Preparation method and application of surface functionalized porous carbon

Abstract

The invention provides a preparation method and application of surface functionalized porous carbon, and belongs to the technical field of carbon materials.The preparation method comprises the following steps that wheat straw is cleaned, dried, smashed and sieved, and straw powder is obtained; putting the straw powder and an ammonium chloride aqueous solution into a steam explosion device, performing steam explosion treatment, performing pressure relief, taking out the straw powder and the ammonium chloride aqueous solution, and drying the straw powder and the ammonium chloride aqueous solution to obtain pretreated straw; putting the pretreated straws into a muffle furnace, calcining in a nitrogen atmosphere, and cooling to obtain biochar; the preparation method comprises the following steps: uniformly mixing porous carbon, diatomite and phenolic resin, then spraying a modifier aqueous solution, then putting the mixture into a ball mill for ball milling treatment, taking out and drying to obtain modified charcoal; and putting the modified biochar into a muffle furnace, calcining in a nitrogen atmosphere, and cooling to obtain the surface functionalized porous carbon. The surface-functionalized porous carbon prepared by the method has excellent adsorption performance, can efficiently remove nitrogen and phosphorus in wastewater, and is widely applied to purification and restoration of water bodies.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon materials, and in particular relates to a preparation method and application of surface functionalized porous carbon. Background Art

[0002] Porous carbon is a carbon material with rich pore structures. These pores can exist at different levels from nanoscale to macroscale. According to the pore size, porous carbon can be further subdivided into microporous carbon (pore size less than 2 nanometers), mesoporous carbon (pore size between 2 and 50 nanometers) and macroporous carbon (pore size greater than 50 nanometers). The pore structure of porous carbon materials gives them unique physical and chemical properties, such as large specific surface area, good chemical stability, controllable pore size and distribution, etc. The pore structure of porous carbon materials is the key to their performance. The size, shape, distribution and connectivity of the pores will directly affect the performance indicators of the material such as adsorption capacity, diffusion rate, mechanical strength, etc. Based on the above characteristics of porous carbon materials, they show broad application prospects in energy storage and conversion such as supercapacitors, lithium-ion batteries, environmental protection such as pollutant adsorption, heavy metal removal, biomedicine such as drug carriers, tissue engineering scaffolds and other fields.

[0003] Nitrogen and phosphorus pollutants in water bodies are usually phosphates (PO4 3- ), nitrate (NO3 - ) and other forms, and nitrogen and phosphorus pollution often occurs at the same time. Excessive nitrogen and phosphorus can lead to eutrophication of water bodies, promote excessive growth of algae, and thus affect water quality and even cause an imbalance in the ecosystem. In this case, it is crucial to find an effective purification method. As an important adsorption material, porous carbon has shown great potential in water purification and remediation due to its unique pore structure and large specific surface area. However, for negatively charged groups such as phosphate and nitrate, the adsorption capacity of porous carbon is relatively weak, because the surface of porous carbon is usually also negatively charged, which leads to electrostatic repulsion between charges of the same kind, reducing the adsorption efficiency.

[0004] In order to solve the above problems, the existing technology modifies the surface of porous carbon by chemical methods, introduces functional groups, and enhances its chemical affinity with nitrogen and phosphorus; or loads metal ions on porous carbon, uses these metal ions to form precipitation with phosphorus, and improves adsorption efficiency; or prepares composite materials of porous carbon and other materials such as zeolite, clay minerals, etc., and uses these materials for the good adsorption performance of nitrogen and phosphorus. Through these improvement measures, the adsorption efficiency of porous carbon materials for nitrogen and phosphorus in water purification can be improved to a certain extent. However, the above modification methods are often complicated and costly, and the adsorption capacity of porous carbon is limited and regeneration and recovery are difficult, which still cannot meet the needs of the existing market. Therefore, there is an urgent need for a surface functionalized porous carbon with excellent adsorption performance that can efficiently remove nitrogen and phosphorus from wastewater. Summary of the invention

[0005] The purpose of the present invention is to provide a surface functionalized porous carbon, which can efficiently remove nitrogen and phosphorus from wastewater, and the preparation method thereof is simple and easy to industrialize.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing surface functionalized porous carbon comprises the following steps:

[0008] Step I: washing and drying the wheat straw, crushing and sieving to obtain straw powder; placing the straw powder and ammonium chloride aqueous solution in a steam explosion device, performing steam explosion treatment, and drying to obtain pretreated straw; placing the pretreated straw in a muffle furnace, calcining, and cooling to obtain biochar;

[0009] Step II, mix the biochar, diatomaceous earth and phenolic resin evenly, then spray the modifier aqueous solution, place them in a ball mill for ball milling, take them out and dry them to obtain modified biochar; put the modified biochar into a muffle furnace, calcine, and cool them to obtain the surface functionalized porous carbon.

[0010] Preferably, a method for preparing surface functionalized porous carbon comprises the following steps:

[0011] Step I, washing and drying the wheat straw, crushing and sieving to obtain straw powder; placing 50-70 parts by weight of the straw powder and 60-80 parts by weight of an aqueous solution of ammonium chloride in a steam explosion device, performing steam explosion treatment, releasing the pressure, taking out and drying to obtain pretreated straw; placing the pretreated straw in a muffle furnace, calcining under a nitrogen atmosphere, and cooling to obtain biochar;

[0012] Step II, 10-30 parts by weight of biochar, 0.1-0.4 parts by weight of diatomaceous earth and 0.1-0.3 parts by weight of phenolic resin are uniformly mixed, and then 3-5 parts by weight of a modifier aqueous solution are sprayed, and then placed in a ball mill for ball milling treatment, taken out and dried to obtain modified biochar; the modified biochar is placed in a muffle furnace, calcined under a nitrogen atmosphere, and cooled to obtain the surface functionalized porous carbon.

[0013] The invention uses wheat straw, a renewable agricultural resource, as a raw material, and performs steam explosion (steam explosion) treatment by adding an ammonium chloride aqueous solution to loosen the straw structure and increase its porosity. This process can not only make the straw structure more fluffy, but also the ammonium radical groups adsorbed on the surface of the straw fiber act as an etchant of the microporous structure in the subsequent high-temperature calcination, helping to form carbon-nitrogen-carbon bonds and amine functional groups. These amine functional groups can stabilize the metal nano-oxides formed by the modifiers (cerium salts and iron salts) through coordination, firmly bonding them to the microporous structure, thereby improving the adsorption capacity and recycling rate of the porous carbon. Moreover, during the high-temperature calcination, a part of the ammonium radical groups decompose to generate ammonia and react with carbon, which helps to form a porous carbon material with high porosity, further enhancing its physical adsorption capacity, and achieving the removal of nitrogen and phosphorus at the same time.

[0014] In order to further improve the adsorption performance, the present invention uses diatomite, phenolic resin and modifier (cerium salt and iron salt) to perform porous molding and surface functionalization modification on homemade biochar, which effectively overcomes the problem that the porous carbon prepared by the existing method has low adsorption capacity and is prone to secondary pollution in water purification. Among them, diatomite, as an inorganic synergistic material, not only plays the role of bonding molding, but also can assist in loading metal nano-oxides, enhancing the overall structural stability and adsorption performance of the adsorbent material. Phenolic resin forms a stable carbon skeleton during high-temperature calcination as a binder, and its rich macropores provide more contact sites for the adsorbent, enhancing the surface binding force of the adsorbent material. The modifier (cerium salt and iron salt) is uniformly dispersed on the inner and outer surfaces of the porous structure by wet ball milling, and metal nano-oxides can be generated in situ on the material structure during high-temperature calcination. In addition, the modifier also has the effect of activating diatomite, thereby further expanding the specific surface area of ​​the adsorbent material and increasing the adsorption active sites.

[0015] Furthermore, a method for preparing surface functionalized porous carbon comprises the following steps:

[0016] Step I, washing and drying the wheat straw, crushing it through a 150-300 mesh sieve to obtain straw powder; placing 50-70 parts by weight of the straw powder and 60-80 parts by weight of an aqueous solution of ammonium chloride in a steam explosion device, steam explosion treating for 4-8 minutes, releasing the pressure, taking it out and drying it to obtain pretreated straw; placing the pretreated straw in a muffle furnace, calcining it in a nitrogen atmosphere for 120-180 minutes, and cooling it to room temperature to obtain biochar;

[0017] Step II, 10-30 parts by weight of biochar, 0.1-0.4 parts by weight of diatomaceous earth and 0.1-0.3 parts by weight of phenolic resin are mixed evenly, and then 3-5 parts by weight of a modifier aqueous solution are sprayed, and then placed in a ball mill for ball milling for 30-50 minutes, taken out and dried to obtain modified biochar; the modified biochar is placed in a muffle furnace, calcined for 100-150 minutes in a nitrogen atmosphere, and cooled to room temperature to obtain the surface functionalized porous carbon.

[0018] Preferably, the concentration of the aqueous ammonium chloride solution in step I is 22-26 wt %.

[0019] Preferably, the conditions for the steam explosion treatment in step I are: pressure 1-2 MPa, temperature 80-100°C.

[0020] Preferably, the calcination temperature in step I is 500-600°C.

[0021] Preferably, the ball milling speed in step II is 300-400 rpm.

[0022] Preferably, the calcination temperature in step II is 400-500°C.

[0023] Preferably, the aqueous modifier solution consists of cerium chloride, ferric chloride and water.

[0024] Furthermore, the modifier aqueous solution consists of 4-6wt% cerium chloride, 8-12wt% ferric chloride and the balance water.

[0025] Furthermore, the average particle size of the diatomaceous earth is 15-18 μm.

[0026] Furthermore, the viscosity of the phenolic resin is 5200-5600 mPa·s (25° C.).

[0027] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0028] 1. The present invention provides a preparation method and application of surface functionalized porous carbon. The prepared surface functionalized porous carbon has excellent adsorption capacity, stable performance, will not cause secondary pollution, can efficiently remove nitrogen and phosphorus in wastewater, and its preparation method is simple and easy to industrialize.

[0029] 2. The present invention pretreats wheat straw by using an aqueous solution of ammonium chloride combined with steam explosion, which not only makes the straw structure more fluffy, but also the ammonium groups adsorbed on the surface of the straw fibers act as an etchant for the microporous structure during subsequent high-temperature calcination, helping to form carbon-nitrogen-carbon bonds and amine functional groups, stabilizing the metal nano-oxides formed by the modifiers (cerium salts and iron salts), and during high-temperature calcination, a portion of the ammonium groups decompose to produce ammonia and react with carbon, which helps to form a porous carbon material with high porosity, further enhancing its physical adsorption capacity.

[0030] 3. The present invention uses diatomaceous earth, phenolic resin and modifiers (cerium salts and iron salts) to perform porous molding and surface functionalization modification on homemade biochar. The diatomaceous earth not only plays a role in bonding and molding, but also can assist in loading metal nano-oxides, thereby enhancing the overall structural stability and adsorption performance of the adsorption material; the phenolic resin forms a stable carbon skeleton during high-temperature calcination, thereby enhancing the surface binding force of the adsorption material; the modifiers (cerium salts and iron salts) can generate metal nano-oxides in situ on the material structure during high-temperature calcination, and also have the function of activating diatomaceous earth, thereby expanding the specific surface area of ​​the adsorption material and increasing the adsorption active sites, thereby effectively overcoming the problems of low adsorption capacity and easy secondary pollution of porous carbon prepared by existing methods in water purification treatment. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a method for preparing surface functionalized porous carbon, comprising the following steps:

[0034] Step I, washing and drying the wheat straw, crushing it through a 150-mesh sieve to obtain straw powder; placing 50 parts by weight of the straw powder and 60 parts by weight of a 22wt% ammonium chloride aqueous solution into a steam explosion device, steam-exploding it at 1MPa and 80°C for 8 minutes, releasing the pressure, taking it out and drying it to obtain pretreated straw; placing the pretreated straw into a muffle furnace, calcining it at 500°C in a nitrogen atmosphere for 180 minutes, and cooling it to room temperature to obtain biochar;

[0035] Step II, mix 10 parts by weight of biochar, 0.1 parts by weight of diatomaceous earth and 0.1 parts by weight of phenolic resin, then spray 3 parts by weight of modifier aqueous solution, and then place it in a planetary ball mill for 30 minutes, the ball mill speed is 400rpm, take it out and dry it to obtain modified biochar; the modifier aqueous solution is composed of 4wt% cerium chloride, 8wt% ferric chloride and the balance water; put the modified biochar into a muffle furnace, calcine it at 400℃ in a nitrogen atmosphere for 150 minutes, cool it to room temperature, and obtain the surface functionalized porous carbon. Among them, diatomaceous earth has an average particle size of 17μm and a bulk density of 0.42g / cm 3 The phenolic resin used was phenolic resin PF9501, with free phenol content of 14.46%, solid content of 57%, viscosity of 5400 mPa·s (25° C.), and pH of 7.90.

[0036] Example 2

[0037] This embodiment provides a method for preparing surface functionalized porous carbon, comprising the following steps:

[0038] Step I, washing and drying the wheat straw, crushing it through a 200-mesh sieve to obtain straw powder; placing 60 parts by weight of the straw powder and 70 parts by weight of a 24wt% ammonium chloride aqueous solution into a steam explosion device, steam-exploding it at 1.5MPa and 90°C for 6 minutes, releasing the pressure, taking it out and drying it to obtain pretreated straw; placing the pretreated straw into a muffle furnace, calcining it at 550°C in a nitrogen atmosphere for 150 minutes, and cooling it to room temperature to obtain biochar;

[0039] Step II, mix 20 parts by weight of biochar, 0.3 parts by weight of diatomaceous earth and 0.2 parts by weight of phenolic resin, then spray 4 parts by weight of modifier aqueous solution, and then place it in a planetary ball mill for 40 minutes, the ball mill speed is 350rpm, take it out and dry it to obtain modified biochar; the modifier aqueous solution is composed of 5wt% cerium chloride, 10wt% ferric chloride and the balance water; put the modified biochar into a muffle furnace, calcine it at 450℃ in a nitrogen atmosphere for 120 minutes, cool it to room temperature, and obtain the surface functionalized porous carbon. Among them, diatomaceous earth has an average particle size of 17μm and a bulk density of 0.42g / cm 3 The phenolic resin used was phenolic resin PF9501, with free phenol content of 14.46%, solid content of 57%, viscosity of 5400 mPa·s (25° C.), and pH of 7.90.

[0040] Example 3

[0041] This embodiment provides a method for preparing surface functionalized porous carbon, comprising the following steps:

[0042] Step I, washing and drying the wheat straw, crushing it through a 300-mesh sieve to obtain straw powder; placing 70 parts by weight of the straw powder and 80 parts by weight of a 26wt% ammonium chloride aqueous solution into a steam explosion device, steam-exploding it at 2MPa and 100°C for 4 minutes, releasing the pressure, taking it out and drying it to obtain pretreated straw; placing the pretreated straw into a muffle furnace, calcining it at 600°C in a nitrogen atmosphere for 120 minutes, and cooling it to room temperature to obtain biochar;

[0043] Step II, mix 30 parts by weight of biochar, 0.4 parts by weight of diatomaceous earth and 0.3 parts by weight of phenolic resin, then spray 5 parts by weight of modifier aqueous solution, and then place it in a planetary ball mill for 50 minutes, the ball mill speed is 300rpm, take it out and dry it to obtain modified biochar; the modifier aqueous solution is composed of 6wt% cerium chloride, 12wt% ferric chloride and the balance water; put the modified biochar into a muffle furnace, calcine it at 500℃, nitrogen atmosphere for 100 minutes, cool it to room temperature, and obtain the surface functionalized porous carbon. Among them, diatomaceous earth has an average particle size of 17μm and a bulk density of 0.42g / cm 3 The phenolic resin used was phenolic resin PF9501, with free phenol content of 14.46%, solid content of 57%, viscosity of 5400 mPa·s (25° C.), and pH of 7.90.

[0044] Comparative Example 1

[0045] The difference between this comparative example and Example 2 is that step I in the preparation method of the surface functionalized porous carbon is different, which is as follows: the wheat straw is washed and dried, and crushed through a 200-mesh sieve to obtain straw powder; the straw powder is placed in a muffle furnace, calcined at 550° C. in a nitrogen atmosphere for 150 min, and cooled to room temperature to obtain biochar.

[0046] Comparative Example 2

[0047] The difference between this comparative example and Example 2 is that step I in the preparation method of the surface functionalized porous carbon is different, which is as follows: the wheat straw is washed and dried, and crushed through a 200-mesh sieve to obtain straw powder; 60 parts by weight of the straw powder and 70 parts by weight of a 24wt% ammonium chloride aqueous solution are mixed evenly, allowed to stand, and dried to obtain pretreated straw; the pretreated straw is placed in a muffle furnace, calcined at 550°C in a nitrogen atmosphere for 150 minutes, and cooled to room temperature to obtain biochar.

[0048] Comparative Example 3

[0049] The difference between this comparative example and Example 2 is that no diatomaceous earth is added in step II of the preparation method of the surface functionalized porous carbon, which is specifically as follows: 20 parts by weight of biochar and 0.2 parts by weight of phenolic resin are evenly mixed, then sprayed with 4 parts by weight of a modifier aqueous solution, and then placed in a planetary ball mill for ball milling for 40 minutes at a ball mill speed of 350 rpm, taken out and dried to obtain modified biochar; the modifier aqueous solution consists of 5wt% cerium chloride, 10wt% ferric chloride and the remainder water; the modified biochar is placed in a muffle furnace, calcined at 450°C in a nitrogen atmosphere for 120 minutes, and cooled to room temperature to obtain the surface functionalized porous carbon.

[0050] Comparative Example 4

[0051] The difference between this comparative example and Example 2 is that no phenolic resin is added in step II of the preparation method of the surface functionalized porous carbon, which is specifically as follows: 20 parts by weight of biochar and 0.3 parts by weight of diatomaceous earth are evenly mixed, and then 4 parts by weight of a modifier aqueous solution are sprayed, and then placed in a planetary ball mill for ball milling for 40 minutes at a ball mill speed of 350 rpm, and then taken out and dried to obtain modified biochar; the modifier aqueous solution consists of 5wt% cerium chloride, 10wt% ferric chloride and the remainder water; the modified biochar is placed in a muffle furnace, calcined at 450°C in a nitrogen atmosphere for 120 minutes, and cooled to room temperature to obtain the surface functionalized porous carbon.

[0052] Comparative Example 5

[0053] The difference between this comparative example and Example 2 is that the aqueous modifier solution in step II consists of 15wt% cerium chloride and the balance water, specifically as follows: 20 parts by weight of biochar, 0.3 parts by weight of diatomaceous earth and 0.2 parts by weight of phenolic resin are evenly mixed, then sprayed with 4 parts by weight of the aqueous modifier solution, and then placed in a planetary ball mill for ball milling for 40 minutes at a ball milling speed of 350rpm, taken out and dried to obtain modified biochar; the aqueous modifier solution consists of 15wt% cerium chloride and the balance water; the modified biochar is placed in a muffle furnace, calcined at 450°C in a nitrogen atmosphere for 120 minutes, and cooled to room temperature to obtain the surface functionalized porous carbon.

[0054] Comparative Example 6

[0055] The difference between this comparative example and Example 2 is that the modifier aqueous solution in step II consists of 15wt% ferric chloride and the balance water, specifically as follows: 20 parts by weight of biochar, 0.3 parts by weight of diatomaceous earth and 0.2 parts by weight of phenolic resin are evenly mixed, then sprayed with 4 parts by weight of the modifier aqueous solution, and then placed in a planetary ball mill for ball milling for 40 minutes, the ball milling speed is 350rpm, and then taken out and dried to obtain modified biochar; the modifier aqueous solution consists of 15wt% ferric chloride and the balance water; the modified biochar is placed in a muffle furnace, calcined at 450°C in a nitrogen atmosphere for 120 minutes, and cooled to room temperature to obtain the surface functionalized porous carbon.

[0056] Performance Testing

[0057] The adsorption performance of the surface functionalized porous carbon obtained in the above Examples 1-3 and Comparative Examples 1-6 was determined by a wastewater purification test. The specific method is as follows: 0.15 parts by weight of the surface functionalized porous carbon was added to 500 parts by weight of wastewater (NO3 - The concentration is 100mg / L, PO4 3- The concentration was 200 mg / L) and the adsorption test was carried out at room temperature and 100 rpm shaking conditions. The adsorption time was 1-24 hours with an interval of 1 hour. After sampling and filtration, the NO3 in the filtrate was determined. - PO4 3- The concentrations of , and the removal rates were calculated respectively. The results are shown in Table 1.

[0058] Table 1 Performance test results

[0059]

[0060] It can be seen from the above performance test results that the surface functionalized porous carbon prepared in Examples 1-3 has excellent adsorption capacity and stable performance, and can efficiently remove nitrogen and phosphorus in wastewater. In particular, the comprehensive performance of Example 2 is the most outstanding. This is mainly because the present invention pretreats wheat straw by using an aqueous ammonium chloride solution combined with steam explosion, which helps to form a porous carbon material with high porosity and enhances the adsorption capacity. In addition, diatomaceous earth, phenolic resin and modifiers (cerium salts and iron salts) are used to perform porous molding and surface functionalization modification on the homemade biochar, which effectively overcomes the problem of low adsorption capacity of existing porous carbon, and can efficiently adsorb and remove nitrogen and phosphorus in wastewater.

[0061] However, the comparative examples were significantly inferior to the embodiments in the corresponding performance tests because they did not adopt the necessary technical solutions. In comparative examples 1-2, ammonium chloride aqueous solution combined with steam explosion was not used to pretreat the wheat straw, and it can be seen that the adsorption and removal effects of nitrogen and phosphorus decreased, proving that the above-mentioned technical means have an important influence on its effects. In comparative examples 3-5, diatomaceous earth, phenolic resin or modifiers (cerium salts and iron salts) were not used to perform surface functionalization modification on the homemade biochar. From the results, it can be seen that this leads to a decrease in the adsorption and removal effects of porous carbon on nitrogen and phosphorus. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0062] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing surface functionalized porous carbon, characterized in that: The following steps are involved: Step I, washing and drying the wheat straw, crushing and sieving to obtain straw powder; placing 50-70 parts by weight of the straw powder and 60-80 parts by weight of an aqueous solution of ammonium chloride into a steam explosion device, performing steam explosion treatment, releasing the pressure, taking out and drying to obtain pretreated straw; The pretreated straw is placed in a muffle furnace, calcined under a nitrogen atmosphere, and cooled to obtain biochar; Step II, 10-30 parts by weight of biochar, 0.1-0.4 parts by weight of diatomaceous earth and 0.1-0.3 parts by weight of phenolic resin are uniformly mixed, and then 3-5 parts by weight of a modifier aqueous solution are sprayed, and then placed in a ball mill for ball milling treatment, taken out and dried to obtain modified biochar; the modified biochar is placed in a muffle furnace, calcined under a nitrogen atmosphere, and cooled to obtain the surface functionalized porous carbon.

2. The method for preparing surface functionalized porous carbon according to claim 1, characterized in that: The following steps are involved: Step I: washing and drying the wheat straw, crushing it through a 150-300 mesh sieve to obtain straw powder; placing 50-70 parts by weight of the straw powder and 60-80 parts by weight of an aqueous solution of ammonium chloride into a steam explosion device, steam-exploding it for 4-8 minutes, releasing the pressure, taking it out and drying it to obtain pretreated straw; The pretreated straw was placed in a muffle furnace, calcined for 120-180 min under a nitrogen atmosphere, and cooled to room temperature to obtain biochar; Step II, 10-30 parts by weight of biochar, 0.1-0.4 parts by weight of diatomaceous earth and 0.1-0.3 parts by weight of phenolic resin are mixed evenly, and then 3-5 parts by weight of a modifier aqueous solution are sprayed, and then placed in a ball mill for ball milling for 30-50 minutes, taken out and dried to obtain modified biochar; the modified biochar is placed in a muffle furnace, calcined for 100-150 minutes in a nitrogen atmosphere, and cooled to room temperature to obtain the surface functionalized porous carbon.

3. The method for preparing surface functionalized porous carbon according to claim 1, characterized in that: The modifier aqueous solution consists of cerium chloride, ferric chloride and water.

4. The method for preparing surface functionalized porous carbon according to claim 3, characterized in that: The modifier aqueous solution consists of 4-6 wt % of cerium chloride, 8-12 wt % of ferric chloride and the balance of water.

5. The method for preparing surface functionalized porous carbon according to claim 1, characterized in that: The concentration of the aqueous ammonium chloride solution in step I is 22-26 wt %.

6. The method for preparing surface functionalized porous carbon according to claim 1, characterized in that: The conditions of the steam explosion treatment in step I are: pressure 1-2 MPa, temperature 80-100°C.

7. The method for preparing surface functionalized porous carbon according to claim 1, characterized in that: The calcination temperature in step I is 500-600°C.

8. The method for preparing surface functionalized porous carbon according to claim 1, characterized in that: The calcination temperature in step II is 400-500°C.

9. A surface functionalized porous carbon, characterized in that: Prepared according to the method according to any one of claims 1 to 8.

10. Use of the surface functionalized porous carbon according to claim 9 as an adsorption material in water treatment.

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