Preparation method and application of vanadium-based oxide modified graphene oxide composite material
By preparing vanadium-based oxide-modified graphene oxide composite materials, the problems of poor stability and poor adsorption effect of existing adsorbent materials were solved, achieving efficient adsorption and economical recovery of uranium.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-12
- Publication Date
- 2026-04-10
AI Technical Summary
Existing adsorbent materials suffer from poor stability and ineffective adsorption when removing uranium (VI) from water, making it difficult to treat the uranium in an economical and efficient manner.
A method for preparing vanadium-based oxide modified graphene oxide composite material was adopted. By adding vanadium pentoxide and oxalic acid to a graphene oxide dispersion, followed by hydrothermal reaction and annealing, VrG material was formed, which improved the mechanical stability and adsorption performance of the material.
It achieves highly efficient adsorption of uranium, the material is easy to recycle, reduces costs, and improves adsorption performance.
Smart Images
Figure CN121819795A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vanadium-based material preparation methods, and in particular to a method for preparing vanadium-based oxide-modified graphene oxide composite materials and their applications. Background Technology
[0002] Uranium is a naturally occurring radioactive element, with its hexavalent state (U(VI)) being the most common and stable form in aqueous solution, widely used in nuclear power generation, nuclear weapons manufacturing, and medical treatment. However, the radioactivity of uranium leads to its accumulation in the environment, causing long-term harm to ecosystems and human health. Therefore, removing U(VI) from wastewater through cost-effective and efficient treatment methods is crucial. Membrane separation, chemical precipitation, biological treatment, and adsorption are currently the most commonly used methods for uranium(VI) adsorption and separation. Among these, adsorption methods have received widespread attention due to their low energy consumption and simple operation. The selection of adsorbent materials is critical to the uranium adsorption effect.
[0003] Currently, adsorbent materials such as activated carbon, zeolite, covalent organic frameworks (COFs), and metal-organic frameworks (MOFs) have been developed. However, existing materials suffer from poor stability and inadequate adsorption performance. Therefore, there is a need to develop a novel and highly efficient uranium adsorbent material. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a vanadium-based oxide-modified graphene oxide composite material and its application. This method is rapid and low-cost, and the prepared material can be used to remove uranium from uranium-containing wastewater. By loading vanadium-based oxides, the material is easily recyclable, and the mechanical stability and adsorption performance of the graphene oxide are improved. The material of this invention shows promising application prospects in uranium-containing wastewater treatment.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] In a first aspect, the present invention provides a method for preparing a vanadium-based oxide-modified graphene oxide composite material, the method comprising the following steps:
[0007] (1) At room temperature, vanadium pentoxide was used as the vanadium source, oxalic acid as the reducing agent, and graphene oxide dispersion as the carbon substrate was added to deionized water and mixed in a constant temperature water bath at 75°C for 1 hour to obtain a mixed solution.
[0008] (2) The mixed solution obtained in step (1) is transferred to the reaction vessel and heated at 180°C. After cooling, the solid product is collected through a 0.22 μm filter membrane and washed with anhydrous ethanol and deionized water in sequence until the filtrate is colorless. After drying, the composite material precursor is obtained.
[0009] (3) Grind and sieve the composite material precursor obtained in step (2) to obtain a uniform powder, and then anneal it under an inert atmosphere to obtain the vanadium-based oxide modified graphene oxide composite material (denoted as VrG material).
[0010] In one specific embodiment, the molar ratio of vanadium pentoxide and oxalic acid in step (1) is 1:2.
[0011] In one specific embodiment, the concentration of the graphene oxide dispersion is 3 mg / mL and the volume is 10 mL.
[0012] In one specific implementation, the reactor is heated at 180°C for 3 hours in step (2).
[0013] In one specific implementation, step (3) involves annealing at 400°C for 1 hour in a tube furnace.
[0014] A concentration of 3 mg / mL ensures that the graphene oxide sheets can fully self-assemble into a complete network without excessive stacking that blocks the pores; a hydrothermal temperature of 180 °C drives the assembly and initial reduction, which avoids both structural looseness and framework collapse; annealing at 400 °C deeply repairs defects to improve conductivity while preserving the three-dimensional porous structure. Together, these three factors achieve the optimal balance between the material's specific surface area and conductivity.
[0015] In one specific implementation, a 200-mesh sieve is used for sieving in step (3).
[0016] Secondly, the present invention provides a vanadium-based oxide modified graphene oxide composite material prepared by the above-described preparation method.
[0017] Thirdly, the present invention provides the application of the above-mentioned vanadium-based oxide modified graphene oxide composite material in the removal of uranium-containing wastewater.
[0018] This invention employs an efficient and economical process to synthesize VrG materials, which improves the adsorption performance for uranium, solves the problems of material mechanical instability and difficulty in separation in water, facilitates recycling, and saves costs. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the synthesis steps for VrG composite materials.
[0021] Figure 2 This is a scanning electron microscope image of VrG.
[0022] Figure 3 The graph shows a comparison of the adsorption performance of different VrG composite materials for uranyl ions obtained in Examples 1-7. Detailed Implementation
[0023] The principles and features of the present invention are described below. The embodiments given are only for explaining the present invention and are not intended to limit the scope of the present invention.
[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0025] Example 1
[0026] Preparation of VrG-1
[0027] 1 mmol of V₂O₅ and 2 mmol of C₂H₂O₄·2H₂O powder were weighed and dissolved in 40 mL of deionized water. Then, 10 mL of graphene oxide (3 mg / mL) was added to the mixture, and the solution was stirred at 75 °C for 1 hour. The solution was then transferred to a 100 mL PTFE-lined autoclave and heated at 180 °C for 3 hours. The synthesized precursor was centrifuged multiple times with deionized water and alcohol, respectively, and then dried in an oven at 60 °C for 2 hours. Finally, the dried material was annealed at 400 °C for 1 hour under an Ar₂ atmosphere, and the resulting black powder was named VrG-1.
[0028] Example 2
[0029] Preparation of VrG-2
[0030] 2 mmol of V₂O₅ and 4 mmol of C₂H₂O₄·2H₂O powder were weighed and dissolved in 40 mL of deionized water. Then, 10 mL of graphene oxide (3 mg / mL) was added to the mixture, and the solution was stirred at 75 °C for 1 hour. The solution was then transferred to a 100 mL PTFE-lined autoclave and heated at 180 °C for 3 hours. The synthesized precursor was centrifuged multiple times with deionized water and alcohol, respectively, and then dried in an oven at 60 °C for 2 hours. Finally, the dried material was annealed at 400 °C for 1 hour under an Ar₂ atmosphere, and the resulting black powder was named VrG-2.
[0031] Example 3
[0032] Preparation of VrG-3
[0033] 3 mmol of V₂O₅ and 6 mmol of C₂H₂O₄·2H₂O powder were weighed and dissolved in 40 mL of deionized water. Then, 10 mL of graphene oxide (3 mg / mL) was added to the mixture, and the solution was stirred at 75 °C for 1 hour. The solution was then transferred to a 100 mL PTFE-lined autoclave and heated at 180 °C for 3 hours. The synthesized precursor was centrifuged multiple times with deionized water and alcohol, respectively, and then dried in an oven at 60 °C for 2 hours. Finally, the dried material was annealed at 400 °C for 1 hour under an Ar₂ atmosphere, and the resulting black powder was named VrG-3.
[0034] Example 4
[0035] Preparation of VrG-4
[0036] 4 mmol of V₂O₅ and 8 mmol of C₂H₂O₄·2H₂O powder were weighed and dissolved in 40 mL of deionized water. Then, 10 mL of graphene oxide (3 mg / mL) was added to the mixture, and the solution was stirred at 75 °C for 1 hour. The solution was then transferred to a 100 mL PTFE-lined autoclave and heated at 180 °C for 3 hours. The synthesized precursor was centrifuged multiple times with deionized water and alcohol, respectively, and then dried in an oven at 60 °C for 2 hours. Finally, the dried material was annealed at 400 °C for 1 hour under an Ar₂ atmosphere, and the resulting black powder was named VrG-4.
[0037] Example 5
[0038] Preparation of VrG-5
[0039] 5 mmol of V₂O₅ and 10 mmol of C₂H₂O₄·2H₂O powder were weighed and dissolved in 40 mL of deionized water. Then, 10 mL of graphene oxide (3 mg / mL) was added to the mixture, and the solution was stirred at 75 °C for 1 hour. The solution was then transferred to a 100 mL PTFE-lined autoclave and heated at 180 °C for 3 hours. The synthesized precursor was centrifuged multiple times with deionized water and alcohol, respectively, and then dried in an oven at 60 °C for 2 hours. Finally, the dried material was annealed at 400 °C for 1 hour under an Ar₂ atmosphere, and the resulting black powder was named VrG-5.
[0040] Example 6
[0041] Preparation of VrG-6
[0042] 6 mmol of V₂O₅ and 12 mmol of C₂H₂O₄·2H₂O powder were weighed and dissolved in 40 mL of deionized water. Then, 10 mL of graphene oxide (3 mg / mL) was added to the mixture, and the solution was stirred at 75 °C for 1 hour. The solution was then transferred to a 100 mL PTFE-lined autoclave and heated at 180 °C for 3 hours. The synthesized precursor was centrifuged multiple times with deionized water and alcohol, respectively, and then dried in an oven at 60 °C for 2 hours. Finally, the dried material was annealed at 400 °C for 1 hour under an Ar₂ atmosphere, and the resulting black powder was named VrG-6.
[0043] Example 7
[0044] Preparation of VrG-7
[0045] 7 mmol of V₂O₅ and 14 mmol of C₂H₂O₄·2H₂O powder were weighed and dissolved in 40 mL of deionized water. Then, 10 mL of graphene oxide (3 mg / mL) was added to the mixture, and the solution was stirred at 75 °C for 1 hour. The solution was then transferred to a 100 mL PTFE-lined autoclave and heated at 180 °C for 3 hours. The synthesized precursor was centrifuged multiple times with deionized water and alcohol, respectively, and then dried in an oven at 60 °C for 2 hours. Finally, the dried material was annealed at 400 °C for 1 hour under an Ar₂ atmosphere, and the resulting black powder was named VrG-7.
[0046] Example 8
[0047] This embodiment provides a performance test of a vanadium-based oxide modified graphene oxide (VrG) composite material for removing uranium amide ions from uranium-containing wastewater.
[0048] The uranium adsorption performance of VrG-1, VrG-2, VrG-3, VrG-4, VrG-5, VrG-6, and VrG-7 obtained in Examples 1-7 was compared and analyzed. The method was as follows:
[0049] To conduct the adsorption experiment, a 1000 mg / L U(VI) solution (UO2(NO3)2·6H2O) was prepared beforehand. Subsequently, solutions of different concentrations (10–40 mg / L) were diluted. The pH of the entire solution was then controlled to 4 using a negligible volume of 0.1 mol / L nitric acid solution or 0.1 mol / L sodium hydroxide solution. In 100 mL Erlenmeyer flasks, 10 mg of VrG-1, VrG-2, VrG-3, VrG-4, VrG-5, VrG-6, and VrG-7 were mixed with 20 mL of U(VI) solution, respectively. To ensure adsorption efficiency, the adsorbent was uniformly dispersed in the U(VI) solution using ultrasound. The Erlenmeyer flasks were then placed in a shaker and reacted at 25 °C and 200 rpm for 120 min. After the absorption process was complete, the adsorbent was separated from the mixture using a 0.22 μm filter membrane. The concentration of uranyl ions before and after adsorption was determined by azoarsine III spectrophotometry. Figure 3 The graph shows the adsorption performance of VrG-1, VrG-2, VrG-3, VrG-4, VrG-5, VrG-6, and VrG-7 obtained in Examples 1 to 7 for uranium ions at an initial uranium concentration of 20 mg / L. Compared with the uranium removal rates of the other examples, the VrG-6 composite material has a higher uranium removal rate, reaching a maximum of 98.2%.
[0050] Example 9
[0051] The effect of the dosage of the VrG-6 composite material prepared in Example 6 on the adsorption performance was determined.
[0052] (1) Prepare 20 mL of uranium-containing solution with an initial concentration of 20 mg / L at room temperature and adjust the pH to 4.0.
[0053] (2) The material was added to the uranium solution in a gradient of 0.2, 0.5, 1.0, 1.5 and 2.0 g / L, and the reaction was shaken for two hours.
[0054] (3) The concentration of uranium in the water sample in step (2) was determined by azoarsine III spectrophotometry, and the results are shown in Table 1.
[0055] Table 1. Effect of different VrG-6 dosages on uranium adsorption efficiency
[0056] Dosage (g / L) 0.2 0.5 1 1.5 2 Adsorption efficiency (%) 82.89 96.04 96.21 95.00 95.00
[0057] Example 10
[0058] The effect of pH value on the adsorption performance of the VrG-6 composite material prepared in Example 6 was determined:
[0059] (1) Prepare 20 mL of a solution with an initial concentration of 20 mg / L. The pH value of the uranium solution is to be within the range of 2 to 6. Adjust the pH value to different values using 0.1 mol / L HCl and 0.1 mol / L NaOH.
[0060] (2) Based on the experimental results of Example 9, and balancing the removal effect and cost factors, the material was selected to be added to the uranium-containing solution at a dosage of 0.5 g / L. The results are shown in Table 2.
[0061] Table 2. Effect of VrG-6 on uranium adsorption efficiency at different pH values.
[0062] pH 2 3 4 5 6 Adsorption efficiency (%) 96.30 97.07 97.51 96.81 96.30
[0063] Example 11
[0064] The effect of adsorption time on uranium adsorption performance of the VrG-6 composite material prepared in Example 6 was determined:
[0065] (1) Prepare 20 ml of uranium-containing solution with an initial concentration of 20 mg / L and adjust the pH to 4.0.
[0066] (2) Add 10 mg of the VrG-6 adsorbent prepared in Example 6 to the solution in step (1), shake the reaction at room temperature, and take water samples at 5, 10, 30, 60, 90 and 120 minutes respectively. Filter the samples with a 0.22 μm water-based filter and set them aside for later use.
[0067] (3) The concentration of uranium in the water sample in step (2) was determined by azoarsine III spectrophotometry, and the results are shown in Table 3.
[0068] Table 3 Effect of different reaction times on uranium adsorption efficiency
[0069] Reaction time (min) 5 10 30 60 90 120 Adsorption efficiency (%) 65.17 77.53 84.10 95.78 95.34 96.04
[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Those skilled in the art should understand that changes and modifications can be made to the above embodiments without departing from the spirit of the present invention, and all such changes and modifications fall within the scope defined by the appended claims.
Claims
1. A method for preparing a vanadium-based oxide-modified graphene oxide composite material, characterized in that, The preparation method includes the following steps: (1) At room temperature, vanadium pentoxide was used as the vanadium source, oxalic acid as the reducing agent, and graphene oxide dispersion as the carbon substrate was added to deionized water and mixed in a constant temperature water bath at 75°C for 1 hour to obtain a mixed solution. (2) The mixed solution obtained in step (1) is transferred to the reaction vessel and heated at 180°C. After cooling, the solid product is collected through a 0.22 μm filter membrane and washed with anhydrous ethanol and deionized water until the filtrate is colorless. After drying, the composite material precursor is obtained. (3) Grind and sieve the composite material precursor obtained in step (2) to obtain a uniform powder, and then anneal it under an inert atmosphere to obtain the vanadium-based oxide modified graphene oxide composite material.
2. The preparation method according to claim 1, characterized in that, The molar ratio of vanadium pentoxide to oxalic acid in step (1) is 1:
2.
3. The preparation method according to claim 1, characterized in that, The concentration of the graphene oxide dispersion in step (1) is 3 mg / mL, and the added volume is 10 mL.
4. The preparation method according to claim 1, characterized in that, The heating reaction in step (2) takes 3 hours.
5. The preparation method according to claim 1, characterized in that, The annealing process in step (3) is performed at a temperature of 400°C for 1 hour.
6. The preparation method according to claim 1, characterized in that, In step (3), a 200-mesh sieve is used for sieving.
7. A vanadium-based oxide modified graphene oxide composite material prepared by any one of the preparation methods of claims 1 to 6.
8. The application of the vanadium-based oxide modified graphene oxide composite material as described in claim 7 in the removal of uranium-containing wastewater.