Ni1Co1 catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of catalytic materials, in particular to a Ni1Co1 catalyst and a preparation method and application thereof.The preparation method of the Ni1Co1 catalyst comprises the steps that water-soluble nickel salt and water-soluble cobalt salt are dissolved in water, and a first solution is obtained; naOH and Na2CO3 are dissolved in water, and a second solution is obtained; and mixing the first solution and the second solution, carrying out a co-precipitation reaction, and carrying out drying treatment to obtain the Ni1Co1 catalyst. The Ni1Co1 catalyst obtained by the preparation method disclosed by the invention has ordered and regular two-dimensional flaky repetitive units and uniformly distributed active sites, so that the catalytic efficiency and the stability of the Ni1Co1 catalyst are remarkably improved. In addition, the Ni1Co1 catalyst obtained by the invention can activate peroxymonosulfate to quickly degrade DNA basic groups and organic pollutants in an aqueous solution.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic materials, and in particular to a Ni1Co1 catalyst and a preparation method and application thereof. Background Art

[0002] Water pollution can directly threaten human health, destroy biodiversity and cause many ecological and environmental problems, which needs to arouse people's great concern. The concentration of antibiotics in water bodies has increased year by year, which not only affects the growth and reproduction of aquatic organisms, but also aggravates the spread of antibiotic resistance, forms resistant strains, and increases the difficulty of disease transmission and treatment. The bioaccumulation and transmission of resistance genes will disrupt the regional ecological balance and endanger human health. Because the resistance gene molecules are extremely stable, they are difficult to remove by conventional treatment methods. Therefore, developing a method to quickly and efficiently destroy the molecular structure of resistance genes and degrade the DNA bases therein has become a problem that needs to be solved urgently.

[0003] In the study of water treatment and DNA degradation, there is a problem of balancing efficiency and selectivity. Among the many emerging water treatment technologies, advanced oxidation technologies (AOPs) have attracted much attention due to their ability to efficiently generate reactive oxygen species (ROSs) and rapidly degrade stubborn organic pollutants in water. However, in the study of rapid removal of DNA bases by peroxymonosulfate (PMS), the disordered catalysts prepared by traditional preparation methods usually show low catalytic efficiency and stability due to the lack of regular structure and uniform distribution of active sites, which limits their performance in complex reactions. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a Ni1Co1 catalyst and a preparation method and application thereof. The present invention uses water-soluble nickel salt, water-soluble cobalt salt, NaOH and Na2CO3 as raw materials, and prepares the Ni1Co1 catalyst through a coprecipitation reaction. The Ni1Co1 catalyst obtained by the preparation method of the present invention has an ordered and regular two-dimensional sheet-like repeating unit and uniformly distributed active sites, which significantly improves the catalytic efficiency and stability of the Ni1Co1 catalyst. The Ni1Co1 catalyst obtained by the present invention can activate peroxymonosulfate to quickly degrade DNA bases and organic pollutants in aqueous solution.

[0005] In order to achieve the above purpose, the technical solution adopted in this application is:

[0006] The first object of the present invention is to provide a method for preparing a Ni1Co1 catalyst, comprising the following steps:

[0007] A water-soluble nickel salt and a water-soluble cobalt salt are dissolved in water to obtain a solution No. 1.

[0008] Dissolve NaOH and Na2CO3 in water to obtain solution No. 2.

[0009] Solution 1 and solution 2 are mixed and co-precipitated. In the co-precipitation reaction, NaOH provides an alkaline environment, while Na2CO3 regulates the pH value and also provides carbonate ions, which promotes Ni 2+ and Co 2+ The concentration exceeds the solubility of its hydroxide, thus inducing Ni 2+ and Co 2+ With OH - Coprecipitation to form nickel-cobalt double hydroxide to obtain Ni1Co1 catalyst; + 、Co + , the molar ratio of NaOH and Na2CO3 is 1:0.98~1.2:1:0.98~1.2.

[0010] Preferably, the coprecipitation reaction conditions are: stirring at 60° C. to 80° C. for 16 h to 18 h.

[0011] Preferably, the water-soluble cobalt salt is selected from cobalt nitrate, cobalt sulfate, cobalt chloride or cobalt acetate; the water-soluble nickel salt is selected from nickel nitrate, nickel sulfate, cobalt chloride or nickel acetate.

[0012] Preferably, the drying conditions of the Ni1Co1 catalyst are: drying at 50°C to 80°C for 10h to 24h.

[0013] The second object of the present invention is to provide a Ni1Co1 catalyst prepared by the above preparation method.

[0014] Preferably, in the Ni1Co1 catalyst, a plurality of nickel-cobalt double hydroxides are arranged in layers, and nickel hydroxide and cobalt hydroxide in the nickel-cobalt double hydroxide are arranged alternately.

[0015] The third object of the present invention is to provide the use of the above Ni1Co1 catalyst in the preparation of an organic pollutant degradation agent or a DNA base degradation agent.

[0016] Preferably, the application method in the preparation of a DNA base degrading agent is:

[0017] The Ni1Co1 catalyst is mixed with a DNA base solution in the presence of peroxymonosulfate.

[0018] Preferably, the mass volume ratio of the Ni1Co1 catalyst, the DNA base solution and the peroxymonosulfate is 1.8g-2.2g:1mL:55g-65g; wherein the mass concentration of the DNA base in the DNA base solution is 2mg / L-30mg / L.

[0019] Preferably, the pH value of the DNA base solution is 2-11.

[0020] Preferably, the application method in preparing an organic pollutant degradation agent is:

[0021] The Ni1Co1 catalyst is mixed with an organic pollutant solution in the presence of peroxymonosulfate.

[0022] Preferably, the mass volume ratio of the Ni1Co1 catalyst, the organic pollutant solution and the peroxymonosulfate is 1g-3g: 2mL-4mL: 1g-2g; wherein the mass concentration of the organic pollutant solution is 20mg / L-40mg / L.

[0023] Preferably, the organic pollutant in the organic pollutant solution is selected from chloroquine phosphate, norfloxacin, oxytetracycline or tetracycline.

[0024] Preferably, the stirring rate of the mixing is 300 rpm / min to 500 rpm / min.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention provides a method for preparing a Ni1Co1 catalyst, comprising dissolving a water-soluble nickel salt and a water-soluble cobalt salt in water to obtain a first solution; dissolving NaOH and Na2CO3 in water to obtain a second solution; mixing the first solution and the second solution and performing a coprecipitation reaction. In the coprecipitation reaction, NaOH provides an alkaline environment, while Na2CO3 regulates the pH value and also provides carbonate ions, thereby promoting Ni 2+ and Co 2+ The concentration exceeds the solubility of its hydroxide, thus inducing Ni 2+ and Co 2+ With OH - Coprecipitation to form nickel-cobalt double hydroxide to obtain Ni1Co1 catalyst; + 、Co + , the molar ratio of NaOH and Na2CO3 is 1:0.98~1.2:1:0.98~1.2.

[0027] Compared with the disordered catalyst in the prior art, the present invention uses NaOH to provide an alkaline environment through a co-precipitation reaction, and Na2CO3 regulates the pH value while providing CO3 2- This dual-component adjustment method helps to form a more uniform and dense Ni1Co1 catalyst structure. 2+ and Co 2+ With OH -Co-precipitation forms nickel-cobalt double hydroxide. In nickel-cobalt double hydroxide, nickel hydroxide and cobalt hydroxide are arranged alternately. The nickel-cobalt double hydroxide in the Ni1Co1 catalyst is a sheet-like structure, which is stacked in layers to form a highly regular and repetitive two-dimensional system.

[0028] In terms of active sites, the Ni atoms and Co atoms in the Ni1Co1 catalyst achieve synergistic effects at the nanoscale, increasing the number of active sites of the Ni1Co1 catalyst. In addition, the layered structure of the nickel-cobalt double hydroxide provides the Ni1Co1 catalyst with a large specific surface area, and by optimizing the surface arrangement, electronic structure and atomic coordination of the Ni1Co1 catalyst, the Ni1Co1 catalyst has high active sites.

[0029] 2. The Ni1Co1 catalyst prepared by the present invention can rapidly and effectively degrade DNA bases in water by activating peroxymonosulfate. Among them, the removal rate of thymine is as high as 100%, the degradation rate of adenine is also 96.0%, the degradation rate of cytosine is 83.9%, and the degradation rate of guanine is 77.2%. The Ni1Co1 catalyst effectively activates peroxymonosulfate to generate reactive oxygen species (ROSs) with strong oxidizing ability. These ROSs greatly promote the removal process of DNA bases and accelerate the overall reaction rate.

[0030] In addition, the Ni1Co1 catalyst prepared by the present invention has a synergistic strengthening effect with peroxymonosulfate, and can better remove a variety of organic pollutants. Among them, at an initial mass concentration of 30 mg / L, the removal rate of chloroquine phosphate reached 100%, the removal rate of norfloxacin was 87.0%, the removal rate of oxytetracycline was 93.7%, and the removal rate of tetracycline was as high as 96.8%.

[0031] 3. The preparation method of the Ni1Co1 catalyst of the present invention is simple to operate, and the raw materials are cheap and easily available, thereby significantly reducing the production cost; in addition, the Ni1Co1 catalyst obtained by the present invention can maintain the property of being insoluble in water after completing the catalytic reaction, effectively avoiding any form of secondary pollution to the water body; and the Ni1Co1 catalyst has a stable structure and can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 These are the SEM images and EDS energy spectra of the Ni1Co1 catalyst prepared in Example 1 of the present invention, wherein (a) is the SEM image magnified at 200 nm, (b) is the SEM image magnified at 50 nm, (c) is the EDS energy spectrum of Ni, and (d) is the EDS energy spectrum of Co.

[0033] Figure 2The results of DNA base degradation by Ni1Co1 catalyst, PMS, PDS, Ni1Co1 / PDS and Ni1Co1 / PM prepared in Example 1 of the present invention, wherein (a) is adenine, (b) is cytosine, (c) is thymine, and (d) is guanine.

[0034] Figure 3 The graphs show the degradation results of DNA bases by Ni1Co1 / PMS of the present invention at different pH values, wherein (a) is adenine, (b) is cytosine, (c) is thymine, and (d) is guanine.

[0035] Figure 4 The graphs show the degradation results of DNA bases by Ni1Co1 / PMS of the present invention in the presence of different coexisting anions, wherein (a) is adenine, (b) is cytosine, (c) is thymine, and (d) is guanine.

[0036] Figure 5 This is a test diagram of the degradation of DNA bases in different water qualities by Ni1Co1 / PMS of the present invention.

[0037] Figure 6 This is the Zeta potential diagram of the Ni1Co1 catalyst prepared in Example 1 of the present invention under different acid and base environments.

[0038] Figure 7 These are the EIS, LSV and IT diagrams of Ni1Co1 / PMS / T of the present invention, where (a) is the EIS diagram; (b) is the LSV diagram, and (c) is the IT diagram. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in combination with the data in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The following experimental methods and detection methods are conventional methods unless otherwise specified; the following reagents and raw materials are commercially available unless otherwise specified. Peroxymonosulfate, denoted as PMS; Peroxydisulfate, denoted as PDS; DNA, or deoxyribonucleic acid, is an important molecule for storing genetic information in organisms, and is composed of four DNA bases: adenine, referred to as A; cytosine, referred to as C; guanine, referred to as G and thymine, referred to as T; The 1 in the catalyst Ni1Co1 catalyst refers to the atomic ratio of Ni and Co being 1:1.

[0041] In view of the defects of the prior art, the present invention provides a method for preparing a Ni1Co1 catalyst, comprising the following steps: dissolving a water-soluble nickel salt and a water-soluble cobalt salt in water to obtain a first solution; dissolving NaOH and Na2CO3 in water to obtain a second solution; mixing the first solution and the second solution and performing a coprecipitation reaction, wherein NaOH provides an alkaline environment, and Na2CO3 regulates the pH value while also providing carbonate ions to promote Ni 2+ and Co 2+ The concentration exceeds the solubility of its hydroxide, thus inducing Ni 2+ and Co 2+ With OH - Coprecipitation to form nickel-cobalt double hydroxide to obtain Ni1Co1 catalyst; + 、Co + , the molar ratio of NaOH and Na2CO3 is 1:0.98~1.2:1:0.98~1.2.

[0042] Compared with the disordered catalyst in the prior art, the present invention uses NaOH to provide an alkaline environment through a co-precipitation reaction, and Na2CO3 not only regulates the pH value, but also provides CO3 2- This dual-component adjustment method helps to form a more uniform and dense Ni1Co1 catalyst structure. 2+ and Co 2+ With OH - Co-precipitation forms nickel-cobalt double hydroxide. In nickel-cobalt double hydroxide, nickel hydroxide and cobalt hydroxide are arranged alternately. The nickel-cobalt double hydroxide in the Ni1Co1 catalyst is a sheet-like structure, which is stacked in layers to form a highly regular and repetitive two-dimensional system.

[0043] In terms of active sites, the Ni atoms and Co atoms in the Ni1Co1 catalyst achieve synergistic effects at the nanoscale, increasing the number of active sites of the Ni1Co1 catalyst. In addition, the layered structure of the nickel-cobalt double hydroxide provides the Ni1Co1 catalyst with a large specific surface area, and by optimizing the surface arrangement, electronic structure and atomic coordination of the Ni1Co1 catalyst, the Ni1Co1 catalyst has high active sites.

[0044] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments:

[0045] Example 1

[0046] A method for preparing a Ni1Co1 catalyst comprises the following steps:

[0047] S1. Dissolve 1 mmol nickel nitrate and 1 mmol cobalt nitrate in 30 mL deionized water and mix well to obtain solution No. 1; set aside.

[0048] Dissolve 1 mmol of NaOH and 1 mmol of Na2CO3 in 30 mL of deionized water and mix well to obtain solution No. 2; set aside.

[0049] S2. Place solution No. 1 and solution No. 2 in a 100 mL polytetrafluoroethylene liner, then place in a reactor, heat in a forced air drying oven, keep at 80° C. for 16 h, and then place in a 60° C. constant temperature forced air drying oven for 10 h to obtain a Ni1Co1 catalyst.

[0050] Example 2

[0051] A method for preparing a Ni1Co1 catalyst comprises the following steps:

[0052] S1. Dissolve 2 mmol nickel nitrate and 2 mmol cobalt nitrate in 30 mL deionized water and mix well to obtain solution No. 1; set aside.

[0053] Dissolve 1 mmol of NaOH and 1 mmol of Na2CO3 in 30 mL of deionized water and mix well to obtain solution No. 2; set aside.

[0054] S2. Place solution No. 1 and solution No. 2 in a 100 mL polytetrafluoroethylene liner, then place in a reactor, heat in a forced air drying oven, keep at 80° C. for 16 h, and then place in a 60° C. constant temperature forced air drying oven for 10 h to obtain a Ni1Co1 catalyst.

[0055] Example 3

[0056] A method for preparing a Ni1Co1 catalyst comprises the following steps:

[0057] S1. Dissolve 1 mmol nickel nitrate and 0.98 mmol cobalt nitrate in 30 mL deionized water and mix well to obtain solution No. 1; set aside.

[0058] Dissolve 1 mmol of NaOH and 0.98 mmol of Na2CO3 in 30 mL of deionized water and mix well to obtain solution No. 2; set aside.

[0059] S2. Place solution No. 1 and solution No. 2 in a 100 mL polytetrafluoroethylene liner, then place in a reactor, heat in a forced air drying oven, keep at 80° C. for 16 h, and then place in a 60° C. constant temperature forced air drying oven for 10 h to obtain a Ni1Co1 catalyst.

[0060] Example 4

[0061] A method for preparing a Ni1Co1 catalyst comprises the following steps:

[0062] S1. Dissolve 1 mmol nickel nitrate and 1.2 mmol cobalt nitrate in 30 mL deionized water and mix well to obtain solution No. 1; set aside.

[0063] Dissolve 1 mmol of NaOH and 1.2 mmol of Na2CO3 in 30 mL of deionized water and mix well to obtain solution No. 2; set aside.

[0064] S2. Place solution No. 1 and solution No. 2 in a 100 mL polytetrafluoroethylene liner, then place in a reactor, heat in a forced air drying oven, keep at 80° C. for 16 h, and then place in a 60° C. constant temperature forced air drying oven for 10 h to obtain a Ni1Co1 catalyst.

[0065] Examples 1 to 4 of the present invention all prepared Ni1Co1 catalysts with substantially the same morphology. The Ni1Co1 catalyst prepared in Example 1 was subjected to an electron microscope scanning test.

[0066] observe Figure 1 It is concluded that the Ni1Co1 catalyst obtained in Example 1 of the present invention is a two-dimensional sheet structure stacked in layers, and is highly ordered. This morphology gives the Ni1Co1 catalyst a larger specific surface area, thereby greatly increasing the contact opportunity between the Ni1Co1 catalyst and PMS, and effectively promoting the improvement of reaction efficiency. In addition, the nickel-cobalt double metal hydroxide sheet structure is stacked in a layered manner, ensuring that the active sites can be evenly distributed and fully exposed, providing favorable conditions for the rapid and uniform activation of PMS on the catalyst surface. Therefore, the Ni1Co1 catalyst can efficiently generate strong oxidizing substances, thereby achieving rapid and efficient degradation of DNA bases.

[0067] The Ni1Co1 catalyst prepared in Example 1 of the present invention is used as an example to remove four DNA bases in water, and the degradation effect is explored. The specific application method is as follows:

[0068] Application method:

[0069] (1) Use ultrapure water to prepare four DNA base solutions with a mass concentration of 30 mg / L, namely adenine solution, cytosine solution, guanine solution and thymine solution, and set them aside.

[0070] a. Take 5 portions of adenine solution and place them in a beaker, each portion is 30 mL. Add 30 mg of Ni1Co1 catalyst, 30 mg of PMS, 30 mg of PDS, 20 mg of Ni1Co1 catalyst and 10 mg of PMS, and 20 mg of Ni1Co1 catalyst and 10 mg of PDS to the 5 portions of adenine solution, then stir at 500 r / min for 30 min, and measure the mass concentration of the adenine solution in the beaker; similarly, weigh 5 portions of cytosine solution, 5 portions of guanine solution and 5 portions of thymine solution for degradation experiment. The test results are as follows: Figure 2 As shown, the systems with 30 mg of Ni1Co1 catalyst, 30 mg of PMS, 30 mg of PDS, 20 mg of Ni1Co1 catalyst and 10 mg of PMS, and 20 mg of Ni1Co1 catalyst and 10 mg of PDS are recorded as Catalyst, PMS, PDS, Catalyst+PDS, and Catalyst+PMS, respectively.

[0071] b. Take 7 parts of adenine solution and place them in a beaker, 30 mL each, and adjust the pH of the adenine solution to 2, 3, 5, 7, 8.23, 9, and 11 respectively; then add 20 mg of Ni1Co1 catalyst and 10 mg of PMS to the 7 parts of adenine solution, stir at 400 r / min for 30 minutes, and measure the mass concentration of the adenine solution in the beaker. Similarly, weigh 7 parts of cytosine solution, 7 parts of guanine solution, and 7 parts of adenine solution for degradation experiments; among them, the pH values ​​of the 7 parts of adenine solution are 2, 3, 5, 5.09, 7, 9, and 11 respectively; the pH values ​​of the 7 parts of guanine solution and the 7 parts of adenine solution are 2, 3, 5, 7, 8.6, 9, and 11 respectively; the pH values ​​of the 7 parts of thymine solution and the 7 parts of adenine solution are 1.78, 2, 3, 5, 7, 9, and 11 respectively. The test results are as follows Figure 3 The system of thymine degradation after activation of PMS by Ni1Co1 catalyst prepared in Example 1 is recorded as Ni1Co1 / PMS / T; the system of PMS activation by Ni1Co1 catalyst prepared in Example 1 of the present invention is recorded as Ni1Co1 / PMS.

[0072] c. Take 5 portions of adenine solution and place them in a beaker, each portion is 30 mL, and adjust the adenine solution to contain H2PO4 at a concentration of 2 mM / L. - , Cl - 、CO3 2- 、SO4 2- and HCO3 -; Then, 20 mg of Ni1Co1 catalyst and 10 mg of PMS were added to 5 adenine solutions respectively, and after stirring at a stirring rate of 400 r / min for 30 min, the mass concentration of adenine solution in the beaker was measured; an adenine solution prepared with ultrapure water was used as a blank control group, recorded as Blank. Similarly, 5 cytosine solutions, 5 guanine solutions, and 5 thymine solutions were weighed for degradation experiments. The test results are shown in the figure below. Figure 4 shown.

[0073] (2) Using tap water, Ningdong groundwater, Shahu surface water, and Zhongwei section of the Yellow River water as solvents, four DNA base solutions with a mass concentration of 30 mg / L were prepared, namely adenine solution, cytosine solution, guanine solution, and thymine solution; 30 mL of adenine solution prepared with different solvents was weighed and placed in different beakers, and then 20 mg of Ni1Co1 catalyst and 10 mg of PMS were added to the four adenine solutions respectively. After stirring at 400 r / min for 30 min, the mass concentration of the adenine solution in the beaker was measured; similarly, cytosine solution, guanine solution, and thymine solution were weighed and subjected to degradation experiments. The test results are shown in Figure 2. Figure 5 shown.

[0074] Below, the Ni1Co1 catalyst prepared in Example 1 of the present invention is used as an example to remove other pollutants, including chloroquine phosphate, norfloxacin, oxytetracycline and tetracycline, and the removal effect is explored. The specific application method is as follows: 20 mg of Ni1Co1 catalyst and 10 mg of PMS are taken and uniformly mixed with 30 mL of a pollutant solution having a mass concentration of 30 mg / L, and 2 mL of solution sample is taken every 5 min, i.e., Ni1Co1 / PMS / pollutant, and filtered through a 0.22 μm water filter membrane. The concentration of the remaining pollutants in the solution sample is then detected by high performance liquid chromatography (HPLC), and the specific test method is as follows:

[0075] a. Chloroquine phosphate: The HPLC system was performed on a Waters 2695 diode array detector, and the measured concentration was the residual mass concentration of chloroquine phosphate after degradation, with a detection wavelength of 343 nm. The liquid chromatography used a C-18 column (model HC-C18InertSustain, specification 4.6mm×150mm, particle size 5μm), and the column temperature was set to 35°C. The mobile phase consisted of a solution of acetonitrile and 0.3% triethylamine (pH adjusted to 3.3 with phosphoric acid) in a volume ratio of 10:90. The flow rate was set to 1 mL / min.

[0076] b. Norfloxacin: The HPLC system was performed on a Waters 2695 diode array detector. The measured concentration was the residual mass concentration of norfloxacin after degradation, and the detection wavelength was 280 nm. The instrument parameters were: the chromatographic column was (HC-C18 InertSustain, 4.6 mm × 150 mm, 5 μm), the mobile phase was a mixture of tetrabutylamine (tetrabutyl bromamide solution: acetonitrile = 94:6 = V:V), and the flow rate was 0.9 mL / min.

[0077] c. Oxytetracycline: The HPLC system was performed on a Waters 2695 diode array detector, and the measured concentration was the residual mass concentration of oxytetracycline after degradation, with a detection wavelength of 357 nm. The liquid chromatography used a C-18 column (HC-C18 InertSustain, 4.6 mm×150 mm, 5 μm), and the mobile phase consisted of acetonitrile and 0.1% phosphoric acid solution (40 / 60, V / V), with a flow rate of 1 mL / min.

[0078] d. Tetracycline: The HPLC system was performed on a Waters 2695 diode array detector. The measured concentration was the residual mass concentration of norfloxacin after degradation, and the detection wavelength was 358 nm. The instrument parameters were: the chromatographic column was (HC-C18 InertSustain, 4.6 mm × 150 mm, 5 μm), the separation was performed under the mobile phase conditions of acetonitrile and methanol (acetonitrile: methanol = 2: 1 = V: V), and the flow rate was 0.8 mL / min.

[0079] Among them, within 30 minutes, the removal rate of norfloxacin with an initial mass concentration of 30 mg / L was 87.0%, the removal rate of oxytetracycline with an initial mass concentration of 30 mg / L was 93.7%, the removal rate of tetracycline with an initial mass concentration of 30 mg / L was 96.8%, and the removal rate of chloroquine phosphate with an initial mass concentration of 30 mg / L reached 100%.

[0080] observe Figure 2It is concluded that the simultaneous action of Ni1Co1 catalyst and PMS can greatly improve the removal rate of four DNA bases. Only adding Ni1Co1 catalyst cannot achieve the degradation effect on four DNA bases, which proves that Ni1Co1 catalyst alone cannot quickly remove DNA bases. DNA bases cannot be degraded when PMS is used alone, and the activation effect of Ni1Co1 on PDS is not good, that is, the degradation effect is poor. Therefore, the combined use of Ni1Co1 catalyst and PMS has the best degradation effect on four DNA bases, among which the removal rate of thymine reaches 100%, the degradation rate of adenine is 96.0%, cytosine is 83.9%, and guanine is 77.2%. Ni1Co1 catalyst has an activation effect on PMS, can produce a variety of strong oxidizing substances, increase the concentration of free radicals and non-free radicals in the DNA base solution, act on DNA bases together, promote their removal, and accelerate the reaction. Therefore, Ni1Co1 catalyst and PMS have a synergistic strengthening effect, which can better remove a variety of organic pollutants, including chloroquine phosphate, norfloxacin, oxytetracycline, and tetracycline.

[0081] observe Figure 3 It was concluded that after changing the pH value of the DNA base solution, the removal efficiency of the four DNA bases was affected differently. Under different pH conditions, the degradation rates of the four DNA bases were inhibited to varying degrees. The difference between pH and the surface charge (pHPZC) of the Ni1Co1 catalyst affected the charge characteristics of the catalyst, which in turn affected the degradation effect. In particular, the degradation of adenine was most affected by pH changes because its surface charge distribution was more uniform and more stable. Cytosine and thymine were better degraded under acidic conditions, while guanine was less affected by pH and showed better pH tolerance. Under acidic / neutral pH conditions, the Ni1Co1 catalyst was positively charged, which was conducive to enhancing the interaction between the pollutant and the Ni1Co1 catalyst and promoting degradation; while under alkaline conditions, the Ni1Co1 catalyst was negatively charged and the degradation efficiency was significantly reduced. In summary, the interfacial effect of the Ni1Co1 catalyst promoted the degradation of the four DNA bases, especially under acidic / neutral conditions.

[0082] Figure 4 The results show that H2PO4 - and SO4 2- The effect of Ni1Co1 / PMS on DNA base degradation is relatively small. - When CO3 2- and HCO3 - After cleavage, the degradation of adenine, cytosine and thymine was significantly inhibited. - 、CO32- and HCO3 - The presence of both has an inhibitory effect on the degradation of DNA bases.

[0083] observe Figure 5 It was concluded that when the Ni1Co1 catalyst and PMS acted synergistically, they showed good stability in DNA base solutions prepared with different water qualities, especially the degradation of guanine, and the process was hardly affected by changes in water quality. Even under complex water conditions, thymine can achieve a degradation rate of about 60%. In contrast, the degradation of adenine and cytosine is more sensitive and is greatly affected by water quality factors. The interaction between DNA base pairs makes the degradation of thymine and guanine destroy the overall structure of DNA bases, thereby affecting the damage of other adjacent or paired DNA bases. In summary, the synergistic effect of Ni1Co1 catalyst and PMS is not only highly practical, but also has good environmental adaptability, which provides strong support for its application in wastewater treatment processes.

[0084] The difference between the pH of the DNA base solution and the pHPZC of the Ni1Co1 catalyst is the determining factor of the surface charge properties of the Ni1Co1 catalyst. In order to clarify the interface effect of the Ni1Co1 catalyst, the Zeta potential of the Ni1Co1 catalyst was characterized. The test method of the Zeta potential is as follows:

[0085] The dispersion of Ni1Co1 catalyst is added to the sample cell of the Zeta potential instrument using the (Particle AnalyzerLitesizer 500) device. An electric field is applied, and the instrument irradiates the Ni1Co1 catalyst with a 633nm laser and measures the angle change of the scattered light of the Ni1Co1 catalyst. According to the migration speed of the Ni1Co1 catalyst and the electric field strength, the instrument software calculates the Zeta potential value.

[0086] observe Figure 6 It is concluded that under the same conditions, the pHPZC of DNA base A is larger, which means that the surface of DNA base A carries more negative charge and is more susceptible to H + and OH - The effect of concentration is also most significant due to pH. DNA base C is better degraded under acidic conditions, which is consistent with the Zeta potential, so it can catalyze the reaction through electrostatic attraction, and the same is true for DNA base T. However, it is worth noting that DNA base G is less affected by pH, because the difference in pHPZC with Ni1Co1 / PMS in G is negligible. In other words, the Zeta potential value is relatively low, and its surface charge characteristics are weak, so under different pH conditions, its charge density and degree of ionization do not change much, thus showing pH tolerance.

[0087] observe Figure 7 (a) shows that the semicircle diameter of Ni1Co1 / PMS / T is smaller than that of Ni1Co1 / PMS and smaller than that of Ni1Co1 catalyst, indicating that when Ni1Co1 catalyst, PMS and base T form a catalytic system, it has a lower electron transfer resistance, which is beneficial to the internal electron transfer in the PMS activation process. This is because the interaction between Ni1Co1 prepared by the present invention and PMS accelerates the electron output rate of thymine, thereby forming a high-speed electron transfer pathway between Ni1Co1 / PMS / T. Figure 7 (b) shows that when PMS and base T are present, the current increases significantly, with a higher current density, which accelerates the electron transfer process in the catalytic system. Figure 7 (c) shows that when PMS was added at 300s, an obvious positive current flow immediately appeared, indicating that PMS underwent a redox reaction on the electrode surface, causing electron redistribution, generating ROS, initiating electron transfer, and generating a metastable Ni1Co1 / PMS system. Subsequently, base T was added at 600s, and since base T adsorbed on the electrode surface, it temporarily hindered charge transfer and generated a reverse current. However, as base T degraded, current was generated from the metastable reaction complex (electron mediator) to PMS (electron acceptor), and the current density returned to normal.

[0088] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0089] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a Ni1Co1 catalyst, characterized in that: The following steps are involved: Dissolving a water-soluble nickel salt and a water-soluble cobalt salt in water to obtain a solution No. 1; Dissolve NaOH and Na2CO3 in water to obtain solution No. 2; Solution 1 and solution 2 are mixed and co-precipitated. In the co-precipitation reaction, NaOH provides an alkaline environment, and Na2CO3 regulates the pH value while also providing carbonate ions to promote Ni 2+ and Co 2+ The concentration exceeds the solubility of its hydroxide, thus inducing Ni 2+ and Co 2+ With OH - Coprecipitation forms nickel-cobalt double hydroxide to obtain Ni1Co1 catalyst; Among them, Ni + 、Co + , the molar ratio of NaOH and Na2CO3 is 1:0.98~1.2:1:0.98~1.

2.

2. The method for preparing the Ni1Co1 catalyst according to claim 1, characterized in that: The conditions of the coprecipitation reaction are: stirring at 60°C to 80°C for 16h to 18h.

3. A Ni1Co1 catalyst prepared by the preparation method according to any one of claims 1 to 2.

4. The Ni1Co1 catalyst according to claim 3, characterized in that In the Ni1Co1 catalyst, several nickel-cobalt double hydroxides are arranged in layers, and nickel hydroxide and cobalt hydroxide are arranged alternately.

5. Use of the Ni1Co1 catalyst according to claim 4 in the preparation of an organic pollutant degradation agent or a DNA base degradation agent.

6. Use of the Ni1Co1 catalyst according to claim 5 in the preparation of a DNA base degradation agent, characterized in that: The application method is: The Ni1Co1 catalyst is mixed with a DNA base solution in the presence of peroxymonosulfate.

7. Use of the Ni1Co1 catalyst according to claim 6 in the preparation of a DNA base degradation agent, characterized in that: The mass volume ratio of Ni1Co1 catalyst, DNA base solution and peroxymonosulfate is 1.8g~2.2g:1mL:55g~65g; Wherein, the mass concentration of DNA bases in the DNA base solution is 2 mg / L to 30 mg / L.

8. The use of the Ni1Co1 catalyst according to claim 5 in the preparation of an organic pollutant degradation agent, characterized in that: The application method is: The Ni1Co1 catalyst is mixed with an organic pollutant solution in the presence of peroxymonosulfate.

9. Use of the Ni1Co1 catalyst according to claim 8 in the preparation of an organic pollutant degradation agent, characterized in that: The mass volume ratio of Ni1Co1 catalyst, organic pollutant solution and peroxymonosulfate is 1g~3g:2mL~4mL:1g~2g; Wherein, the mass concentration of the organic pollutant solution is 20mg / L~40mg / L.

10. Use of the Ni1Co1 catalyst according to claim 8 in preparing an organic pollutant degradation agent, characterized in that: The organic pollutant in the organic pollutant solution is selected from chloroquine phosphate, norfloxacin, oxytetracycline or tetracycline.

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