Preparation method and application of zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst

Abstract

The invention provides a preparation method of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst, and belongs to the technical field of activated molecular oxygen advanced oxidation catalytic materials for sewage treatment. Then adding the amorphous iron oxyhydroxide and anhydrous cupric sulfate into distilled water, mixing, adding sodium borohydride, and carrying out reduction reaction to prepare the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst; the catalyst prepared by the invention can be recycled and has high catalytic performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalytic materials for activated molecular oxygen in sewage treatment, and particularly relates to a preparation method and application of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst. Background Art

[0002] The water bodies generated by industrial production contain a large number of harmful organic compounds, which have high drug resistance and are difficult to degrade in biological treatment. The advanced oxidation process of activating molecular oxygen can efficiently degrade refractory organic pollutants, completely decompose harmful substances by generating strong oxidants, and significantly improve water quality.

[0003] However, the activation of molecular oxygen (O2) is a challenging process, mainly due to its stable triplet ground state and high O=O bond energy (about 498 kJ / mol). Molecular oxygen has two unpaired electrons with the same spin in the ground state, which restricts its reaction with most organic molecules by the spin conservation rule and results in slow reaction kinetics. In addition, the activation of molecular oxygen usually requires the generation of highly reactive intermediates (such as singlet oxygen, superoxide radicals, etc.), and the generation and regulation conditions of these intermediates are complex, and it is easy to cause over-oxidation or side reactions, making it difficult to achieve selective oxidation. The development of efficient catalysts is the key to molecular oxygen activation, but the design and optimization of catalysts face high difficulties and are easily affected by reaction conditions. In the absence of a catalyst, the activation of molecular oxygen often requires high temperature and high pressure conditions, increasing energy consumption and safety hazards. Although these challenges can be partially overcome by means such as photochemistry, electrochemistry or enzyme catalysis, the efficient and selective activation of molecular oxygen remains an important research direction in the fields of chemistry and biology.

[0004] Although zero-valent copper shows good activity in some reactions as a catalyst, its disadvantages such as easy oxidation, agglomeration, low selectivity, difficult recovery and sensitivity to reaction conditions limit its wide application. To overcome these problems, surface modification, support loading or alloy formation with other metals are usually required, but these methods also increase the complexity of preparation and use.

[0005] Although amorphous iron oxyhydroxide has advantages such as high specific surface area and abundant surface active sites as a catalyst, its disadvantages such as poor structural stability, easy agglomeration, reaction condition limitations, low selectivity and difficult recovery limit its wide application. To overcome these problems, modification (such as doping, loading or composite with other materials) is usually required.

[0006] There is no report on the research of zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst in the prior art. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention provides a preparation method and application of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst.

[0008] The technical solution of the present invention is as follows:

[0009] A preparation method of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst, comprising the following steps:

[0010] S1. Mix ferric nitrate nonahydrate and ammonium bicarbonate evenly in ethanol to obtain a first mixed solution, then stir the first mixed solution at room temperature for reaction. After the reaction ends, perform solid-liquid separation to obtain a reaction product, wash and dry the reaction product to obtain amorphous iron oxyhydroxide;

[0011] S2. Add the amorphous iron oxyhydroxide prepared in step S1 and anhydrous copper sulfate to distilled water according to a preset ratio to obtain a second mixed solution, pass nitrogen into the second mixed solution and then stir for a certain period of time to form a homogeneous mixed solution; then, under the conditions of passing nitrogen and stirring, add a sodium borohydride solution to make the mixed solution undergo a reduction reaction. After the reaction ends, perform solid-liquid separation to obtain a reaction product, wash and freeze-dry the reaction product to obtain a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst.

[0012] According to a preferred embodiment of the present invention, in step S1, the mass percentage of the total solute in the first mixed solution is 0.7% - 0.9%, and the molar ratio of ferric nitrate nonahydrate to ammonium bicarbonate is 1:3.

[0013] More preferably, the mass percentage of the total solute in the first mixed solution is 0.75% - 0.81%.

[0014] According to a preferred embodiment of the present invention, in step S1, the stirring time is more than 7.5 h, and the washing process uses anhydrous ethanol to wash 2 - 4 times; the drying temperature is 50 - 55 °C.

[0015] More preferably, in step S1, the stirring time is 7.5 - 8.5 h; the drying time is 11 - 13 h.

[0016] According to a preferred embodiment of the present invention, in step S1 or step S2, after the reaction ends, solid-liquid separation is performed by centrifugation.

[0017] More preferably, the centrifugation speed is more than 8000 r / min.

[0018] According to a preferred embodiment of the present invention, in step S2, the mass percentage of the total solute in the second mixed solution is 0.4% - 0.7%.

[0019] Further preferably, the mass percentage of the total solute in the second mixed solution is 0.41% to 0.67%.

[0020] Preferably according to the present invention, in step S2, the molar ratio of anhydrous copper sulfate to amorphous iron oxyhydroxide is (1 to 2):(1 to 2).

[0021] Further preferably, in step S2, the molar ratio of anhydrous copper sulfate to amorphous iron oxyhydroxide is 1:1.

[0022] Preferably according to the present invention, in step S2, the mass percentage of the sodium borohydride solution is 0.30% to 0.40%;

[0023] Further preferably, the volume ratio of the added sodium borohydride solution to the volume of the second mixed solution is 1:1.

[0024] Further preferably, the mass percentage of the sodium borohydride solution is 0.36% to 0.40%.

[0025] Preferably according to the present invention, in step S2, the stirring time of the second mixed solution while introducing nitrogen is more than 0.3 h.

[0026] Further preferably, in step S2, the stirring time of the second mixed solution while introducing nitrogen is 0.3 to 0.6 h.

[0027] Preferably according to the present invention, in step S2, the sodium borohydride solution is added dropwise to the mixed solution.

[0028] Preferably according to the present invention, in step S2, the stirring time after the addition of the sodium borohydride solution is completed is more than 0.3 h.

[0029] Preferably according to the present invention, in step S2, the washing process uses distilled water and absolute ethanol to wash 3 to 5 times in sequence.

[0030] Preferably according to the present invention, in step S2, the freeze-drying time is more than 46 h.

[0031] Further preferably, in step S2, the freeze-drying time is 46 to 50 h.

[0032] Application of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared by the above method in treating organic wastewater.

[0033] Preferably according to the present invention, application of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared by the above method in degrading one or more of the organic wastewater pollutants tetracycline, oxytetracycline, rhodamine B, and norfloxacin.

[0034] The beneficial effects of the present invention at least include the following:

[0035] 1. The present invention prepares a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst. This catalyst loads zero-valent copper on amorphous iron oxyhydroxide through a reduction method, fully exerting the synergistic effect of the two in the catalytic reaction. Experimental results show that compared with single amorphous iron oxyhydroxide or zero-valent copper, the catalytic performance of the composite catalyst is significantly improved. In addition, by regulating the addition amounts of amorphous iron oxyhydroxide and zero-valent copper in the preparation process, a catalyst with excellent and stable performance is prepared.

[0036] 2. The present invention prepares a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst. By loading zero-valent copper on the surface of amorphous iron oxyhydroxide, it uniformly coats the outer surface of amorphous iron oxyhydroxide. This structural design not only provides more active sites for reactants but also effectively solves the problem of easy agglomeration of zero-valent copper during the reaction process, thus significantly improving the catalytic performance of the catalyst. In addition, this preparation method is simple and easy to implement, and can efficiently prepare a catalyst with high catalytic performance and good cycle stability, providing a new technical approach for related catalytic reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 SEM diagram of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in Example 1 of the present invention.

[0038] Figure 2 FTIR spectra of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst, amorphous iron oxyhydroxide, and zero-valent copper prepared in Example 1 of the present invention.

[0039] Figure 3 XRD diagrams of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst, amorphous iron oxyhydroxide, and zero-valent copper prepared in Example 1 of the present invention.

[0040] Figure 4 Comparison diagram of the degradation effects of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalysts prepared in Examples 1 to 3 of the present invention on oxytetracycline.

[0041] Figure 5 Comparison diagram of the cyclic degradation effects of oxytetracycline by using the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in Example 1 of the present invention.

[0042] Figure 6 Comparison diagram of the degradation effects of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in Example 1 of the present invention and catalysts in different systems on oxytetracycline.

[0043] Figure 7Comparison diagram of the degradation effect of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in Example 1 of the present invention on oxytetracycline in different water bodies.

[0044] Figure 8 Comparison diagram of the degradation effect of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in Example 1 of the present invention on different pollutants. Detailed implementation manners

[0045] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0046] The experimental methods used in the following examples are all conventional methods unless otherwise specified.

[0047] The materials, reagents, etc. used in the following examples can be obtained from commercial sources unless otherwise specified.

[0048] Source of reagent materials:

[0049] Ferric nitrate nonahydrate (Fe(NO3)3·9H2O), ammonium bicarbonate (NH4HCO3), and sodium borohydride (NaBH4) were purchased from Sinopharm Chemical Reagent Co., Ltd.

[0050] Anhydrous copper sulfate (CuSO4) was purchased from Macklin.

[0051] Iron oxyhydroxide (α-FeOOH) was purchased from Aladdin (CAS: 20344-49-4).

[0052] Example 1

[0053] A preparation method of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst includes the following steps:

[0054] S1. Weigh 0.404 g of Fe(NO3)3·9H2O and 0.2372 g of NH4HCO3 and dissolve them in 100 mL of ethanol to obtain a first mixed solution, and magnetically stir it at room temperature for 8 h; after the reaction ends, centrifuge the product for 3 min at 8000 r / min to separate the product, wash it with ethanol, wash it 3 times, and dry it at 50 °C for 12 h to obtain amorphous iron oxyhydroxide;

[0055] S2. Weigh 0.1601 g of CuSO4 and 0.0889 g of amorphous iron oxyhydroxide and dissolve them in 50 mL of distilled water. After purging with nitrogen, stir magnetically for 30 min to mix evenly to obtain a second mixed solution. Then, under the condition of purging with nitrogen and magnetic stirring, drop 0.1 M of the same volume of NaBH4 solution into the second mixed solution at a rate of 1 - 2 drops per second for the reduction reaction. After the NaBH4 solution is completely dropped, continue stirring for 30 min, and then centrifuge the reacted substance at 8000 r / min for 3 min for solid-liquid separation. Wash the reaction product with distilled water and absolute ethanol three times in sequence, and then dry it in a freeze dryer for 48 h to prepare zero-valent copper / amorphous iron oxyhydroxide.

[0056] In the said preparation method, purging with nitrogen is to isolate air and prevent oxidation.

[0057] The SEM image of the zero-valent copper / amorphous iron oxyhydroxide prepared in Example 1 is as Figure 1 shown. It can be seen from the figure that zero-valent copper uniformly covers the amorphous iron oxyhydroxide.

[0058] The FTIR spectrum of the zero-valent copper / amorphous iron oxyhydroxide composite material prepared in Example 1 is as Figure 2 shown. The following characteristic absorption peaks can be observed from the figure: a band caused by physically adsorbed water is shown near 3400 cm -1 , while the band at 1630 cm -1 is the bending vibration of the hydroxyl group; the vibration at 1388 cm-1 is the O-H deformation vibration: the deformation vibration of the hydroxyl group may also appear in this region. Amorphous iron oxyhydroxide contains a large number of hydroxyl groups, and there may be interactions between these hydroxyl groups, resulting in a change in the frequency of their deformation vibration; the band at 1050 cm-1 is proven to be the bending vibration band of Fe-OH in amorphous iron oxyhydroxide; a strong vibration peak appears at 625 cm -1 , which is attributed to the crystal structure of Cu2O. From the above conclusions, it can be obtained that amorphous iron oxyhydroxide and zero-valent copper exist in the composite material, proving the successful compounding of the material.

[0059] As Figure 3 shown, the XRD pattern further verifies the composition of the composite material. The peaks at 2θ = 43.3°, 50.4° and 74.1° correspond to the (111), (200) and (220) crystal planes of zero-valent copper (JCPDS 04-0836), indicating that zero-valent copper exists in the composite material in crystal form. However, due to its amorphous structure, amorphous iron oxyhydroxide does not show obvious characteristic peaks in the XRD pattern. This is consistent with the FTIR analysis results, further proving the existence of amorphous iron oxyhydroxide in the composite material, but its characteristic peaks are masked by the overall structure of the composite material, only showing the characteristic peaks of zero-valent copper.

[0060] To investigate the degradation rate of oxytetracycline by the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in this example, the following method was used for the degradation test: At room temperature, 10 mg of the catalyst was added to 95 mL of distilled water. After adjusting the pH of the above mixture to 7.0 ± 0.1 with sodium hydroxide and hydrochloric acid, it was aerated for 2 min, and then 5 mL of 200 mg / L oxytetracycline was added to start the degradation experiment. The experiment was carried out under magnetic stirring conditions. The degradation effect of the catalyst on oxytetracycline was illustrated by testing the change in the ultraviolet absorption spectrum of the solution (the ultraviolet wavelength of oxytetracycline is 355 nm). The results showed that after 30 min of reaction, the OTC degradation rate reached 96.2%.

[0061]

[0062] In the formula, C is the concentration of oxytetracycline at a certain reaction time, and C0 is the initial concentration of oxytetracycline.

[0063] Example 2

[0064] A preparation method of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst includes the following steps:

[0065] S1. Weigh 0.404 g of Fe(NO3)3·9H2O and 0.2372 g of NH4HCO3 and dissolve them in 100 mL of ethanol to obtain a first mixture, and magnetically stir it at room temperature for 8 h; after the reaction ends, centrifuge the product for 3 min at 8000 r / min to separate it, wash it with ethanol, wash it 3 times, and dry it at 50 °C for 12 h to obtain amorphous iron oxyhydroxide;

[0066] S2. Weigh 0.1601 g of CuSO4 and 0.1779 g of amorphous iron oxyhydroxide and dissolve them in 50 mL of distilled water. After introducing nitrogen, magnetically stir for 30 min to mix evenly to obtain a second mixture; then, under the condition of introducing nitrogen and magnetic stirring, drop 0.1 M of the same volume of NaBH4 solution into the second mixture at a rate of 1 - 2 drops per second for the reduction reaction. After the NaBH4 solution is completely dropped, continue to stir for 30 min, and then centrifuge the reacted substance for 3 min at 8000 r / min for solid-liquid separation; wash the reaction product 3 times with distilled water and anhydrous ethanol in turn, and then dry it in a freeze dryer for 48 h to obtain zero-valent copper / amorphous iron oxyhydroxide.

[0067] To investigate the catalytic effect of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in Example 2 on OTC, the test conditions of Example 1 were adopted. The results showed that the degradation rate of the catalyst prepared in this example for OTC was 88.2%, which decreased compared with the degradation rate of 96.2% of the catalyst prepared in Example 1.

[0068] Example 3

[0069] A preparation method of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst comprises the following steps:

[0070] S1. Weigh 0.404 g of Fe(NO3)3·9H2O and 0.2372 g of NH4HCO3 and dissolve them in 100 mL of ethanol to obtain a first mixed solution, and magnetically stir it at room temperature for 8 h; after the reaction ends, centrifuge the product for 3 min at 8000 r / min to separate it, wash it with ethanol for 3 times, and dry it at 50 °C for 12 h to obtain amorphous iron oxyhydroxide;

[0071] S2. Weigh 0.1601 g of CuSO4 and 0.0445 g of amorphous iron oxyhydroxide and dissolve them in 50 mL of distilled water, introduce nitrogen, and magnetically stir for 30 min to mix evenly to obtain a second mixed solution; then, under the condition of introducing nitrogen and magnetic stirring, drop 0.1 M of the same volume of NaBH4 solution into the second mixed solution at a rate of 1-2 drops per second for a reduction reaction. After the NaBH4 solution is completely dropped, continue to stir for 30 min, and then centrifuge the reacted substance for 3 min at 8000 r / min for solid-liquid separation; wash the reaction product with distilled water and anhydrous ethanol 3 times in sequence, and then dry it in a freeze dryer for 48 h to obtain zero-valent copper / amorphous iron oxyhydroxide.

[0072] In order to explore the catalytic effect of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in Example 3 on OTC, the test conditions of Example 1 were adopted. The results show that the degradation rate of the catalyst prepared in this example for OTC is 85.3%, which is lower than the degradation rate of 96.2% of the catalyst prepared in Example 1.

[0073] The degradation effects of OTC in Examples 1 to 3 are as Figure 4 shown. It can be seen from the figure that the catalyst prepared in Example 1 has the highest catalytic efficiency for OTC. That is, when the molar ratio of amorphous iron oxyhydroxide to zero-valent copper in the catalyst is 1:1, the prepared catalyst can exhibit excellent degradation performance.

[0074] Specifically, during the research process, the catalytic effect of the material prepared when the molar ratio of amorphous iron oxyhydroxide to zero-valent copper is 1:1 (i.e., the catalyst prepared in Example 1) on OTC was also investigated. The cyclic test was carried out in the following manner: At room temperature, 10 mg of the catalyst was added to 95 mL of distilled water. After adjusting the pH of the above mixture to 7.0 ± 0.1 with sodium hydroxide and hydrochloric acid, aeration was carried out for 2 min, 5 mL of 200 mg / L oxytetracycline was added, and the degradation experiment was started, and the results were recorded. After degradation, the material was centrifuged at 8000 r / min for 3 min with a centrifuge to separate the material. The separated material was washed 3 - 5 times with distilled water and ethanol, and finally freeze-dried for 48 h. The above experiment was repeated 5 times to test the cyclic degradation effect.

[0075] The results are as Figure 5 shown. It can be seen from the figure that after 5 cycles of catalysis, the degradation rate of OTC can still reach more than 80%. The results show that the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared in this example has excellent cyclic degradability for OTC.

[0076] Example 4

[0077] A preparation method of a zero-valent copper / iron oxyhydroxide activated molecular oxygen catalyst includes the following steps:

[0078] S1. Weigh 0.1601 g of CuSO4 and 0.0889 g of iron oxyhydroxide (α-FeOOH) and dissolve them in 50 mL of distilled water. After introducing nitrogen, magnetic stirring is carried out for 30 min to mix evenly to obtain a second mixed solution; then, under the condition of introducing nitrogen and magnetic stirring, a 0.1 M NaBH4 solution of the same volume is dropped into the second mixed solution at a rate of 1 - 2 drops / second for the reduction reaction. After the NaBH4 solution is completely dropped, stirring is continued for 30 min, and then the reaction product is centrifuged at 8000 r / min for 3 min for solid-liquid separation; the reaction product is washed 3 times with distilled water and absolute ethanol in sequence, and then dried in a freeze dryer for 48 h to obtain zero-valent copper / iron oxyhydroxide.

[0079] In order to explore the catalytic effect of the zero-valent copper / iron oxyhydroxide prepared in Example 4 on OTC, the test conditions of Example 1 were adopted. The results show that the degradation rate of the catalyst prepared in this example for OTC is 91.2%, which is lower than that of the catalyst prepared in Example 1, which is 96.2%.

[0080] Preparation method of zero-valent copper:

[0081] Weigh 0.1601 g of CuSO4 and dissolve it in 50 mL of distilled water. After purging with nitrogen, stir magnetically for 30 min. Then, under the condition of purging with nitrogen and magnetic stirring, dropwise add 0.1 M NaBH4 solution of the same volume into the mixture at a rate of 1 - 2 drops per second for the reduction reaction. After the NaBH4 solution is completely dropped, continue stirring for 30 min, and then centrifuge the reacted substance at 8000 r / min for 3 min for solid-liquid separation. Wash the reaction product with distilled water and absolute ethanol three times in sequence, and then dry it in a freeze dryer for 48 h to obtain zero-valent copper.

[0082] In addition, the inventors also compared the degradation of OTC by amorphous iron hydroxide (the amorphous iron hydroxide prepared in step S1 of Example 1), zero-valent copper, zero-valent copper / amorphous iron hydroxide prepared in Example 1, and zero-valent copper / iron hydroxide prepared in Example 4 under the same conditions (the OTC degradation method described in Example 1). The results are as Figure 6 shown. The results in the figure further verify the excellent degradation ability of the zero-valent copper / amorphous iron hydroxide activated molecular oxygen catalyst for OTC. The main reason for its effective degradation of OTC is that: the zero-valent copper / amorphous iron hydroxide activates molecular oxygen to generate reactive species ( 1 O2, ·OH, ·O2 - etc.). These reactive species attack the OTC molecules and finally mineralize them into CO2 and H2O, thereby achieving the degradation of OTC.

[0083] Example 5

[0084] To explore the degradation effect of the zero-valent copper / amorphous iron hydroxide activated molecular oxygen catalyst prepared in Example 1 on oxytetracycline in actual water bodies, using the degradation experimental conditions in Example 1, replace distilled water with the Yellow River water, Daming Lake water, tap water, and Jiazi Lake water, and conduct degradation tests on oxytetracycline. The test results are as Figure 7 shown. It can be seen from the figure that the degradation effects of oxytetracycline in the Yellow River water, Daming Lake water, tap water, and Jiazi Lake water at 60 min are 62.0%, 55.3%, 60.5%, and 58.3% respectively. The above experimental results show that the zero-valent copper / amorphous iron hydroxide activated molecular oxygen catalyst can effectively remove oxytetracycline in actual water bodies. This test can appropriately extend the degradation time to achieve a better treatment effect.

[0085] Example 6

[0086] To explore the degradation effect of the zero-valent copper / amorphous iron hydroxide activated molecular oxygen catalyst prepared in Example 1 on different organic pollutants, using the degradation experimental conditions in Example 1, replace oxytetracycline with rhodamine B, methylene blue, tetracycline, and norfloxacin, and conduct degradation tests. The test results are as Figure 8As shown, it can be seen from the figure that the degradation efficiencies of rhodamine B, methylene blue, tetracycline and norfloxacin at 60 min are 88.5%, 51.5%, 97.1% and 51.2% respectively. The above experimental results indicate that the zero-valent copper / amorphous iron hydroxide activated molecular oxygen catalyst can degrade various organic pollutants. This test can appropriately extend the degradation time to achieve better treatment effects.

[0087] In summary, the preparation method of the zero-valent copper / amorphous iron hydroxide activated molecular oxygen catalyst proposed by the present invention combines zero-valent copper and amorphous iron hydroxide, which can give full play to the catalytic performance of both, making the finally prepared catalyst exhibit more excellent catalytic performance; in the above way, a zero-valent copper / amorphous iron hydroxide activated molecular oxygen catalyst that can be recycled and has high catalytic performance can be easily prepared.

Claims

1. A preparation method of a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst, characterized in that, It includes the following steps: S1. Mix ferric nitrate nonahydrate and ammonium bicarbonate evenly in ethanol to obtain a first mixed solution, then stir the first mixed solution at room temperature for reaction. After the reaction ends, perform solid-liquid separation to obtain a reaction product, wash and dry the reaction product to prepare amorphous iron oxyhydroxide; S2. Add the amorphous iron oxyhydroxide prepared in step S1 and anhydrous copper sulfate to distilled water according to a preset ratio to obtain a second mixed solution. Pass nitrogen into the second mixed solution and then stir for a certain period of time to form a homogeneous mixed solution; then, under the conditions of passing nitrogen and stirring, add a sodium borohydride solution to make the mixed solution undergo a reduction reaction. After the reaction ends, perform solid-liquid separation to obtain a reaction product, wash and freeze-dry the reaction product to prepare a zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst.

2. The method according to claim 1, wherein In step S1, the mass percentage of the total solute in the first mixed solution is 0.7% - 0.9%, and the molar ratio of ferric nitrate nonahydrate to ammonium bicarbonate is 1:3; Preferably, the mass percentage of the total solute in the first mixed solution is 0.75% - 0.81%.

3. The method according to claim 1, characterized in that In step S1, the stirring time is more than 7.5 h, and the washing process uses anhydrous ethanol to wash 2 - 4 times; the drying temperature is 50 - 55 °C; Preferably, in step S1, the stirring time is 7.5 - 8.5 h; the drying time is 11 - 13 h.

4. The method according to claim 1, characterized in that, In step S1 or step S2, after the reaction ends, perform solid-liquid separation by centrifugation; Preferably, the centrifugation speed is more than 8000 r / min.

5. The method according to claim 1, wherein In step S2, the mass percentage of the total solute in the second mixed solution is 0.4% - 0.7%; Preferably, the mass percentage of the total solute in the second mixed solution is 0.41% - 0.67%.

6. The method according to claim 1, characterized in that, In step S2, the molar ratio of anhydrous copper sulfate to amorphous iron oxyhydroxide is (1 - 2):(1 - 2); Preferably, in step S2, the molar ratio of anhydrous copper sulfate to amorphous iron oxyhydroxide is 1:

1. Preferably, in step S2, the mass percentage of the sodium borohydride solution is 0.30% - 0.40%; Preferably, the volume ratio of the added sodium borohydride solution to the volume of the second mixed solution is 1:

1. Preferably, the mass percentage of the sodium borohydride solution is 0.36% - 0.40%.

7. The method according to claim 1, characterized in that In step S2, the stirring time for passing nitrogen into the second mixed solution is more than 0.3 h; Preferably, in step S2, the stirring time for passing nitrogen into the second mixed solution is 0.3 - 0.6 h.

8. The method according to claim 1, wherein In step S2, drop the sodium borohydride solution into the mixed solution; Preferably, in step S2, the stirring time after the addition of the sodium borohydride solution is completed is more than 0.3 h; Preferably, in step S2, the washing process uses distilled water and anhydrous ethanol to wash 3 - 5 times in sequence; Preferably, in step S2, the freeze-drying time is more than 46 h; Preferably, in step S2, the freeze-drying time is 46 - 50 h.

9. Use of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared by the method according to any one of claims 1-8 in the treatment of organic wastewater.

10. The application according to claim 9, characterized in that, Use of the zero-valent copper / amorphous iron oxyhydroxide activated molecular oxygen catalyst prepared by the method according to any one of claims 1-8 in the degradation of one or more of the organic wastewater pollutants tetracycline, oxytetracycline, rhodamine B, and norfloxacin.

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