A catalyst for treating organic matter with waste salt and a preparation method and application thereof

Abstract

The present application relates to the field of wastewater treatment catalytic materials, and particularly relates to a kind of waste salt treatment organic catalyst and its preparation method and application, including the following structure: titanium-based boron-doped diamond electrode;Nitrogen-doped nanocarbon layer, grown on the surface of the titanium-based boron-doped diamond electrode;Zirconium oxide coated iron oxide core-shell particles, loaded on the surface of the nitrogen-doped nanocarbon layer;Sulfonated polypyrrole-graphene oxide composite hydrogel, filled in the gap between the nitrogen-doped nanocarbon layer.The present application breaks through the mass transfer barrier of high salt by synergistic effect of anti-chlorine poisoning confined catalysis and electrically driven enrichment, and realizes efficient degradation of organic matter.

Description

Technical Field

[0001] This invention relates to the field of catalytic materials for wastewater treatment, specifically to a catalyst for treating organic matter from waste salts, its preparation method, and its application. Background Technology

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

[0003] In chemical oxidation methods, Fenton oxidation technology is widely used due to its high efficiency and economy. The traditional Fenton reaction utilizes the reaction of ferrous ions with hydrogen peroxide to generate highly oxidizing hydroxyl radicals (·OH), which can effectively degrade various organic pollutants. However, in high-salt environments, a large number of chloride ions compete with ferrous ions for binding, significantly inhibiting the efficiency of the Fenton reaction. This necessitates the addition of excessive amounts of iron salts, resulting in the generation of large amounts of iron sludge and causing 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 iron oxide particles. This catalyst is prepared in situ by solvothermal followed by high-temperature calcination. The iron oxide nanoparticles formed have a synergistic coupling effect with the nitrogen-doped carbon material, 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 supported on cobalt oxide. This catalyst utilizes surface polymerization to encapsulate a nitrogen-containing conductive polymer on the surface of nano-Fe3O4, followed by high-temperature calcination to obtain a core-shell structure. While this catalyst exhibits high catalytic activity and magnetic recovery characteristics, its catalytic efficiency is significantly inhibited under high-salt conditions, and it lacks the ability to directionally enrich organic matter.

[0006] CN111266126B discloses a sulfur-doped graphitic carbon nitride nanosheet-supported graphene and iron oxide composite magnetic photocatalyst, which has advantages such as high photocatalytic activity, good stability, and easy recovery. However, this catalyst mainly relies on the photocatalytic mechanism, and in the treatment of high-salt wastewater, high solution turbidity will seriously affect the light penetration ability and reduce the catalytic efficiency.

[0007] CN107020144B discloses a magnetic nitrogen-doped reduced graphene oxide composite catalyst, which is prepared by hydrothermal reaction after mixing urea as nitrogen source and reducing agent with magnetic graphene oxide [4]. This catalyst can catalyze the generation of highly active sulfate radicals from persulfate, which can be used to degrade recalcitrant organic pollutants in water. However, under high salinity conditions, the catalytic efficiency decreases significantly, and the catalyst surface lacks an effective organic matter enrichment mechanism.

[0008] CN112340853B discloses a hybrid hydrogel carrier for treating high-salt wastewater, comprising functional microorganisms and a conductive hydrogel carrier, wherein magnetic iron oxide particles and compatible substances are uniformly distributed on the surface and inside of the conductive hydrogel carrier. While this technology shows some treatment effect in high-salt environments, it mainly relies on microbial degradation, resulting in a slow treatment rate and poor tolerance to toxic organic matter.

[0009] Existing technologies for treating high-salinity organic wastewater suffer from the following major problems: First, in high-salinity environments, the traditional Fenton reaction is strongly inhibited by chloride ions, resulting in a sharp decline in oxidation efficiency and requiring excessive addition of iron salts, leading to secondary pollution from large amounts of iron sludge. Second, while wet catalytic oxidation can avoid the generation of iron sludge, the low mass transfer efficiency inherent in high-salinity wastewater systems severely restricts the catalytic effect, with reaction kinetic constants being only 1 / 3 to 1 / 5 of those in low-salinity systems. Third, existing catalysts lack effective organic matter enrichment mechanisms, making it difficult to achieve efficient catalytic degradation in high-salinity environments. Fourth, existing technologies cannot achieve pure brine reuse; the mixed salt components generated 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 industrial raw material standards, with nearly 97% of the crystallized salt ultimately becoming hazardous waste and forced to be landfilled.

[0010] Therefore, there is an urgent need to develop a new type of 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 the pure reuse of brine, so as to solve the technical bottlenecks faced by existing technologies in the treatment of high-salt organic wastewater. Summary of the Invention

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

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

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

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

[0015] Zirconia-coated iron oxide core-shell particles are loaded onto the surface of the nitrogen-doped carbon nanolayer to form catalytic active centers;

[0016] Sulfonated polypyrrole-graphene oxide composite hydrogels are used to fill the gaps between the nitrogen-doped carbon nanolayers to enrich organic matter.

[0017] The catalyst in this scheme achieves highly efficient synergistic effects under high-salt environments through a multi-level structural design. A titanium-based boron-doped diamond electrode serves as the conductive substrate, possessing excellent electrochemical stability and a wide potential window, providing a stable electron transport channel for the system. The grown nitrogen-doped carbon nanolayers form a three-dimensional conductive network; their abundant pyridine nitrogen / graphite nitrogen sites significantly enhance electron transfer efficiency and simultaneously serve as a support framework for active sites. Zirconia-coated iron oxide core-shell particles are anchored to the surface of the carbon nanolayers. The zirconia coating effectively isolates chloride ions from poisoning the iron active centers, while the internal iron oxide cores achieve directional dissolution and regeneration of iron ions under an electric field. The sulfonated polypyrrole-graphene oxide composite hydrogel filling the gaps between the carbon nanolayers possesses both ion exchange and hydrophobic adsorption functions. Sulfonic acid groups capture cationic organic matter through electrostatic attraction, while graphene sheets enrich aromatic pollutants through π-π interactions, forming a locally high-concentration reaction microenvironment. Through spatial and functional coupling, these components construct an integrated enrichment-catalysis-mineralization platform.

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

[0019] Preferably, the nitrogen-doped carbon nanolayer has a thickness of 50-100 nm and a nitrogen doping amount of 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 method for preparing the zirconium oxide-coated iron oxide core-shell particles includes:

[0022] Step (a) Disperse iron oxide nanoparticles in anhydrous ethanol and treat with ultrasonic power of 300W for 30 min;

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

[0024] Step (c) Hydrothermal reaction at 160-180℃ for 6-12 hours;

[0025] Step (d) After magnetic field separation, vacuum dry at 60°C.

[0026] The catalyst preparation process in this scheme follows a stepwise construction principle of substrate modification, carbon nanolayer growth, active site loading, and functional phase filling. A boron-doped diamond electrode based on titanium is deposited onto a pretreated titanium plate via chemical vapor deposition to form a boron-doped diamond layer, creating a highly stable electrochemical interface. The nitrogen-doped carbon nanolayer is grown using magnetron sputtering of an iron / aluminum bimetallic layer as a catalyst. Vertical orientation growth of carbon nanotubes is achieved through a gas-solid phase reaction in an acetylene / ammonia atmosphere, with active nitrogen atoms from ammonia cracking simultaneously incorporated into the carbon lattice. Zirconia-coated iron oxide core-shell particles are deposited in situ on the iron oxide surface via hydrothermal reaction, forming a dense core-shell structure through crystallization. The loading process relies on ultrasonic dispersion to encourage particle embedding into defect sites on the carbon nanotube surface. Sulfonated polypyrrole-graphene oxide composite hydrogel is in situ filled via electrochemical co-deposition. Pyrrole monomers polymerize on graphene oxide sheets to form a cross-linked network. The introduction of sodium styrene sulfonate endows the gel with ion exchange functionality, and constant current deposition ensures the hydrogel's penetration and strong bonding within the gaps between the carbon nanolayers.

[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: 1-5 g / L;

[0030] Sodium styrene sulfonate: 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, characterized by the following steps:

[0033] Step (1) Titanium-based boron-doped diamond electrode treatment: After the titanium plate is sandblasted and acid-washed, a boron-doped diamond layer is grown by chemical vapor deposition.

[0034] Step (2) Growth of nitrogen-doped nano-carbon layer: A nitrogen-doped nano-carbon layer is grown on the surface of a titanium-based boron-doped diamond electrode by magnetron sputtering of an iron / aluminum bimetallic layer in an acetylene / ammonia atmosphere at 630-650℃.

[0035] Step (3) Zirconia-coated iron oxide core-shell particle loading: The particles are ultrasonically dispersed in ethanol and loaded onto the surface of nitrogen-doped carbon nanolayers;

[0036] Step (4) Sulfonated polypyrrole-graphene oxide composite hydrogel filling: The hydrogel synthesis raw material is coated on the surface of the nano-carbon layer, at 4-5 mA / cm 2 A catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300-400 seconds.

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

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

[0039] This solution also discloses an application of the catalyst described above in the treatment of high-salinity wastewater.

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

[0041] The application method includes the following steps:

[0042] The catalyst was used as the cathode and formed an electrode pair with a titanium-based boron-doped diamond anode with an electrode spacing of 5-10 mm. Then, a DC voltage of 0.8-1.2 V was applied to control the sodium chloride concentration in the wastewater to ≥3 wt%, and aeration was used to maintain a dissolved oxygen concentration of ≥5 mg / L. After the reaction was terminated, the reverse voltage of -1.0 V was switched and maintained for 10 min.

[0043] The cathode synchronization achieves the following functions:

[0044] (I) Electroreduction of dissolved oxygen to generate hydrogen peroxide;

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

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

[0047] Compared to 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 channel. Vertically oriented nitrogen-doped carbon nanolayers form a three-dimensional conductive network; the exposed pyridine nitrogen sites on their surface significantly enhance electron capture and transfer capabilities, while also providing a topological framework for anchoring active centers. Zirconia-coated iron oxide core-shell particles are chemically bonded to the carbon nanotube surface; the dense zirconia coating forms a chloride ion-selective barrier, and the internal iron oxide core achieves controllable release and regeneration of iron species under electric field regulation. A sulfonated polypyrrole-graphene oxide composite hydrogel filling the gaps between the carbon nanolayers constructs an amphiphilic microenvironment; sulfonic acid groups enrich cationic pollutants through ion exchange, while graphene domains capture nonpolar organic matter through hydrophobic interactions, forming a locally high-concentration reaction interface. The four-layer structure achieves a synergistic enrichment-catalysis-protection mechanism through precise matching of steric hindrance and electron channels.

[0049] 2. The catalyst preparation process in this scheme adopts a step-by-step in-situ synthesis strategy to achieve atomic-level control of interface bonding. A conformal diamond layer is formed on a titanium substrate via chemical vapor deposition of a titanium-based boron-doped diamond electrode, and boron doping induces sp... 3 -sp 2 Hybridized transition states ensure the conductivity and stability of the electrodes. Nitrogen-doped carbon nanolayers undergo gas-solid growth mediated by an iron / aluminum bimetallic catalytic layer. Carbon radicals generated from acetylene cracking are co-intercalated with nitrogen species in an ammonia atmosphere, forming a vertically oriented nitrogen-doped carbon lattice. Zirconia-coated iron(III) oxide core-shell particles achieve interfacial atomic recombination through hydrothermal crystallization. Zirconium oxychloride precursors hydrolyze and condense on the iron(III) oxide surface, forming a zirconium oxide coating with oxygen vacancies. Lattice mismatch stress is alleviated by Zr-O-Fe bond bridging. The composite hydrogel achieves nanoscale confinement filling through electrochemical deposition. Pyrrole monomers electropolymerize on graphene oxide sheets to form an interpenetrating network, while sulfonic acid groups are simultaneously incorporated into the polymer backbone. Constant current driving ensures molecular-level dense filling of the gel within micron-scale gaps.

[0050] 3. In this electrocatalytic system, the catalyst achieves efficient degradation and closed-loop degradation through multiphase interfacial reactions. A triple cascade reaction occurs on the cathode surface: dissolved oxygen is reduced to hydrogen peroxide via a two-electron path at the edge sites of nitrogen-doped carbon nanotubes; iron ions seeping from the zirconia layer trigger a Fenton-like reaction within the confined space with hydrogen peroxide, generating highly reactive hydroxyl radicals; the negative electric field of the cathode drives anionic pollutants to migrate to the electrode surface, where they are dynamically captured and enriched by the hydrogel. The zirconia coating acts as an ion sieve, selectively blocking chloride ions from approaching the active center and eliminating the free radical quenching effect. On the anode side, chloride ions are preferentially oxidized to generate active chlorine species, which diffuse along the concentration gradient to the cathode region to mineralize residual organic matter. The reverse voltage switching at the reaction termination stage forces the adsorbed pollutants to desorb through electric field reversal and are deeply oxidized by active chlorine into inorganic small molecules. This process forms a dynamic equilibrium of electromigration enrichment-confined catalysis-anode oxygen replenishment, breaking through the mass transfer limitations of the high-salt system, and simultaneously achieving complete mineralization of organic matter and pure reuse of the salt matrix. Detailed Implementation

[0051] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0052] General Implementation Examples

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

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

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

[0056] Step (2) Growth of nitrogen-doped carbon nanolayers:

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

[0058] Step (3) Zirconia-coated iron oxide core-shell particles loading:

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

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

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

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

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

[0064] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 2 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0066] Preparation of composite hydrogel:

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

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

[0069] Sodium styrene sulfonate: 0.1-0.3 mol / L;

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

[0071] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4-5 mA / cm². 2The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300-400 s at 25±1℃, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60℃ for 2 h.

[0072] Example 1

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

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

[0075] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0076] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0077] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0080] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0081] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0082] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0084] Preparation of composite hydrogel:

[0085] Pyrrole monomer: 0.5 mol / L;

[0086] Graphene oxide: 1 g / L;

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

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

[0089] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0090] Example 2

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

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

[0093] Step (2) Growth of nitrogen-doped carbon nanolayers:

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

[0095] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0098] Step (c) Hydrothermal reaction at 170℃ for 8 hours to form a zirconium oxide coating layer;

[0099] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

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

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

[0102] Preparation of composite hydrogel:

[0103] Pyrrole monomer: 0.8 mol / L;

[0104] Graphene oxide: 3 g / L;

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

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

[0107] The composite hydrogel was coated onto the surface of the carbon nanolayer, and the temperature was 4.5 mA / cm². 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 350 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0108] Example 3

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

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

[0111] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0112] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an atmosphere with an acetylene to ammonia gas flow ratio of 1:3. The carbon nanolayer thickness was controlled at 90 nm, the growth time was 60 min, and the nitrogen doping amount was 5.4 at%.

[0113] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0116] Step (c) Hydrothermal reaction at 175℃ for 10 hours to form a zirconium oxide coating layer;

[0117] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0118] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 2 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0120] Preparation of composite hydrogel:

[0121] Pyrrole monomer: 1.2 mol / L;

[0122] Graphene oxide: 4 g / L;

[0123] Sodium styrene sulfonate: 0.25 mol / L;

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

[0125] The composite hydrogel was coated onto the surface of the carbon nanolayer at 5 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 380 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0126] Example 4

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

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

[0129] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0130] Magnetron sputtering of iron / aluminum bimetallic layer: In an atmosphere with an acetylene and ammonia gas flow ratio of 1:3, a total pressure of 20 kPa, and a temperature of 640℃, a nitrogen-doped nano-carbon layer was grown on the iron / aluminum bimetallic layer. The growth time was 50 min, the thickness of the nano-carbon layer was controlled at 65 nm, and the nitrogen doping amount was 4.8 at%. The growth of nitrogen-doped nano-carbon layer was completed.

[0131] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0134] Step (c) Hydrothermal reaction at 165℃ for 11 hours to form a zirconium oxide coating layer;

[0135] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0136] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1.2 mg / mL. This dispersion was then coated onto the surface of a nitrogen-doped carbon nanolayer and subjected to 100 W plasma treatment for 5 min under an argon atmosphere to achieve loading.

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

[0138] Preparation of composite hydrogel:

[0139] Pyrrole monomer: 0.7 mol / L;

[0140] Graphene oxide: 2 g / L;

[0141] Sodium styrene sulfonate: 0.15 mol / L;

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

[0143] The composite hydrogel was coated onto the surface of the carbon nanolayer, and the temperature was 4.2 mA / cm². 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 340 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0144] Example 5

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

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

[0147] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0148] Magnetron sputtering of iron / aluminum bimetallic layer: In an atmosphere with an acetylene and ammonia gas flow ratio of 1:3, a total pressure of 20 kPa, and a temperature of 650℃, a nitrogen-doped nano-carbon layer was grown on the iron / aluminum bimetallic layer. The growth time was 55 min, the thickness of the nano-carbon layer was controlled at 85 nm, and the nitrogen doping amount was 5.1 at%.

[0149] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0152] Step (c) Hydrothermal reaction at 175℃ for 7 hours to form a zirconium oxide coating layer;

[0153] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

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

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

[0156] Preparation of composite hydrogel:

[0157] Pyrrole monomer: 1.1 mol / L;

[0158] Graphene oxide: 4 g / L;

[0159] Sodium styrene sulfonate: 0.22 mol / L;

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

[0161] The composite hydrogel was coated onto the surface of the carbon nanolayer, and the temperature was 4.7 mA / cm². 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 370 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0162] Example 6

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

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

[0165] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0166] Magnetron sputtering of iron / aluminum bimetallic layer: In an atmosphere with an acetylene and ammonia gas flow ratio of 1:3, a total pressure of 20 kPa, and a temperature of 650 °C, a nitrogen-doped nano-carbon layer was grown on the iron / aluminum bimetallic layer. The growth time was 60 min, the thickness of the nano-carbon layer was controlled at 85 nm, and the nitrogen doping amount was 5.3 at%. The growth of nitrogen-doped nano-carbon layer was completed.

[0167] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0170] Step (c) Hydrothermal reaction at 178℃ for 9 hours to form a zirconium oxide coating layer;

[0171] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0172] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1.9 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and subjected to 100 W plasma treatment for 5 min under an argon atmosphere to achieve loading.

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

[0174] Preparation of composite hydrogel:

[0175] Pyrrole monomer: 1.4 mol / L;

[0176] Graphene oxide: 4.5 g / L;

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

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

[0179] The composite hydrogel was coated onto the surface of the carbon nanolayer, and the temperature was 4.9 mA / cm². 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 390 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0180] Comparative Example 1

[0181] The difference from Example 1 is that the growth of the nano-carbon layer is insufficient:

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

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

[0184] Step (2) Growth of nitrogen-doped carbon nanolayers:

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

[0186] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0189] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0190] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0191] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0193] Preparation of composite hydrogel:

[0194] Pyrrole monomer: 0.5 mol / L;

[0195] Graphene oxide: 1 g / L;

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

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

[0198] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0199] Comparative Example 2

[0200] The difference from Example 1 is that the iron(III) oxide is not coated with zirconium oxide:

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

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

[0203] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0204] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0205] Step (3) Loading of iron oxide core-shell particles:

[0206] Iron oxide nanoparticles with a particle size of 20 nm were ultrasonicated at 300 W for 30 min in anhydrous ethanol to obtain a solid concentration of 1 mg / mL. The solid was then coated on the surface of a nitrogen-doped carbon nanolayer and subjected to plasma treatment at 100 W for 5 min in an argon atmosphere to achieve loading.

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

[0208] Preparation of composite hydrogel:

[0209] Pyrrole monomer: 0.5 mol / L;

[0210] Graphene oxide: 1 g / L;

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

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

[0213] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0214] Comparative Example 3

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

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

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

[0218] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0219] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0220] Step (3) Zirconia-coated iron oxide core-shell particles loading:

[0221] Step (a) Fe3O4 nanoparticles with a particle size of 20 nm were sonicated in anhydrous ethanol at 300 W for 30 min to obtain a dispersion with a solid concentration of 10 mg / mL.

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

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

[0224] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0225] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

[0226] Step (4) Filling with sulfonated polypyrrole-graphene oxide composite hydrogel:

[0227] Preparation of composite hydrogel:

[0228] Pyrrole monomer: 0.5 mol / L;

[0229] Graphene oxide: 1 g / L;

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

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

[0232] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0233] Comparative Example 4

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

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

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

[0237] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0238] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0239] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0242] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0243] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0244] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 5 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100 W plasma under an argon atmosphere for 5 min to achieve loading.

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

[0246] Preparation of composite hydrogel:

[0247] Pyrrole monomer: 0.5 mol / L;

[0248] Graphene oxide: 1 g / L;

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

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

[0251] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0252] Comparative Example 5

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

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

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

[0256] Step (2) Growth of nitrogen-doped carbon nanolayers:

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

[0258] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0261] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0262] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0263] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0265] Preparation of composite hydrogel:

[0266] Pyrrole monomer: 0.5 mol / L;

[0267] Graphene oxide: 1 g / L;

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

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

[0270] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0271] Comparative Example 6

[0272] The difference from the previous example is that the prepared zirconium oxide-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconium oxide-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was then coated onto the surface of a nitrogen-doped carbon nanolayer and dried at 50°C to achieve loading.

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

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

[0275] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0276] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0277] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0280] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0281] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0282] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was then coated onto the surface of a nitrogen-doped carbon nanolayer and dried at 50 °C to achieve loading.

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

[0284] Preparation of composite hydrogel:

[0285] Pyrrole monomer: 0.5 mol / L;

[0286] Graphene oxide: 1 g / L;

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

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

[0289] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0290] Comparative Example 7

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

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

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

[0294] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0295] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0296] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0299] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0300] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0301] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated onto the surface of a nitrogen-doped carbon nanolayer and subjected to 100W plasma treatment for 5 min under an argon atmosphere to achieve loading, thus obtaining a catalyst for treating organic matter from waste salt.

[0302] Comparative Example 8

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

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

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

[0306] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0307] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0308] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0311] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0312] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0313] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0315] Preparation of composite hydrogel:

[0316] Pyrrole monomer: 0.5 mol / L;

[0317] Graphene oxide: 1 g / L;

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

[0319] The composite hydrogel was coated onto the surface of the carbon nanolayer at 4 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[0320] Comparative Example 9

[0321] The difference from Example 1 is that a composite hydrogel was coated onto the surface of the carbon nanolayer and vacuum dried at 60°C for 2 hours to obtain a catalyst for treating organic matter from waste salt:

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

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

[0324] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0325] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0326] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0329] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0330] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0331] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0333] Preparation of composite hydrogel:

[0334] Pyrrole monomer: 0.5 mol / L;

[0335] Graphene oxide: 1 g / L;

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

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

[0338] A composite hydrogel was coated onto the surface of a carbon nanolayer and dried under vacuum at 60°C for 2 hours to obtain a catalyst for treating organic matter from 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 from waste salt includes the following steps:

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

[0343] Step (2) Growth of nitrogen-doped carbon nanolayers:

[0344] Nitrogen-doped carbon nanolayers were grown on an iron / aluminum bimetallic layer at a total pressure of 20 kPa and an acetylene to ammonia gas flow ratio of 1:3 for 45 min, with a carbon nanolayer thickness of 80 nm and a nitrogen doping amount of 4.8 at%.

[0345] Step (3) Zirconia-coated iron oxide core-shell particles 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 obtain a dispersion with a solid concentration of 10 mg / mL.

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

[0348] Step (c) Hydrothermal reaction at 160℃ for 12 hours to form a zirconium oxide coating layer;

[0349] Step (d): Separate under a 0.5T magnetic field for 10 min, then vacuum dry at 60℃ for 6 h;

[0350] The prepared zirconia-coated iron oxide was ultrasonically dispersed in ethanol to obtain a zirconia-coated iron oxide core-shell particle dispersion with a solid mass concentration of 1 mg / mL. This dispersion was coated on the surface of a nitrogen-doped carbon nanolayer and treated with 100W plasma for 5 min under an argon atmosphere to achieve loading.

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

[0352] Preparation of composite hydrogel:

[0353] Pyrrole monomer: 0.5 mol / L;

[0354] Graphene oxide: 1 g / L;

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

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

[0357] The composite hydrogel was coated onto the surface of the carbon nanolayer at 10 mA / cm. 2 The catalyst for treating organic matter from waste salt was obtained by constant current deposition for 300 s at 25 °C, followed by soaking in 0.1 mol / L sulfuric acid solution for 30 min, rinsing with deionized water until neutral, and vacuum drying at 60 °C for 2 h.

[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 the cathode, and a titanium-based boron-doped diamond anode is used to form an electrode pair with an electrode spacing of 10 mm. Then, a DC voltage of 1.0 V is applied, the sodium chloride concentration in the wastewater is controlled at 4 wt%, and the dissolved oxygen concentration is maintained at 6 mg / L during aeration to treat organic wastewater. After the reaction is terminated, the reverse voltage of -1.0 V is switched and maintained for 10 min.

[0359] Performance testing: 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-mentioned organic matter in the water was measured after treatment, as shown in Table 2.

[0363] Table 2. Organic matter content in water samples after catalyst treatment in the examples and comparative examples.

[0364]

[0365]

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

[0367] Compared to Example 1: In Comparative Example 1, insufficient growth of the nano-carbon layer and incomplete development of the three-dimensional conductive network significantly reduced the density of exposed pyridine nitrogen / graphite nitrogen catalytic sites, leading to a decrease in the efficiency of hydrogen peroxide generation via the two-electron oxygen reduction pathway. Simultaneously, the weakened support structure reduced the dispersion of subsequently loaded core-shell particles, decreased the effective contact area of ​​active centers, and hindered the overall catalytic reaction kinetics. In Comparative Example 2, the iron(III) oxide core was directly exposed to a high-salt environment, where chloride ions competitively poisoned the iron active sites through complexation, irreversibly quenching hydroxyl radicals. Uncontrolled iron ion dissolution disrupted the solid-liquid interface equilibrium, causing the Fenton-like reaction chain to break, and the dissolved iron combined with organic byproducts to form a more stable reaction. Complexes exacerbate catalytic deactivation; in Comparative Example 3, the excessively thick ceramic coating layer forms a dense diffusion barrier, severely hindering 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 accumulation of lattice stress inside the coating layer induces microcracks, forming chloride ion permeation channels; in Comparative Example 4, the excessively high core-shell particle loading concentration induces an aggregation effect, blocking the surface pores of the nitrogen-doped carbon layer and weakening the hydrogel's ability to permeate and fill nano-gap; the integrity of the coating layer at the edge of the agglomerates is damaged, and the locally exposed Fe3O4 becomes a chloride ion attack target, forming a weak region of catalytic failure; in Comparative Example 5, the lack of a metal catalytic layer leads to disordered growth of the nitrogen-doped carbon layer, and the carbon lattice sp 2Increased bonding defects and broken electron transport channels; non-uniform nitrogen doping leads to an imbalance in the distribution of catalytic active sites (pyridine nitrogen), resulting in a significant increase in electrochemical interfacial impedance; in Comparative Example 6, thermal drying instead of plasma treatment only achieves physical adsorption, without forming chemical bonds between particles and the carbon layer; the weak interfacial bonding causes core-shell particles to detach during electrochemical oscillations, resulting in a continuous loss of active centers, and the detached particles adsorb pollutants to form a masking layer, hindering mass transfer in the electrode reaction; in Comparative Example 7, the lack of hydrogel enrichment function prevents negatively charged organic matter from accumulating on the electrode surface through electrostatic attraction and π-π interactions; insufficient concentration of bulk pollutants leads to the electrocatalytic reaction being controlled by mass transfer diffusion, resulting in a mismatch between the free radical generation rate and the organic matter migration rate; in Comparative Example 8, unsulfonated polypyrrole loses its ionization... The exchange capacity of cationic pollutants is reduced, causing them to be repelled from the cathode surface by electrostatic repulsion. At the same time, the decreased hydrophilicity of the hydrogel weakens the capture of polar organic matter, destroying the foundation for the construction of a local high-concentration microenvironment. In Comparative Example 9, thermal drying replaces electrodeposition, causing the hydrogel to shrink and solidify, failing to penetrate into the nanoscale gaps of the nitrogen-doped carbon layer, resulting in a surface covering rather than a three-dimensional interpenetrating structure at the composite catalytic interface. Micron-sized pores are generated between the gel and the carbon layer, drastically reducing the probability of contact between the active center and pollutants. In Comparative Example 10, high current density drives the rapid polymerization of pyrrole monomers, forming a highly cross-linked dense gel network, compressing the internal mass transfer channels. Graphene oxide sheets are stacked parallel to the electrode orientation 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 an organic substance with waste salt, characterized by comprising a metal oxide and a zeolite. The application relates to a catalyst for treating organic matters in waste salt, and belongs to the field of environmental protection. The catalyst comprises the following structures: A titanium-based boron-doped diamond electrode; A nitrogen-doped nanocarbon layer grown on the surface of the titanium-based boron-doped diamond electrode; Zirconium oxide-coated ferroferric oxide core-shell particles loaded on the surface of the nitrogen-doped nanocarbon layer; 2. The catalyst for treating waste salt organic matter according to claim 1, characterized in that, A sulfonated polypyrrole-graphene oxide composite hydrogel filled in the gap of the nitrogen-doped nanocarbon layer.

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

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

5. The catalyst for treating waste salt organic matter 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 %. The preparation method of the zirconium oxide-coated ferroferric oxide core-shell particles comprises the following steps: Step (a) dispersing ferroferric oxide nanoparticles in anhydrous ethanol, and treating for 30 min under an ultrasonic power of 300 W; Step (b) adding zirconium oxychloride to a final concentration of 0.1-0.5 mol / L; Step (c) hydrothermal reaction at 160-180 DEG C for 6-12 h; 6. The catalyst for treating waste salt organic matter according to claim 1, characterized in that, Step (d) vacuum drying at 60 DEG C after magnetic field separation. The synthesis raw materials of the sulfonated polypyrrole-graphene oxide composite hydrogel comprise: Pyrrole monomer: 0.5-1.5 mol / L; Graphene oxide: 1-5 g / L; Sodium p-styrenesulfonate: 0.1-0.3 mol / L; 7. A method for producing a catalyst for treating an organic substance with waste salt according to any one of claims 1 to 6, characterized by Supporting electrolyte: sodium perchlorate 0.1 mol / L. The application further discloses a preparation method of the catalyst. The preparation method comprises the following steps: Step (1) titanium-based boron-doped diamond electrode treatment: after sand blasting and acid pickling of a titanium plate, a boron-doped diamond layer is grown through chemical vapor deposition; Step (4) sulfonated polypyrrole-graphene oxide composite hydrogel filling: the synthesis of raw materials of sulfonated polypyrrole-graphene oxide composite hydrogel in claim 6 is coated on the surface of nano-carbon layer, and the current is 4-5 mA / cm 2 Constant current deposition 300-400s, obtain waste salt treatment organic catalyst.

8. The method for preparing the catalyst for treating organic matter from waste salt according to claim 7, characterized in that, Step (2) nitrogen-doped nanocarbon layer growth: an iron / aluminum double-metal layer is magnetron sputtered on the surface of the titanium-based boron-doped diamond electrode, a nitrogen-doped nanocarbon layer is grown in an ethyne / ammonia atmosphere at 630-650 DEG C; 9. The method for preparing the catalyst for treating organic matter from waste salt according to claim 7, characterized in that, Step (3) zirconium oxide-coated ferroferric oxide core-shell particle loading: the particles obtained in claim 5 are ultrasonically dispersed in ethanol and loaded on the surface of the nitrogen-doped nanocarbon layer; Step (3) after the zirconium oxide-coated ferroferric oxide core-shell particles are loaded, plasma treatment is carried out in an argon atmosphere, the power is 100 W, and the time is 5 min. Step (4) after deposition for 300-400 s, the titanium-based boron-doped diamond electrode is immersed in a 0.1 mol / L sulfuric acid solution for 30 min to carry out protonation.

10. The catalyst for treating organic matters in waste salt is applied to high-salt wastewater treatment.

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