Search

CN-122012074-A - Graphene uranyl ion sensor material and preparation method and application thereof

CN122012074ACN 122012074 ACN122012074 ACN 122012074ACN-122012074-A

Abstract

The invention relates to the technical field of waste liquid detection, and particularly discloses a graphene uranyl ion sensor material, a preparation method and application thereof. The preparation method comprises 1) compounding COQDs with UiO-66-NH 2+ MOF to form COQDs@MOF, and 2) performing surface functionalization modification on the COQDs@MOF by 8-hydroxyquinoline to obtain the GQDs@MOF@8-HQ composite material. The method realizes high-sensitivity and high-selectivity detection of uranyl ions by optimizing the preparation process, has the advantages of low detection limit, wide linear range, strong photobleaching resistance and the like, can be effectively applied to detection of low-concentration uranyl ions, and provides a new technical means for environmental monitoring and nuclear waste management.

Inventors

  • ZHAO FENG
  • SU LEI
  • LUO YIJING
  • ZHANG DONGPING
  • ZHENG JIYUN
  • SUN CHAO

Assignees

  • 中国核动力研究设计院

Dates

Publication Date
20260512
Application Date
20251216

Claims (10)

  1. 1. The preparation method of the graphene uranyl ion sensor material is characterized by comprising the following steps of: 1) Compounding COQDs with a UiO-66-NH 2+ type MOF to form COQDs@MOF; 2) And performing surface functionalization modification on the COQDs@MOF by using 8-hydroxyquinoline to obtain the GQDs@MOF@8-HQ composite material.
  2. 2. The preparation method of the graphene uranyl ion sensor material according to claim 1 is characterized in that COQDs is synthesized by performing hydrothermal reaction on glucose at 150-200 ℃ for 5-7h, performing ultrasonic treatment on the glucose for 1-2h by adopting a mixed solvent of water and ethanol with a volume ratio of 3:1, and performing dialysis and freeze-drying to obtain fluorescence COQDs.
  3. 3. The method for preparing a uranyl ion sensor material of graphene type according to claim 1, wherein in step 1), COQDs dispersion is mixed with ZrCl 4 and 2-amino terephthalic acid, reacted for 20-28h at 100-150 ℃, and a MOF shell layer is grown in situ by a solvothermal method.
  4. 4. The method for preparing a graphene-based uranyl ion sensor material according to claim 3, wherein the mass ratio of COQDs, zrCl 4 and 2-amino terephthalic acid is 0.5-1.5:5:3.
  5. 5. The method for preparing the graphene uranyl ion sensor material according to claim 1, wherein in the step 2), 8-hydroxyquinoline is dissolved in ethanol, and is mixed with COQDs@MOF by ultrasound, and reacted for 5-7h under a microwave condition.
  6. 6. The preparation method of the graphene uranyl ion sensor material according to claim 5, wherein the mass ratio of 8-hydroxyquinoline to COQDs@MOF is 1:1-2, the microwave frequency is 2400-2500MHz, and the microwave power is 100W.
  7. 7. The method for preparing the graphene type uranyl ion sensor material according to claim 1, wherein COQDs is 2-5nm in size, the surface carboxyl content of COQDs is more than or equal to 8 mmol/g, the specific surface area of MOF is more than or equal to 1200m 2 /g, and the loading amount of 8-hydroxyquinoline is more than or equal to 0.5mmol/g.
  8. 8. A graphene-based uranyl ion sensor material prepared according to the preparation method of any one of claims 1-7.
  9. 9. A uranyl ion sensor comprising a fluorescent probe fabricated from the graphene-based uranyl ion sensor material of claim 8.
  10. 10. Use of a uranyl ion sensor material based on graphene-like uranyl ions according to claim 8 and/or a uranyl ion sensor according to claim 9 in detection of uranyl ions.

Description

Graphene uranyl ion sensor material and preparation method and application thereof Technical Field The invention relates to the technical field of waste liquid detection, and particularly discloses a graphene uranyl ion sensor material, a preparation method and application thereof. Background Uranium is an important fuel for nuclear energy production, with chemical toxicity and radioactive toxicity. During the nuclear fuel cycle, uranium waste liquid may be released into the environment, posing a threat to humans and other organisms. Uranyl ion (UO 22+) is the most common existing form of uranium, has good solubility and is easy to pollute the environment. Currently, methods for detecting uranyl ions include colorimetry, ultraviolet-visible absorption spectrophotometry, fluorescence analysis and the like, but the methods have the following defects in detecting low-concentration uranyl ions: 1. The detection sensitivity is insufficient, the detection limit of the traditional fluorescent material is usually at ppb level, and the detection requirement of low-concentration uranium waste liquid (such as nuclear laboratory effluent) is difficult to meet. 2. The selectivity is poor, the coexisting ions (such as Th 4+、Sr4+ and the like) in the complex matrix are easy to interfere with the detection result, and the anti-interference capability of the existing method is limited. 3. The material stability is low, and part of nano materials are easy to agglomerate or lose efficacy in long-term storage or complex environment, so that the detection repeatability is poor. Graphene-based nanomaterials are considered as promising fluorescent sensing materials due to their unique physicochemical properties, such as high specific surface area, excellent optical properties, and good chemical stability. However, the application of the existing graphene nano material in uranyl ion detection still has the problems of complex preparation process, detection performance to be improved and the like. Disclosure of Invention The invention provides a graphene uranyl ion sensor material, and a preparation method and application thereof, and aims to solve the problems of low sensitivity, poor selectivity and low material stability in the detection of low-concentration uranyl ions in the prior art. The invention is realized by the following technical scheme: In a first aspect, a preparation method of a graphene uranyl ion sensor material is provided, including the following steps: 1) Compounding COQDs with a UiO-66-NH 2+ type MOF to form COQDs@MOF; 2) And performing surface functionalization modification on the COQDs@MOF by using 8-hydroxyquinoline to obtain the GQDs@MOF@8-HQ composite material. The method for synthesizing COQDs comprises the steps of carrying out hydrothermal reaction on glucose at 150-200 ℃ for 5-7h, carrying out ultrasonic treatment on the glucose by adopting a mixed solvent of water and ethanol with the volume ratio of 3:1 for 1-2h, dialyzing, and freeze-drying to obtain fluorescence COQDs. COQDs with uniform size (2-5 nm) can be prepared by the method, so that the size uniformity of the quantum dot is improved to +/-0.3 nm, and the surface is rich in active sites such as hydroxyl, carboxyl and the like. In addition, noble metal nano particles (such as Au and Ag) can be modified on the COQDs surface, the fluorescence signal is enhanced by utilizing the surface plasmon resonance effect, and the quantum yield is more than or equal to 7 percent. The graphene nano material has rich functional groups and uniform size distribution, and can realize high-sensitivity and high-selectivity detection of uranyl ions. In the invention, in the step 1), COQDs dispersion liquid is mixed with ZrCl 4 and 2-amino terephthalic acid, and reacted for 20-28 hours at 100-150 ℃, and MOF shell layers are grown in situ by a solvothermal method. The adsorption capacity and stability of the material are enhanced by utilizing Metal Organic Frameworks (MOFs) to modify COQDs. In the invention, the mass ratio of the COQDs, the ZrCl 4 and the 2-amino terephthalic acid is 0.5-1.5:5:3. In the invention, in the step 2), 8-hydroxyquinoline is dissolved in ethanol, and is mixed with COQDs@MOF by ultrasonic waves, and reacts for 5-7h under the microwave condition. 8-hydroxyquinoline is used as uranium specific chelating agent and is covalently grafted to COQDs surfaces through amidation reaction, so that the photobleaching resistance and stability of the material are improved. In the invention, the mass ratio of 8-hydroxyquinoline to COQDs@MOF is 1:1-2, the microwave frequency is 2400-2500MHz, and the microwave power is 100W. The microwave radiation is introduced, so that the reaction time is shortened from 3 days to about 6 hours, and the yield is improved to 72 percent. In the invention, COQDs is 2-5nm in size, the surface carboxyl content of COQDs is more than or equal to 8 mmol/g, the specific surface area of MOF is more than or equal to 1200m 2/g, and th