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CN-121988405-A - High-crystallinity metal sulfide ZnIn2S4Preparation method and application of photocatalyst

CN121988405ACN 121988405 ACN121988405 ACN 121988405ACN-121988405-A

Abstract

The invention relates to the technical field of catalyst materials and discloses a preparation method and application of a high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst, wherein the preparation method comprises the steps of uniformly mixing ZnS, in 2 S 3 , S powder and molten salt, placing the mixture In a vacuum closed environment for pyrolysis at 400-800 ℃, and then sequentially carrying out water washing and acid washing; and annealing the cleaned pyrolysis product In an argon atmosphere at 100-300 ℃ to obtain a metal sulfide ZnIn 2 S 4 sample. The ZnIn 2 S 4 sample obtained by the auxiliary calcination of the vacuum tube-sealing fused salt has the characteristics of high crystallinity, low defect concentration, regular morphology and the like, and has important research value in the field of photocatalysis application such as photocatalytic decomposition of water hydrogen.

Inventors

  • CHEN SHANSHAN
  • LI CHENYANG

Assignees

  • 南开大学

Dates

Publication Date
20260508
Application Date
20260324

Claims (10)

  1. 1. The preparation method for preparing the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using vacuum tube-sealing molten salt to assist calcination is characterized by comprising the following steps of: s1, uniformly mixing ZnS, in 2 S 3 , S powder and molten salt, and performing pyrolysis In a vacuum sealed environment at 400-800 ℃; s2, after pyrolysis is finished, washing and pickling pyrolysis products sequentially by using secondary water and an acid solution; and S3, annealing the cleaned pyrolysis product in an argon atmosphere at 100-300 ℃ to obtain the metal sulfide ZnIn 2 S 4 photocatalyst.
  2. 2. The method for preparing the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using the vacuum tube-sealing molten salt for auxiliary calcination according to claim 1, wherein In the step S1, the molar ratio of ZnS to In 2 S 3 is 1:1-1:5, S powder accounts for 10-20 wt% of the total weight, and the molten salt accounts for 15-25 wt% of the total weight.
  3. 3. The preparation method of the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using the vacuum tube-sealing molten salt for auxiliary calcination as claimed in claim 1, wherein the molten salt is single molten salt or double molten salt. The single molten salt is LiCl, naCl, KCl, rbCl, csCl, mgCl 2 、CaCl 2 or SrCl 2 , the double molten salts are the two-by-two combination of the single molten salt, and the corresponding molar ratio is 3:1-3:3.
  4. 4. The method for preparing the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using the fused salt assisted calcination of the vacuum tube-sealing as claimed in claim 1, wherein the materials in the step S1 are uniformly mixed and then placed in a vacuum quartz tube, and the vacuum quartz tube is heated and pyrolyzed in a muffle furnace.
  5. 5. The preparation method of the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using the vacuum tube-sealing molten salt for auxiliary calcination, which is disclosed in claim 1, is characterized in that the heating rate of pyrolysis in the step S1 is 10-20 ℃ per minute, and the pyrolysis time is 3-8 hours.
  6. 6. The method for preparing the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using the fused salt assisted calcination of the vacuum tube-sealing as claimed in claim 1, wherein the water washing step in the step S2 is that the pyrolyzed product is added into deionized water, and the mixture is stirred, treated by ultrasonic, and then is kept stand and filtered to obtain supernatant.
  7. 7. The preparation method of the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using the vacuum tube-sealing molten salt for auxiliary calcination, which is disclosed in claim 1, is characterized in that the acid solution is sulfuric acid solution with the mass concentration of 30-55%, and the acid washing time is 1-15 min.
  8. 8. The method for preparing the high-crystallinity metal sulfide ZnIn 2 S 4 photocatalyst by using the fused salt for the vacuum tube sealing to assist the calcination as claimed in claim 1, wherein the annealing time is 1-5 h.
  9. 9. A metal sulphide ZnIn 2 S 4 photocatalyst prepared by the preparation process of any one of claims 1 to 8.
  10. 10. Use of the high crystallinity metal sulfide ZnIn 2 S 4 photocatalyst according to claim 9 in photocatalytic reactions.

Description

Preparation method and application of high-crystallinity metal sulfide ZnIn 2S4 photocatalyst Technical Field The invention relates to the technical field of catalyst materials, in particular to a preparation method and application of a high-crystallinity metal sulfide ZnIn 2S4 photocatalyst. Background The binary metal sulfide ZnIn 2S4 is a kind of narrow band gap semiconductor photocatalyst (forbidden band width is 2.2-2.4 eV), has stronger visible light absorption capacity, and is widely focused in the field of photocatalytic conversion research. However, the material faces many challenges in practical application, such as low separation efficiency of photo-generated carriers, many surface defects of the catalyst and extremely easy oxidation of surface sulfur element by photo-generated holes, so that the activity and stability of the material in the reaction process are insufficient, and further development of the material is limited. In recent years, various methods have been tried to synthesize ZnIn 2S4, including a hydrothermal (solvent) method, a sol-gel method, a thermal decomposition method, a chemical vapor deposition method, and the like, each of which is characterized as follows: Hydrothermal (solvothermal) is the most common method for preparing metal sulfide photocatalytic materials, particularly heterogeneous reactions that are carried out in closed systems at temperatures above the boiling point of the mineralizer, under standard atmospheric pressure. The hydrothermal method is used for carrying out chemical synthesis reaction in aqueous solution, so that the metal sulfide nano material with controllable morphology and size can be obtained, and the solvothermal method is similar to the hydrothermal method, and the metal sulfide nano material with special morphology is synthesized by using an organic solvent as a reaction medium. The hydrothermal (solvothermal) method has the advantages of lower reaction temperature, controllable product morphology and size and the like. However, the ZnIn 2S4 material synthesized by the method generally has the defects of poor crystallinity, more surface defect sites and the like, and seriously hinders the separation and migration of photogenerated carriers. Although the solvothermal method can reduce the defects to a certain extent, the problem that the organic reagent is stored in a small amount on the surface of the material due to the volatilization of the solvent which is difficult to avoid in the high-temperature process is extremely difficult to remove, and the defect density is high is not solved. The sol-gel process is one of the production of solid material from small molecule, and is one kind of sol-gel process with inorganic metal salt or organic metal compound, such as metal alkoxide, as material and through hydrolysis-polycondensation reaction of precursor to form colloid solution. In the reaction process, the solvent gradually volatilizes to increase the viscosity of the sol system, and then the sol system is converted into elastic gel substances, and finally the target product is obtained under the low-temperature condition. The sol-gel method has relatively simple process and lower cost, and can also realize effective regulation and control of the morphology of ZnIn 2S4. However, the constantly volatilized organic reagent in the preparation process causes environmental pollution, and the effective removal of the organic reagent remaining on the surface of the catalyst at the later stage limits the subsequent effective application. The basic principle of the thermal decomposition method is the same as that of the chemical vapor deposition method, namely, the high-temperature annealing is adopted to lead the raw materials to realize a series of processes of decomposition, gasification, crystallization and the like. This process is a complex systematic process, generally depending on the reactants and reaction conditions, requiring high temperature and pressure conditions. This is due to the increased chemical activity of the reactants under high temperature conditions, which are more prone to reactions. Under high pressure conditions, the concentration of the reactants increases, which in turn facilitates the reaction. Meanwhile, the distance between reactant molecules can be shortened under high pressure, and the possibility of reaction is improved. The method can solve the partial defects (such as poor crystallization degree) of the current ZnIn 2S4 material, but also has the problems of high reaction temperature, long time, harmful tail gas emission and the like. In addition, the chemical vapor deposition method is mainly applied to the fields of film growth and device preparation, and few reports are reported in the field of photocatalysis at present. The analysis shows that the prior ZnIn 2S4 synthesis method has advantages and disadvantages, wherein the main problems are that the crystallization degree of the sample is poor and the defect