a novel method for synthesizing ZnIn by a simple and feasible hydrothermal method under the condition of low temperature₂S₄/KCa₂Nb₃O₁₀A method for preparing a two-dimensional nanosheet heterojunction composite photocatalytic material.

The invention is realized by the following steps:

step 1, preparing potassium calcium niobate nanosheets (KCa)₂Nb₃O₁₀)：

Weighing a certain amount of dried K₂CO₃、CaCO₃And Nb₂O₅Fully grinding and mixing the materials in a mortar, putting the materials in a semi-closed crucible, and transferring the crucible to a temperature-rising tube furnace with automatic program temperature control for calcination. Naturally cooling to room temperature, taking out, grinding into powder with mortar, and adding into HNO₃The solution was stirred for several days to carry out protonation. Washing the white precipitate obtained by protonation with deionized water and absolute ethyl alcohol to remove HNO₃Centrifuging, and drying to obtain white solid HCa₂Nb₃O₁₀。

Weighing a certain amount of HCa₂Nb₃O₁₀Adding a certain amount of tetrabutylammonium hydroxide solution and a proper amount of deionized water, stirring for several days, and centrifuging to obtain an upper layer colloid substance. Then dropwise adding the colloidal substance into KCl solution to obtain white precipitate, washing the precipitate with deionized water and anhydrous ethanol, centrifuging, and drying in vacuum drying oven to obtain KCa₂Nb₃O₁₀Nanosheets.

Step 2, preparation of ZnIn₂S₄/KCa₂Nb₃O₁₀Two-dimensional nanosheet heterojunction composite material:

take KCa₂Nb₃O₁₀Mixing the nanosheets in a certain amount of water and glycerol, stirring uniformly, and adding ZnCl₂，InCl₃·4H₂O and thioacetamide solid, putting the obtained mixed liquid into a round-bottom flask, performing oil bath reaction, centrifugally washing and drying in vacuum to obtain ZnIn₂S₄/KCa₂Nb₃O₁₀A two-dimensional nanosheet heterojunction composite material.

In step 1, a reaction raw material K₂CO₃、CaCO₃And Nb₂O₅In, K⁺、Ca²⁺And Nb⁵⁺In a molar ratio of 1.1: 2: 3.

in the step 1, the calcining temperature of the tubular furnace is 1100-1400 ℃, and the calcining time of the tubular furnace is 8-16 h. The optimum calcination temperature is 1200 ℃.

In step 1, HNO₃The concentration of the solution was 5 mol. L^-1The protonation time is 3-5 days.

In the step 1, the mass fraction of the tetrabutylammonium hydroxide solution is 10%, and the protonation product is stirred in the tetrabutylammonium hydroxide solution for 5-10 days; the concentration of KCl solution is 2 mol.L^-1。

In step 2, KCa₂Nb₃O₁₀、ZnCl₂、InCl₃·4H₂The mass ratio of O to thioacetamide is 100: 6.41-25.62: 13.78-55.12: 7.11 to 28.42.

Further, KCa₂Nb₃O₁₀、ZnCl₂、InCl₃·4H₂The optimal mass ratio of O to thioacetamide is 100: 12.81: 27.56: 14.21.

in the step 2, the oil bath reaction temperature is 60-100 ℃, and the oil bath reaction time is 1-3 h.

In the step 2, the temperature of vacuum is 60 ℃, and the drying time is 24 h.

ZnIn prepared by the invention₂S₄/KCa₂Nb₃O₁₀Two-dimensional heterojunction composite photocatalytic material for reducing CO₂Use for the preparation of CO.

The method comprises the following steps of analyzing the morphology and structure of a product by using an X-ray diffractometer (XRD), a Transmission Electron Microscope (TEM) and a high-resolution transmission electron microscope (HRTEM), irradiating and reducing carbon dioxide by using a xenon lamp to perform a photocatalytic activity experiment, determining the type of the reduced product by using the CEAULIGHT GC-7920 gas chromatography retention time, and comparing the actual measurement peak area with the standard peak area to determine the efficiency of reducing carbon dioxide so as to evaluate the performance of the photocatalytic reduction of carbon dioxide.

Has the advantages that:

(1) by constructing ZnIn₂S₄/KCa₂Nb₃O₁₀The two-dimensional heterostructure photocatalyst can increase the light absorption capacity of the material, improve the solar energy utilization rate, enhance the photocatalytic stability and endow the photocatalytic material with practical application value.

(2) The constructed two-dimensional heterostructure photocatalyst has rich heterogeneous interfaces, can effectively promote the separation of photo-generated carriers and improve the carrier utilization rate, thereby enhancing the photocatalytic CO₂And (4) reducing activity.

(3) ZnIn synthesized by the invention₂S₄、KCa₂Nb₃O₁₀The nano-sheet morphology is extremely thin, and the constructed composite material has a compact and rich heterogeneous interface. The heterostructure product exhibits excellent visible light photocatalytic reduction of CO₂Active, optimal ratio product (ZnIn)₂S₄20 percent of mass) activity reaches 4.69 mu mol g^-1·h^-1Is a pure phase ZnIn₂S₄Nanosheet, KCa₂Nb₃O₁₀12.31 times and 1.95 times that of the nanoplatelets. The method is simple, convenient and feasible, is easy to repeat, the prepared product has excellent performance, and CO is reduced in photocatalysis₂The method has wide application prospect in the field.

Drawings

FIG. 1 shows KCa₂Nb₃O₁₀、ZnIn₂S₄And 20% -ZnIn₂S₄/KCa₂Nb₃O₁₀An XRD spectrogram of the two-dimensional nanosheet heterojunction composite photocatalyst;

FIG. 2(a-c) shows pure KCa₂Nb₃O₁₀Pure ZnIn₂S₄、ZnIn₂S₄/KCa₂Nb₃O₁₀A transmission electron microscope photo of the two-dimensional nanosheet heterojunction composite photocatalytic material; (d) is ZnIn₂S₄/KCa₂Nb₃O₁₀Two-dimensional nanosheet heterojunction compoundingHigh resolution transmission electron micrographs of photocatalytic materials;

FIG. 3(a) shows a monomer KCa₂Nb₃O₁₀、ZnIn₂S₄And ZnIn of different mass ratios₂S₄/KCa₂Nb₃O₁₀A CO yield graph of the two-dimensional nanosheet heterojunction composite photocatalytic material; (b) is a monomer KCa₂Nb₃O₁₀、ZnIn₂S₄And ZnIn of different mass ratios₂S₄/KCa₂Nb₃O₁₀And (3) a CO generation rate graph of the two-dimensional nanosheet heterojunction composite photocatalytic material.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.