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CN-121992437-A - Zirconium-based MOFs composite material loaded with carbon nitride quantum dots, and preparation method and application thereof

CN121992437ACN 121992437 ACN121992437 ACN 121992437ACN-121992437-A

Abstract

The invention belongs to the field of preparation of photoelectrocatalysis materials, and discloses a zirconium-based MOFs composite material loaded with carbon nitride quantum dots, and a preparation method and application thereof. The composite material is prepared by a solid phase method, has the advantages of simple method, low cost, easy amplification, no toxic solvent, and environmental protection. The zirconium-based MOFs composite material loaded with the carbon nitride quantum dots prepared by the invention maintains the advantages of large specific surface area and rich pore canal structure of the MOFs material, and the zirconium-based MOFs composite material loaded with the carbon nitride quantum dots shows excellent hydrogen production performance when being used as a photoelectrode material for producing hydrogen by photoelectrocatalysis decomposition of water.

Inventors

  • WU JIAOJIAO
  • XU XIANGYA
  • JIN QIUYAN
  • LI WEI

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (11)

  1. 1. A zirconium-based MOFs composite material loaded with carbon nitride quantum dots comprises a zirconium-based MOFs carrier and loaded carbon nitride quantum dots, wherein nitrogen elements in the carbon nitride quantum dots exist in the form of pyrrole nitrogen.
  2. 2. The carbon nitride quantum dot loaded zirconium-based MOFs composite according to claim 1, wherein, In the zirconium-based MOFs composite material loaded with the carbon nitride quantum dots, the content of nitrogen atoms is 1-10 atom percent, preferably 2-5 atom percent in terms of atomic percent.
  3. 3. A method for preparing the carbon nitride quantum dot loaded zirconium-based MOFs composite material according to any one of claims 1 to 2, comprising the steps of mixing and heating components including a nitrogen-rich organic precursor, zirconium salt and an organic ligand for reaction.
  4. 4. A method of preparation according to claim 3, comprising the specific steps of: (1) Mixing components comprising a nitrogen-rich organic precursor, an organic acid compound, zirconium salt and an organic ligand to obtain a composite material precursor; (2) Carrying out hydrothermal reaction on the composite material precursor obtained in the step (1); (3) And (3) carrying out post-treatment on the product obtained after the reaction in the step (2) to obtain the zirconium-based MOFs composite material loaded with the carbon nitride quantum dots.
  5. 5. The method according to claim 4, wherein the step (1) is performed by mixing the nitrogen-rich organic precursor and the organic acid compound and then sufficiently grinding the mixture to obtain a mixture A, mixing the zirconium salt and the organic ligand and then sufficiently grinding the mixture B, and mixing the mixture A and the mixture B and then sufficiently grinding the mixture A and the mixture B to obtain the composite precursor.
  6. 6. The method according to claim 4 or 5, wherein in the step (1): the nitrogen-rich organic precursor is selected from at least one of organic amine compounds, preferably at least one of urea, thiourea and melamine, and/or, The organic acid compound is selected from at least one of polybasic fatty acid compounds, preferably at least one of polybasic fatty acid compounds of C2-C8, more preferably at least one of citric acid, malic acid and oxalic acid, and/or, The zirconium salt is selected from at least one of soluble inorganic zirconium salts, preferably at least one of zirconium chloride, zirconium oxychloride and zirconium nitrate, and/or, The organic ligand is selected from at least one of aromatic polybasic acid or derivatives thereof, preferably at least one of terephthalic acid, 2-amino terephthalic acid and 2, 5-dihydroxyterephthalic acid, and/or, The molar ratio of the organic acid compound to the nitrogen-rich organic precursor is 1 (1-50), preferably 1 (1-10), and/or, The molar ratio of the zirconium salt to the organic ligand is 1 (1-50), preferably 1 (1-10).
  7. 7. The preparation method according to claim 5, wherein the mass ratio of the mixture A to the mixture B is 1 (1-100), preferably 1 (5-20).
  8. 8. The method according to claim 4, wherein in the step (2): the temperature of the hydrothermal reaction is 80-250 ℃, preferably 120-200 ℃, and/or, The hydrothermal reaction time is 1-48 hours, preferably 6-24 hours.
  9. 9. The method according to claim 4, wherein the post-treatment in the step (3) comprises the steps of washing, filtering, and drying, preferably, The solvent used for cleaning is alcohol solvent, more preferably at least one of ethanol, methanol and isopropanol, and/or, The cleaning adopts a stirring cleaning mode, more preferably, the stirring cleaning time is 1-10 h, and/or, The drying temperature is 50-200 ℃, more preferably 80-180 ℃.
  10. 10. An electrode material comprising the carbon nitride quantum dot-loaded zirconium-based MOFs composite material according to any one of claims 1 to 2 or the carbon nitride quantum dot-loaded zirconium-based MOFs composite material obtained by the preparation method according to any one of claims 3 to 9.
  11. 11. Use of the carbon nitride quantum dot-loaded zirconium-based MOFs composite material according to any one of claims 1-2, or the carbon nitride quantum dot-loaded zirconium-based MOFs composite material obtained by the preparation method according to any one of claims 3-9, or the electrode material according to claim 10 in photoelectrocatalytic decomposition of water to produce hydrogen.

Description

Zirconium-based MOFs composite material loaded with carbon nitride quantum dots, and preparation method and application thereof Technical Field The invention belongs to the field of preparation of photoelectrocatalysis materials, and relates to a zirconium-based MOFs composite material loaded with carbon nitride quantum dots, and a preparation method and application thereof. Background Photoelectrocatalytic decomposition of water to produce hydrogen has attracted attention in recent years as a technology capable of converting solar energy into hydrogen energy. Compared with direct water electrolysis hydrogen production, the photoelectrocatalysis water decomposition hydrogen production can produce partial photogenerated voltage by virtue of the photoelectrode, and can realize water hydrogen decomposition under lower external bias. The Metal Organic Frameworks (MOFs), also called porous coordination polymers, are two-dimensional or three-dimensional porous nano materials synthesized by two-stage building units, metal cation salts or clusters and multi-tooth organic ligands with coordination connection, and have the characteristics of large specific surface area, high porosity, designable structure, easiness in functionalization of metal centers and ligands, and the like. MOFs are widely applied to the fields of gas adsorption separation, chemical sensing, biological medicine and the like, and have potential application prospects in the aspects of light, electricity and photoelectrocatalysis. The zirconium (Zr) based MOFs have the advantages of large specific surface area, good thermal stability and good chemical stability. However, the band gap is narrow, electron holes are easy to recombine and the conductivity is poor, so that the Zr-based MOFs are limited in further application in the field of photocatalysis. Carbon nitride is an organic polymer material composed of tris-s-triazine structural units, and is widely studied in the field of photocatalysis due to the characteristics of tunable energy band structure, various preparation methods, low cost and the like. However, the electron transmission performance of bulk phase carbon nitride prepared by the traditional direct pyrolysis of nitrogen-rich precursor is poor, and the problem of poor photoelectrode conductivity exists when the precursor is applied to the field of photoelectrocatalysis. Disclosure of Invention In order to solve the problems that electron holes are easy to combine and the conductivity is poor when Zr-based MOFs are applied to photoelectrocatalysis, the invention provides a Zr-based MOFs (CNQDs/Zr-MOFs) composite material loaded with carbon nitride quantum dots, and a preparation method and application thereof. The Carbon Nitride Quantum Dots (CNQDs) are used as electron capture hydrazine, so that the electron and hole separation efficiency of the Zr-MOFs can be obviously improved, and the prepared CNQDs/Zr-MOFs show good photoelectrocatalysis hydrogen decomposition performance. In order to achieve the above purpose, the present invention adopts the following technical scheme. The first aspect of the invention provides a zirconium-based MOFs composite material loaded with carbon nitride quantum dots, which comprises a zirconium-based MOFs carrier and the loaded carbon nitride quantum dots, wherein nitrogen elements in the carbon nitride quantum dots exist in the form of pyrrole nitrogen. According to the carbon nitride quantum dot-loaded zirconium-based MOFs composite material, the content of nitrogen atoms is 1-10 atom percent in terms of atomic percentage, and can be 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10atom percent or a numerical value between any two numerical ranges, preferably, the content of nitrogen atoms is 2-5 atom percent. The second aspect of the invention provides a preparation method of the carbon nitride quantum dot loaded zirconium-based MOFs composite material, which comprises the steps of mixing and heating components including a nitrogen-rich organic precursor, zirconium salt and an organic ligand for reaction. According to the invention, the preparation method of the zirconium-based MOFs composite material loaded with the carbon nitride quantum dots specifically comprises the following steps: (1) Mixing components comprising a nitrogen-rich organic precursor, an organic acid compound, zirconium salt and an organic ligand to obtain a composite material precursor; (2) Carrying out hydrothermal reaction on the composite material precursor obtained in the step (1); (3) And (3) carrying out post-treatment on the product obtained after the reaction in the step (2) to obtain the zirconium-based MOFs composite material loaded with the carbon nitride quantum dots. According to the preparation method of the carbon nitride quantum dot-loaded zirconium-based MOFs composite material, in the step (1), the following operation mode is preferably adopted, wherein a nitrogen-rich organic precursor and an organic acid compound are mixed and