Preparation method and application of CuInS2 / C3N5 photocatalytic material

Abstract

The invention discloses a CuInS2 / C3N5 photocatalytic material, and relates to a preparation method and application of an aqueous solution of the CuInS2 / C3N5 photocatalytic material. The preparation method comprises the following steps: preparing a CuInS2 quantum dot solution by adopting a water-phase one-pot method; the C3N5 photocatalytic material is prepared, and a target product is prepared in an aqueous solution by a relatively simple process at a relatively low temperature. The CuInS2 / C3N5 photocatalytic material has the characteristics of obvious exciton absorption, ultra-small size and water-soluble heat dispersion. The method can be applied to the fields of photocatalysis, photoelectrocatalysis, electrocatalysis, light emitting diodes, solar cells, photoelectric sensing and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of nanomaterials, and relates to a preparation method and application of a CuInS2 / C3N5 photocatalytic material, and specifically to a water-soluble CuInS2 / C3N5 photocatalytic material and an aqueous phase synthesis preparation method and application thereof. Background Art

[0002] Today, the consumption of fossil energy is accompanied by the rise in global temperatures. People are facing two major crises: energy shortage and excessive carbon emissions. Nuclear energy, as an efficient and clean energy, is the main development direction of future energy. There are about 4 billion tons of uranium in the ocean, which can be used for a long time. However, due to the complex environment of the ocean and the extremely low uranium concentration, it is difficult to extract uranium from the ocean. Therefore, the use of photocatalytic technology to extract uranium from the ocean has attracted the attention of more and more researchers. Designing efficient, low-cost, and environmentally friendly visible light-driven photocatalysts has become a research hotspot.

[0003] In 2023, Li et al. used a solvothermal method to prepare a sandwich-like ZnIn2S4 / Ti3C2 composite material with strong interface coupling (Sandwich-like 2D / 2D ZnIn2S4 / Ti3C2 composite for highly efficient photocatalytic reduction of U(VI). Journal of Radioanalytical and NuclearChemistry[J], 332: 2759-2770). By improving the utilization rate of solar energy and promoting the separation of photogenerated electrons and holes, the composite material was endowed with higher photocatalytic performance. In 2024, Meng et al. constructed an S-type heterojunction by C3N5 and Fe2O3 (Photo-enhanced uranium recovery from spent fuel reprocessing wastewater via S-scheme 2D / 0D C3N5 / Fe2O3 heterojunctions[J]. SusMat, 2024, 4(2): e199.), and achieved a photocatalytic reduction effect of 93.38% on U(VI) without the need for a hole sacrificial agent.

[0004] CuInS2 / C3N5 photocatalytic material is a heterojunction semiconductor material composed of I-III-VI group direct bandgap semiconductor CuInS2 and polymer semiconductor C3N5, where the bandgap width of CuInS2 at room temperature is about 1.53eV, and the bandgap width of C3N5 at room temperature is about 2.19eV. These two semiconductor materials have a high extinction coefficient in the visible light region. This photocatalytic material does not contain highly toxic heavy metals such as Cd and Pb, and has a wide range of application scenarios in the fields of photocatalysis, light-emitting diodes, solar cells, photoelectric sensors, etc. Summary of the invention

[0005] The purpose of the present invention is to provide a preparation and application of CuInS2 / C3N5 photocatalytic material. + andIn 2+ The molar ratio and the usage amount of C3N5 can improve the photocatalytic performance of CuInS2 / C3N5 materials.

[0006] In addition, the heterojunction quantum dots obtained by the present invention can also be used in the fields of light-emitting diodes, photoelectric sensors, solar cells, etc.

[0007] In order to achieve the above object, the present invention provides a method for preparing a doped catalytic material, the method comprising the steps of:

[0008] (1) Synthesis of CuInS2 quantum dot solution:

[0009] Add cuprous salt and indium salt into deionized water, drip citric acid or glutathione or trithiocyanate aqueous solution into the solution, then drip NaOH and stir, adjust the pH value of the solution to 8-11, heat the sodium sulfide aqueous solution to 80-150°C and drip into the above solution, then put into a hydrothermal kettle and heat to 120-200°C for 10-60h, take out after cooling to room temperature, and obtain CuInS2 quantum dot solution; the organic solvent is selected from dimethylformamide, dimethylacetamide, diethylformamide, diethylacetamide, methanol, ethanol, isopropanol, glycerol, n-butanol, n-octanol and the like.

[0010] (2) Synthesis of C3N5 photocatalytic materials:

[0011] Weigh 10-100 g of melamine or 2,4,6-triazido-1,3,5-triazine or 3-amino-1,2,4-triazole and put it in a crucible. Put the crucible in a muffle furnace or a vacuum tube furnace, heat it from room temperature to 350-650° C. within 60-180 min and keep it for 1-10 h. Then, cool it to room temperature within 60-180 min, take out the crucible, grind the obtained sample in a mortar to obtain a C3N5 photocatalytic material.

[0012] (3) Synthesis of CuInS2 / C3N5 photocatalytic materials:

[0013] Take C3N5 photocatalytic material and add it to CuInS2 quantum dot solution and mix evenly. Then place the mixture in a hydrothermal autoclave, heat it to 120-200°C for 10-60 hours, take it out after cooling to room temperature, separate the solid and liquid and dry it to obtain CuInS2 / C3N5 photocatalytic material.

[0014] Preferably, the molar ratio of the cuprous salt to the indium salt is 1:1 to 1:50.

[0015] Preferably, the heating rate is 1-20°C / min.

[0016] Preferably, the concentration of NaOH is 0.1 mol / L to 10 mol / L; the purity of the organic solvent is 90% to 99%.

[0017] Preferably, the stirring is carried out at room temperature for 1 to 5 hours.

[0018] Preferably, the heating to 120-200° C. is maintained for 10-60 hours.

[0019] Preferably, the method for preparing the CuInS2 / C3N5 photocatalytic material is characterized in that the cuprous salt is selected from one or more of CuCl, CuCN, CuBr, CuI, CuAc and CuSCN; the indium salt is selected from one or more of In(NO3)3, InAc3, In(Cl)3, In(SO4)3, InI3 and InBr3.

[0020] Preferably, after the solid-liquid separation, an organic alcohol is used to disperse the solid, and then solid-liquid separation is performed to remove unreacted substances.

[0021] Another object of the present invention is to provide a CuInS2 / C3N5 photocatalytic material prepared by the method described.

[0022] Another object of the present invention is to provide the application of the CuInS2 / C3N5 photocatalytic material prepared by the method in the fields of photocatalysis, light-emitting diodes, solar cells, photoelectric sensors, etc.

[0023] The CuInS2 / C3N5 photocatalytic material of the present invention and its preparation and application have the following advantages:

[0024] (1) The CuInS2 / C3N5 photocatalytic material obtained by the present invention is a low-dimensional semiconductor nanomaterial;

[0025] (2) The present invention adopts an aqueous phase synthesis method, uses relatively low-priced inorganic salts as precursors, and prepares CuInS2 / C3N5 photocatalytic materials in large quantities through a simple synthesis process;

[0026] (3) The present invention can control the size and band gap of the material by controlling the molar ratio of Cu to In, the amount of C3N5 added, the reaction temperature and the reaction time during the reaction process. The preparation method has strong controllability, easy controllable process parameters, and is safe, green and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the XRD spectrum of the photocatalytic material prepared in Example 1-2 of the present invention.

[0028] Figure 2 This is the XPS spectrum of the photocatalytic material prepared in Example 1 of the present invention.

[0029] Figure 3 This is a SEM image of the photocatalytic material prepared in Example 1 of the present invention.

[0030] Figure 4 This is the XRD spectrum of the photocatalytic material prepared in Comparative Example 1-2 of the present invention.

[0031] Figure 5 This is a graph showing the relationship between the photocatalytic reduction of U(VI) and time of the photocatalytic materials prepared in Examples 1-2 and Comparative Examples 1-2 of the present invention.

[0032] Figure 6 (a) XPS spectrum, (b) UV-Vis spectrum, (c) emission spectrum, and (d) SEM spectrum of the photocatalytic material prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] A method for preparing CuInS2 / C3N5 photocatalytic material is as follows:

[0036] (1) Preparation of CuInS2 quantum dot solution

[0037] 0.02mmol CuAc is added into 20mL deionized water and stirred, 0.1mol In(Ac)3 is added during stirring, ultrasonic dispersion is performed to obtain a mixed solution; 1.2g thiocyanate is dissolved in 20mL deionized water and added into the mixed solution for stirring, and a 1mol / L sodium hydroxide (NaOH) solution is added dropwise under stirring to make the pH value of the solution reach 8-11 to obtain a precursor solution; 4-10mmol sodium sulfide nonahydrate (Na2S·9H2O) is dissolved in 200mL deionized water and heated to 100°C, then added into the precursor solution, and heated in a hydrothermal autoclave at 120-200°C for 5-30h to obtain a CuInS2 quantum dot solution.

[0038] (2) Preparation of C3N5 photocatalytic materials

[0039] Weigh 50-100 g of 3-amino-1,2,4-triazole and put it in a crucible. Put the crucible into a muffle furnace or a vacuum tube furnace, raise the temperature from room temperature to 550°C within 120 minutes and maintain it for 2 hours. Then, cool it to room temperature within 120 minutes, take out the crucible, and grind the prepared sample in a mortar to obtain a C3N5 photocatalytic material.

[0040] (3) Preparation of CuInS2 / C3N5 photocatalytic materials

[0041] Take 100 mg of C3N5 photocatalytic material and place it in 100 mL of CuInS2 quantum dot solution. After stirring for 2 hours, place the mixture in a polytetrafluoroethylene-lined hydrothermal autoclave, heat it to 130°C and keep it for 10 to 80 hours. After heating, cool it to room temperature, centrifuge it and wash it with an organic alcohol solution for 3 to 5 times, and vacuum dry it at 60 to 80°C to obtain CuInS2 / C3N5 photocatalytic material.

[0042] Example 2

[0043] A preparation method of CuInS2 / C3N4 photocatalytic material

[0044] (1) Preparation of CuInS2 quantum dot solution

[0045] 0.02mmol CuSCN is added into 20mL deionized water and stirred, 0.1mol In(Ac)3 is added during stirring, ultrasonic dispersion is performed to obtain a mixed solution; 0.72g reduced glutathione (GSH) is dissolved in 20mL deionized water and added into the mixed solution for stirring, and a 1mol / L sodium hydroxide (NaOH) solution is added dropwise under stirring to make the pH value of the solution reach 8-11 to obtain a precursor solution; 4-10mmol sodium sulfide nonahydrate (Na2S·9H2O) is dissolved in 200mL deionized water and heated to 100°C, then added into the precursor solution, and heated at 120-200°C for 5-30h in a hydrothermal autoclave to obtain a CuInS2 quantum dot solution.

[0046] (2) Preparation of C3N4 photocatalytic materials

[0047] The preparation method is substantially the same as step (2) in Example 1, except that 3-amino-1,2,4-triazole is replaced by melamine.

[0048] (3) Preparation of CuInS2 / C3N4 photocatalytic materials

[0049] The preparation method is basically the same as step (3) in Example 1, except that 200 mg of C3N4 photocatalytic material is taken.

[0050] Comparative Example 1

[0051] A method for preparing a CuInS2 photocatalytic material is as follows:

[0052] (1) Preparation of CuInS2 quantum dot solution

[0053] The preparation method of the CuInS2 quantum dot solution is the same as that of the CuInS2 quantum dot solution in Example 1.

[0054] (2) Preparation of CuInS2 photocatalytic materials

[0055] Take 200 mL of CuInS2 quantum dot solution, add 200 mL of methanol to aggregate the CuInS2 quantum dots, then centrifuge and wash with ethanol 3 to 5 times to remove unreacted ions, and then vacuum dry at 60 to 80°C for 10 hours to obtain CuInS2 photocatalytic material.

[0056] Comparative Example 2

[0057] A method for preparing a C3N5 photocatalytic material is as follows:

[0058] The preparation method of C3N5 photocatalytic material is the same as the preparation method of C3N5 photocatalytic material in Example 1.

[0059] Experimental Example Photocatalytic Reduction of Uranyl Ions

[0060] The photocatalytic reduction of uranyl ions (U(VI)) was carried out in a photocatalytic reactor made of quartz glass. The specific experimental process is as follows:

[0061] Take 20 mg of the synthesized material as a photocatalyst (photocatalytic material prepared in each embodiment or comparative example) and disperse it in 50 mL of a 100 mg / L uranyl nitrate solution, and stir continuously. Use circulating cooling water to control the temperature at 25±0.2°C. First, perform a dark reaction in a light-proof environment for 60 minutes. After reaching adsorption equilibrium, use a xenon lamp (300W) to irradiate and perform a light reaction. Sampling is performed at regular intervals until the uranium concentration in the remaining solution reaches equilibrium; the sample is filtered using a 0.22 μm filter head, and the resulting filtrate is subjected to a color reaction of the remaining U(VI) in the solution after photocatalysis using deionized water, hydrochloric acid and an aqueous solution of azo-III. The color reaction will form a purple complex, and the maximum absorption of the complex is at a wavelength of 652 mm. The proportion of reduced U(VI) is analyzed using ultraviolet-visible spectrophotometry.

[0062] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A preparation method and application of CuInS2 / C3N5 photocatalytic material, characterized in that: The method is prepared in an aqueous phase, and the steps are: (1) Synthesis of CuInS2 quantum dot solution: Add cuprous salt and indium salt to deionized water or an organic solvent, drip citric acid or glutathione or trithiocyanate aqueous solution into the solution, then drip NaOH and stir, adjust the pH value of the solution to 8-11, heat the sodium sulfide aqueous solution to 80-150°C and drip into the above solution, then put it into a hydrothermal kettle and heat it to 120-200°C for 10-60h, take it out after cooling to room temperature, and obtain a CuInS2 quantum dot solution; the organic solvent is selected from dimethylformamide, dimethylacetamide, diethylformamide, diethylacetamide, methanol, ethanol, isopropanol, glycerol, n-butanol, n-octanol and the like. (2) Synthesis of C3N5 photocatalytic materials: Weigh 10-100g of melamine or 2,4,6-triazido-1,3,5-triazine or 3-amino-1,2,4-triazole and put it in a crucible. Put the crucible into a muffle furnace or a vacuum tube furnace filled with high-purity nitrogen. Heat the temperature from room temperature to 350-650°C within 60-180min and keep it for 1-10h. Then cool the temperature to room temperature within 60-180min, take out the crucible, grind the obtained sample in a mortar to obtain a C3N5 photocatalytic material. (3) Synthesis of CuInS2 / C3N5 photocatalytic materials: Take C3N5 photocatalytic material and add it to CuInS2 quantum dot solution and mix evenly. Then place the mixture in a hydrothermal autoclave, heat it to 120-200°C for 10-80 hours, take it out after cooling to room temperature, separate the solid and liquid and dry it to obtain CuInS2 / C3N5 photocatalytic material.

2. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 1, characterized in that: The molar ratio of the cuprous salt to the indium salt is 1:1 to 1:

50.

3. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 1, characterized in that: The heating rate is 1-20°C / min.

4. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 1, characterized in that: The concentration of NaOH is 0.1 mol / L to 10 mol / L, and the purity of the organic solvent is 90% to 99%.

5. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 1, characterized in that: The mixture was stirred at room temperature for 1 to 5 hours.

6. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 1, characterized in that: The heating to 120-200° C. is maintained for 10-60 hours.

7. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 1, characterized in that: The temperature is raised to 350-650° C. and maintained for 1-10 hours.

8. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 1, characterized in that: The cuprous salt is selected from CuCl, CuCN, CuBr, CuI, Cu2Se, Cu2S, CuAc, CuSCN, CF3O3SCu, Cu2Te and C 12 H 10 One or more of CuO2P; the indium salt is selected from one or more of In(NO3)3, InAc3, In(Cl)3, In(SO4)3, InI3 and InBr3.

9. The method for preparing the CuInS2 / C3N5 photocatalytic material according to any one of claims 1 to 8, characterized in that: After the solid-liquid separation, the solid is dispersed with alcohols, and then the solid-liquid separation is performed again to remove unreacted substances.

10. CuInS2 / C3N5 photocatalytic material prepared by the method according to any one of claims 1 to 9.

11. The method for preparing the CuInS2 / C3N5 photocatalytic material according to claim 10, characterized in that: The CuInS2 / C3N5 photocatalytic material is used in photocatalysis, photoelectrocatalysis, electrocatalysis, light-emitting diodes, solar cells and photoelectric sensing.

Images