CN115007205B - Methyl isothiocyanate intercalation hydrotalcites and its preparation method and application - Google Patents

Abstract

The invention provides a methyl isothiocyanate intercalation hydrotalcite, its preparation method and application. The preparation method comprises the following steps: dissolving a divalent metal salt and a trivalent metal salt in an aqueous solution according to a preset ratio to obtain a mixed salt solution; slowly adding the mixed salt solution and a hydroxide solution to a reaction tank filled with pure water Stir and mix in the container, the solution after the dropwise addition is aged in a water bath, suction filtered, washed, and dried to obtain a copper-magnesium-iron hydrotalcite precursor; the copper-magnesium-iron hydrotalcite precursor is impregnated in methyl isothiocyanate In the solution, the methyl isothiocyanate intercalation hydrotalcite is obtained through ultrasonic dispersion, impregnation, suction filtration, washing and drying. The hydrotalcite-like action catalyst provided by the invention is applied to the degradation of wastewater containing antibiotics, can be carried out under normal temperature and pressure, and has the advantages of high organic matter removal rate and low cost.

Description

Methyl isothiocyanate intercalation hydrotalcites and its preparation method and application

technical field

The invention belongs to the technical field of catalysts, and in particular relates to a methyl isothiocyanate intercalated hydrotalcite and its preparation method and application.

Background technique

Advanced oxidation advanced treatment technology is an effective way to further improve water quality. It has the characteristics of easy operation, high removal efficiency, thorough oxidation and easy control. Among them, wet catalytic oxidation technology has broad application prospects because of its high treatment efficiency and low cost. The catalytic degradation efficiency of wet catalytic oxidation technology mainly lies in the generation of reactive oxygen species with different properties, such as hydrogen peroxide, superoxide radicals, hydroxyl radicals and singlet oxygen. Among them, singlet oxygen is an important reactive oxygen species due to the existence of unoccupied π* orbitals, and has been widely used in photochemical reactions and advanced oxidation treatment technologies.

The generation of singlet oxygen typically results from energy transfer between the excited triplet state of the photosensitizer and the triplet ground state of the oxygen molecule. In addition, trap-state holes, hydroxyl radicals, metal ions, etc. can also serve as electron acceptors to oxidize superoxide anion to generate singlet oxygen through the electron transfer process. Since the generation of singlet oxygen is usually accompanied by the generation of other reactive oxygen species, singlet oxygen plays an important role in organic synthesis, advanced oxidation, and photoelectric reactions. Therefore, it is particularly important to enhance the generation of singlet oxygen in mild environments.

In the related art, the generation of singlet oxygen can be based on photoexcitation and non-photoexcitation processes, but singlet oxygen is mostly generated by photosensitizers under photoexcitation conditions. Currently, the development of materials that generate singlet oxygen without photoexcitation is still lacking.

Layered double hydroxides (LDHs), namely hydrotalcites, as a new type of catalyst material, can use wet catalytic oxidation of air and dissolved oxygen to achieve economical, green, stable and low-energy advanced oxidation treatment technology. At present, there is a technical problem that the electron transfer ability is insufficient, resulting in a low yield of singlet oxygen.

Contents of the invention

The object of the present invention is to improve a kind of methyl isothiocyanate intercalation hydrotalcite-like hydrotalcite that can produce singlet oxygen rapidly with interlayer electron channel, and this methyl isothiocyanate intercalation hydrotalcite-like is used as catalyst in the antibiotic-containing The degradation of waste water can be carried out under normal temperature and pressure, and has the advantages of high organic matter removal rate and low cost.

In order to achieve the above object, the invention provides a kind of preparation method of methyl isothiocyanate intercalation hydrotalcite, and described preparation method comprises the following steps:

Step 1. Dissolving a divalent metal salt and a trivalent metal salt in an aqueous solution according to a preset ratio to obtain a mixed salt solution, the divalent metal salt being copper salt and magnesium salt, and the trivalent metal salt being iron salt;

Step 2. Slowly add the mixed salt solution and hydroxide solution dropwise into a reactor filled with pure water for stirring and mixing, and isolate CO ₂ in the air. After the dropwise addition, the solution is aged in a water bath, suction filtered, Washing and drying to obtain a copper-magnesium-iron hydrotalcite precursor;

Step 3, immerse the copper-magnesium-iron hydrotalcite precursor in the methyl isothiocyanate solution, and obtain methyl isothiocyanate intercalated hydrotalcite through ultrasonic dispersion, impregnation, suction filtration, washing, and drying. Methyl thiocyanate intercalation hydrotalcites have interlayer electron channels built by intercalation of methyl isothiocyanate to produce singlet oxygen; wherein, the mass ratio of the hydrotalcite-like precursor to methyl isothiocyanate For: 1: (0.05 ~ 1).

In a specific embodiment, in step 3, the concentration of the methyl isothiocyanate solution is 0.02-0.08 mol/L.

In a specific embodiment, in step 3, the time for ultrasonic dispersion is 5-30 minutes; the conditions for the immersion are: the immersion temperature is a water bath temperature of 68-75°C, and the immersion time is 18-24 hours; the dry The conditions are: the drying temperature is 50-60° C., and the drying time is 16-24 hours.

In a specific embodiment, in step 1, the molar ratio of the copper salt, magnesium salt, and iron salt is (2-4):(1-3):1.

In a specific embodiment, in step 2, the temperature of the mixed solution is controlled to be 60-70° C., and the pH of the solution is controlled to be 5-12 during the stirring and mixing process.

In a specific embodiment, in step 2, the water bath aging conditions are: the water bath temperature is 68-72°C, the aging time is 12-24h, and the drying conditions are: the drying temperature is 78 ~82℃, the drying time is 8~16h.

In a specific embodiment, in step 2, the hydroxide solution is a sodium hydroxide solution, and the concentration of the sodium hydroxide solution is 1-3 mol/L.

The present invention also provides a methyl isothiocyanate-intercalated hydrotalcite-like, which is prepared by the above-mentioned preparation method.

The present invention also provides an application of the methyl isothiocyanate intercalated hydrotalcite prepared by the above-mentioned preparation method as a catalyst in degrading organic wastewater containing antibiotics.

In a specific embodiment, the methyl isothiocyanate intercalated hydrotalcite is used as a catalyst to degrade antibiotics at normal temperature and pressure, and the antibiotic is ciprofloxacin.

The beneficial effects of the present invention at least include:

1. The methyl isothiocyanate intercalation hydrotalcites provided in the present invention, on the one hand, use strong electron-withdrawing organic small molecule methyl isocyanate (CH ₃ NCS) intercalation to build interlayer electron channels in the copper-magnesium-iron class In hydrotalcite, improving the electron transfer ability can quickly generate more singlet oxygen; on the other hand, the surface of this type of hydrotalcite has a high concentration of oxygen vacancies, which can absorb dissolved oxygen in water as an oxidant and generate a large amount of active oxygen such as singlet oxygen. Species; in this way, methyl isothiocyanate intercalation hydrotalcite has a higher singlet oxygen yield, and when it is used as a catalyst for the degradation of organic wastewater containing antibiotics, it has the advantages of high organic matter removal rate and low cost.

2. The methyl isothiocyanate intercalation hydrotalcites provided in the present invention build interlayer electronic channels through methyl isocyanate intercalation, which reduces the activation energy of the catalytic reaction and improves the electron transfer capability. It is used as a catalyst for wet catalytic reactions The application can be carried out under normal temperature and pressure without adding any oxidant, and can efficiently oxidize and remove organic matter in wastewater, especially the new pollutant ciprofloxacin.

Three, the preparation method process of methyl isothiocyanate intercalation hydrotalcites provided by the present invention is simple, and reaction condition is gentle, does not need high temperature and high pressure and any organic solvent, has the advantage of low energy consumption, low cost, high yield, has Conducive to industrialized production.

Description of drawings

Fig. 1 is the SEM figure of the hydrotalcite-like prepared in embodiment 1 and embodiment 3;

Fig. 2 is the FT-IR figure of the hydrotalcite-like prepared in embodiment 1～4;

Fig. 3 is the EIS figure of the hydrotalcite-like prepared in embodiment 1～4;

Fig. 4 is the ESR spectrogram of the hydrotalcite-like prepared in embodiment 3;

Fig. 5 is the degradation effect diagram of the hydrotalcite-like prepared in Examples 1-4;

Fig. 6 is the effect diagram of degrading ciprofloxacin at different pHs using the methyl isothiocyanate intercalated hydrotalcite prepared in Example 3 as a catalyst;

Fig. 7 is a graph of the cycle performance of the methyl isothiocyanate intercalated hydrotalcite prepared in Example 3 as a catalyst.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and embodiments, but the present invention can be implemented in various ways limited and covered by the claims.

The copper salt in the present invention includes at least one of copper nitrate, copper sulfate, and copper chloride, the magnesium salt includes at least one of magnesium nitrate, magnesium sulfate, and magnesium chloride, and the iron salt includes at least one of iron nitrate, iron sulfate, and iron chloride. One, in the following examples, the copper salt selected is copper nitrate, the magnesium salt is magnesium nitrate, and the iron salt is iron nitrate.

Example 1

Preparation of copper-magnesium-iron hydrotalcite: weigh 48.32g copper salt (Cu(NO ₃ ) ₂ ·3H ₂ O), 25.64g magnesium salt (Mg(NO ₃ ) ₂ ·6H ₂ O) and 26.93g iron salt ( Fe(NO ₃ ) ₃ 9H ₂ O) was added to constant volume with pure water to obtain 500mL copper-magnesium-iron salt composite solution, wherein the molar ratio of Cu ²⁺ : Mg ²⁺ : Fe ³⁺ was 6:3:2; Add 24.00 g of sodium hydroxide to pure water to obtain 500 mL of sodium hydroxide solution (the molar solubility of sodium hydroxide is 1.2 mol/L). The prepared copper-magnesium-iron salt complex solution and sodium hydroxide solution are slowly added dropwise and mixed into a container filled with pure water through a peristaltic pump, vigorously stirred at a water bath temperature of 70°C, and nitrogen is introduced to prevent air _CO2 interference, control the pH of the reaction solution to maintain it at 9.8-10.2, and the end point of the titration is that the copper-magnesium-iron salt complex solution and/or sodium hydroxide solution are added dropwise. After the dropwise addition, the solution was aged in a water bath at 70°C for 18 hours. After the aging was completed, it was suction-filtered. After the suction filtration, it was repeatedly washed with pure water several times, and dried in an oven at 80°C for 12 hours. The solid is ground to obtain copper-magnesium-iron hydrotalcite, which is denoted as CuMgFe-LDH.

Example 2

1) Preparation of hydrotalcite precursor: 48.32g copper salt (Cu(NO ₃ ) ₂ ·3H ₂ O), 25.64g magnesium salt (Mg(NO ₃ ) ₂ ·6H ₂ O) and 26.93g iron salt ( Fe(NO ₃ ) ₃ 9H ₂ O) was added to constant volume with pure water to obtain 500mL copper-magnesium-iron salt composite solution, wherein the molar ratio of Cu ²⁺ : Mg ²⁺ : Fe ³⁺ was 6:3:2; Add 24.00 g of sodium hydroxide to pure water to obtain 500 mL of sodium hydroxide solution (the molar solubility of sodium hydroxide is 1.2 mol/L). The prepared copper-magnesium-iron salt complex solution and sodium hydroxide solution are slowly added dropwise and mixed into a container filled with pure water through a peristaltic pump, vigorously stirred at a water bath temperature of 70°C, and nitrogen is introduced to prevent air _CO2 interference, control the pH of the reaction solution to maintain it at 9.8-10.2, and the end point of the titration is that the copper-magnesium-iron salt complex solution and/or sodium hydroxide solution are added dropwise. After the dropwise addition, the solution was aged in a water bath at 70°C for 18 hours. After the aging was completed, it was suction-filtered. After the suction filtration, it was repeatedly washed with pure water several times, and dried in an oven at 80°C for 12 hours. The solid is ground to obtain a copper-magnesium-iron hydrotalcite precursor.

2) Preparation of methyl isothiocyanate intercalated hydrotalcites: Weigh 0.1g of CH ₃ NCS and dissolve and disperse them in 50ml of deionized water in a 250mL beaker, weigh 2 grams of copper-magnesium-iron hydrotalcite precursors and immerse in In the completely dissolved CH ₃ NCS solution, ultrasonically disperse for 10 minutes, immerse in a water bath at 75°C for 12 hours, then filter with suction, wash the filter residue repeatedly with pure water, and then put the washed block sample into the muffle furnace The drying temperature was 70°C and the drying time was 16 hours. The dried sample was ground to obtain methyl isothiocyanate intercalation hydrotalcite, which was recorded as CuMgFe-CH ₃ NCS _0.1 LDH.

Example 3

1) Preparation of hydrotalcite precursor: 48.32g copper salt (Cu(NO ₃ ) ₂ ·3H ₂ O), 25.64g magnesium salt (Mg(NO ₃ ) ₂ ·6H ₂ O) and 26.93g iron salt ( Fe(NO ₃ ) ₃ 9H ₂ O) was added to constant volume with pure water to obtain 500mL copper-magnesium-iron salt composite solution, wherein the molar ratio of Cu ²⁺ : Mg ²⁺ : Fe ³⁺ was 6:3:2; Add 24.00 g of sodium hydroxide to pure water to obtain 500 mL of sodium hydroxide solution (the molar solubility of sodium hydroxide is 1.2 mol/L). The prepared copper-magnesium-iron salt complex solution and sodium hydroxide solution are slowly added dropwise and mixed into a container filled with pure water through a peristaltic pump, vigorously stirred at a water bath temperature of 70°C, and nitrogen is introduced to prevent air _CO2 interference, control the pH of the reaction solution to maintain it at 9.8-10.2, and the end point of the titration is that the copper-magnesium-iron salt complex solution and/or sodium hydroxide solution are added dropwise. After the dropwise addition, the solution was aged in a water bath at 70°C for 18 hours. After the aging was completed, it was suction-filtered. After the suction filtration, it was repeatedly washed with pure water several times, and dried in an oven at 80°C for 12 hours. The solid is ground to obtain a copper-magnesium-iron hydrotalcite precursor.

2) Preparation of methyl isothiocyanate intercalation hydrotalcite: Weigh 0.15g of CH ₃ NCS and dissolve and disperse in 50ml deionized water in a 250mL beaker, weigh 2 grams of copper-magnesium-iron hydrotalcite precursor and impregnate In the completely dissolved CH ₃ NCS solution, ultrasonically disperse for 10 minutes, immerse in a water bath at 75°C for 12 hours, then filter with suction, wash the filter residue repeatedly with pure water, and then put the washed block sample into the muffle furnace The drying temperature was 70°C and the drying time was 16 hours. The dried sample was ground to obtain methyl isothiocyanate intercalation hydrotalcite, which was recorded as CuMgFe-CH ₃ NCS _0.15 LDH.

Example 4

1) Preparation of hydrotalcite precursor: 48.32g copper salt (Cu(NO ₃ ) ₂ ·3H ₂ O), 25.64g magnesium salt (Mg(NO ₃ ) ₂ ·6H ₂ O) and 26.93g iron salt ( Fe(NO ₃ ) ₃ 9H ₂ O) was added to constant volume with pure water to obtain 500mL copper-magnesium-iron salt composite solution, wherein the molar ratio of Cu ²⁺ : Mg ²⁺ : Fe ³⁺ was 6:3:2; Add 24.00 g of sodium hydroxide to pure water to obtain 500 mL of sodium hydroxide solution (the molar solubility of sodium hydroxide is 1.2 mol/L). The prepared copper-magnesium-iron salt complex solution and sodium hydroxide solution are slowly added dropwise and mixed into a container filled with pure water through a peristaltic pump, vigorously stirred at a water bath temperature of 70°C, and nitrogen is introduced to prevent air _CO2 interference, control the pH of the reaction solution to maintain it at 9.8-10.2, and the end point of the titration is that the copper-magnesium-iron salt complex solution and/or sodium hydroxide solution are added dropwise. After the dropwise addition, the solution was aged in a water bath at 70°C for 18 hours. After the aging was completed, it was suction-filtered. After the suction filtration, it was repeatedly washed with pure water several times, and dried in an oven at 80°C for 12 hours. The solid is ground to obtain a copper-magnesium-iron hydrotalcite precursor.

2) Preparation of methyl isothiocyanate intercalation hydrotalcite: Weigh 0.2g of CH ₃ NCS and dissolve and disperse in 50ml of deionized water in a 250mL beaker, weigh 2g of copper-magnesium-iron hydrotalcite precursor and impregnate in In the completely dissolved CH ₃ NCS solution, ultrasonically disperse for 10 minutes, immerse in a water bath at 75°C for 12 hours, then filter with suction, wash the filter residue repeatedly with pure water, and then put the washed block sample into the muffle furnace The drying temperature was 70°C and the drying time was 16 hours. The dried sample was ground to obtain methyl isothiocyanate intercalation hydrotalcite, which was recorded as CuMgFe-CH ₃ NCS _0.2 LDH.

Please refer to Figures 1 to 4 in conjunction, wherein Figure 1 is the SEM image of the hydrotalcite-like prepared in Example 1 and Example 3, and Figure 2 is the FT-IR image of the hydrotalcite-like prepared in Example 1-4, Fig. 3 is the EIS diagram of the hydrotalcite-like prepared in Examples 1-4; Fig. 4 is the ESR spectrum of the hydrotalcite-like prepared in Example 3.

Both SEM images in Figure 1 have a nanosheet structure, that is to say, there is no obvious difference before and after CH ₃ NCS targeting, but the anchoring of CH ₃ NCS makes the smooth surface of CuMgFe-LDH rougher and the edge structure defects are clear. The FT-IR diagram in Figure 2 shows that the CO ₃ ^2- existing in the interlayer of CuMgFe-LDH decreases sharply after CH ₃ NCS intercalation, indicating that CH ₃ NCS successfully replaced the CO ₃ ^2- existing in the interlayer, confirming the The insertion of CH ₃ NCS is mainly located in the interlayer structure rather than surface binding. Figure 3 shows the EIS of CuMgFe LDH, CuMgFe-CH ₃ NCS _0.1 LDHCuMgFe-CH ₃ NCS _0.15, LDHCuMgFe-CH ₃ NCS _0.2 LDH from top to bottom. The radius of the ₃ NCS _0.1 LDH electrode is significantly smaller than that of the CuMgFe LDH electrode, and as the loading increases, the radius of the CuMgFe-CH ₃ NCS LDH electrode gradually decreases, which represents the surface area of the CuMgFe-CH ₃ NCS LDH catalyst after loading CH ₃ NCS. The charge transport resistance is weaker, and the reduction of transport resistance accelerates the transfer ability and efficiency of electronic charges, and accelerates the transfer of active free radicals. The ESR spectrum in Fig. 4 can prove the existence of ·OH and ·O2 _- radicals in DMPO in water or methanol, and at the same dose of CuMgFe- _CH3 NCS _0.15 LDH, the existence of _1O2 is proved by TEMPO.

Catalytic degradation experiment:

The experimental conditions are: normal temperature and pressure;

The waste water used is: the organic waste water containing antibiotic ciprofloxacin, the mass concentration of ciprofloxacin is 10mg/L;

The instruments used include:

Example 5

Using the methyl isothiocyanate intercalated hydrotalcite CuMgFe-CH ₃ NCS _0.1 LDH prepared in Example 2 as a catalyst, a catalytic degradation experiment was carried out on organic wastewater containing ciprofloxacin at normal temperature and pressure. The experimental process is as follows: Weigh 0.1 g of the hydrotalcite-like product prepared in Example 2 as a catalyst and put it into a conical flask containing organic wastewater, and use a needle to absorb it at 0, 5, 10, 20, 25, 60, and 120 minutes respectively Filtrate, and use the polyethersulfone (PES) filter tip that aperture is 0.22 μ m to transfer in the cuvette, test the absorbance of ciprofloxacin in the filtrate at different times with ultraviolet absorption spectrum, and change into concentration, to test its degradation The specific results are shown in Figure 5.

Embodiment 6 to Embodiment 8

The experimental methods of Examples 6 to 8 are the same as those of Example 5, the difference being that the catalyst used in Example 6 is the methyl isothiocyanate intercalated hydrotalcite CuMgFe-CH ₃ NCS _0.15 prepared in Example 3 LDH is used as a catalyst; the catalyst used in Example 7 is the methyl isothiocyanate intercalated hydrotalcite CuMgFe-CH ₃ NCS _0.2 LDH prepared in Example 4 is used as a catalyst; the catalyst used in Example 8 is prepared in Example 1 The copper-magnesium-iron hydrotalcites are denoted as CuMgFe-LDH; the experimental results are shown in Figure 5.

Figure 5 is a diagram of the degradation effect of the hydrotalcite-like prepared in Examples 1-4. It can be seen from the figure that with the increase of CH ₃ NCS loading, the degradation of ciprofloxacin by the modified CH ₃ NCS The ability is obviously improved.

Example 9

Using the methyl isothiocyanate intercalated hydrotalcite CuMgFe-CH ₃ NCS _0.15 LDH prepared in Example 3 as a catalyst, a catalytic degradation experiment was carried out on organic wastewater containing ciprofloxacin at normal temperature and pressure. The experimental process is as follows: Weigh 0.1 g of the hydrotalcite-like product prepared in Example 2 as a catalyst and put it into an Erlenmeyer flask containing organic wastewater, and adjust the pH value of the solution to be degraded to 3, respectively at 0, 5, 10, and 20 , 25, 60, and 120 min, draw the filtrate with a needle tube, and transfer it to a cuvette with a polyethersulfone (PES) filter head with an aperture of 0.22 μm, and test the absorbance of ciprofloxacin in the filtrate at different times with ultraviolet absorption spectroscopy, And converted into concentration, to test its degradation effect, the specific results are shown in Figure 6.

Examples 10-13

The experimental method of embodiment 10～embodiment 13 is identical with embodiment 9, and its difference is, the pH value of embodiment 9 to be degraded solution is 3; The pH value of embodiment 10 to be degraded solution is 5; Embodiment 11 to be degraded solution The pH value of the solution to be degraded is 7; the pH value of the solution to be degraded in Example 12 is 9; the pH value of the solution to be degraded in Example 13 is 11; the specific results are shown in Figure 6.

Fig. 6 is a graph showing the effect of degrading ciprofloxacin at different pH using the methyl isothiocyanate intercalated hydrotalcite prepared in Example 3 as a catalyst. It can be seen from Figure 6 that the catalytic reaction system of CuMgFe-CH ₃ NCS _0.15 LDH as a catalyst is feasible, indicating that methyl isothiocyanate intercalated hydrotalcites have a very wide pH tolerance range in the process of treating wastewater .

Example 14

Using the methyl isothiocyanate intercalated hydrotalcite CuMgFe-CH ₃ NCS _0.15 LDH prepared in Example 3 as a catalyst, a catalytic degradation experiment was carried out on organic wastewater containing ciprofloxacin at normal temperature and pressure. Weigh 0.1g of methyl isothiocyanate intercalation hydrotalcite CuMgFe-CH ₃ NCS _0.15 LDH prepared in Example 3 and put it into a conical flask filled with organic waste water as a catalyst, adjust the pH of the solution to 7, respectively At 0, 5, 10, 20, 25, 60, and 120 minutes, draw the filtrate with a needle, and transfer it to a cuvette with a polyethersulfone (PES) filter head with a pore size of 0.22 μm, and use ultraviolet absorption spectroscopy to test the filtrate at different times. The absorbance of ciprofloxacin to test its degradation effect. After the reaction, the catalyst was obtained by suction filtration, and then the catalyst was put into an oven to dry at 70°C. Afterwards, the dried CuMgFe-CH ₃ NCS _0.15 LDH was used again, the catalyst was recycled 4 times, and the absorbance of ciprofloxacin was tested by ultraviolet absorption spectrum, and converted into concentration to test its degradation effect; the specific results are shown in Figure 7 Show.

Fig. 7 is a graph of the cycle performance of the methyl isothiocyanate intercalated hydrotalcite prepared in Example 3 as a catalyst. It can be seen from Figure 7 that with the continuous use of the catalytic cycle, the degradation efficiency of CuMgFe-CH ₃ NCS _0.15 LDH is almost the same after 4 cycles, and the removal rate is higher than 79.99%, which shows that the intercalation of methyl isothiocyanate The hydrotalcite-like catalyst material can be used repeatedly and has good stability.

See Table 1 for the comparison table of the degrading effect of ciprofloxacin by using methyl isothiocyanate intercalation hydrotalcite-like CuMgFe-CH ₃ NCS _0.15 LDH as a catalyst in the prior art and the example of the present invention.

Compared with other treatment processes for removing ciprofloxacin, the material process provided by this patent has the lowest unit power consumption, indicating that it has more considerable industrial economic benefits.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deductions and substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (8)

1. The application of the methyl isothiocyanate intercalated hydrotalcite-like compound is characterized in that the application of the methyl isothiocyanate intercalated hydrotalcite-like compound as a catalyst in degrading organic wastewater containing antibiotics, wherein the preparation method of the methyl isothiocyanate intercalated hydrotalcite-like compound comprises the following steps:

step one, dissolving divalent metal salt and trivalent metal salt in an aqueous solution according to a preset proportion to obtain a mixed salt solution, wherein the divalent metal salt is copper salt and magnesium salt, and the trivalent metal salt is ferric salt;

step two, slowly dripping the mixed salt solution and the hydroxide solution into a reactor filled with pure water for stirring and mixing, and isolating CO in the air ₂ Aging the solution after the dripping is finished in a water bath, filtering, washing and drying to obtain a copper-magnesium-iron hydrotalcite precursor;

immersing a copper-magnesium-iron hydrotalcite-like precursor in methyl isothiocyanate solution, and performing ultrasonic dispersion, immersion, suction filtration, washing and drying to obtain methyl isothiocyanate intercalated hydrotalcite-like compound, wherein the methyl isothiocyanate intercalated hydrotalcite-like compound is provided with an interlayer electronic channel constructed by methyl isothiocyanate intercalation to generate singlet oxygen; wherein, the mass ratio of the hydrotalcite-like precursor to the methyl isothiocyanate is 1: (0.05-1).

2. The use according to claim 1, wherein the methyl isothiocyanate intercalated hydrotalcite-like compound is used as a catalyst to degrade an antibiotic, which is ciprofloxacin, at normal temperature and pressure.

3. The use according to claim 1, wherein in step three, the concentration of the methyl isothiocyanate solution is between 0.02 and 0.08mol/L.

4. The use according to claim 1, wherein in step three, the time of ultrasonic dispersion is between 5 and 30 minutes; the conditions of the impregnation are as follows: the dipping temperature is 68-75 ℃ of the water bath temperature, and the dipping time is 18-24 h; the drying conditions are as follows: the drying temperature is 50-60 ℃, and the drying time is 16-24 h.

5. The use according to claim 1, wherein in step one, the molar ratio of copper salt, magnesium salt, iron salt is (2-4): (1-3): 1.

6. the use according to claim 1, wherein in step two, the temperature of the mixed solution is controlled to be 60-70 ℃ and the pH of the solution is controlled to be 5-12 during the stirring and mixing process.

7. The use according to claim 1, wherein in step two, the conditions of the water bath ageing are: the water bath temperature is 68-72 ℃, the aging time is 12-24 hours, and the drying conditions are as follows: the drying temperature is 78-82 ℃, and the drying time is 8-16 h.

8. The use according to claim 1, wherein in step two, the hydroxide solution is sodium hydroxide solution, and the concentration of the sodium hydroxide solution is 1-3 mol/L.