Hydrophilic graphite oxide particle material prepared by electrochemical method and application thereof

Abstract

The application discloses a kind of hydrophilic graphite oxide particle materials prepared by electrochemical method and application thereof, the hydrophilic graphite oxide particle material is prepared by the following method: S1, select graphite as anode, insert into electrolyte, electrolysis (electrochemical oxidation) is carried out under constant potential;S2, after electrolysis, the obtained electrolytic solution is filtered, and the filtrate is centrifuged, to obtain the hydrophilic graphite oxide particle material.The graphite particle material obtained by the application has the characteristics of reducibility, can be used for heavy metal wastewater treatment, and can reduce heavy metal ions and recover.The application uses green and environmentally friendly electrochemical oxidation method to prepare hydrophilic graphite oxide particles, the process flow is simple, there is no special material preparation site requirement, no secondary pollution, and the dispersibility of the prepared oxidizing graphite particles in aqueous solution is good, not easy to agglomerate, and has no toxic and harmful effect on the environment.

Description

Technical Field

[0001] This invention relates to the field of environmental chemistry, specifically to a hydrophilic graphite oxide particle material prepared by an electrochemical method and its application, particularly a hydrophilic graphite oxide particle material with reducing properties, its preparation method and application, and especially a method for preparing hydrophilic graphite oxide particles of different sizes and its application in the recovery of pollutants and valuable precious metals from environmental water bodies. Background Technology

[0002] Water pollution is becoming increasingly serious, posing a severe threat to the ecological environment and human health. Large quantities of various organic pollutants, heavy metal ions, and other harmful substances are discharged into water bodies, causing immense damage to water resources. How to efficiently remove pollutants from water bodies has become one of the hot topics in environmental chemistry research.

[0003] Graphite oxide is a graphite derivative containing numerous oxygen-containing functional groups, primarily carboxyl, hydroxyl, and epoxy groups. The presence of these functional groups endows it with excellent hydrophilicity and chemical activity. Graphite oxide also possesses a large specific surface area and abundant pore structure, enabling it to effectively adsorb pollutants from water. Furthermore, graphite oxide materials exhibit good chemical stability and mechanical strength, maintaining their structure and properties even in complex aquatic environments. In addition, graphite oxide materials demonstrate good dispersibility, allowing them to be uniformly distributed in water and fully contact pollutants, thereby improving treatment efficiency. Although graphite oxide raw materials are inexpensive, its preparation processes (such as chemical oxidation and ultrasonic exfoliation) consume large amounts of chemical reagents and energy, resulting in high overall preparation costs. Moreover, precisely controlling the size distribution of graphite oxide particles during preparation remains a challenge, potentially affecting the material's performance and application effectiveness. Therefore, developing a green preparation method for hydrophilic graphite oxide particles of different sizes holds promise for playing a greater role in environmental protection, reducing material preparation costs, simplifying related processes, and providing greener technological support for solving water pollution problems.

[0004] Graphite oxide materials have wide applications in various fields, such as water treatment, electrochemical sensors, energy storage, composite materials, medical and biotechnology, and infrared environmental remediation. We designed and synthesized an electrochemical oxidation method to prepare hydrophilic graphite particles of different sizes, and applied them to the environmental water remediation process, effectively achieving the removal of target pollutants and the recovery of precious metal ions from environmental water. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a hydrophilic graphite oxide particle material prepared by an electrochemical method and its application, thereby solving the problem of difficulty in controlling the size distribution of graphite oxide particles in traditional technologies.

[0006] The electrolytes of this invention are all water, conventional acid and alkali solutions, or small molecule inorganic salt solutions (with a single composition, no additional organic matter added, no strong oxidizing properties, and no intercalation effect of ions). At extremely low concentrations (pH = 1-12 or not exceeding 5 mmol / L), only weak conductivity is guaranteed. At the same time, only at higher electrolysis voltages (25-60V) and appropriate electrode spacing can the current be guaranteed to act on the surface of the graphite anode (high voltage, low conductivity). Random electrons break the C-C bonds (C-C breaks near the particles), causing the graphite surface to detach in a granular manner and peel off irregularly.

[0007] If high concentrations or other ions (such as nitrate) are used, they can intercalate between graphite layers during electrolysis, thus achieving exfoliation and yielding layered graphene (without surface defects), rather than graphite particles.

[0008] The electrolyte used in this invention has a simple composition and low solubility. The current applied to the electrode can only act on the electrode graphite. Under relatively high voltage (25-60V), the surface graphite structure is destroyed, creating carbon defect sites that store electrons, thus exhibiting reducing properties. The resulting graphite plate has a honeycomb structure. In other words, this invention allows current to act on the surface of the anode graphite, producing a destructive effect, irregularly breaking the carbon-carbon junction (CC), and causing graphite particles (non-graphite sheets, graphene) to detach. Furthermore, the graphite particles carry electrons on their surface, exhibiting reducing properties, and can be used for heavy metal wastewater treatment to reduce and recover heavy metal ions. This material can directly reduce metal ions without the need for additional reagents, pH adjustment, or temperature application. The material has abundant carbon defect structures and a certain amount of mobile electrons (graphene is completely exfoliated and lacks carbon defects), enabling direct reduction of metal ions. The hydrophilicity is highly dispersed in an aqueous environment (1-3000 mg·L⁻¹). -1 ).

[0009] The objective of this invention is achieved through the following solution:

[0010] In a first aspect, the present invention provides a hydrophilic graphite oxide particle material prepared by an electrochemical method, which is obtained by the following method:

[0011] S1. Graphite is selected as the anode, and the anode and cathode are inserted into the electrolyte to carry out electrolysis (electrochemical oxidation) under constant potential.

[0012] S2. After electrolysis, the obtained electrolytic solution is filtered, and the filtrate is centrifuged to obtain the hydrophilic graphite oxide particle material.

[0013] In one embodiment of the present invention, in step S1, the cathode used for electrolysis is graphite. The graphite material, used as the electrode, is treated as follows before use: the surface of the purchased graphite material is polished with sandpaper of 2000-8000 mesh; then the polished graphite material is washed with ultrapure water and air-dried at room temperature. The purity of the graphite material reaches 99.999%. The electrolyte volume is 10-5000 mL, and the reaction time under constant potential is 1-500 h.

[0014] In one embodiment of the present invention, in step S1, the electrolyte includes one or more of ultrapure water, acid solution, alkaline solution, and salt solution. The pH of the ultrapure water, acid solution, and alkaline solution is 1-12, preferably 2-11; the solubility of the salt solution does not exceed 5 mmol / L.

[0015] The acid solution is one or more of hydrochloric acid solution and acetic acid solution;

[0016] The alkaline solution is one or more of sodium hydroxide solution and ammonia solution;

[0017] The salt solution is one or more of the following: sodium chloride solution, potassium chloride solution, sodium bicarbonate solution, magnesium sulfate solution, calcium chloride solution, sodium acetate solution, and sodium carbonate solution.

[0018] In one embodiment of the present invention, the electrolysis voltage in step S1 is 25-60V.

[0019] In one embodiment of the present invention, in step S1, the electrode spacing is 6-10cm, preferably 8cm.

[0020] In one embodiment of the present invention, in step S1, different electrolyte components result in different conductivity during electrolysis, which can prepare hydrophilic graphite oxide particles of different sizes, thereby achieving size control. For example, when ultrapure water is used as the electrolyte for electrolysis, the smaller the current generated, the smaller the particle size; the larger the current, the larger the particle size (high conductivity and excessive current will not be able to act on the surface of the graphite anode and break the C-C bonds).

[0021] In one embodiment of the present invention, in step S2, filtration is performed using filter paper (fast, medium, or slow speed) or a filter membrane (0.22-0.8 micrometers). When the purity of the graphite electrode is insufficient, large particles increase significantly, and filtration can remove large particle precipitates visible to the naked eye.

[0022] In one embodiment of the present invention, in step S2, the size range of the obtained hydrophilic graphite oxide particles is 3-80 nm, preferably 5-50 nm. The electrolysis product contains particles of different sizes. By controlling the electrolysis parameters (voltage or electrolyte), the majority of the particles obtained are no larger than 80 nm, with a small number of larger particles (80-800 nm). The supernatant in the filtrate contains small particles, while the lower layer contains large particles. Based on the distribution of particle size in the filtrate, multi-step centrifugation can separate hydrophilic graphite oxide particles of different sizes. This step can further centrifuge the supernatant or lower layer; the more times the separation is performed, the more uniform the size of the hydrophilic graphite oxide particles in the resulting separated liquid.

[0023] As the particle size increases (80-800nm), the surface defect density decreases, the stored electron density also decreases, and the reducing effect becomes weaker. When the particles reach the micron level, the stored electron content per unit mass of graphite particles further decreases, and in applications, it mainly plays an adsorption role (without a reducing effect, comparable to conventional carbon powder and graphene powder).

[0024] In one embodiment of the present invention, in step S2, the centrifugation speed is 1000-15000 rpm and the centrifugation time is 10-60 min.

[0025] In one embodiment of the present invention, in step S2, the obtained hydrophilic graphite oxide particle material is a hydrophilic graphite oxide particle dispersion obtained by centrifugation. The prepared graphite oxide particle material can be highly dispersed in an aqueous solution. The hydrophilic graphite oxide particles act as electron donors, providing electrons with a capacity of 0.01-0.2 mmol·g. -1 The final product is uniformly dispersed in the solution and can be highly dispersed in the aqueous solution without further ultrasonic dispersion or the addition of additional dispersants or stabilizers.

[0026] Secondly, this invention provides an application of the aforementioned hydrophilic graphite oxide particulate material in the reduction of heavy metal ions. This application is for environmental remediation. The graphite particulate material obtained by this invention has reducing properties and can be used for heavy metal wastewater treatment, reducing and recovering heavy metal ions.

[0027] The application includes the recovery of heavy metals obtained after reducing heavy metal ions.

[0028] The metal ions include one or more of dichromate ions, chloroaurate ions, and permanganate ions.

[0029] The heavy metal ions are those derived from heavy metal wastewater and / or environmental water bodies.

[0030] As one embodiment of the present invention, the application includes the following steps: adding the hydrophilic graphite oxide particle material to a body of water containing heavy metal ions (heavy metal wastewater system or environmental water body), and stirring to mix evenly. The concentration of heavy metal ions is 0.1-1000 mg·L⁻¹. -1 .

[0031] Its application in heavy metal wastewater treatment includes the following steps:

[0032] (1) The hydrophilic graphite oxide particles are added to a heavy metal wastewater system; the concentration of heavy metal ions in the wastewater is 0.1-1000 mg·L⁻¹. -1 ;

[0033] (2) Stir the mixture from step (1) until it is evenly mixed.

[0034] Adding a hydrophilic graphite oxide particle dispersion to heavy metal wastewater can reduce heavy metal ion pollutants and remove toxic species from the wastewater.

[0035] This invention utilizes electrochemistry as a green and pollution-free method to prepare hydrophilic graphite oxide particles. It leverages the numerous oxygen functional groups inherent in the hydrophilic graphite oxide particles, such as hydroxyl (-OH), carboxyl (-COOH), and epoxy (-O-), which endow them with excellent hydrophilicity and chemical reactivity, enabling diverse applications. Furthermore, based on the controllability and ease of operation of the electrochemical method, the size of the hydrophilic graphite oxide particles can be controlled by adjusting the applied voltage or altering the electrolyte composition.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) The electrochemical oxidation method used in this invention is simple, has no special requirements for the synthesis site, and produces no other secondary pollution during the preparation process.

[0038] (2) The synthesis method of hydrophilic graphite oxide particles is simple, easy to promote, and has no toxic side effects on the environment.

[0039] (3) The size of hydrophilic graphite oxide particles can be controlled by adjusting the electrochemical potential, separation methods and electrolyte composition.

[0040] (4) The hydrophilic graphite oxide particle material prepared by the present invention has the characteristic of reduction, which can realize the conversion of high-valence toxic Cr(VI) in water into non-toxic Cr(III).

[0041] (5) The hydrophilic graphite oxide particle material prepared by the present invention has the characteristic of reduction, which can realize the reduction of noble metal ions in water to elemental substances and realize the recovery process of noble metal ions in water. Attached Figure Description

[0042] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0043] Figure 1 This is a TEM image of the graphene oxide particles prepared in Example 1;

[0044] Figure 2 This is a TEM image of the graphene oxide particles prepared in Example 2;

[0045] Figure 3 This is a TEM image of the graphene oxide particles prepared in Example 3;

[0046] Figure 4 This is a diagram showing the effect of dichromate removal in Example 4;

[0047] Figure 5 The XPS spectrum of Cr 2p, a product of the dichromate removal process in Example 4;

[0048] Figure 6 This is a diagram showing the effect of dichromate removal in Example 5;

[0049] Figure 7 The XPS spectrum of Au 4f in the reaction product of Example 6;

[0050] Figure 8 This is a diagram showing the effect of dichromate removal in Comparative Example 1;

[0051] Figure 9 The XPS spectrum of Au 4f in the reaction product of Comparative Example 2;

[0052] Figure 10 TEM image of the graphene product in Comparative Example 3;

[0053] Figure 11 This is a TEM image of the product prepared in Comparative Example 4. Detailed Implementation

[0054] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0055] This invention provides an electrochemical oxidation method for preparing graphite particulate materials. These graphite particulate materials exhibit high dispersibility in aqueous solutions and good hydrophilicity. Furthermore, in wastewater treatment applications, these hydrophilic graphite particulate materials possess certain reducing properties, and their electron-donating ability as an electron donor is 0.01-0.2 mmol·g. -1 .

[0056] The graphite particle material is prepared by using graphite as an electrode and forming a two-electrode electrochemical system with electrolytes such as aqueous solutions. The graphite particle material is then placed in environmental water bodies polluted by heavy metal ions to reduce the toxicity of the water.

[0057] Example 1

[0058] Preparation of oxidized graphite particulate materials:

[0059] Two clean graphite plates (10 cm × 10 cm) were inserted into 1500 mL of electrolyte (pH = 4.5, solvent was water, pH adjusted with hydrochloric acid) to form an electrochemical oxidation system for preparing hydrophilic graphite oxide. The power supply was turned on, and the input voltage for the electrochemical oxidation method was set to 45 V. After power was applied, bubbles were generated on the surfaces of both the positive and negative graphite plates in the electrochemical oxidation system. After a reaction period (15 h), the color of the electrolyte solution changed from colorless and transparent to light brownish-yellow, and finally to yellowish-brown. The electrolyte was filtered through a filter membrane, yielding a bright yellow solution. This solution was centrifuged at 15000 rpm for 45 min, and the supernatant was collected. This supernatant was then centrifuged again at 15000 rpm for 45 min. Hydrophilic graphite particles with a particle size of approximately 40 nm and a concentration of approximately 1500 mg·L⁻¹ were obtained. -1 .

[0060] Figure 1 Scanning transmission electron microscopy (STEM) images of oxidized graphite particles, from... Figure 1 It can be seen that the oxidized graphite particles are uniform in size.

[0061] Example 2

[0062] Preparation of oxidized graphite particulate materials:

[0063] Two clean graphite plates (10 cm × 10 cm) were inserted into 1500 mL of ultrapure water (pH = 7) electrolyte to form an electrochemical oxidation system for preparing hydrophilic graphite oxide materials. The power supply was turned on, and the input voltage for the electrochemical oxidation method was set to 30 V. After power was applied, bubbles were generated on the surfaces of both the positive and negative graphite plates in the electrochemical oxidation system. After a reaction period (20 h), the color of the electrolyte solution changed from colorless and transparent to light brownish-yellow, and finally to yellowish-brown. The electrolyte was filtered using a filter membrane, yielding a bright yellow solution. This solution was centrifuged at 15000 rpm for 45 min, and the supernatant was collected. This was repeated with another centrifugation at 15000 rpm for 45 min, yielding hydrophilic graphite particles with a uniform size of approximately 5 nm and a concentration of approximately 600 mg·L⁻¹. -1 .

[0064] Figure 2 Scanning transmission electron microscopy (STEM) images of oxidized graphite particles, from... Figure 2 It can be seen that the oxidized graphite particles are uniform in size and highly dispersed, with no agglomeration.

[0065] Dichromate removal efficiency test

[0066] Evaluation of the reduction effect of chromate ions in wastewater: The hydrophilic graphite particles from Example 2 were added to the aqueous solution of chromate ions, stirred evenly, and the reaction was initiated. The chromate ion concentration in the solution was determined according to the diphenylcarbazide spectrophotometric method in the national standard GB 7467-87. The specific procedure was as follows: After the reaction started, 1 mL of the reaction solution was taken into a 10 mL colorimetric tube, diluted to 10 mL, and an additional 0.6 mL of deionized water was added as a blank sample. At each determined sampling time point, 1 mL of the reaction solution was taken into a 10 mL colorimetric tube, diluted to 10 mL, and then 100 μL of a 1:1 phosphoric acid solution and 100 μL of a 1:1 sulfuric acid solution were added. Finally, 400 μL of the colorimetric reagent (0.2 g of diphenylcarbazide dissolved in 50 mL of acetone solution and diluted to 100 mL with water) was added. After shaking well, the solution was transferred to a 10 mm cuvette, and the absorbance after subtracting the blank was measured using a UV spectrophotometer. The maximum absorbance value at 540 nm was recorded. The concentration of chromate ions in the solution was calculated using the pre-prepared standard curve. The initial concentration of chromate ions was 2.5-10 mg / L. -1 The concentration of the hydrophilic graphite particles was 300 mg·L⁻¹. -1 The reaction volume was 50 mL, and the initial reaction pH was 3.0.

[0067] Figure 4 The graph shows the reduction effect of mixing hydrophilic graphite particles with chromate solution at different concentration ratios. Figure 4It can be seen that the amount of chromium ions reduced per unit time is positively correlated with the mass concentration of graphite particles, and a unit mass (per gram) of graphite particles can provide 0.07-0.10 mmol of electrons. Figure 5 The XPS results are from a black powder obtained by freeze-drying a solution of graphite particles and chromate solution. The results show that hydrophilic graphite particles can reduce dichromate to Cr(III).

[0068] Test on the recovery effect of precious metal ions in water

[0069] Evaluation of the recovery effect of precious metal ions in water: The hydrophilic graphite particles from Example 2 were added to an aqueous solution of chloroaurate ions, stirred evenly, and the reaction was initiated. The mass concentration of the precious metal Au(III) was 500 mg·L⁻¹. -1 The mass concentration of the graphite particulate material is 1000 mg·L⁻¹. -1 The reaction volume was 25 mL, and the pH was 3.0. After mixing graphite particles with chloroauric acid for 48 hours, the mixture was freeze-dried to obtain a dry black powder.

[0070] Figure 7 The image shows the X-ray photoelectron spectroscopy (XPS) test results of the freeze-dried sample. The test results show that the XPS test only detected the signal peak of elemental Au. After the graphite particles react with chloroauric acid, chloroauric acid can be reduced to elemental gold.

[0071] Example 3

[0072] Preparation of oxidized graphite particulate materials:

[0073] Two clean graphite plates (10 cm × 10 cm) were inserted into 1500 mL of simulated groundwater (KCl = 1 mmol·L⁻¹). -1 NaHCO3 = 2 mmol·L -1 MgSO4 = 0.5 mmol·L -1 CaCl2 = 0.5 mmol·L -1 In the electrolyte, an electrochemical oxidation system for preparing hydrophilic graphite oxide materials was constructed. The power supply was turned on, and the input voltage for the electrochemical oxidation method was set to 30V. After energization, bubbles were generated on the surfaces of the positive and negative graphite plates in the electrochemical oxidation system. After a period of reaction (10 hours), the color of the electrolyte solution changed from colorless and transparent to light brownish-yellow, and finally to yellowish-brown. The electrolyte was filtered using a filter membrane, yielding a bright yellow solution. This solution was centrifuged at 15000 rpm for 45 minutes, and the supernatant was collected to obtain hydrophilic graphite particles with a particle size of approximately 10 nm. Figure 3 ).

[0074] Evaluation of the reduction effect of chromate ions in wastewater:

[0075] The hydrophilic graphite particles from Example 3 were added to an aqueous solution of chromate ions and stirred until homogeneous to initiate the reaction. The concentration of chromate ions in the solution was determined using the diphenylcarbazide spectrophotometric method according to the national standard GB 7467-87, following the same procedure as in Example 4. The initial concentration of chromate ions was 2.5 mg·L⁻¹. -1 The concentration of hydrophilic graphite particles is 1000-3000 mg·L⁻¹. -1 The reaction volume was 50 mL, and the initial reaction pH was 3.0.

[0076] Figure 6 This is a graph showing the reduction effect of chromate solution. (From...) Figure 6 It is known that graphite particles have reducing properties, and the amount of chromium ions reduced per unit time is positively correlated with the mass concentration of the graphite particles.

[0077] Comparative Example 1

[0078] Evaluation of the reduction effect of chromate ions in wastewater: Commercial graphite powder was used to replace the hydrophilic graphite particles in Application Example 1, while other experimental conditions remained consistent with Application Example 1. Figure 8 It can be seen that the concentration of chromate ions in the solution hardly changes as the reaction time progresses, indicating that commercial graphite powder does not have the ability to reduce chromate ions.

[0079] Comparative Example 2

[0080] Replace the hydrophilic graphite particles in Application Example 2 with commercial graphite powder, while keeping other experimental conditions the same as in Example 6. Figure 9 The image shows the XPS test results after mixing. As can be seen from the test results, only the Au(III) signal peak was detected by the XPS test, indicating that the graphite powder material cannot reduce chloroauric acid to elemental gold after mixing with chloroauric acid.

[0081] Examples 4-7

[0082] The preparation method is basically the same as that in Example 1, except that the electrolyte and its concentration, voltage and other parameters are shown in Table 1.

[0083] Comparative Examples 3-4

[0084] The preparation method is basically the same as that in Example 1, except that the electrode solution and its concentration, voltage and other parameters are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] The oxidized graphite particles obtained in Examples 1, 4, and 5 had a particle size of approximately 40 nm, as determined by dynamic light scattering. The results of Examples 3, 6, and 7 showed that the higher the applied voltage and the greater the system current, the larger the particle size of the separated oxidized graphite particles. In Comparative Example 3, the electrolyte was changed to 0.2 mol·L⁻¹. -1 The sulfuric acid solution, and other operating methods are the same as in Example 3, such as... Figure 10 As shown, the obtained product is an ultrathin graphene film. In Comparative Example 4, the voltage was too low, and the product appeared as a graphene thin film. Figure 11 ).

[0089] This invention discloses an electrochemical oxidation method for preparing hydrophilic graphite oxide particles of different sizes and their applications. Graphite material electrodes are used as positive and negative electrodes, and a potentiostatic method is employed to prepare the graphite oxide particles. The prepared graphite oxide particles exhibit high hydrophilicity and can also be used for the remediation of environmental wastewater, such as in the reduction of heavy metal ions.

[0090] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. Use of a hydrophilic graphite oxide particulate material for the reduction of heavy metal ions, characterized in that, The hydrophilic graphite oxide particle material is prepared by the following method: S1, selecting graphite as an anode, inserting the anode and a cathode into an electrolyte, and electrolyzing under a constant potential; S2, after electrolysis is completed, filtering the obtained electrolytic solution, and centrifugally separating the filtrate to obtain the hydrophilic graphite oxide particle material; In step S1, the electrolyte includes one or more of ultrapure water, an acid solution, a base solution, and a salt solution; the pH of the ultrapure water, the acid solution, and the base solution is 1-12; the solubility of the salt solution is not more than 5 mmol / L; the acid solution is one or more of a hydrochloric acid solution and an acetic acid solution; the base solution is one or more of a sodium hydroxide solution and ammonia water; and the salt solution is one or more of a sodium chloride solution, a potassium chloride solution, a sodium bicarbonate solution, a magnesium sulfate solution, a calcium chloride solution, a sodium acetate solution, and a sodium carbonate solution; In step S1, the voltage of electrolysis is 25-60 V; and the electrode spacing is 6-10 cm; In step S2, the size range of the obtained hydrophilic graphite oxide particle material is 3-80 nm.

2. Use according to claim 1, characterized in that, The heavy metal ions include one or more of dichromate ions, chloroaurate ions, and permanganate ions.

3. Use according to claim 1, characterized in that, The application includes the following steps: adding the hydrophilic graphite oxide particle material to a water body containing heavy metal ions, and stirring and uniformly mixing.

4. Use according to claim 1, characterized in that, In step S2, the centrifugal rotation speed is 1000-15000 rpm, and the centrifugal time is 10-60 min.

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