Catalyst for treating organic matters by using waste salt as well as preparation method and application of catalyst

Abstract

The invention relates to the field of waste water treatment catalytic materials, in particular to a catalyst for treating organic matter through waste salt and a preparation method and application of the catalyst. The nitrogen-doped nano carbon layer grows on the surface of the titanium-based boron-doped diamond electrode; the zirconium oxide coated ferroferric oxide core-shell particles are loaded on the surface of the nitrogen-doped nano carbon layer; and the sulfonated polypyrrole-graphene oxide composite hydrogel is filled in gaps of the nitrogen-doped nano carbon layer. According to the invention, chlorine poisoning resisting confinement catalysis and electric drive enrichment are cooperated, so that a high-salt mass transfer barrier is broken through, and efficient degradation of organic matters is realized.

Description

Technical Field

[0001] The present invention relates to the field of wastewater treatment catalytic materials, and in particular to a catalyst for treating organic matter with waste salt, and a preparation method and application thereof. Background Art

[0002] High-salinity organic wastewater is a common pollutant in industrial production. Its treatment is difficult and costly, making it a pressing challenge in the environmental protection field. High-salinity organic wastewater primarily originates from industries such as petrochemicals, pharmaceuticals, pesticides, and dyes. It is characterized by high salinity, high organic content, and complex composition. Currently, treatment technologies for high-salinity organic wastewater primarily include biological, physical, and chemical oxidation methods.

[0003] Among chemical oxidation methods, Fenton oxidation technology is widely used due to its high efficiency and cost-effectiveness. The traditional Fenton reaction utilizes ferrous ions to react with hydrogen peroxide to produce highly oxidizing hydroxyl radicals (·OH), which effectively degrade various organic pollutants. However, in high-salt environments, large amounts of chloride ions compete with ferrous ions for binding, significantly inhibiting the efficiency of the Fenton reaction. This necessitates excessive addition of iron salts, resulting in the production of large amounts of iron sludge and secondary pollution.

[0004] To address the limitations of the traditional Fenton reaction, researchers have developed a variety of improved catalysts. CN103560257B discloses a nitrogen-doped carbon oxygen reduction catalyst containing ferroferric oxide particles. This catalyst is prepared in situ by a solvent-thermal method followed by high-temperature calcination. The resulting ferroferric oxide nanoparticles and nitrogen-doped carbon material produce a synergistic coupling effect, which improves the catalytic activity of the oxygen reduction reaction [1]. However, the application effect of this catalyst in high-salt environments is limited, and it lacks an effective organic matter enrichment mechanism.

[0005] CN109701576A discloses a core-shell magnetic nitrogen-doped carbon sphere persulfate catalyst loaded with cobalt oxide. This catalyst utilizes a surface polymerization reaction to coat a nitrogen-containing conductive polymer on the surface of nano-ferroferric oxide. This catalyst is then calcined at high temperature to produce a core-shell catalyst. While this catalyst exhibits high catalytic activity and magnetic recovery properties, its catalytic efficiency is significantly suppressed in high-salt environments and it lacks the ability to selectively enrich organic matter.

[0006] CN111266126B discloses a composite magnetic photocatalyst composed of sulfur-doped graphite-phase carbon nitride nanosheets loaded with graphene and ferrosoferric oxide. This catalyst boasts high photocatalytic activity, good stability, and easy recovery. However, this catalyst primarily relies on a photocatalytic mechanism. In high-salt wastewater treatment, high solution turbidity can severely affect light penetration and reduce catalytic efficiency.

[0007] CN107020144B discloses a magnetic nitrogen-doped reduced graphene oxide composite catalyst. The catalyst is prepared by mixing urea as a nitrogen source and a reducing agent with magnetic graphene oxide and then undergoing a hydrothermal reaction [4]. The catalyst can catalyze persulfate to produce highly active sulfate radicals, which are used to degrade refractory organic pollutants in water. However, in a high-salt environment, the catalytic efficiency decreases significantly, and there is a lack of an effective organic matter enrichment mechanism on the catalyst surface.

[0008] CN112340853B discloses a hybrid hydrogel carrier for treating high-salinity wastewater. The carrier comprises functional microorganisms and a conductive hydrogel carrier, with magnetic ferroferric oxide particles and a compatible substance evenly distributed on the surface and within the conductive hydrogel carrier. While this technology demonstrates some effectiveness in high-salinity environments, it relies primarily on microbial degradation, resulting in slow treatment and poor tolerance to toxic organic matter.

[0009] The existing technology has the following major problems when treating high-salt organic wastewater: First, the traditional Fenton reaction is strongly inhibited by chloride ions in a high-salt environment, the oxidation efficiency drops sharply, and excessive addition of iron salts is required to cause a large amount of iron sludge secondary pollution; Second, although wet catalytic oxidation can avoid the generation of iron sludge, the low mass transfer efficiency unique to the high-salt wastewater system seriously restricts the catalytic effect, and the reaction kinetic constant is only 1 / 3-1 / 5 of that of the low-salt system; Third, the existing catalyst lacks an effective organic matter enrichment mechanism, making it difficult to achieve efficient catalytic degradation in a high-salt environment; Fourth, the existing technology makes it difficult to achieve pure brine reuse. The impure salt components produced in the evaporation and crystallization stage are complex, and the residual trace organic matter and heavy metals make it difficult for the recovered salt to meet the industrial raw material standards. Nearly 97% of the crystallized salt eventually becomes hazardous waste and is forced to be disposed of in landfills.

[0010] Therefore, there is an urgent need to develop a new catalyst that can efficiently catalyze the degradation of organic pollutants in a high-salt environment, has the function of enriching organic matter and can achieve pure brine reuse, so as to solve the technical bottlenecks faced by existing technologies in the treatment of high-salt organic wastewater. Summary of the Invention

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] A catalyst for treating organic matter with waste salt, comprising:

[0013] Titanium-based boron-doped diamond electrode;

[0014] A nitrogen-doped nanocarbon layer is grown on the surface of the titanium-based boron-doped diamond electrode;

[0015] Zirconium oxide-coated ferroferric oxide core-shell particles are loaded on the surface of the nitrogen-doped nanocarbon layer to form catalytic active centers;

[0016] Sulfonated polypyrrole-graphene oxide composite hydrogel is filled in the gaps of the nitrogen-doped nanocarbon layer and is used for enriching organic matter.

[0017] The catalyst in this scheme achieves efficient synergistic effects in high-salt environments through a multi-level structural design. A titanium-based boron-doped diamond electrode serves as a conductive substrate, exhibiting excellent electrochemical stability and a wide potential window, providing a stable electron transport channel for the system. The grown nitrogen-doped nanocarbon layer forms a three-dimensional conductive network. The abundant pyridinic / graphitic nitrogen sites on its surface significantly enhance electron transfer efficiency and serve as a support framework for active sites. Zirconia-coated ferroferric oxide core-shell particles are anchored to the surface of the nanocarbon layer. The zirconia coating effectively isolates the chloride ions from poisoning the iron active centers, while the internal ferroferric oxide core enables directional dissolution and regeneration of iron ions under the action of an electric field. The sulfonated polypyrrole-graphene oxide composite hydrogel filling the interstices of the nanocarbon layer combines ion exchange and hydrophobic adsorption capabilities. The sulfonic acid groups capture cationic organic matter through electrostatic attraction, while the graphene sheets enrich aromatic pollutants through π-π interactions, forming a localized high-concentration reaction microenvironment. Through spatial and functional coupling, these components form an integrated enrichment-catalysis-mineralization platform.

[0018] Preferably, in the zirconium oxide-coated ferroferric oxide core-shell particles, the ferroferric oxide particle size is 10-30 nm, and the thickness of the zirconium oxide coating layer is 2-5 nm.

[0019] Preferably, the thickness of the nitrogen-doped nanocarbon layer is 50-100 nm, and the nitrogen doping amount is 3-8 at %.

[0020] Preferably, in the sulfonated polypyrrole-graphene oxide composite hydrogel, the mass ratio of sulfonated polypyrrole to graphene oxide is 1:0.2-1, and the swelling rate is 300-500%.

[0021] Preferably, the preparation method of the zirconium oxide-coated ferroferric oxide core-shell particles comprises:

[0022] Step (a) dispersing ferrosoferric oxide nanoparticles in anhydrous ethanol and treating with ultrasound at a power of 300 W for 30 min;

[0023] Step (b) adding zirconium oxychloride to a final concentration of 0.1-0.5 mol / L;

[0024] Step (c) hydrothermal reaction at 160-180° C. for 6-12 hours;

[0025] Step (d) vacuum drying at 60° C. after magnetic field separation.

[0026] The catalyst preparation process in this scheme follows a step-by-step construction principle: substrate modification, nanocarbon layer growth, active site loading, and functional phase filling. A boron-doped diamond layer is deposited on a pretreated titanium plate via chemical vapor deposition on a titanium-based boron-doped diamond electrode, forming a highly stable electrochemical interface. A magnetron-sputtered iron / aluminum bimetallic layer is used as a catalyst for the growth of the nitrogen-doped nanocarbon layer. A gas-solid phase reaction in an acetylene / ammonia atmosphere results in vertically oriented carbon nanotubes (CNTs). Active nitrogen atoms generated by ammonia decomposition are simultaneously incorporated into the carbon lattice. Zirconia-coated ferroferric oxide core-shell particles are hydrothermally deposited with a zirconia precursor on the FeO surface, forming a dense core-shell structure upon crystallization. The loading process relies on ultrasonic dispersion to facilitate particle embedding into CNT surface defects. Sulfonated polypyrrole-graphene oxide composite hydrogels are in situ filled by electrochemical co-deposition. Pyrrole monomers polymerize on the graphene oxide sheets to form a cross-linked network. The introduction of sodium p-styrene sulfonate imparts ion exchange functionality to the gel. Galvanostatic deposition ensures the hydrogel's penetration and strong bonding within the interstices of the nanocarbon layers.

[0027] Preferably, the raw materials for synthesizing the sulfonated polypyrrole-graphene oxide composite hydrogel include:

[0028] Pyrrole monomer: 0.5-1.5 mol / L;

[0029] Graphene oxide: 1-5g / L;

[0030] Sodium p-styrenesulfonate: 0.1-0.3 mol / L;

[0031] Supporting electrolyte: sodium perchlorate 0.1 mol / L.

[0032] This solution also discloses a method for preparing the catalyst described above, which is characterized by sequentially carrying out:

[0033] Step (1) titanium-based boron-doped diamond electrode treatment: after sandblasting and pickling the titanium plate, chemical vapor deposition grows a boron-doped diamond layer;

[0034] Step (2) Growth of nitrogen-doped nanocarbon layer: magnetron sputtering of an iron / aluminum bimetallic layer on the surface of a titanium-based boron-doped diamond electrode in an acetylene / ammonia atmosphere at 630-650° C. to grow a nitrogen-doped nanocarbon layer;

[0035] Step (3) Loading the zirconia-coated ferroferric oxide core-shell particles: ultrasonically dispersing the particles in ethanol and loading them on the surface of the nitrogen-doped nanocarbon layer;

[0036] Step (4) Filling of sulfonated polypyrrole-graphene oxide composite hydrogel: coating the hydrogel synthesis raw material on the surface of the nanocarbon layer, and 2 The constant current deposition was carried out for 300-400 seconds to obtain a catalyst for treating organic matter with waste salt.

[0037] Preferably, after loading in step (3), plasma treatment is performed in an argon atmosphere with a power of 100 W and a time of 5 minutes.

[0038] Preferably, after the deposition in step (4), the substrate is immersed in a 0.1 mol / L sulfuric acid solution for 30 minutes for protonation.

[0039] This proposal also discloses an application of the above-mentioned catalyst in the treatment of high-salt wastewater.

[0040] In the treatment of high-salinity wastewater, the catalyst in this scheme serves as the cathode, forming an electrocatalytic system with a titanium-based boron-doped diamond anode, synergistically degrading organic matter through multiple mechanisms. A cascade reaction occurs on the cathode surface: dissolved oxygen is reduced via a two-electron pathway on the nitrogen-doped carbon nanotube surface to produce hydrogen peroxide. Simultaneously, ferroferric oxide within the zirconia coating releases controlled iron ions under electric field control. The contact between the two triggers a Fenton-like reaction to produce hydroxyl radicals. The negative electric field near the cathode drives negatively charged organic matter to migrate toward the electrode surface, where it is captured and enriched by the hydrogel, significantly increasing the local pollutant concentration. The zirconia coating selectively removes chloride ions, eliminating their quenching effect on free radical reactions. The anode preferentially oxidizes chloride ions to produce active chlorine species, deeply mineralizing residual organic fragments. A reverse voltage is applied at the reaction termination stage to promote the desorption of adsorbed pollutants and their complete decomposition by active chlorine, ensuring the purity of the salt crystallization process. This system, through a closed-loop pathway of electromigration enrichment, in-situ catalytic oxidation, and terminal purification, achieves efficient organic matter removal and salt resource reuse in high-salinity wastewater.

[0041] The application method includes the following steps:

[0042] The catalyst is used as a cathode to form an electrode pair with a titanium-based boron-doped diamond anode with an inter-electrode distance of 5-10 mm. A DC voltage of 0.8-1.2 V is then applied to control the sodium chloride concentration of the wastewater to be ≥3wt%, and aeration is used to maintain the dissolved oxygen concentration to be ≥5 mg / L. After the reaction is terminated, the reverse voltage is switched to -1.0 V for 10 minutes.

[0043] The cathode synchronization realizes the following functions:

[0044] (1) electroreduction of dissolved oxygen to generate hydrogen peroxide;

[0045] (II) reducing ferric ions to regenerate ferrous ions;

[0046] (III) Drive negatively charged organic matter to migrate to the catalyst surface.

[0047] Compared with existing technologies, the advantages of this solution are:

[0048] 1. The catalyst in this scheme achieves functional coupling through a multi-level spatial configuration. A titanium-based boron-doped diamond electrode serves as a rigid substrate, endowing the system with a wide potential window and extreme chemical stability, forming the main electron transport pathway. Vertically oriented nitrogen-doped nanocarbon layers form a three-dimensional conductive network. The exposed pyridinic nitrogen sites on their surfaces significantly enhance electron capture and transfer capabilities, while also providing a topological framework for anchoring active centers. Zirconia-coated ferroferric oxide core-shell particles are chemically bonded to the carbon nanotube surface. The dense zirconia coating forms a chloride ion-selective barrier, while the internal ferroferric oxide core enables controlled release and regeneration of iron species under electric field regulation. Sulfonated polypyrrole-graphene oxide composite hydrogels filling the interstices of the nanocarbon layers create an amphiphilic microenvironment. Sulfonic acid groups enrich cationic pollutants through ion exchange, while graphene domains capture non-polar organic matter through hydrophobic interactions, forming a locally high-concentration reaction interface. The four-layer structure achieves a synergistic mechanism of enrichment, catalysis, and protection through the precise matching of steric hindrance and electron access.

[0049] 2. The catalyst preparation process of this scheme adopts a step-by-step in-situ synthesis strategy to achieve atomic-level control of interface bonding. Titanium-based boron-doped diamond electrodes are deposited on titanium substrates by chemical vapor deposition to form a conformal diamond layer. The sp 3 -sp 2 Hybrid transition states ensure electrode conductivity and stability. Nitrogen-doped nanocarbon layers undergo gas-solid growth mediated by an iron / aluminum bimetallic catalytic layer. Carbon radicals generated by acetylene decomposition are embedded in a co-lattice with nitrogen species in an ammonia atmosphere, forming a vertically oriented nitrogen-doped carbon lattice. Zirconia-coated ferroferric oxide core-shell particles achieve interfacial atomic recombination through hydrothermal crystallization. The zirconium oxychloride precursor hydrolyzes and condenses on the surface of ferroferric oxide to form a zirconia coating with oxygen vacancies. The lattice mismatch stress is alleviated by Zr-O-Fe bond bridging. The composite hydrogel achieves nano-confined filling through electrochemical deposition. Pyrrole monomers are electropolymerized on graphene oxide sheets to form an interpenetrating network. Sulfonic acid groups are simultaneously incorporated into the polymer backbone. Constant current drive ensures that the gel achieves molecular-level dense filling in micron-scale gaps.

[0050] 3. The catalyst in this scheme achieves a highly efficient closed-loop degradation process in an electrocatalytic system through a multiphase interfacial reaction. A triple cascade reaction occurs at the cathode surface: dissolved oxygen is reduced to hydrogen peroxide via a two-electron pathway at the edge sites of the nitrogen-doped carbon tubes. Iron ions seeping from the zirconium oxide layer react with hydrogen peroxide in a confined space, triggering a Fenton-like reaction, generating highly reactive hydroxyl radicals. The negative cathode electric field drives anionic pollutants to migrate to the electrode surface, where they are dynamically captured and enriched by the hydrogel. The zirconium oxide coating acts as an ion screen, selectively blocking chloride ions from accessing the active sites, eliminating the free radical quenching effect. On the anode side, chloride ions are preferentially oxidized to form active chlorine species, which diffuse along the concentration gradient to the cathode region to mineralize residual organic matter. Reverse voltage switching at the termination stage of the reaction forces the adsorbed pollutants to desorb through the electric field reversal, where they are deeply oxidized by the active chlorine to small inorganic molecules. This process forms a dynamic equilibrium of electromigration enrichment, confined catalysis, and anode oxygenation, overcoming the mass transfer limitations of high-salt systems while simultaneously achieving complete mineralization of organic matter and pure reuse of the salt matrix. DETAILED DESCRIPTION

[0051] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0052] Overall embodiment

[0053] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0054] Step (1) titanium-based boron-doped diamond electrode treatment:

[0055] The titanium plate was sandblasted with 120-mesh corundum for 10 min and then pickled with 10 wt% oxalic acid solution at 40°C for 30 min. The boron-doped diamond layer was then grown by chemical vapor deposition (CVD). The reaction gas was methane / hydrogen / trimethylboron in a volume ratio of 1:100:0.5. The deposition pressure was 5 kPa, the temperature was 800°C, the time was 6 h, and the boron doping concentration was 1×10 21 atoms / cm 3 , complete the processing of titanium-based boron-doped diamond electrodes;

[0056] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0057] Magnetron sputtering of an iron / aluminum bimetallic layer: An iron / aluminum bimetallic layer was prepared on the surface of a titanium-based boron-doped diamond electrode by magnetron sputtering. The sputtering power was 200 W, the Ar gas pressure was 0.5 Pa, and the resulting iron layer thickness was 20 nm and the aluminum layer thickness was 5 nm. Subsequently, the titanium-based boron-doped diamond electrode sputtered with the iron / aluminum bimetallic layer was placed in an acetylene / ammonia atmosphere to grow a nitrogen-doped nanocarbon layer (acetylene and ammonia gas flow ratio of 1:3, total pressure of 20 kPa, growth at 630-650 ° C for 30-60 min, controlling the nanocarbon layer thickness to 50-100 nm, and the nitrogen doping amount to 5±0.5 at%) to complete the growth of the nitrogen-doped nanocarbon layer:

[0058] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0059] First, zirconium oxide-coated ferrosoferric oxide is prepared by the following steps:

[0060] Step (a) Fe3O4 nanoparticles (particle size 25±5 nm) were sonicated in anhydrous ethanol at 300W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0061] Step (b) adding zirconium oxychloride to a final concentration of 0.1-0.5 mol / L;

[0062] Step (c) hydrothermal reaction at 160-180° C. for 6-12 hours to form a zirconium oxide coating layer;

[0063] Step (d) magnetic field separation (intensity 0.5 T, time 10 min), vacuum drying at 60° C. for 6 h;

[0064] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 2 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0065] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0066] Composite hydrogel preparation:

[0067] Pyrrole monomer: 0.5-1.5 mol / L;

[0068] Graphene oxide: 1-5g / L;

[0069] Sodium p-styrenesulfonate: 0.1-0.3 mol / L;

[0070] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0071] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2The catalyst was deposited at a constant current for 300-400 seconds at a temperature of 25±1° C., immersed in a 0.1 mol / L sulfuric acid solution for 30 minutes, rinsed with deionized water until neutral, and dried in a vacuum at 60° C. for 2 hours to obtain a catalyst for treating organic matter with waste salt.

[0072] Example 1

[0073] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0074] Step (1) titanium-based boron-doped diamond electrode treatment;

[0075] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0076] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0077] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0078] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0079] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0080] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0081] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0082] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0083] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0084] Composite hydrogel preparation:

[0085] Pyrrole monomer: 0.5 mol / L;

[0086] Graphene oxide: 1g / L;

[0087] Sodium p-styrenesulfonate: 0.1 mol / L;

[0088] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0089] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0090] Example 2

[0091] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0092] Step (1) titanium-based boron-doped diamond electrode treatment;

[0093] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0094] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 40 minutes, the thickness of the nanocarbon layer was controlled to be 70 nm, and the nitrogen doping amount was 4.5 at%.

[0095] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0096] Step (a) Fe3O4 nanoparticles with a particle size of 25 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0097] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0098] Step (c) hydrothermal reaction at 170° C. for 8 hours to form a zirconium oxide coating layer;

[0099] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0100] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1.5 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100 W plasma for 5 min under an argon atmosphere to achieve loading.

[0101] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0102] Composite hydrogel preparation:

[0103] Pyrrole monomer: 0.8 mol / L;

[0104] Graphene oxide: 3g / L;

[0105] Sodium p-styrenesulfonate: 0.2 mol / L;

[0106] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0107] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 350 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0108] Example 3

[0109] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0110] Step (1) titanium-based boron-doped diamond electrode treatment;

[0111] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0112] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The thickness of the nanocarbon layer was controlled to be 90 nm, the growth time was 60 min, and the nitrogen doping level was 5.4 at%.

[0113] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0114] Step (a) Fe3O4 nanoparticles with a particle size of 30 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0115] Step (b) adding zirconium oxychloride to a final concentration of 0.4 mol / L;

[0116] Step (c) hydrothermal reaction at 175° C. for 10 hours to form a zirconium oxide coating layer;

[0117] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0118] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 2 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0119] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0120] Composite hydrogel preparation:

[0121] Pyrrole monomer: 1.2 mol / L;

[0122] Graphene oxide: 4g / L;

[0123] Sodium p-styrenesulfonate: 0.25 mol / L;

[0124] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0125] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 380 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0126] Example 4

[0127] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0128] Step (1) titanium-based boron-doped diamond electrode treatment;

[0129] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0130] Magnetron sputtering of an iron / aluminum bimetallic layer: A nitrogen-doped nanocarbon layer was grown on the iron / aluminum bimetallic layer in an atmosphere with an acetylene to ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa at 640°C for 50 minutes. The thickness of the nanocarbon layer was controlled to be 65 nm, and the nitrogen doping amount was 4.8 at%.

[0131] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0132] Step (a) Fe3O4 nanoparticles with a particle size of 22 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0133] Step (b) adding zirconium oxychloride to a final concentration of 0.2 mol / L;

[0134] Step (c) hydrothermal reaction at 165° C. for 11 hours to form a zirconium oxide coating layer;

[0135] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0136] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1.2 mg / mL. The dispersion was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100 W plasma for 5 min under an argon atmosphere to achieve loading.

[0137] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0138] Composite hydrogel preparation:

[0139] Pyrrole monomer: 0.7 mol / L;

[0140] Graphene oxide: 2g / L;

[0141] Sodium p-styrenesulfonate: 0.15 mol / L;

[0142] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0143] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 340 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0144] Example 5

[0145] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0146] Step (1) titanium-based boron-doped diamond electrode treatment;

[0147] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0148] Magnetron sputtering of an iron / aluminum bimetallic layer: A nitrogen-doped nanocarbon layer was grown on the iron / aluminum bimetallic layer in an atmosphere with an acetylene to ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa at 650°C for 55 minutes. The thickness of the nanocarbon layer was controlled to be 85 nm, and the nitrogen doping amount was 5.1 at%.

[0149] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0150] Step (a) Fe3O4 nanoparticles with a particle size of 26 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0151] Step (b) adding zirconium oxychloride to a final concentration of 0.4 mol / L;

[0152] Step (c) hydrothermal reaction at 175° C. for 7 hours to form a zirconium oxide coating layer;

[0153] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0154] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1.6 mg / mL. The dispersion was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading.

[0155] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0156] Composite hydrogel preparation:

[0157] Pyrrole monomer: 1.1 mol / L;

[0158] Graphene oxide: 4g / L;

[0159] Sodium p-styrenesulfonate: 0.22 mol / L;

[0160] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0161] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 370 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0162] Example 6

[0163] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0164] Step (1) titanium-based boron-doped diamond electrode treatment;

[0165] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0166] Magnetron sputtering of an iron / aluminum bimetallic layer: A nitrogen-doped nanocarbon layer was grown on the iron / aluminum bimetallic layer in an atmosphere with an acetylene to ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa at 650°C for 60 minutes. The thickness of the nanocarbon layer was controlled to be 85 nm, and the nitrogen doping amount was 5.3 at%.

[0167] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0168] Step (a) Fe3O4 nanoparticles with a particle size of 28 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0169] Step (b) adding zirconium oxychloride to a final concentration of 0.45 mol / L;

[0170] Step (c) hydrothermal reaction at 178° C. for 9 hours to form a zirconium oxide coating layer;

[0171] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0172] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1.9 mg / mL. The dispersion was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading.

[0173] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0174] Composite hydrogel preparation:

[0175] Pyrrole monomer: 1.4 mol / L;

[0176] Graphene oxide: 4.5 g / L;

[0177] Sodium p-styrenesulfonate: 0.28 mol / L;

[0178] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0179] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 390 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0180] Comparative Example 1

[0181] The difference from Example 1 is that the nanocarbon layer is not grown enough:

[0182] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0183] Step (1) titanium-based boron-doped diamond electrode treatment;

[0184] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0185] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 40 minutes, the carbon nanolayer thickness was 45 nm, and the nitrogen doping amount was 4.8 at%.

[0186] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0187] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0188] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0189] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0190] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0191] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0192] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0193] Composite hydrogel preparation:

[0194] Pyrrole monomer: 0.5 mol / L;

[0195] Graphene oxide: 1g / L;

[0196] Sodium p-styrenesulfonate: 0.1 mol / L;

[0197] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0198] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0199] Comparative Example 2

[0200] The difference from Example 1 is that the ferrosoferric oxide is not coated with zirconium oxide:

[0201] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0202] Step (1) titanium-based boron-doped diamond electrode treatment;

[0203] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0204] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0205] Step (3) Fe3O4 core-shell particle loading:

[0206] 20nm ferroferric oxide nanoparticles were ultrasonicated in anhydrous ethanol at 300W for 30min to obtain a solid concentration of 1mg / mL, coated on the surface of the nitrogen-doped nanocarbon layer, and treated with 100W plasma for 5min in an argon atmosphere to achieve loading.

[0207] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0208] Composite hydrogel preparation:

[0209] Pyrrole monomer: 0.5 mol / L;

[0210] Graphene oxide: 1g / L;

[0211] Sodium p-styrenesulfonate: 0.1 mol / L;

[0212] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0213] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0214] Comparative Example 3

[0215] The difference from Example 1 is that the zirconium oxide coating layer is too thick:

[0216] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0217] Step (1) titanium-based boron-doped diamond electrode treatment;

[0218] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0219] The nitrogen-doped nanocarbon layer is grown on the iron / aluminum bimetallic layer in an atmosphere of acetylene and ammonia gas with a flow ratio of 1:3 at a total pressure of 20 kPa at 650 ℃, a growth time of 45 min, a carbon nanolayer thickness of 80 nm, and a nitrogen doping amount of 4.8 at%.

[0220] Step (3) loading of the zirconium oxide-coated ferroferric oxide core-shell particles:

[0221] Step (a) ferroferric oxide nanoparticles with a particle size of 20 nm are ultrasonically dispersed in anhydrous ethanol at 300 W for 30 min to obtain a dispersion liquid with a solid concentration of 10 mg / mL;

[0222] Step (b) zirconium oxychloride is added to a final concentration of 0.6 mol / L;

[0223] Step (c) hydrothermal reaction at 160 ℃ for 12 h to form a zirconium oxide coating layer;

[0224] Step (d) after separation under a magnetic field with a strength of 0.5 T for 10 min, vacuum drying at 60 ℃ for 6 h;

[0225] The prepared zirconium oxide-coated ferroferric oxide is ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion liquid with a solid mass concentration of 1 mg / mL, which is coated on the surface of the nitrogen-doped nanocarbon layer, and is treated by plasma at 100 W for 5 min in an argon atmosphere to achieve loading;

[0226] Step (4) filling of the sulfonated polypyrrole-graphene oxide composite hydrogel:

[0227] Preparation of the composite hydrogel:

[0228] Pyrrole monomer: 0.5 mol / L;

[0229] Graphene oxide: 1 g / L;

[0230] Sodium p-styrenesulfonate: 0.1 mol / L;

[0231] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0232] The composite hydrogel is coated on the surface of the nanocarbon layer, and the current density is 4 mA / cm 2 Constant current deposition for 300 s, temperature 25 ℃, after soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinse with deionized water to neutral, vacuum drying at 60 ℃ for 2 h, to obtain a waste salt treated organic matter catalyst.

[0233] Comparative Example 4

[0234] The difference from Example 1 is that the solid concentration of the zirconium oxide-coated ferroferric oxide core-shell particle dispersion liquid is too high, which is 5 mg / mL:

[0235] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0236] Step (1) titanium-based boron-doped diamond electrode treatment;

[0237] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0238] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0239] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0240] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0241] Step (b) adding zirconium oxychloride to a final concentration of 0.1 mol / L;

[0242] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0243] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0244] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 5 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0245] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0246] Composite hydrogel preparation:

[0247] Pyrrole monomer: 0.5 mol / L;

[0248] Graphene oxide: 1g / L;

[0249] Sodium p-styrenesulfonate: 0.1 mol / L;

[0250] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0251] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0252] Comparative Example 5

[0253] The difference from Example 1 is that no iron / aluminum bimetallic layer is prepared:

[0254] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0255] Step (1) titanium-based boron-doped diamond electrode treatment;

[0256] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0257] A nitrogen-doped nanocarbon layer was grown on the surface of a titanium-based boron-doped diamond electrode at 650°C in an atmosphere with an acetylene to ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping level was 4.8 at%.

[0258] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0259] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0260] Step (b) adding zirconium oxychloride to a final concentration of 0.1 mol / L;

[0261] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0262] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0263] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0264] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0265] Composite hydrogel preparation:

[0266] Pyrrole monomer: 0.5 mol / L;

[0267] Graphene oxide: 1g / L;

[0268] Sodium p-styrenesulfonate: 0.1 mol / L;

[0269] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0270] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0271] Comparative Example 6

[0272] The difference from the embodiment is that the prepared zirconium oxide-coated ferroferric oxide is ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which is coated on the surface of the nitrogen-doped nanocarbon layer and dried at 50°C to achieve the loading:

[0273] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0274] Step (1) titanium-based boron-doped diamond electrode treatment;

[0275] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0276] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0277] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0278] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0279] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0280] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0281] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0282] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and dried at 50°C to achieve loading.

[0283] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0284] Composite hydrogel preparation:

[0285] Pyrrole monomer: 0.5 mol / L;

[0286] Graphene oxide: 1g / L;

[0287] Sodium p-styrenesulfonate: 0.1 mol / L;

[0288] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0289] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0290] Comparative Example 7

[0291] The difference from the embodiment is that there is no hydrogel filling:

[0292] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0293] Step (1) titanium-based boron-doped diamond electrode treatment;

[0294] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0295] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0296] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0297] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0298] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0299] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0300] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0301] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading and obtain a catalyst for waste salt treatment of organic matter.

[0302] Comparative Example 8

[0303] The difference from Example 1 is that sodium p-styrene sulfonate is not added:

[0304] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0305] Step (1) titanium-based boron-doped diamond electrode treatment;

[0306] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0307] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0308] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0309] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0310] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0311] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0312] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0313] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0314] Step (4) polypyrrole-graphene oxide composite hydrogel filling:

[0315] Composite hydrogel preparation:

[0316] Pyrrole monomer: 0.5 mol / L;

[0317] Graphene oxide: 1g / L;

[0318] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0319] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0320] Comparative Example 9

[0321] The difference from Example 1 is that the composite hydrogel is coated on the surface of the nanocarbon layer and dried in vacuum at 60° C. for 2 h to obtain a catalyst for treating organic matter with waste salt:

[0322] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0323] Step (1) titanium-based boron-doped diamond electrode treatment;

[0324] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0325] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0326] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0327] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0328] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0329] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0330] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0331] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0332] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0333] Composite hydrogel preparation:

[0334] Pyrrole monomer: 0.5 mol / L;

[0335] Graphene oxide: 1g / L;

[0336] Sodium p-styrenesulfonate: 0.1 mol / L;

[0337] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0338] The composite hydrogel was coated on the surface of the nanocarbon layer and dried in vacuum at 60° C. for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0339] Comparative Example 10

[0340] The difference from Example 1 is that at 10 mA / cm 2 Constant current deposition:

[0341] A method for preparing a catalyst for treating organic matter with waste salt comprises the following steps:

[0342] Step (1) titanium-based boron-doped diamond electrode treatment;

[0343] Step (2) Growth of nitrogen-doped nanocarbon layer:

[0344] A nitrogen-doped nanocarbon layer was grown on an iron / aluminum bimetallic layer at 650°C in an atmosphere with an acetylene / ammonia gas flow ratio of 1:3 and a total pressure of 20 kPa. The growth time was 45 minutes, the carbon nanolayer thickness was 80 nm, and the nitrogen doping amount was 4.8 at%.

[0345] Step (3) Zirconium oxide coated ferroferric oxide core-shell particle loading:

[0346] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to prepare a dispersion with a solid concentration of 10 mg / mL;

[0347] Step (b) adding zirconium oxychloride to a final concentration of 0.3 mol / L;

[0348] Step (c) hydrothermal reaction at 160° C. for 12 hours to form a zirconium oxide coating layer;

[0349] Step (d) separation in a 0.5T magnetic field for 10 min, followed by vacuum drying at 60°C for 6 h;

[0350] The prepared zirconium oxide-coated ferroferric oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated ferroferric oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL, which was then coated on the surface of the nitrogen-doped nanocarbon layer and treated with 100W plasma for 5 minutes under an argon atmosphere to achieve loading;

[0351] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0352] Composite hydrogel preparation:

[0353] Pyrrole monomer: 0.5 mol / L;

[0354] Graphene oxide: 1g / L;

[0355] Sodium p-styrenesulfonate: 0.1 mol / L;

[0356] Supporting electrolyte: sodium perchlorate 0.1 mol / L;

[0357] The composite hydrogel was coated on the surface of the nanocarbon layer and the 2 The catalyst was deposited at constant current for 300 s at 25°C, immersed in 0.1 mol / L sulfuric acid solution for 30 min, rinsed with deionized water until neutral, and dried in vacuum at 60°C for 2 h to obtain a catalyst for treating organic matter with waste salt.

[0358] The embodiments and comparative examples of this scheme achieve functional application through the following method: the catalyst prepared in the embodiments and comparative examples is used as a cathode to form an electrode pair with a titanium-based boron-doped diamond anode with an inter-electrode distance of 10 mm. A DC voltage of 1.0 V is then applied to control the sodium chloride concentration of the wastewater to 4 wt %, and aeration is used to maintain the dissolved oxygen concentration at 6 mg / L to treat organic wastewater. After the reaction is terminated, the reverse voltage is switched to -1.0 V for 10 minutes.

[0359] Performance test: The organic matter content of the treated wastewater samples is shown in Table 1.

[0360] Table 1 Organic matter content in water samples

[0361]

[0362] The content of the above organic matter in the water was detected after treatment, as shown in Table 2.

[0363] Table 2 Organic matter content in water samples after treatment with catalysts of Examples and Comparative Examples

[0364]

[0365]

[0366] The embodiment utilizes a titanium-based boron-doped diamond electrode as a rigid conductive skeleton, providing a high-speed electron transmission channel under a wide potential window; the nitrogen-doped nanocarbon layer grown on its surface constructs a three-dimensional catalytic interface, and the pyridinic nitrogen / graphitic nitrogen sites significantly reduce the energy barrier for hydrogen peroxide generation, accelerating two-electron oxygen reduction; in the zirconium oxide-coated ferroferric oxide core-shell particles, the zirconium oxide dense layer selectively screens chloride ions and establishes a nano-confined space. The internal ferroferric oxide achieves directional dissolution and regeneration of iron ions under electric field control, triggering a localized, efficient Fenton-like reaction; the sulfonated polypyrrole-graphene oxide composite hydrogel filled in the gaps of the carbon layer, through the synergistic effect of ion exchange of sulfonic acid groups and π-π stacking of graphene sheets, constructs a dynamic enrichment layer on the electrode surface, increasing the pollutant concentration by 1-2 orders of magnitude, breaking through the mass transfer limitations of high-salt environments. The four-layer cascade design forms a complete degradation closed loop of electromigration enrichment → confined catalysis → free radical mineralization → terminal purification, fundamentally solving the problems of salt effect inhibition and chloride ion poisoning.

[0367] Compared with Example 1: In Comparative Example 1, due to insufficient growth of the nanocarbon layer and incomplete development of the three-dimensional conductive network, the density of the pyridinic nitrogen / graphitic nitrogen catalytic sites exposed on the surface is significantly reduced, resulting in a decrease in the efficiency of generating hydrogen peroxide by the two-electron oxygen reduction pathway; at the same time, the weakened support force of the carrier skeleton causes the dispersion of the subsequently loaded core-shell particles to decrease, the effective contact area of ​​the active center is reduced, and the overall catalytic reaction kinetics is hindered; in Comparative Example 2, the ferroferric oxide core is directly exposed to a high salt environment, and the chloride ions poison the iron active sites through complex competition and irreversibly quench the hydroxyl radicals; the uncontrolled dissolution of iron ions destroys the solid-liquid interface equilibrium, resulting in the breakage of the Fenton-like reaction chain, and the dissolved iron combines with the organic by-products to form a more stable Complex, aggravating catalytic deactivation; Comparative Example 3: The overly thick ceramic coating forms a dense diffusion barrier, which seriously hinders the directional migration of iron ions from the core-shell structure to the reaction interface, limiting the dissolution-regeneration cycle rate of iron species under electric field control; the lattice stress accumulation inside the coating induces microcracks, forming chloride ion penetration channels; Comparative Example 4: The core-shell particle loading concentration is too high, causing agglomeration effect, blocking the surface pores of the nitrogen-doped carbon layer, and weakening the penetration and filling ability of the hydrogel in the nano-gap; the integrity of the coating at the edge of the agglomerate is damaged, and the locally exposed Fe3O4 becomes the target of chloride ion attack, forming a weak area of ​​catalytic failure; Comparative Example 5: The lack of a metal catalyst layer leads to disordered growth of the nitrogen-doped carbon layer, and the carbon lattice sp 2The increase of bonding defects and the breakage of electron transport channels; the uneven distribution of catalytic active sites (pyridine nitrogen) caused by non-uniform nitrogen doping, which significantly increases the impedance of the electrochemical interface; the thermal drying instead of plasma treatment in Comparative Example 6 only realizes physical adsorption, and the particles and carbon layers do not form chemical bonding; the weak interfacial bonding force makes the core-shell particles fall off in the electrochemical shock, and the active centers are continuously lost; the particles that fall off adsorb pollutants to form a shielding layer, hindering the electrode reaction mass transfer; the lack of enrichment function of hydrogel in Comparative Example 7 makes it impossible for negatively charged organic matter to concentrate on the electrode surface through electrostatic attraction and π-π interaction; the insufficient concentration of bulk pollutants leads to the electrocatalytic reaction being controlled by mass transfer diffusion, and the mismatch between the generation rate of free radicals and the migration rate of organic matter; the unsulfonated polypyrrole in Comparative Example 8 loses ion exchange ability, and cationic pollutants are far away from the cathode surface due to electrostatic repulsion; at the same time, the decrease of hydrophilicity of hydrogel weakens the capture of polar organic matter and destroys the foundation of building a local high-concentration microenvironment; the thermal drying instead of electrodeposition in Comparative Example 9 causes the shrinkage and solidification of hydrogel, which fails to penetrate into the nanoscale gap of the nitrogen-doped carbon layer, resulting in the formation of a surface layer covering the composite catalytic interface rather than a three-dimensional interpenetrating structure; micron-sized pores are generated between the gel and the carbon layer, and the contact probability of active centers and pollutants decreases sharply; the high current density in Comparative Example 10 drives the pyrrole monomer to polymerize too quickly, forming a highly cross-linked dense gel network, and the internal mass transfer channel is compressed; the graphene oxide layers are oriented and stacked in parallel under a strong electric field, blocking the longitudinal diffusion path of pollutants, and the enrichment function becomes a physical barrier.

Claims

1. A catalyst for treating organic matter with waste salt, characterized in that: Includes the following structures: Titanium-based boron-doped diamond electrode; A nitrogen-doped nanocarbon layer is grown on the surface of the titanium-based boron-doped diamond electrode; Zirconium oxide-coated ferroferric oxide core-shell particles are loaded on the surface of the nitrogen-doped nanocarbon layer; The sulfonated polypyrrole-graphene oxide composite hydrogel is filled in the gaps of the nitrogen-doped nanocarbon layer.

2. The catalyst for treating organic matter with waste salt according to claim 1, characterized in that In the zirconium oxide-coated ferroferric oxide core-shell particles, the ferroferric oxide particle size is 10-30 nm, and the thickness of the zirconium oxide coating layer is 2-5 nm.

3. The catalyst for treating organic matter with waste salt according to claim 1, characterized in that The length of the nitrogen-doped nanocarbon layer is 5-15 μm, the diameter is 50-100 nm, and the nitrogen doping amount is 3-8 at %.

4. The catalyst for treating organic matter with waste salt according to claim 1, characterized in that In the sulfonated polypyrrole-graphene oxide composite hydrogel, the mass ratio of sulfonated polypyrrole to graphene oxide is 1:0.2-1, and the swelling rate is 300-500%.

5. The catalyst for treating organic matter with waste salt according to claim 1, characterized in that The preparation method of the zirconium oxide-coated ferroferric oxide core-shell particles comprises: Step (a) dispersing ferrosoferric oxide nanoparticles in anhydrous ethanol and treating with ultrasound at a power of 300 W for 30 min; Step (b) adding zirconium oxychloride to a final concentration of 0.1-0.5 mol / L; Step (c) hydrothermal reaction at 160-180° C. for 6-12 hours; Step (d) vacuum drying at 60° C. after magnetic field separation.

6. The catalyst for treating organic matter with waste salt according to claim 1, characterized in that The raw materials for synthesizing the sulfonated polypyrrole-graphene oxide composite hydrogel include: Pyrrole monomer: 0.5-1.5 mol / L; Graphene oxide: 1-5g / L; Sodium p-styrenesulfonate: 0.1-0.3 mol / L; Supporting electrolyte: sodium perchlorate 0.1 mol / L.

7. A method for preparing a catalyst for treating organic matter with waste salt according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step (1) titanium-based boron-doped diamond electrode treatment: after sandblasting and pickling the titanium plate, chemical vapor deposition grows a boron-doped diamond layer; Step (2) Growth of nitrogen-doped nanocarbon layer: magnetron sputtering of an iron / aluminum bimetallic layer on the surface of a titanium-based boron-doped diamond electrode in an acetylene / ammonia atmosphere at 630-650° C. to grow a nitrogen-doped nanocarbon layer; Step (3) Loading the Zirconia-coated Fe3O4 core-shell particles: Ultrasonic dispersion of the particles obtained in claim 5 in ethanol, and loading the particles on the surface of the nitrogen-doped nanocarbon layer; Step (4) Filling the sulfonated polypyrrole-graphene oxide composite hydrogel: coating the synthetic raw material of the sulfonated polypyrrole-graphene oxide composite hydrogel according to claim 6 on the surface of the nanocarbon layer, and 2 The constant current deposition was carried out for 300-400 seconds to obtain a catalyst for treating organic matter with waste salt.

8. The method for preparing a catalyst for treating organic matter with waste salt according to claim 7, characterized in that: Step (3) After the zirconium oxide-coated ferroferric oxide core-shell particles are loaded, plasma treatment is performed in an argon atmosphere with a power of 100 W and a time of 5 minutes.

9. The method for preparing a catalyst for treating organic matter with waste salt according to claim 7, characterized in that: After step (4) deposition for 300-400 seconds, the sample was immersed in a 0.1 mol / L sulfuric acid solution for 30 minutes for protonation.

10. A catalyst for treating organic matter with waste salt according to any one of claims 1 to 6, used in the treatment of high-salt wastewater.

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