Boron-doped Co-Cu bimetallic catalyst and preparation method and application thereof

Abstract

The invention discloses a boron-doped Co-Cu bimetallic catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts. The boron-doped Co-Cu bimetallic catalyst comprises cobalt oxide and copper oxide and is doped with element boron to form a metal borate phase, and the metal borate phase at least comprises Co3BO5 and CuB2O4. In addition, the invention also provides a preparation method of the boron-doped Co-Cu bimetallic catalyst, which comprises the following steps: S1, adding a precipitator into a mixed solution containing cobalt salt and copper salt, and then carrying out hydrothermal reaction at 150-250 DEG C to obtain a cobalt-copper precursor; and S2, mixing and grinding the cobalt-copper precursor and a boron source, and then roasting at 400-600 DEG C to obtain the boron-doped Co-Cu bimetallic catalyst. The catalyst provided by the invention can be used for efficiently activating NaClO and realizing rapid removal of organic pollutants.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a boron-doped Co-Cu bimetallic catalyst, its preparation method, and its application. Background Technology

[0002] In current water supply and drainage treatment practices, sodium hypochlorite has always held a central position due to its excellent broad-spectrum disinfection properties and environmental friendliness. Although it possesses a synergistic effect in degrading micropollutants in water, relying solely on chemical oxidation often faces challenges such as long reaction cycles and low reagent utilization when treating chemically stable persistent organic pollutants. To overcome this bottleneck, developing novel catalytic materials capable of efficiently catalyzing the breaking of O-Cl bonds in NaClO, thereby enhancing its degradation ability through free radical or non-free radical pathways, has become a key path to improve the efficiency of existing water treatment processes.

[0003] Recalcitrant organic pollutants are widely present in wastewater from industries such as dyeing, pharmaceuticals, and chemicals. Conventional treatment methods (adsorption, biodegradation, coagulation and sedimentation, etc.) suffer from drawbacks such as long treatment cycles, low mineralization levels, and the potential for secondary pollution, making it difficult to meet increasingly stringent emission standards. Therefore, advanced oxidation technologies, capable of generating highly oxidizing free radicals to efficiently mineralize recalcitrant organic matter, have become a research hotspot in the water treatment field. Among these, systems using sodium hypochlorite (NaClO) as an oxidant offer significant advantages due to their high oxidizing power across a wide pH range, low cost, and on-site preparation capability. However, NaClO itself has limited direct oxidizing capacity and readily generates toxic organochlorine byproducts in the presence of high concentrations of organic matter, limiting its effectiveness when used alone.

[0004] In existing technologies, research on catalytic materials for NaClO activation is relatively limited. Some studies have reported on improving the oxidation performance of NaClO under specific conditions using transition metal oxides, composite metal catalysts, or carbon-supported metal systems. For example, some literature reports the use of Cu–O–Mn metal components loaded on activated carbon supports for NaClO catalytic oxidation of pollutants. This type of system is usually obtained through impregnation-drying-calcination processes, which can improve the treatment effect and NaClO utilization efficiency under certain conditions. Another study prepared bead-like NiOx(OH)y catalysts for hypochlorite conversion / decomposition, obtained by impregnating γ-alumina microspheres with nickel salts and oxidizing them under alkaline conditions. In addition, there are reports on the use of Ni–Fe / Al2O3 bimetallic catalysts coupled with NaClO systems for dye oxidative degradation, the preparation of which involves metal salt precursor loading / calcination steps. However, the aforementioned publicly available solutions are mostly geared towards specific pollutants or specific operating conditions, and the material systems and preparation routes are relatively dispersed. At the same time, some systems may still have problems such as strong dependence on process conditions, insufficient adaptability to complex water quality and insufficient long-term stability. Mature, universal, efficient and stable catalytic materials and preparation technology routes have not yet been formed.

[0005] The activation efficiency of NaClO can be significantly improved by introducing suitable catalysts. Heterogeneous catalysts of transition metals (such as Co, Cu, and Fe) have been successfully applied in activating oxidants such as persulfates and peroxides. Their reversible multivalent redox behavior helps promote the decomposition of oxidants to generate free radicals. For example, Cu(II) shows superior activation performance to Fe(II) and Co(II) in the NaClO system, degrading approximately 77% of organic matter within 60 minutes; Co(II) itself has a weak activation effect on NaClO and is easily deactivated. Existing cobalt-copper catalytic systems still suffer from problems such as moderate activity, susceptibility to interference under complex water quality conditions, and insufficient long-term stability.

[0006] In the field of NaClO activation, there is a lack of research and application reports on bimetallic oxide catalysts with excellent catalytic performance. Therefore, there is an urgent need to develop a novel, highly efficient, stable, and environmentally friendly catalyst to overcome the shortcomings of existing NaClO activation technologies. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a boron-doped Co-Cu bimetallic catalyst, its preparation method and application, thereby solving the technical problem of how to improve the activation performance of NaClO in degrading organic pollutants in the prior art.

[0008] To achieve the above-mentioned technical objectives, the present invention provides a boron-doped Co-Cu bimetallic catalyst, wherein the catalyst comprises cobalt oxide and copper oxide, and is doped with elemental boron to form a metal borate phase, wherein the metal borate phase includes Co3BO5 and CuB2O4.

[0009] In any embodiment, the molar ratio of Co to Cu in the catalyst is 1:(0.08-0.12).

[0010] Furthermore, this invention also proposes a method for preparing the above-mentioned boron-doped Co-Cu bimetallic catalyst, comprising the following steps:

[0011] S1. Add a precipitant to a mixed solution containing cobalt salt and copper salt, and then carry out a hydrothermal reaction at 150-250℃ to obtain a cobalt-copper precursor.

[0012] S2. The cobalt-copper precursor is mixed and ground with a boron source, and then calcined at 400-600℃ to obtain the boron-doped Co-Cu bimetallic catalyst.

[0013] In any embodiment, in step S1, the cobalt salt is at least one of cobalt nitrate, cobalt sulfate, cobalt acetate, and cobalt chloride, and / or the copper salt is at least one of copper nitrate, copper sulfate, copper acetate, and copper chloride; and / or the precipitant is at least one of sodium bicarbonate, sodium carbonate, sodium hydroxide, and urea.

[0014] In any embodiment, in step S2, the boron source is at least one of boric acid, borax, and boric anhydride.

[0015] In any embodiment, in step S1, the hydrothermal reaction is carried out at 150-250°C for 2-6 hours.

[0016] In any embodiment, in step S2, the calcination time at 400-600°C is 1-4 hours.

[0017] In any embodiment, in step S2, the boron source and the cobalt-copper precursor are mixed and ground at a mass ratio of (0.8-1.2):1.

[0018] Furthermore, this invention also proposes the application of the above-mentioned boron-doped Co-Cu bimetallic catalyst or the boron-doped Co-Cu bimetallic catalyst prepared by the above-mentioned preparation method in the oxidative degradation of organic pollutants by activated sodium hypochlorite.

[0019] In any embodiment, the pH of the reaction solution is 3-9, the mass concentration of sodium hypochlorite is 0.1%-1%, the initial mass concentration of the organic pollutants to be degraded is 10-100 mg / L, and the concentration of the catalyst is 25-100 mg / L.

[0020] Compared with existing technologies, the beneficial effects of this invention include: the catalyst proposed in this invention can efficiently activate NaClO, achieving rapid removal of organic pollutants. The catalyst of this invention can remove nearly 80% of the target pollutants within 5 minutes, and the degradation rate can exceed 90% within 10 minutes, significantly improving the efficiency of NaClO in degrading organic pollutants. Research in this invention shows that the Co–Cu bimetallic catalyst has a faster interfacial electron transfer rate and more diverse active sites compared to single metals, exhibiting a synergistic effect in the activation of chlorine-containing oxidants in NaClO. Attached Figure Description

[0021] Figure 1 The XRD diffraction pattern is the crystal structure and surface state analysis of the catalyst prepared in Example 1.

[0022] Figure 2 The graphs show the degradation performance test curves of the catalysts prepared in Example 1 and Comparative Example 1 of this invention (comparison of the removal rate of methylene blue (MB) by different catalytic systems).

[0023] Figure 3 This is a diagram showing the broad applicability of the catalyst prepared in Example 1 of this invention to degrade different types of organic pollutants.

[0024] Figure 4 The graph shows the effect of inorganic anions and humic acid on the MB removal rate of the catalyst prepared in Example 1 of this invention.

[0025] Figure 5 This is a stability test diagram of the catalyst prepared in Example 1 of the present invention for repeated use. Detailed Implementation

[0026] This specific embodiment provides a boron-doped Co-Cu bimetallic catalyst, characterized in that the catalyst comprises cobalt oxide and copper oxide, and is doped with elemental boron to form a metal borate phase, wherein the metal borate phase includes Co3BO5 and CuB2O4, and the molar ratio of Co to Cu in the catalyst is 1:(0.08–0.12). The doping ratio of boron relative to the metal is approximately 5%–20%. The catalyst is a carrier-free powder material and can be used to activate sodium hypochlorite in a homogeneous suspension system.

[0027] This specific embodiment also proposes a method for preparing a boron-doped Co-Cu bimetallic catalyst, including the following steps:

[0028] S1. A precipitant is added to a mixed solution containing cobalt salt and copper salt, followed by a hydrothermal reaction at 150–250°C for 2–6 hours to obtain a cobalt-copper precursor; wherein the cobalt salt is at least one of cobalt nitrate, cobalt sulfate, cobalt acetate, and cobalt chloride, and the copper salt is at least one of copper nitrate, copper sulfate, copper acetate, and copper chloride; wherein the precipitant is at least one of sodium bicarbonate, sodium carbonate, sodium hydroxide, and urea.

[0029] S2. The cobalt-copper precursor and the boron source are mixed and ground at a mass ratio of 1:(0.8-1.2), and then calcined at 400-600℃ for 1-4 hours to obtain the boron-doped Co-Cu bimetallic catalyst; the boron source is at least one of boric acid, borax and boron anhydride.

[0030] This method has simple and controllable process steps, uses inexpensive and readily available raw materials, and is suitable for batch preparation.

[0031] This specific embodiment also proposes the application of the above-mentioned boron-doped Co-Cu bimetallic catalyst or the boron-doped Co-Cu bimetallic catalyst prepared by the above preparation method in the oxidation and degradation of organic pollutants by activated sodium hypochlorite. The pH of the reaction solution is 3-9, the mass concentration of sodium hypochlorite is 0.1%-1%, the initial mass concentration of the organic pollutants to be degraded is 10-100 mg / L, the concentration of the catalyst is 25-100 mg / L, and the reaction temperature is 20-40℃.

[0032] The catalyst can be added at a certain concentration to an aqueous solution containing organic pollutants and NaClO, and the reaction can be carried out under room temperature to medium temperature conditions. Once the catalyst proposed in this invention is introduced, the O–Cl bonds in NaClO are rapidly broken under catalytic action, generating free radicals including superoxide radicals. Singlet oxygen It also contains various reactive oxygen species, including active chlorine (HClO / Cl·), which synergistically oxidize organic pollutants to achieve efficient degradation.

[0033] Other beneficial effects of the present invention include:

[0034] The catalyst of this invention maintains high activity under acidic, neutral, and alkaline conditions, and is suitable for a wide initial pH range of 3–9. Furthermore, it contains anions commonly found in water (such as…). In the presence of natural organic matter (such as humic acid), the catalytic degradation effect is not significantly reduced, demonstrating good adaptability to complex water quality.

[0035] Good stability and environmental friendliness: The catalyst of this invention has a stable structure and excellent reusability. After five consecutive cycles, the pollutant removal rate can still be maintained above 85%, and the leaching concentration of cobalt and copper metals is extremely low, avoiding secondary pollution problems and demonstrating good environmental friendliness.

[0036] Broad-spectrum and highly efficient: The catalyst of this invention exhibits excellent removal effects on various structural types of organic pollutants, including dyes (such as methylene blue and rhodamine B), phenolic compounds, and antibiotics. This demonstrates the broad applicability and excellent application potential of this catalyst in practical industrial wastewater treatment.

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0038] In this invention, the terms "some embodiments," "this embodiment," and examples are used to describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0039] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0040] In this embodiment, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0041] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0042] Example 1

[0043] This embodiment proposes a boron-doped Co-Cu bimetallic catalyst, which is prepared by the following steps:

[0044] S1. Take 2.91g Co(NO3)2·6H2O and 0.24g Cu(NO3)2·3H2O (the molar ratio of Co to Cu is approximately 10:1), dissolve them in 50mL of deionized water, and stir to form a homogeneous metal salt mixture solution. Then prepare 20mL of 1.0M sodium bicarbonate (NaHCO3) solution, and slowly add this precipitant solution dropwise to the above metal salt solution while stirring. After the addition is complete, continue stirring at room temperature for 40 minutes to allow co-precipitation of cobalt and copper ions to form a precursor suspension. Transfer the obtained suspension to the inner liner of a 100mL hydrothermal reactor and react at 200℃ for 4 hours. After the reaction is completed, allow it to cool naturally to room temperature, remove the reaction product, centrifuge to separate the solid, and wash it three times alternately with deionized water and anhydrous ethanol to remove impurity ions. Dry the obtained cobalt-copper precursor solid under vacuum at 80℃ overnight.

[0045] S2. Take the dried cobalt-copper precursor powder and mix it with an equal mass of boric acid (H3BO3). Grind the mixture evenly in a mortar for about 20 minutes. Then, transfer the mixed powder to a muffle furnace and calcine it at 500°C for 2 hours in air to allow boron to be incorporated into the precursor lattice through a high-temperature solid-state reaction. After calcination and cooling, wash the product three times with deionized water and anhydrous ethanol to remove unreacted residual boric acid. Finally, dry the filter cake at 80°C and grind it to obtain a black powdery boron-doped Co-Cu bimetallic catalyst (referred to as Co-Cu-B catalyst). The obtained catalyst mainly contains Co3O4, CuO, Cu2O and other crystalline phases, and a small amount of Co3BO5 and CuB2O4 phases were detected. Figure 1 As shown, this indicates that boron has been successfully incorporated into the cobalt copper oxide system.

[0046] Example 2

[0047] This embodiment proposes a boron-doped Co-Cu bimetallic catalyst, which is prepared by the following steps:

[0048] S1, copper sulfate, and cobalt sulfate were dissolved in 50 mL of deionized water at a Co:Cu molar ratio of 1:0.08, and stirred to form a homogeneous metal salt mixture solution. Then, 20 mL of 1.0 M sodium bicarbonate (NaHCO3) solution was prepared and slowly added dropwise to the metal salt solution with stirring. After the addition was complete, stirring was continued at room temperature for 40 minutes to allow cobalt and copper ions to fully co-precipitate and form a precursor suspension. The resulting suspension was transferred to the inner liner of a 100 mL hydrothermal reactor and reacted at 250 °C for 2 hours. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The reaction product was removed, and the solid was separated by centrifugation. It was washed three times alternately with deionized water and anhydrous ethanol to remove impurity ions. The resulting cobalt-copper precursor solid was vacuum dried overnight at 80 °C.

[0049] S2. The dried cobalt-copper precursor powder was mixed with boric acid (H3BO3) at a molar ratio of 1:0.8 and ground evenly in a mortar for about 20 minutes. The mixed powder was then transferred to a muffle furnace and calcined at 400°C for 4 hours in air to allow boron to be incorporated into the precursor lattice via a high-temperature solid-state reaction. After calcination and cooling, the product was washed three times with deionized water and anhydrous ethanol to remove unreacted residual boric acid. Finally, the filter cake was dried at 80°C and ground to obtain a black powdery boron-doped Co-Cu bimetallic catalyst.

[0050] Example 3

[0051] This embodiment proposes a boron-doped Co–Cu bimetallic catalyst, which is prepared by the following steps:

[0052] S1, copper chloride, and cobalt chloride were dissolved in 50 mL of deionized water at a Co:Cu molar ratio of 1:0.12, and stirred to form a homogeneous metal salt mixture solution. Then, 20 mL of 1.0 M sodium carbonate solution was prepared and slowly added dropwise to the metal salt solution while stirring. After the addition was complete, stirring was continued at room temperature for 40 minutes to allow cobalt and copper ions to fully co-precipitate and form a precursor suspension. The resulting suspension was transferred to a 100 mL hydrothermal reactor and reacted at 150 °C for 6 hours. After the reaction was completed and allowed to cool naturally to room temperature, the reaction product was removed, the solid was separated by centrifugation, and washed three times alternately with deionized water and anhydrous ethanol to remove impurity ions. The resulting cobalt-copper precursor solid was vacuum dried overnight at 80 °C.

[0053] S2. The dried cobalt-copper precursor powder and borax were mixed at a molar ratio of 1:1.2 and ground evenly in a mortar for about 20 minutes. The mixed powder was then transferred to a muffle furnace and calcined at 600°C for 1 hour in air to allow boron to be incorporated into the precursor lattice through a high-temperature solid-state reaction. After calcination and cooling, the product was washed three times with deionized water and anhydrous ethanol to remove unreacted residual borax. Finally, the filter cake was dried at 80°C and ground to obtain a black powdery boron-doped Co-Cu bimetallic catalyst.

[0054] Comparative Example 1

[0055] This comparative example presents a catalyst whose preparation method differs from that of Example 1 in that a boron source is not introduced. Specifically, it is prepared by the following steps:

[0056] S1. Take 2.91g Co(NO3)2·6H2O and 0.24g Cu(NO3)2·3H2O (the molar ratio of Co to Cu is approximately 10:1), dissolve them in 50mL of deionized water, and stir to form a homogeneous metal salt mixture solution. Then prepare 20mL of 1.0M sodium bicarbonate (NaHCO3) solution, and slowly add this precipitant solution dropwise to the above metal salt solution while stirring. After the addition is complete, continue stirring at room temperature for 40 minutes to allow co-precipitation of cobalt and copper ions to form a precursor suspension. Transfer the obtained suspension to the inner liner of a 100mL hydrothermal reactor and react at 200℃ for 4 hours. After the reaction is completed, allow it to cool naturally to room temperature, remove the reaction product, centrifuge to separate the solid, and wash it three times alternately with deionized water and anhydrous ethanol to remove impurity ions. Dry the obtained cobalt-copper precursor solid under vacuum at 80℃ overnight.

[0057] S2. The dried cobalt-copper precursor powder was transferred to a muffle furnace and calcined at 500°C for 2 hours in air. After calcination and cooling, the product was washed three times with deionized water and anhydrous ethanol. Finally, the filter cake was dried at 80°C and ground to obtain the Co-Cu bimetallic catalyst (referred to as Co-Cu catalyst).

[0058] Application Example 1

[0059] The Co-Cu-B catalyst prepared in Example 1 and the Co–Cu catalyst prepared in Comparative Example 1 were used to activate NaClO for the degradation of methylene blue. In this application example, methylene blue (MB), a typical organic dye, was selected as the target pollutant to demonstrate the degradation effect of the catalyst of the present invention on NaClO. MB was prepared into simulated wastewater (100 mL) with an initial mass concentration of 50 mg / L. NaClO solution was added to it to make the effective chlorine concentration reach 0.48% (mass-volume ratio). The initial pH of the solution was adjusted to 7.0 with dilute hydrochloric acid or sodium hydroxide. Then, the Co-Cu-B catalyst prepared in Example 1 or the Co–Cu catalyst prepared in Comparative Example 1 was added to make the catalyst concentration in the solution 50 mg / L. Simulated wastewater with only NaClO added and no catalyst was added was used as a control. The above mixture was reacted at a constant temperature of 35 °C with shaking. During the reaction, 5 mL samples were taken every 5 minutes and filtered through a 0.22 μm microporous membrane to remove catalyst particles. The residual concentration of MB in the solution was then measured. The results are as follows: Figure 2As shown, the degradation rate of MB using the catalyst in Example 1 was approximately 79% after 5 minutes of reaction and reached over 92% after 10 minutes, after which the reaction tended to reach equilibrium. In Comparative Example 1, the undoped boron-coated Co-Cu bimetallic catalyst showed an MB removal rate of less than 50% within 10 minutes under the same conditions. Furthermore, the control group, which only added NaClO and no catalyst, showed an MB removal rate of less than 30% within 10 minutes. This indicates that the catalyst proposed in this invention significantly improves the activation efficiency and degradation rate of NaClO through boron doping.

[0060] The catalytic performance of the catalysts prepared in Examples 2 and 3 is comparable to that of the catalyst prepared in Example 1.

[0061] Further analysis revealed that in the Co-Cu-B / NaClO system, the main active oxygen species involved included hypochlorite / hypochlorous acid (HCI). The reactive chlorine species and peroxides (such as superoxide radicals) produced At the same time, a certain amount of singlet oxygen was also detected. The contribution of hydroxyl radicals (·OH) is relatively small. This indicates that the catalytic system of this invention efficiently degrades the target pollutant through a mechanism that combines free radical and non-free radical pathways. After the above degradation experiments, the solution was tested and found that the leaching concentrations of cobalt and copper ions in the catalyst were extremely low (both below 0.1 mg / L), which can be basically ignored.

[0062] Application Example 2

[0063] Degradation and anti-interference performance tests of multiple pollutants:

[0064] This application example verifies the broad applicability of the catalyst of this invention in degrading different types of organic pollutants, as well as its performance stability under complex water quality conditions. First, Rhodamine B dye (RB), phenol (pH, representing phenolic pollutants), and tetracycline (TC, antibiotic pollutants) were selected as target compounds. Aqueous solutions with an initial concentration of 50 mg / L were prepared for each compound. NaClO (effective chlorine concentration 0.48%) was added to adjust the initial pH to 7, and the Co-Cu-B catalyst prepared in Example 1 (50 mg / L) was added. The reaction was carried out at 35 °C for 25 minutes. After the reaction, the removal rate of each pollutant was measured: the results are as follows. Figure 3 As shown, the decolorization rate of RB reached 99.9%, the removal rate of phenol was approximately 94.1%, and the removal rate of tetracycline was approximately 92.3%. These results demonstrate that the catalyst / NaClO system of this invention not only possesses rapid and efficient oxidation capabilities for dye pollutants (such as MB and RB), but is also applicable to more complex phenolic and pharmaceutical pollutants, exhibiting excellent broad-spectrum degradation capabilities.

[0065] Application Example 3

[0066] To evaluate the catalyst's anti-interference ability under actual aquatic conditions, interference experiments were conducted by adding common inorganic anions and natural organic matter to simulated wastewater containing strontium bromide (MB). An additional 500 mg / L of the catalyst was added to a series of simulated wastewaters containing 50 mg / L MB and 0.48% NaClO. And 10 mg / L of humic acid (HA), with other conditions consistent with Application Example 1, to investigate the degradation effect of MB within a 25-minute reaction time. The experimental results showed that, as Figure 4 As shown, the degradation rate and removal rate of MB after adding the above-mentioned interfering substances are basically the same as those without interference, indicating that common anions and natural organic matter do not have a significant impact on the degradation performance of the catalytic system of this invention. The catalyst of this invention has strong anti-interference ability for complex matrix water samples.

[0067] Application Example 4

[0068] Stability testing of the catalyst for repeated use:

[0069] Using the MB degradation system from Application Example 1 as a model, the catalyst was collected and recovered after 30 minutes of reaction. The surface-adhered products were removed by centrifugation and the catalyst was then added back into a freshly prepared identical reaction system. Five rounds of cyclic degradation experiments were conducted. The results are as follows: Figure 5 As shown, the removal rate of MB exceeded 90% after the first cycle, and decreased slightly in each subsequent cycle, but remained above 86% in the fifth cycle. The concentration of MB in the solution was measured after the cyclic experiment. and The leaching concentrations were all below 0.2 mg / L, indicating that the metal leaching was negligible. Therefore, the catalyst of this invention maintains high levels of catalytic activity and structural stability even after repeated use.

[0070] In summary, the boron-doped Co-Cu bimetallic catalyst provided by this invention overcomes the limitations of existing NaClO activation technology and can be used to construct efficient and stable advanced oxidation processes in water treatment, possessing significant practical value and promising prospects for widespread application. The boron-doped Co–Cu bimetallic catalyst provided by this invention can efficiently and broadly activate sodium hypochlorite to degrade various organic pollutants, and still exhibits excellent stability and anti-interference performance under actual complex water quality conditions. These examples and application cases verify the application potential of the catalyst of this invention in the field of advanced oxidation in water treatment.

[0071] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A boron-doped Co-Cu bimetallic catalyst, characterized in that, The catalyst comprises cobalt oxide and copper oxide, and is doped with elemental boron to form a metal borate phase, wherein the metal borate phase includes Co3BO5 and CuB2O4.

2. The boron-doped Co-Cu bimetallic catalyst according to claim 1, characterized in that, The molar ratio of Co to Cu in the catalyst is 1:(0.08-0.12).

3. A method for preparing a boron-doped Co-Cu bimetallic catalyst, characterized in that, Includes the following steps: S1. Add a precipitant to a mixed solution containing cobalt salt and copper salt, and then carry out a hydrothermal reaction at 150-250℃ to obtain a cobalt-copper precursor. S2. The cobalt-copper precursor is mixed and ground with a boron source, and then calcined at 400-600℃ to obtain the boron-doped Co-Cu bimetallic catalyst.

4. The method for preparing the boron-doped Co-Cu bimetallic catalyst according to claim 3, characterized in that, In step S1, the cobalt salt is at least one of cobalt nitrate, cobalt sulfate, cobalt acetate, and cobalt chloride, and / or the copper salt is at least one of copper nitrate, copper sulfate, copper acetate, and copper chloride; and / or the precipitant is at least one of sodium bicarbonate, sodium carbonate, sodium hydroxide, and urea.

5. The method for preparing the boron-doped Co-Cu bimetallic catalyst according to claim 3, characterized in that, In step S2, the boron source is at least one of boric acid, borax, and boric anhydride.

6. The method for preparing the boron-doped Co-Cu bimetallic catalyst according to claim 3, characterized in that, In step S1, the hydrothermal reaction is carried out at 150-250°C for 2-6 hours.

7. The method for preparing the boron-doped Co-Cu bimetallic catalyst according to claim 3, characterized in that, In step S2, the calcination time at 400-600℃ is 1-4 hours.

8. The method for preparing the boron-doped Co-Cu bimetallic catalyst according to claim 3, characterized in that, In step S2, the boron source and the cobalt-copper precursor are mixed and ground at a mass ratio of (0.8-1.2):

1.

9. The application of a boron-doped Co-Cu bimetallic catalyst according to any one of claims 1-2 or a boron-doped Co-Cu bimetallic catalyst prepared by the preparation method according to any one of claims 3-8 in the oxidative degradation of organic pollutants by activated sodium hypochlorite.

10. The application according to claim 9, characterized in that, The pH of the reaction solution is 3-9, the mass concentration of sodium hypochlorite is 0.1%-1%, the initial mass concentration of the organic pollutants to be degraded is 10-100 mg / L, and the concentration of the catalyst is 25-100 mg / L.

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