An oxygen-rich graphene oxide nanocomposite with high loading of metal oxide and a preparation method and application thereof

Abstract

This invention belongs to the field of inorganic nanocomposites and provides a highly loaded metal oxide-rich graphene oxide nanocomposite material, its preparation method, and its application. The preparation method includes: S1, dispersing graphene oxide in deionized water, adding hydrogen peroxide, stirring and reacting at 60-65℃ for ≥24 hours, centrifuging and washing to obtain oxygen-rich graphene oxide; S2, dispersing the oxygen-rich graphene oxide in a mixed solvent containing N,N-dimethylformamide and water, adding soluble cerium salt, heating and refluxing at 130-132℃ for 5-6 hours, centrifuging, washing, and drying to obtain CeO2 / oxygen-rich graphene oxide nanocomposite material. This invention significantly improves the metal oxide loading, and the resulting composite material can achieve a degradation efficiency of over 97.18% for bisphenol S within 1 minute under natural light conditions. It has the characteristics of simple preparation, green environmental protection, and excellent photocatalytic performance.

Description

Technical Field

[0001] This invention belongs to the field of inorganic nanocomposite materials, specifically a highly loaded metal oxide-rich graphene oxide nanocomposite material, its preparation method, and its application. Background Technology

[0002] Graphene oxide (GO) is an important oxidized derivative of graphene, and its controllable oxygen-containing functional groups, excellent dispersibility, and modifiability have made it a research hotspot in materials science, environmental engineering, and catalytic chemistry. GO sheets have numerous oxygen-containing functional groups grafted onto their surfaces and edges. The basal surfaces primarily graft hydroxyl (-OH) and epoxy (-COC-) groups, while the sheet edges primarily graft carboxyl (-COOH) groups and a small number of carbonyl (C=O) groups. The presence of carboxyl groups gives GO a negative charge in aqueous solution and provides active binding sites (such as coordination bonds, electrostatic interactions, and hydrogen bonds) for subsequent composites with metal ions and metal oxide nanoparticles. Compared to pristine graphene, GO's carbon framework has a few defects and pores due to oxidation. This structural feature does not compromise its large specific surface area advantage of two-dimensional sheets and provides more active sites for photocatalytic reactions.

[0003] Cerium dioxide (CeO2), as an important rare earth metal oxide, possesses advantages such as single crystal form, excellent electrochemical and optical properties, and has broad application prospects in the field of photocatalysis. Preparing nanocomposites by combining CeO2 with GO can leverage their synergistic effect and improve photocatalytic performance. However, existing methods for synthesizing GO / CeO2 nanocomposites mainly suffer from the following problems:

[0004] On the one hand, the existing technologies for carboxylation modification of GO mostly employ chemical grafting methods, such as treating the basal hydroxyl group with chloroacetic acid to convert it into an alkoxycarboxyl group, or modifying it with an azo initiator and then hydrolyzing it into a carboxyl group. These methods involve many synthetic steps and complex reagents, and some methods require the use of moderately toxic reagents, which limits their widespread application.

[0005] On the other hand, existing GO / CeO2 nanocomposites are mostly prepared using a one-step hydrothermal or solvothermal method. For example, existing patent CN201610215972 discloses a three-dimensional porous graphene-cerium dioxide composite photocatalyst, which is prepared by hydrothermal reaction of GO and cerium trichloride. This method involves directly mixing GO and cerium salt followed by hydrothermal treatment. The limited number of oxygen-containing functional groups on the GO surface restricts the loading capacity of CeO2 nanoparticles, and the hydrothermal method requires high-pressure equipment, which is not conducive to large-scale production.

[0006] To address the problems raised in the background art, those skilled in the art have proposed a highly loaded metal oxide-rich graphene oxide nanocomposite material and its preparation method. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a high-load metal oxide-rich graphene oxide nanocomposite material, its preparation method, and its application, thereby resolving the issues in the prior art.

[0008] A method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material includes the following steps:

[0009] S1. Graphene oxide is dispersed in deionized water, hydrogen peroxide is added, and the mixture is stirred under heating conditions. After centrifugation and washing, oxygen-rich graphene oxide is obtained.

[0010] S2. The oxygen-rich graphene oxide obtained in step S1 is dispersed in a mixed solvent containing N,N-dimethylformamide and water. A soluble cerium salt is added, and the mixture is heated under reflux. After centrifugation, washing, and drying, CeO2 / oxygen-rich graphene oxide nanocomposite material is obtained.

[0011] Preferably, in step S1, the mass-to-volume ratio of graphene oxide to deionized water is 0.5 g : 20-30 mL, and the mass-to-volume ratio of graphene oxide to hydrogen peroxide is 0.5 g : 300-400 mL.

[0012] Preferably, in step S1, after the graphene oxide is dispersed in deionized water, it is ultrasonically dispersed at an ultrasonic frequency of 25-40 kHz and an ultrasonic temperature of 20-30℃ for 0.5-1 hours.

[0013] Preferably, the temperature of the stirring reaction under the heating conditions described in step S1 is 60-65°C, the stirring time is ≥24 hours, and the stirring speed is 600-700 rpm.

[0014] Preferably, the ratio of the amount of oxygen-rich graphene oxide, deionized water, N,N-dimethylformamide and soluble cerium salt is: 0.5 g of oxygen-rich graphene oxide : 20-30 mL of deionized water : 200-300 mL of N,N-dimethylformamide : 1-3 g of soluble cerium salt.

[0015] Preferably, in step S2, the temperature of the heating reflux reaction is 130-132°C, the reaction time is 5-6 hours, and the stirring speed is 600-700 rpm.

[0016] Preferably, in step S2, the soluble cerium salt is one or more of cerium nitrate, cerium chloride, and cerium sulfate.

[0017] Preferably, the centrifugation speed is 8000-10000 rpm, the washing is done 3-4 times with deionized water, and the drying temperature is 55-60℃.

[0018] This invention also provides the application of the CeO2 / oxygen-rich graphene oxide nanocomposite material prepared by the above method in the photocatalytic degradation of organic pollutants.

[0019] Preferably, the organic pollutant is bisphenol S (BPS), the photocatalytic degradation is carried out under natural light conditions, and the degradation efficiency of the CeO2 / oxygen-rich graphene oxide nanocomposite material for bisphenol S is not less than 97.18% within 1 minute under natural light conditions.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. In the nanocomposite material provided by the present invention, CeO2 nanoparticles are uniformly and densely loaded on the surface of oxygen-rich graphene oxide substrate, with a particle size of less than 20 nm. The oxygen content is significantly higher than that of untreated GO, and it has a larger specific surface area and more active sites.

[0022] 2. The CeO2 / cGO nanocomposite material prepared by this invention exhibits rapid and efficient photocatalytic degradation performance of bisphenol S under natural light conditions, with a degradation efficiency of up to 97.18% within 1 minute, which is significantly better than the one-step method.

[0023] 3. The reaction medium DMF of this invention can be recovered and reused through vacuum distillation, which reduces production costs and meets the requirements of green chemistry. Attached Figure Description

[0024] Figure 1 The X-ray diffraction (XRD) pattern of the CeO2 / cGO nanocomposite material prepared in Example 1 of this invention;

[0025] Figure 2 The image shows the X-ray photoelectron spectroscopy (XPS) spectrum of the CeO2 / cGO nanocomposite material prepared in Example 1 of this invention.

[0026] Figure 3 Comparison of infrared (IR) spectra of GO, cGO, CeO2 / GO, and CeO2 / cGO;

[0027] Figure 4 The images show scanning electron microscope (SEM) images of GO, cGO, CeO2 / GO, and CeO2 / cGO. Figure 4 A is GO, Figure 4 B stands for cGO. Figure 4 C stands for CeO2 / GO. Figure 4 D stands for CeO2 / cGO;

[0028] Figure 5 Transmission electron microscopy (TEM) images of GO, cGO, CeO2 / GO, and CeO2 / cGO, among which... Figure 5 A is GO, Figure 5 B stands for cGO. Figure 5 C stands for CeO2 / GO. Figure 5 D stands for CeO2 / cGO;

[0029] Figure 6 Here are the electronic energy spectrum (EDS) mappings for GO and cGO, where Figure 6 A is GO, Figure 6 B stands for cGO;

[0030] Figure 7 The following are electronic energy spectrum (EDS) mapping diagrams for CeO2 / GO and CeO2 / cGO, where Figure 7 A is CeO2 / GO, Figure 7 B represents CeO2 / cGO;

[0031] Figure 8 The UV-Vis absorption spectrum of BPS degradation by CeO2 / cGO nanocomposite is shown, in which... Figure 8 A represents the UV absorption spectra of BPS before and after degradation. Figure 8 B represents the effect of degradation time on BPS degradation efficiency;

[0032] Figure 9 The UV-Vis absorption spectrum of BPS degradation by CeO2 / GO nanocomposite is shown, where Figure 9 A represents the UV absorption spectra of BPS before and after degradation. Figure 9 B represents the effect of degradation time on BPS degradation efficiency. Detailed Implementation

[0033] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0034] Reagent source:

[0035] Graphene oxide (GO) can be prepared by a modified Hummers process (see WSH Jr, RE Offeman, Preparation of graphitic oxide, J. Am. Chem. Soc. 80 (6) (1958)) or it can be obtained commercially.

[0036] Cerium nitrate (Ce(NO3)3·6H2O), cerium chloride (CeCl3·7H2O), cerium sulfate (Ce2(SO4)3·8H2O), N,N-dimethylformamide (DMF), bisphenol S (BPS, purity ≥99%), and hydrogen peroxide (H2O2, 30%) were all purchased from Aladdin.

[0037] Bisphenol S (BPS, purity ≥99%) and other reagents were all of analytical grade and purchased from Aladdin.

[0038] Example 1: Preparation of CeO2 / cGO nanocomposite materials

[0039] Preparation of S1, oxygen-rich graphene oxide (cGO)

[0040] Accurately weigh 0.5 g of graphene oxide (GO) and add it to 25 mL of deionized water. Disperse the GO using ultrasound at 35 kHz and 25 °C for 0.5 hours to obtain a homogeneous GO dispersion. Add 350 mL of hydrogen peroxide (30%) to the dispersion and stir at 650 rpm for 24 hours in a 60 °C water bath. After the reaction is complete, centrifuge the reaction solution at 11000 rpm for 10 minutes, discard the supernatant, and wash the precipitate four times with deionized water to obtain a black, viscous, oxygen-rich graphene oxide (cGO).

[0041] Preparation of S2, CeO2 / cGO nanocomposites

[0042] The cGO obtained in step S1 was dispersed in 25 mL of deionized water, and 250 mL of DMF was added. After stirring evenly, 2 g of cerium nitrate (Ce(NO3)3·6H2O) was added, and the mixture was heated under reflux at 650 rpm in an oil bath at 130 °C for 5 hours. After the reaction was completed, the reaction solution was centrifuged at 9000 rpm for 10 minutes, the supernatant was discarded, the precipitate was washed 4 times with deionized water, dried in a vacuum drying oven at 60 °C for 12 hours, and then ground to obtain the CeO2 / cGO nanocomposite material.

[0043] Example 2: Preparation of CeO2 / cGO nanocomposite materials

[0044] Preparation of S1, oxygen-rich graphene oxide (cGO)

[0045] Accurately weigh 0.5 g of graphene oxide (GO) and add it to 20 mL of deionized water. Disperse the GO using ultrasonication at 25 kHz and 20 °C for 1 hour to obtain a homogeneous GO dispersion. Add 300 mL of hydrogen peroxide (30%) to the dispersion and react the mixture at 600 rpm in a 65 °C water bath for 36 hours. After the reaction is complete, centrifuge the reaction solution at 10,000 rpm for 12 minutes, discard the supernatant, and wash the precipitate three times with deionized water to obtain cGO.

[0046] Preparation of S2, CeO2 / cGO nanocomposites

[0047] The cGO obtained in step S1 was dispersed in 20 mL of deionized water, and 200 mL of DMF was added. After stirring evenly, 1.5 g of cerium chloride (CeCl3·7H2O) was added, and the mixture was heated under reflux at 700 rpm in an oil bath at 132 °C for 5.5 hours. After the reaction was completed, the reaction solution was centrifuged at 8000 rpm for 12 minutes, the supernatant was discarded, the precipitate was washed four times with deionized water, dried in a vacuum drying oven at 55 °C for 15 hours, and then ground to obtain the CeO2 / cGO nanocomposite material.

[0048] Example 3: Preparation of CeO2 / cGO nanocomposite materials

[0049] Preparation of S1, oxygen-rich graphene oxide (cGO)

[0050] Accurately weigh 0.5 g of graphene oxide (GO) and add it to 30 mL of deionized water. Disperse the GO using ultrasonication at 40 kHz and 30 °C for 0.75 hours to obtain a homogeneous GO dispersion. Add 400 mL of 30% hydrogen peroxide to the dispersion and react the mixture in a 62 °C water bath at 700 rpm for 48 hours. After the reaction is complete, centrifuge the reaction solution at 12000 rpm for 8 minutes, discard the supernatant, and wash the precipitate four times with deionized water to obtain cGO.

[0051] Preparation of S2, CeO2 / cGO nanocomposites

[0052] The cGO obtained in step S1 was dispersed in 30 mL of deionized water, 300 mL of DMF was added, and after stirring evenly, 3 g of cerium sulfate (Ce2(SO4)3·8H2O) was added. The mixture was heated and refluxed in an oil bath at 131℃ at 600 rpm for 6 hours. After the reaction was completed, the reaction solution was centrifuged at 10000 rpm for 8 minutes, the supernatant was discarded, the precipitate was washed 3 times with deionized water, dried in a vacuum drying oven at 58℃ for 10 hours, and then ground to obtain CeO2 / cGO nanocomposite material.

[0053] Comparative Example 1: Preparation of CeO2 / GO nanocomposites in one step (control)

[0054] To illustrate the advantages of the two-step method of this invention, a one-step method for synthesizing CeO2 / GO nanocomposite materials was used as a control.

[0055] 0.5 g of graphene oxide (GO) was accurately weighed and dispersed in 25 mL of deionized water. The dispersion was ultrasonically dispersed at 35 kHz and 25 °C for 0.5 hours to obtain a homogeneous GO dispersion. 250 mL of DMF was added to the dispersion, and after thorough stirring, 2 g of cerium nitrate (Ce(NO3)3·6H2O) was added. The mixture was then refluxed in an oil bath at 130 °C at 650 rpm for 5 hours. After the reaction was complete, the reaction solution was centrifuged at 9000 rpm for 10 minutes, the supernatant was discarded, and the precipitate was washed four times with deionized water. The precipitate was then dried in a vacuum drying oven at 60 °C for 12 hours and ground to obtain the CeO2 / GO nanocomposite material.

[0056] Example 4: Characterization of CeO2 / cGO nanocomposite material and comparison with comparative example

[0057] Parallel characterization and performance testing were performed on the CeO2 / cGO nanocomposite material prepared in Example 1 and the CeO2 / GO nanocomposite material prepared in Comparative Example 1. The results are as follows: Figure 1-9 As shown in the comparative analysis below.

[0058] 1. XRD Analysis

[0059] like Figure 1 As shown, the diffraction peaks of CeO2 / cGO are in good agreement with the characteristic peaks of the CeO2 standard card (JCPDS No. 34-0394). The diffraction peaks at 2θ=28.5°, 33.1°, 47.5°, 56.3°, 59.1°, 69.4°, 76.7° and 79.1° correspond to the (111), (200), (220), (311), (222), (400), (331) and (420) crystal planes of CeO2, respectively, indicating that CeO2 has been successfully loaded onto cGO and has good crystallinity.

[0060] 2. XPS Analysis

[0061] like Figure 2 As shown, the Ce 3d spectrum contains images corresponding to Ce. 4+ The characteristic peaks of v (882.5 eV), v'' (889.2 eV), v''' (898.2 eV), u (901.0 eV), u'' (907.6 eV) and u''' (916.5 eV) confirmed the formation of CeO2.

[0062] 3. IR Analysis

[0063] like Figure 3 As shown, GO is at approximately 1720 cm. -1 The peak of C=O stretching vibration is observed at approximately 1620 cm⁻¹. -1 The C=C skeletal vibration peak is observed at approximately 1050 cm⁻¹. -1 The cGO peak at approximately 1720 cm⁻¹ exhibits CO stretching vibration. -1 The C=O peak intensity at CeO2 is significantly higher than that of GO, indicating that the carboxyl content of cGO increases significantly after H2O2 treatment. The CeO2 / cGO ratio is approximately 500 cm⁻¹. -1 The presence of characteristic absorption peaks of Ce-O bonds nearby confirms the successful loading of CeO2.

[0064] 4. SEM Comparison

[0065] like Figure 4 As shown, the GO surface is relatively smooth ( Figure 4 A), while more wrinkles appeared on the surface of cGO (A), Figure 4 -B) indicates that H2O2 treatment successfully altered the surface structure of GO, increasing its specific surface area and active sites. CeO2 / GO ( Figure 4 The surface of CeO2 (C-C) contains only a small number of unevenly distributed CeO2 particles, with obvious particle aggregation; while CeO2 / cGO ( Figure 4 -D) The surface is loaded with a large number of CeO2 nanoparticles. The particles are uniformly distributed and have a uniform size, with no obvious agglomeration. This indicates that the two-step method of the present invention significantly improves the loading and dispersion uniformity of CeO2.

[0066] 5. TEM comparison

[0067] like Figure 5 As shown, CeO2 / GO ( Figure 5 CeO2 particles are scarce in CeO2 (-C), with a wide particle size distribution range (5-30 nm), and some regions are unloaded with particles; CeO2 / cGO ( Figure 5 In the -D) layer, CeO2 nanoparticles are uniformly and densely distributed on the cGO sheets, with a particle size of less than 20 nm, and most in the range of 5-10 nm. This demonstrates that oxygen-enriched cGO provides more nucleation sites for CeO2, achieving a high-density, small-particle-size uniform loading.

[0068] 6. EDS Mapping Comparison

[0069] like Figure 6 As shown, the oxygen content of cGO ( Figure 6 -B) was significantly higher than GO ( Figure 6Semi-quantitative analysis showed that the oxygen atom percentage of cGO was approximately 3.2 times that of GO.

[0070] like Figure 7 As shown, CeO2 / GO ( Figure 7 The cerium signal in -A is weak and sparsely distributed; CeO2 / cGO ( Figure 7 -B) The cerium signal intensity is significantly enhanced, and the distribution is more compact. Semi-quantitative analysis shows that the Ce mass percentage of CeO2 / cGO is about 3.1 times that of CeO2 / GO, and the atomic percentage is about 3.5 times, indicating that the method of this invention more than doubles the CeO2 loading.

[0071]

[0072] 7. TGA Comparison

[0073] Within the temperature range of 30-800℃, the weight loss rate of CeO2 / GO is approximately 45%, while that of CeO2 / cGO is only about 25%. Since the weight loss mainly comes from the thermal decomposition of the graphene oxide component, the lower weight loss rate of CeO2 / cGO directly proves that its relative CeO2 content is higher (CeO2 is stable and does not decompose at high temperatures). Calculations show that the actual mass fraction of CeO2 in CeO2 / cGO is approximately 75%, while the mass fraction of CeO2 in CeO2 / GO is approximately 55%, representing an increase in loading of approximately 36%.

[0074] Example 5: Performance Testing and Comparison of Photocatalytic Degradation of BPS by CeO2 / cGO Nanocomposites

[0075] Solution preparation:

[0076] CeO2 / cGO dispersion (1 mg / mL): Accurately weigh 100 mg of CeO2 / cGO nanocomposite material (Example 1), add 100 mL of deionized water, and ultrasonically disperse for 10 minutes.

[0077] CeO2 / GO dispersion (1 mg / mL): Accurately weigh 100 mg of CeO2 / GO nanocomposite material (Comparative Example 1) and prepare it using the same method.

[0078] BPS stock solution (1 mg / mL): Accurately weigh 50 mg of BPS solid powder, dissolve it in 2-5 mL of anhydrous ethanol, and then dilute to 50 mL with deionized water.

[0079] BPS working solution (0.05 mg / mL): Dilute BPS stock solution 20 times with deionized water.

[0080] Photocatalytic degradation experiment:

[0081] Add 100 µL of 1 mg / mL BPS stock solution (equivalent to 0.1 mg BPS) to an EP tube, then add 0.9 mL of deionized water, 50 μL of 0.01% triethanolamine (TEOA), and 1 mL of 1 mg / mL catalyst dispersion (equivalent to 1 mg catalyst) to achieve a final BPS concentration of 0.05 mg / mL and a final catalyst concentration of 0.5 mg / mL. Place the EP tube under natural light (illuminance approximately 8000-10000 Lux, room temperature 25±2℃) and react for 1 minute and 5 minutes, respectively. Centrifuge (12000 rpm, 5 minutes) and collect the supernatant for UV-Vis absorption spectroscopy. Use deionized water as a blank control; the scanning range is 200-400 nm.

[0082] Results analysis:

[0083] like Figure 8 As shown, BPS has a characteristic absorption peak at approximately 257 nm. Figure 8 A), after adding TEOA, a characteristic absorption peak is observed at 294 nm. Figure 8 A), after reacting with CeO2 / cGO nanocomposite material under natural light for 1 minute, the two characteristic absorption peaks of BPS almost completely disappeared. Figure 8 A) Based on the absorption peak intensity, the BPS degradation efficiency reached 97.18%.

[0084] Comparative experiment: Degradation data of CeO2 / GO (Comparative Example 1) under the same conditions were obtained, and the results are shown in the table below:

[0085] sample 1-minute degradation rate 5-minute degradation rate <![CDATA[CeO2 / GO (Comparative Example 1)]]> 13.60% 35.35% <![CDATA[CeO2 / cGO (Example 1)]]> 97.18% 98.30%

[0086] The above results show that the photocatalytic degradation performance of the CeO2 / cGO nanocomposite material prepared by the two-step method of this invention is significantly better than that of the CeO2 / GO prepared by the one-step method, with a degradation rate increase of about 86 percentage points in 1 minute, which reflects the synergistic enhancement effect of the oxygen-rich graphene oxide substrate on the photocatalytic activity of CeO2.

[0087] Example 6: Photocatalytic degradation of BPS with different initial concentrations by CeO2 / cGO nanocomposites

[0088] Following the method of Example 5, the catalyst concentration (Example 1) was fixed at 0.5 mg / mL, and the initial BPS concentrations were set at 0.02 mg / mL, 0.05 mg / mL, 0.10 mg / mL, and 0.20 mg / mL, respectively. The degradation rate was measured after reacting for 1 minute under natural light. Each concentration was repeated three times, and the average value was taken. The results showed that the degradation rate was 62.22% at an initial BPS concentration of 0.025 mg / mL; 73.24% at 0.05 mg / mL; 85.58% at 0.10 mg / mL; and 98.56% at 0.20 mg / mL. This indicates that the composite material of the present invention exhibits good degradation performance over a wide range of pollutant concentrations (0.02-0.10 mg / mL).

[0089] Example 7: Recycling performance of CeO2 / cGO nanocomposites

[0090] Following the method in Example 5, the cyclic performance of the CeO2 / cGO nanocomposite material (Example 1) was tested. After each photocatalytic reaction, the composite material was centrifuged (12000 rpm, 10 minutes), washed three times with deionized water, dried at 60°C for 12 hours, and then reused. The results showed that the degradation rate was 91.7% for the first use; 89.8% for the second; 87.5% for the third; 86.2% for the fourth; and 85.1% for the fifth. After five cycles, the 1-minute degradation efficiency of BPS remained above 85%, indicating that the composite material of the present invention has good cyclic stability and reusability.

[0091] Example 8: DMF Solvent Recovery and Reuse

[0092] The DMF / water mixed solvent after the reaction in Example 1 was recovered by vacuum distillation. Recovery method: The reaction mixture was distilled under vacuum at 60°C and 0.09 MPa, and the distilled DMF / water mixture was collected. Anhydrous magnesium sulfate was added and dried overnight. After filtering to remove the desiccant, it could be reused.

[0093] CeO2 / cGO was synthesized using recycled DMF according to the method in Example 1, and compared with the material synthesized using fresh DMF. The results showed that there were no significant differences between the two materials in terms of XRD, SEM, TEM characterization and photocatalytic degradation performance (the degradation rate was 97.5% in 1 minute when using recycled DMF), indicating that DMF can be recycled and reused, which is beneficial to reducing production costs.

[0094] The embodiments of the present invention are given for the purposes of illustration and description. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing an oxygen-rich graphene oxide nanocomposite material with high loading of metal oxides, characterized in that: Includes the following steps: S1. Graphene oxide is dispersed in deionized water, hydrogen peroxide is added, and the mixture is stirred under heating conditions. After centrifugation and washing, oxygen-rich graphene oxide is obtained. S2. The oxygen-rich graphene oxide obtained in step S1 is dispersed in a mixed solvent containing N,N-dimethylformamide and water. A soluble cerium salt is added, and the mixture is heated under reflux. After centrifugation, washing, and drying, CeO2 / oxygen-rich graphene oxide nanocomposite material is obtained.

2. The method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material as described in claim 1, characterized in that: In step S1, the mass-to-volume ratio of graphene oxide to deionized water is 0.5 g : 20-30 mL, and the mass-to-volume ratio of graphene oxide to hydrogen peroxide is 0.5 g : 300-400 mL.

3. The method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material as described in claim 1, characterized in that: In step S1, the graphene oxide is dispersed in deionized water and then ultrasonically dispersed at an ultrasonic frequency of 25-40 kHz and an ultrasonic temperature of 20-30 °C for 0.5-1 hour.

4. The method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material as described in claim 1, characterized in that: In step S1, the temperature of the stirring reaction under heating conditions is 60-65℃, the stirring time is ≥24 hours, and the stirring speed is 600-700 rpm.

5. The method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material as described in claim 1, characterized in that: The ratio of the amount of oxygen-rich graphene oxide, deionized water, N,N-dimethylformamide and soluble cerium salt is as follows: 0.5 g of oxygen-rich graphene oxide : 20-30 mL of deionized water : 200-300 mL of N,N-dimethylformamide : 1-3 g of soluble cerium salt.

6. The method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material as described in claim 1, characterized in that: In step S2, the temperature of the heating reflux reaction is 130-132℃, the reaction time is 5-6 hours, and the stirring speed is 600-700 rpm.

7. The method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material as described in claim 1, characterized in that: In step S2, the soluble cerium salt is one or more of cerium nitrate, cerium chloride, and cerium sulfate.

8. The method for preparing a highly loaded metal oxide-rich graphene oxide nanocomposite material as described in claim 1, characterized in that: In step S2, the centrifugation speed is 8000-10000 rpm, the machine is washed with deionized water 3-4 times, and the drying temperature is 55-60℃.

9. The application of CeO2 / oxygen-rich graphene oxide nanocomposite material prepared by the method of preparing highly loaded metal oxide-rich graphene oxide nanocomposite material as described in any one of claims 1-8 in the photocatalytic degradation of organic pollutants.

10. A high-load metal oxide-rich graphene oxide nanocomposite material, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

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