Preparation method and application of self-supporting iron-nickel-boron loaded nickel foam composite material

Abstract

The application discloses a preparation method and application of a self-supporting iron-nickel-boron loaded foam nickel composite material, and comprises the following steps: foam nickel is alternately immersed into a reducing agent solution and an iron precursor solution by using an alternate immersion method, metal ions are caused to self-catalytically grow iron-nickel-boron on the surface of the foam nickel, and thus the self-supporting iron-nickel-boron loaded foam nickel composite material is obtained. The composite material can be used for assembling a catalyst module, activating a periodate, and realizing complete degradation of chlorophenol compounds. The self-supporting composite material prepared by the application has high catalytic activity and stability, and the active component is uniformly and firmly distributed, a catalyst module based on the self-supporting composite material effectively avoids separation and recovery difficulties of a powder catalyst in actual application, is convenient for modular management and large-scale amplification, has a wide application prospect, and is especially suitable for use in the field of environmental engineering technology.

Description

Technical Field

[0001] The invention relates to a preparation method of a self-supporting iron-nickel-boron loaded nickel foam composite material and application of the composite material in treating chlorophenol organic pollutants with heterogeneous activated periodate, belonging to the technical field of environmental engineering. Background Art

[0002] Chlorophenols (CPs) are a general term for chlorine-substituted phenol compounds, whose basic structure consists of chlorine replacing a hydrogen atom on a benzene ring. Chlorophenols have strong endocrine disrupting potential, genotoxicity, bioaccumulation ability, cytotoxicity, and carcinogenicity. Some intermediates of chlorophenols are even more toxic. Due to the high chemical inertness of the C-Cl bond on the aromatic ring, traditional removal methods often lack efficiency, selectivity, and environmental sustainability. Therefore, the development of effective chlorophenol removal technologies is crucial. In this regard, advanced oxidation processes based on periodate (PI) are widely used to remove stubborn organic pollutants due to their ease of operation and strong oxidizing ability. However, due to the relatively low redox potential of periodate (+1.6 eV), its ability to oxidize organic pollutants is limited. Generally, periodate can be activated by ultraviolet light, ultrasound, sunlight, microwaves, freezing, transition metal compounds, etc. to generate reactive species or degrade pollutants through non-radical pathways. However, these methods have the disadvantages of high energy input, secondary pollution (such as metal leaching), and inherent defects in the free radical activation pathway (susceptibility to interference in aqueous environments), which limit their application in periodate activation processes. Therefore, the development of catalysts with higher activity and stability is the key to the widespread application of periodate.

[0003] Boron, a metalloid element located between beryllium and carbon in the periodic table, possesses a remarkable ability to bind to a variety of metals and nonmetals. Currently, boron-based catalysts have shown great potential in advanced oxidation processes. To improve the catalytic performance of boron-based catalysts, researchers have developed a variety of approaches, including compositional modification, active species hybridization, and structural engineering. Compared to monometallic borides, bimetallic borides have attracted widespread attention due to their enhanced catalytic performance. Multimetallic coordination enhances electronic conductivity and promotes the formation of abundant active sites, which facilitates catalytic applications. In particular, iron-nickel borides exhibit excellent catalytic activity due to their ease of synthesis through simple chemical processes and their ability to operate stably over a wide pH range. However, existing preparation methods for bimetallic borides are often complex and time-consuming, which may negatively impact catalytic performance. Furthermore, the vigorous reactions during the reaction process can easily lead to agglomeration, making catalyst recovery difficult, further limiting their widespread and economical application.

[0004] To address this problem, one strategy is to load the boride onto a structured support with a high specific surface area and rich pore structure. This not only achieves effective fixation of the boride, but also fully utilizes the structural advantages of the support. Nickel foam materials have become ideal materials for treating organic pollutants due to their excellent mechanical properties, uniform pore distribution, chemical stability, good corrosion resistance, and excellent anti-clogging properties. Although the use of a support is a good strategy, traditional preparation methods generally require additional binding materials and are complex to operate, which is not only time-consuming but also detrimental to improving catalytic performance. For example, patent CN109119257A proposes a method for directly depositing iron, cobalt, and boron on nickel foam using a chemical reduction method. This method first pre-treats the nickel foam with hydrochloric acid, then immerses it in a transition metal salt solution, and quickly drips a reducing solution for reduction deposition. Although the chemical reduction method is simple, the resulting deposits often aggregate, resulting in uneven loading, reduced specific surface area, and reduced catalytic activity. In addition, the resulting cobalt-iron boride material is physically coated on the surface of the nickel foam, rather than growing directly on the nickel foam, making it difficult to prevent the deposit from falling off and ion leaching during the reaction. Patent CN117684201A discloses a method for preparing a porous nickel-molybdenum material that is in-situ loaded with a dual-phase boride. This method first prepares a porous nickel-molybdenum alloy substrate by etching, then reacts it with boron powder, and uses a solid-phase boronization process to synthesize a Mo2NiB2 / Ni3B dual-phase boride on the substrate surface. Although this method can achieve dual-phase boride loading, it is complex, takes a long time to synthesize, consumes a lot of energy, and may cause environmental pollution and high costs, limiting its feasibility for large-scale synthesis.

[0005] In summary, although there are many methods for developing efficient boron-based catalysts to improve their catalytic performance, these methods generally have the disadvantages of pollution problems, cumbersome operations, high raw material costs and high energy consumption, which limit their efficiency and economy in practical applications. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention provides a method for preparing a self-supporting iron-nickel-boron-loaded nickel foam composite material and applies it to the treatment of chlorophenol-based organic pollutants using heterogeneous activated periodate. The present invention aims to address the following technical issues: the difficulty in separating and recovering powdered catalysts; the poor catalytic effect of the overall catalyst, uneven distribution of active components, weak self-supporting capacity, high energy consumption during the preparation process, and high ion leaching; as well as the need for simple and efficient treatment of organic pollutants.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] A method for preparing a self-supporting iron-nickel-boron-loaded nickel foam composite material is characterized by first removing the oxide layer and impurities on the surface of the nickel foam through pretreatment, then alternately immersing the nickel foam in a reducing agent solution and an iron precursor solution using an alternating immersion method to promote the autocatalytic growth of iron-nickel boride by metal ions on the surface of the nickel foam, ultimately obtaining a self-supporting iron-nickel-boron-loaded nickel foam composite material. The specific steps are as follows:

[0009] Step 1: Cut the nickel foam into appropriate sizes, place it in a hydrochloric acid solution for treatment, then wash it with deionized water and anhydrous ethanol in sequence, and finally place it in a drying oven to dry.

[0010] Step 2: dissolving an iron salt in deionized water to prepare a 10-20 wt% iron precursor solution; dissolving sodium borohydride in deionized water to prepare a 5-10 wt% reducing agent solution, and adjusting the pH of the solution to greater than 10 using 0.1-1.0 M sodium hydroxide to prevent self-decomposition of the sodium borohydride.

[0011] Step 3: Immerse the nickel foam in a reducing agent solution, and let it stand for 10-20 seconds after bubbles are observed; then quickly immerse it in an iron precursor solution, and take it out after fully reacting for 10-20 seconds.

[0012] Step 4: Repeat the impregnation process of step 3 until the nickel foam is immersed in the reducing agent solution and no more bubbles are generated. The obtained product is washed and dried to obtain a self-supporting iron-nickel-boron loaded nickel foam composite material.

[0013] Preferably, in step 1, the concentration of the hydrochloric acid solution is 1M.

[0014] Preferably, in step 2, the iron salt can be selected from ferrous chloride tetrahydrate or ferrous sulfate heptahydrate.

[0015] Preferably, the drying conditions in step 1 and step 4 are drying at 60-80° C. for 8-12 hours.

[0016] The self-supporting iron-nickel-boron-loaded nickel foam composite material prepared by the present invention can be used as a heterogeneous catalyst to activate periodate and be applied to the degradation of chlorophenol organic pollutants. The specific application method is as follows:

[0017] First, a chlorophenol treatment device was constructed. Multiple self-supporting iron-nickel-boron-loaded nickel foam composites were assembled into a catalyst module, which was then installed as a reaction unit within the chlorophenol treatment device. A mixture of chlorophenols and periodate wastewater passed through the catalyst module, where the periodate was activated, generating highly reactive free radicals that completely degraded the chlorophenols.

[0018] Catalyst Module Characteristics: The catalyst module is self-supporting without the need for adhesives and exhibits excellent self-supporting capabilities. This allows for easy adjustment of the catalyst module's dimensions to meet varying processing needs by flexibly increasing or decreasing the amount of Fe-Ni-B-loaded nickel foam composite material without damaging the catalyst module.

[0019] Preferably, the periodate includes at least one of potassium periodate and sodium periodate.

[0020] Preferably, the chlorophenol organic pollutants include at least one of 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol.

[0021] Preferably, the chlorophenol organic pollutant treatment device is composed of the following parts: an oxidant storage tank, an organic pollutant tank, a mixing kettle, and a degradation reaction tank, in which multiple groups of catalyst modules are arranged along the pollutant flow direction. During operation, the waste liquid containing the chlorophenol organic pollutants and the periodate solution from the oxidant storage tank are fed into the mixing kettle by a centrifugal pump for uniform stirring, and then transported to the degradation reaction tank by a centrifugal pump. In the degradation reaction tank, multiple catalyst modules are arranged in the flow direction to form the site of the organic pollutant oxidation reaction. Through the catalytic action of the iron-nickel-boron loaded nickel foam composite material, the periodate decomposes to produce active free radicals, and the electron transfer pathway mineralizes the organic pollutants in the solution into CO2 and H2O. After the chlorophenol organic pollutants are treated to meet the standards, the wastewater can be safely discharged.

[0022] Compared with the prior art, the beneficial effects of the present invention are embodied in:

[0023] (1) The preparation method of the self-supporting iron-nickel-boron loaded nickel foam composite material provided by the present invention adopts an alternating impregnation autocatalytic growth strategy for one-step synthesis. The method has a simple process, a short preparation cycle, mild reaction conditions, low energy consumption in the preparation process, a small footprint of the reaction equipment, and is environmentally friendly, and has the potential for large-scale batch production.

[0024] (2) The method for preparing a self-supporting iron-nickel-boron loaded nickel foam composite material provided by the present invention can effectively generate a uniformly dispersed layered iron-nickel boride by precisely controlling the growth process of iron-nickel-boron through alternating impregnation. This unique layered porous structure forms a large amount of void space, providing abundant contact areas and multiple transmission channels for reactants, thereby significantly improving catalytic performance. The present invention successfully overcomes the problems of sediment accumulation, uneven loading, low specific surface area, and poor catalytic activity in traditional methods.

[0025] (3) The self-supporting iron-nickel-boron loaded nickel foam composite material prepared by the present invention uses nickel foam as a matrix. The nickel foam directly reacts with the reducing solution, providing an anchor point for the growth of iron-nickel-boron. The iron-nickel-boron grows directly on the nickel foam, forming a seamless connection between the nickel foam and the iron-nickel-boron, forming a fully connected overall structure with a firm bond, effectively improving the electron transfer rate, and effectively avoiding the problems of active component shedding and ion leaching during catalytic applications.

[0026] (4) The method of the present invention uses nickel foam itself as the nickel source, which simplifies the operation process, significantly reduces costs, and improves environmental friendliness. In addition, by adjusting the amount of synthesis liquid, the size and ratio of the catalyst can be customized according to demand, meeting the requirements of large-scale production of commercial catalysts.

[0027] (5) The self-supporting iron-nickel-boron loaded nickel foam composite material prepared by the present invention exhibits excellent catalytic efficiency and stability by virtue of the synergistic effect of metal boride and bimetallic composite material, successfully solving the limitations of traditional Fenton-type reactions. Bimetallic boride stimulates the high catalytic activity of the material by regulating the electronic structure and surface reconstruction of the active site. Boron-mediated reverse electron transfer enhances the electron enrichment of the metal site, and the surface reconstruction forms active hydroxides, further improving the activity of the catalytic active site. In addition, the three-dimensional structure of the nickel foam provides a large specific surface area, which can expose abundant active sites and promote the transfer of pollutants to the active sites. Experimental results show that the composite material of the present invention achieves 100% degradation efficiency of chlorophenol compounds during the periodate activation process and can be directly used without any post-processing. The material is easy to operate, does not require additional energy input, and the catalyst is easy to recover and recycle, which simplifies the process flow, significantly reduces costs, and fully complies with the principle of green environmental protection. This design effectively solves the problem of separation and recovery of traditional powder catalysts, while supporting modular management and large-scale expansion of oxidation degradation tanks, showing excellent performance and broad application potential in the field of environmental engineering technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The scanning electron microscope (SEM) image of the iron-nickel-boron loaded nickel foam composite material obtained in Example 1 is shown;

[0029] Figure 2 The transmission electron microscope (TEM) image of the iron-nickel-boron loaded nickel foam composite material obtained in Example 1 is shown;

[0030] Figure 3 The scanning transmission electron microscope (STEM) image of the iron-nickel-boron loaded nickel foam composite material obtained in Example 1 is shown ( Figure 3 (a) in the figure), and the corresponding B, Fe and Ni element maps ( Figure 3 (b) to (d));

[0031] Figure 4 A comparison of the specific surface area (BET) of the iron-nickel-boron-loaded nickel foam composite material obtained in Example 1 and a catalyst of the same type is shown;

[0032] Figure 5 A schematic diagram of an organic pollutant treatment device constructed according to the present invention is shown;

[0033] Figure 6 A comparison chart showing the degradation performance of 2,4-dichlorophenol between the iron-nickel-boron loaded nickel foam composite material obtained in Example 1 and the same type of catalyst is shown;

[0034] Figure 7 The results show the repeatability of the Fe-Ni-B-loaded nickel foam composite material obtained in Example 1 in the degradation of 2,4-dichlorophenol.

[0035] Figure 8 The inductively coupled plasma mass spectrometry (ICP-MS) detection results of the iron-nickel-boron loaded nickel foam composite material obtained in Example 1 are shown. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to specific embodiments, but it should be noted that the present invention is not limited to the following embodiments. The preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention.

[0037] Unless otherwise specified, the raw materials used in the embodiments of the present invention are commercially available products and do not require further treatment.

[0038] Example 1

[0039] This embodiment provides a method for preparing a self-supporting iron-nickel-boron loaded nickel foam composite material, the raw materials used are: nickel foam (NF, 99.5%, 2.0 mm thick, 100 ppi, 480 g·m -2 ), hydrochloric acid (HCl, AR), anhydrous ethanol (C2H6O, ≥99.5%), ferrous chloride tetrahydrate (FeCl2·4H2O, 99%), sodium borohydride (NaBH4, AR), sodium hydroxide (NaOH, ≥97%) and deionized water, and complete the following steps:

[0040] S1. Pretreatment of nickel foam substrate:

[0041] Cut the nickel foam substrate into a suitable sample (here, 2 cm × 2 cm) and immerse it in a 1M hydrochloric acid solution and ultrasonicate for 15 minutes to remove the oxide layer and impurities on the surface of the nickel foam. After removal, rinse it with deionized water until neutral. Repeatedly rinse the nickel foam with anhydrous ethanol several times and then dry it at 60°C for 12 hours before use.

[0042] S2. Preparation of reaction solution:

[0043] Ferrous chloride tetrahydrate was dissolved in deionized water to prepare 15 mL of a 20 wt % iron precursor solution; sodium borohydride was dissolved in deionized water to prepare 15 mL of a 10 wt % reducing agent solution, and the pH of the solution was adjusted to 13 using 1 M sodium hydroxide.

[0044] S3, alternating immersion reaction

[0045] Immerse a piece of pretreated nickel foam in the reducing agent solution, count for 10 seconds after bubbles are observed, then quickly immerse it in the iron precursor solution for a full reaction of 10 seconds before taking it out.

[0046] S4. Repeat step S3 multiple times until the nickel foam no longer produces bubbles when immersed in the reducing agent solution. Then, the product is repeatedly rinsed with deionized water until neutral, and then repeatedly washed with anhydrous ethanol several times, and then dried at 60°C for 12 hours to obtain a self-supporting iron-nickel-boron-loaded nickel foam composite material (Fe-Ni-B@NF).

[0047] For comparison, this example also prepared a nickel-boron-loaded nickel foam composite material without iron. The pretreated nickel foam was immersed in a reducing agent solution until bubbles ceased to form. The product was then repeatedly rinsed with deionized water until neutral, then repeatedly washed several times with anhydrous ethanol, and dried at 60°C for 12 hours to obtain a self-supporting nickel-boron-loaded nickel foam composite material (Ni-B@NF).

[0048] For comparison, this example also prepared an iron-nickel-loaded nickel foam composite material without boron addition. The method was as follows: 50 mL of a reaction solution (20 wt% ferric chloride tetrahydrate, 1 wt% urea, and 0.5 wt% ammonium fluoride) was prepared, transferred to a Teflon-lined stainless steel autoclave containing a piece of pretreated nickel foam, and maintained at 120°C for 8 hours. Thereafter, the solution was washed sequentially with deionized water and anhydrous ethanol, and then dried at 60°C for 12 hours to obtain an iron-nickel-loaded nickel foam composite material (Fe-Ni@NF).

[0049] Figure 1 and Figure 2The SEM and TEM images of the iron-nickel-boron loaded nickel foam composite material prepared in this embodiment are respectively shown. From the SEM and TEM images, it can be clearly observed that the surface of the iron-nickel-boron loaded nickel foam composite material is evenly distributed with spherical porous nodules and petal-like structures, and the spherical porous nodules and petal-like structures are spatially interconnected to form a large amount of void space. This unique hierarchical porous structure is expected to provide abundant contact areas and multiple transmission channels for the reactants, thereby significantly improving the catalytic performance. Figure 3 3 is an EDS element scanning diagram of the iron-nickel-boron loaded nickel foam composite material prepared in this example. It can be seen from the diagram that iron, nickel and boron elements are uniformly doped in the nickel foam. Figure 4 This is the BET diagram of the iron-nickel-boron loaded nickel foam composite material prepared in this embodiment. From the figure, it can be seen that the specific surface area of ​​the iron-nickel-boron loaded nickel foam composite material is 12.097m 2 / g, much higher than nickel foam (4.657m 2 / g), nickel-boron loaded nickel foam composite (5.417m 2 / g), iron-nickel loaded nickel foam composite material (4.842m 2 / g), which is consistent with the above conclusion.

[0050] S5. Construction of chlorophenol organic pollutant treatment equipment:

[0051] like Figure 5 As shown, the chlorophenol organic pollutant treatment device consists of an oxidant storage tank, an organic pollutant tank, a mixing kettle, and a degradation reaction tank. A centrifugal pump is used to coordinate the various components. When the organic pollutant treatment device is in operation, the solution in the organic pollutant tank and the periodate solution in the oxidant storage tank are pumped into the mixing kettle by a centrifugal pump. After being stirred evenly in the mixing kettle, they are pumped into the degradation reaction tank by a centrifugal pump. The core component in the degradation reaction tank is a plurality of catalyst modules arranged along the flow direction, which is where the organic oxidation reaction occurs. The construction method is as follows: First, multiple pieces of iron-nickel-boron-loaded nickel foam composite materials are fixedly assembled using a stainless steel mold to produce an integral catalyst module of the iron-nickel-boron-loaded nickel foam composite material, and then the catalyst module is arranged in the degradation reaction tank along the flow direction.

[0052] The organic pollutant solution containing 2,4-dichlorophenol (10 mg / L) and the periodate solution (100 mg / L) are respectively loaded into the organic pollutant tank and the oxidant storage tank, and are pumped into the mixing kettle by a centrifugal pump at an appropriate flow rate ratio (the flow rate ratio in this embodiment is 1:1.2). After being stirred evenly in the mixing kettle, they are pumped into the degradation reaction tank by a centrifugal pump. The organic pollutant solution containing periodate flows through the catalyst module, and the iron-nickel-boron loaded nickel foam composite material decomposes the activated periodate to produce highly active free radicals and electron transfer pathways to mineralize the organic pollutants into CO2 and H2O. The organic pollutants are discharged after being treated to meet the standards. After testing, the final degradation rate of 2,4-dichlorophenol was about 100%.

[0053] Figure 6 This is a comparison chart of the degradation performance of 2,4-dichlorophenol by the iron-nickel-boron loaded nickel foam composite material prepared in this example and the same type of catalyst. It can be seen from the figure that the prepared iron-nickel-boron loaded nickel foam composite material exhibits excellent catalytic activity and can completely degrade organic pollutants within 18 minutes. Figure 7 This is a repeatable experimental diagram of the degradation of 2,4-dichlorophenol by the iron-nickel-boron loaded nickel foam composite material prepared in this example. It can be seen from the figure that the prepared iron-nickel-boron loaded nickel foam composite material still shows excellent degradation effect after four repetitions, indicating that the catalytic effect of the prepared composite material is stable and the active components are firmly distributed.

[0054] For the ion leaching experiment (directly measuring the iron and nickel ions in the post-degradation solution), sample preparation was as follows: 5 mL of the post-degradation solution was added to 15 mL of 65-68% concentrated nitric acid and sonicated for 30 minutes. 2 mL of the supernatant was diluted to 10 mL. The sample was analyzed using an Agilent 7500 Isotope Chronology Laboratory-Laser Ablation Plasma-Mass Spectrometer (LAP-MS). Figure 8 This is the ICP-MS test result of the iron-nickel-boron loaded nickel foam composite material obtained in this example. It can be seen from the figure that the iron and nickel ion leaching during the degradation process of the iron-nickel-boron loaded nickel foam composite material is 45.3 and 6.979 PPB, respectively, which are far below the limit values ​​of the World Health Organization and the European Union.

[0055] The above results show that this method solves the defects of traditional preparation methods such as sediment aggregation, uneven loading, low specific surface area, poor catalytic activity, sediment shedding and large amount of ion leaching during the reaction.

[0056] Example 2

[0057] The preparation method of this embodiment is the same as that of embodiment 1, with the only difference being that in S2, ferrous sulfate heptahydrate is used to prepare the iron precursor solution.

[0058] The results show that the self-supporting Fe-Ni-B loaded nickel foam composite material was successfully prepared in this example.

[0059] Example 3

[0060] The preparation method of this embodiment is the same as that of Example 1, except that in S5, an organic pollutant solution (10 mg / L) containing 2,4,6-trichlorophenol and a periodate solution (100 mg / L) are respectively loaded into an organic pollutant tank and an oxidant storage tank, and then delivered to a mixing kettle by a centrifugal pump at an appropriate flow rate ratio (the flow rate ratio in this embodiment is 1:1.2). After being uniformly stirred in the mixing kettle, the mixture is delivered to a degradation reaction tank by a centrifugal pump.

[0061] The results showed that the final degradation rate of 2,4,6-trichlorophenol was about 100%.

[0062] Example 4

[0063] The preparation method of this embodiment is the same as that of Example 1, except that in S5, an organic pollutant solution (10 mg / L) containing 4-chlorophenol and a periodate solution (100 mg / L) are respectively loaded into an organic pollutant tank and an oxidant storage tank, and then delivered to a mixing kettle by a centrifugal pump at an appropriate flow rate ratio (the flow rate ratio in this embodiment is 1:1.2). After being uniformly stirred in the mixing kettle, the mixture is delivered to the degradation reaction tank by a centrifugal pump.

[0064] The results showed that the final degradation rate of 4-chlorophenol was about 100%.

[0065] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a self-supporting iron-nickel-boron loaded nickel foam composite material, characterized in that: First, the oxide layer and impurities on the surface of the nickel foam are removed by pretreatment. Then, the nickel foam is alternately immersed in a reducing agent solution and an iron precursor solution by an alternating immersion method, which promotes the autocatalytic growth of iron-nickel boride by metal ions on the surface of the nickel foam, thereby obtaining a self-supporting iron-nickel-boron-loaded nickel foam composite material. The specific steps are as follows: Step 1: Place the nickel foam in a hydrochloric acid solution for treatment, then wash it with deionized water and anhydrous ethanol in sequence, and then dry it in a drying oven; Step 2: dissolving an iron salt in deionized water to prepare a 10-20 wt% iron precursor solution; dissolving sodium borohydride in deionized water to prepare a 5-10 wt% reducing agent solution, and adjusting the pH of the solution to greater than 10 using 0.1-1.0 M sodium hydroxide to prevent self-decomposition of the sodium borohydride; Step 3: Immerse the nickel foam in a reducing agent solution, and let it stand for 10-20 seconds after bubbles are observed; then quickly immerse it in an iron precursor solution, and remove it after fully reacting for 10-20 seconds; Step 4: Repeat the impregnation process of step 3 until the nickel foam is immersed in the reducing agent solution and no more bubbles are generated. The obtained product is washed and dried to obtain a self-supporting iron-nickel-boron loaded nickel foam composite material.

2. The preparation method according to claim 1, wherein: In step 1, the concentration of the hydrochloric acid solution is 1 M.

3. The preparation method according to claim 1, wherein: In step 2, the iron salt is any one of ferrous chloride tetrahydrate and ferrous sulfate heptahydrate.

4. The preparation method according to claim 1, wherein: In step 1 and step 4, the drying condition is drying at 60-80° C. for 8-12 hours.

5. A self-supporting iron-nickel-boron loaded nickel foam composite material prepared by the preparation method according to any one of claims 1 to 4.

6. An application of the self-supporting iron-nickel-boron loaded nickel foam composite material according to claim 5, characterized in that: Activated periodate was used as a catalyst to treat chlorophenols.

7. The use according to claim 6, characterized in that: A chlorophenol organic pollutant treatment device is constructed; the self-supporting iron-nickel-boron loaded nickel foam composite material is assembled into a catalyst module, so that a mixed waste liquid of chlorophenol organic pollutants and periodate flows through the catalyst module, thereby activating the periodate and achieving complete degradation of the chlorophenol organic pollutants.

8. The use according to claim 6 or 7, characterized in that: The periodate includes at least one of potassium periodate and sodium periodate.

9. The use according to claim 6 or 7, characterized in that: The chlorophenol organic pollutant is at least one of 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol.

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