CN114772629A - CuxOne-step calcination preparation method of O material and application of O material in degradation of antibiotics - Google Patents

Abstract

The invention discloses a Cu_xPreparation method and application of O material and Cu_xThe O material comprises an oxide complex of monovalent copper and divalent copper, comprising the steps of: 1) dissolving copper oxide and organic compound in organic solvent, heating and reacting for 10-14 hours at the temperature of 100 ℃ and 130 ℃, wherein the copper oxideSelected from the group consisting of copper nitrate, copper acetate and copper sulfate, said organic compound being selected from the group consisting of terephthalic acid, triisopropanolamine and trimesic acid; the molar ratio of copper oxide to organic compound is 1: 0.8-1.2; 2) after the reaction is finished, centrifuging to obtain a solid material, washing and drying; 3) calcining the dried solid material for 1.5-3h at the temperature of 300-400 ℃ under the aerobic condition, and cooling to obtain the catalyst. Cu of the invention_xThe O material has multiple valence states, contains Cu (II) and Cu (I), and can enhance Cu (II)/Cu (I) circulation.

Description

CuxOne-step calcination preparation method of O material and application of O material in degradation of antibiotics

Technical Field

The invention relates to the technical field of photocatalytic treatment and antibiotic treatment, in particular to Cu_xA one-step calcination preparation method of an O material and application thereof in degrading antibiotics.

Background

In recent years, environmental problems caused by antibiotics have been widely reported. Antibiotics, represented by Tetracycline (TC), are receiving increasing attention due to their excessive use in animal husbandry and clinical medicine and their large discharge into environmental media. The use and release of TC in a large amount increases the environmental risk of drug-resistant bacteria, so that the effective elimination of the environmental risk and harm is of great significance.

Various technologies are currently used to remove TC from wastewater, including membrane separation, adsorption, and biological treatment. However, these methods all expose some disadvantages during processing. For example, membrane separation adsorption removes TC by physical means rather than degradation, resulting in TC remaining present. In this case, it is highly desirable to select an effective technique for eliminating TC in consideration of the disadvantages of the above-described methods.

Advanced Oxidation Processes (AOPs) are considered to be one of the most effective techniques for removing TC from environmental media due to their high degradation efficiency and detoxification capability to refractory contaminants. At present, AOPs mainly comprise three types of Fenton, Fenton-like and oxidation, wherein OH is the main type. Sulfate radical type AOPs (SR-AOPs) have a great advantage in controlling persistent organic pollutants by activating Peroxymonosulfate (PMS) as compared to OH-based AOPs.

Metal Organic Frameworks (MOFs) are attractive crystalline materials composed of Metal nodes (Fe, Co, Cu, etc.) and organic linkers, and are widely used in the field of activating PMS. Besides the radical activation pathway, there is a non-radical activation pathway, which is considered as a very excellent activation method due to its low energy cost and excellent oxidation ability. However, Cu-MOFs derived copper oxides have little utility and mechanism as SR-AOPs catalysts.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide Cu_xA one-step calcination preparation method of an O material and application thereof in degrading antibiotics.

In order to realize the purpose, the invention adopts the technical scheme that:

cu_xMethod for preparing O material, Cu_xThe O material is mixed valence copper oxide, and comprises the following steps:

1) dissolving a copper oxide and an organic compound in an organic solvent, and heating for reaction for 10-14h at the temperature of 100-130 ℃, wherein the copper oxide is selected from copper nitrate, copper acetate and copper sulfate, and the organic compound is selected from terephthalic acid, triisopropanolamine and trimesic acid; the molar ratio of copper oxide to organic compound is 1: 0.8-1.2;

2) after the reaction is finished, centrifuging to obtain a solid material, washing and drying;

3) calcining the dried solid material for 1.5-3h at the temperature of 300-.

Preferably, the washing in step 2) is sequentially washed by the organic solvent, ethanol and deionized water in step 1), and preferably 3 times by using each detergent.

Preferably, the calcination in the step 3) is carried out in a muffle furnace, the temperature rising program is 4-6 ℃/min, preferably 5 ℃/min, and the calcination is carried out for 2 h; the calcination temperature is 300-380 ℃. The calcination temperature is preferably 300-370 ℃ or 320-370 ℃ or 330-360 ℃ or 350 ℃.

Preferably, the copper oxide is reacted with the organic compound in step 1) at 120 ℃ for 12 h; the copper oxide is copper nitrate, the organic compound is terephthalic acid, and the organic solvent is dimethylformamide; the preferred molar ratio of copper nitrate to terephthalic acid is 1: 1.

Cu obtained by the method of any one of the above processes_xThe application of the O material in degrading antibiotics.

Preferably, the antibiotic is tetracycline.

Preferably, the application method is to mix Cu_xAdding the O material into a solution containing antibiotics, and adding activated peroxymonosulfate to perform degradation reaction after the adsorption-desorption balance is achieved.

In the application technical scheme, the concentration of the antibiotic is 10-25mg/L, preferably 20 mg/L;

Cu_xthe adding amount of the O material is 0.05-0.15g/L, preferably 0.1 g/L;

the addition amount of the activated peroxymonosulfate is 0.25 to 2mmol/L, preferably 0.75 mmol/L;

the degradation reaction time is 50 minutes or more, preferably 55 or 60 minutes or more.

The beneficial effects of the invention are: cu prepared by calcining Cu-MOFs under certain temperature condition and aerobic condition_xO material having multiple valence states, containing Cu (II) and Cu (I), and capable of enhancing Cu (II)/Cu (I) cycling. The Cu-MOFs derivative Cu is prepared by a simple and easily-obtained one-step calcining method_xO, the material is a green photocatalytic material, a complex precursor does not need to be prepared, unnecessary chemical agents do not need to be added, and the finally synthesized material does not need to be purified; after multiple photoreactions, the catalyst shows good stability and reusability, has very high degradation rate on tetracycline, and can reach 100% of the degradation rate of tetracycline in deionized water.

Drawings

FIG. 1 is Cu_xXRD (a) and FT-IR (b) spectra of O-350, and SEM images of Cu-BDC (c) and CuxO-350 (d).

FIG. 2 shows TC at Cu-BDC + PMS and Cu_xDegradation efficiency (a) and kinetics (b) in O-350+ PMS system.

FIG. 3 shows PMS at Cu-BDC + PMS and Cu_xDecomposition efficiency in O-350+ PMS system.

FIG. 4 shows Cu obtained at different calcination temperatures_xXrd (a) and eis (d) of O, TC degradation efficiency (b) and kinetics (c) thereof.

Figure 5 is the degradation efficiency results of TC in PMS alone systems.

FIG. 6 is PMS activated Cu_xCirculation ability of O-350 to degrade TC.

Figure 7 is the result of the degradation efficiency of TC in water from different sources.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to be limiting.

The experimental procedures in the following examples are all conventional procedures unless otherwise specified; the chemical reagents and materials used, unless otherwise specified, are conventional in the art and are commercially available.

Example 1 preparation of Cu_xO

The method comprises the following steps:

10mmol of copper nitrate and 10mmol of terephthalic acid (H) were weighed₂BDC) is dissolved in 50ml of DMF (Dimethyl Formamide), after the DMF is completely dissolved, the mixture is reacted in a stainless steel reaction kettle (at 120 ℃) for 12 hours and centrifuged to obtain a solid material, the solid material is respectively washed by DMF, ethanol and deionized water for 3 times and then dried in an oven, and the obtained material is the metal organic framework material Cu-BDC. Calcining the Cu-BDC solid in a muffle furnace at 350 ℃, wherein the temperature rise program is 5 ℃/min, calcining for 2h, and finally marking the obtained material as Cu_xO-350, the material obtained by calcination at 300 ℃ and 400 ℃ being denoted as Cu_xO-300 and Cu_xO-400。

For the obtained Cu-BDC and Cu_xO-350XRD and FT-IR spectral analysis, Scanning Electron Microscope (SEM) analysis, and the results are shown in FIG. 1: shown in FIG. 1a, Cu_xThe characteristic peaks of O-350 are at 29.5, 36.4, 42.3, 61.3 and 73.5 deg., corresponding to Cu₂The (110), (111), (200), (220) and (311) planes of O (JCPDS 05-0667). CuO (JSPDS45-0937) exhibits a series of diffraction peaks at 32.5, 35.5, 38.7, 48.7, 53.5, 58.3 and 61.5 degrees, corresponding to the (-110), (002), (111), (202), (020), (202) and (-113) planes. The results show that after the Cu-BDC is calcined at 350 ℃, Cu is obtained_xO-350 contains an oxide composite material of monovalent copper and divalent copper.

The FTIR technology is utilized to research Cu-BDC and Cu_xThe surface group characteristics of O-350 are observed as shown in FIG. 1 b. The vibration of the Cu-BDC is concentrated at 1390cm^-1And 400-700cm^-1Is H₂-COOH of BDC and Cu-O, indicating Cu in Cu-MOFs²⁺And H₂The BDCs are tightly coupled. For Cu-BDC and Cu_xO-350, two distinct peaks centered at 1600 and 3400cm^-1These two peaks are generated by the oscillation of OH groups by M-OH and adsorbed water. Cu_xO-350 at 400-700cm^-1The vibration intensity is higher than that of Cu-BDC, indicating that the calcination process favors the formation of more Cu-O.

From FIGS. 1c and d, it is found that Cu-BDC and Cu_xO-350 has similar dimensions and microscopic morphology (parallelogram). Cu in contrast to Cu-BDC_xThe O-350 has a rough surface, and a plurality of pores are distributed on the surface due to the precipitation of the organic ligand in the high-temperature calcination process. It can accelerate the migration of organic contaminants, increase the surface area, and thus increase the number of reaction sites.

By analysis, Cu_xO-300、Cu_xO-400 and Cu_xThe XRD, FT-IR spectra and SEM of O-350 are similar.

Example 2 tetracycline degradation (TC) assay

The catalytic degradation experiments were performed in 250ml beakers with magnetic stirring at room temperature. To a 200mL of LTC solution (20mg/L) was added 0.02g of the catalyst Cu prepared in example 1_xO, the adsorption-desorption equilibrium is reached (20min), and then 0.75mmol/L PMS is added into the solution to start the degradation reaction.At each predetermined time, the reaction solution was extracted, immediately filtered through a 0.22 μm filter, and the concentration of TC was measured by uv spectrophotometry at λ 357 nm. Quantification of PMS was monitored by uv-vis spectrophotometer after staining with potassium iodide, λ 352 nm. The results are shown in FIGS. 2-5.

In FIG. 2a, only Cu-BDC or Cu_xThe removal efficiency of O-350 on TC was below 20%, indicating a negligible contribution to adsorption. In the presence of PMS, Cu_xThe degradation efficiency of O-350 is about 1.5 times higher than that of Cu-BDC, and Cu is obtained after 60min_xThe degradation efficiency of the O-350+ PMS system on TC can reach 100 percent. In addition, the experimental data were simulated using quasi-first order kinetics ln (Ct/Co) ═ kt. As can be seen from FIG. 2b, Cu_xThe k value of the O-350+ PMS system is 0.104min^-1Is 8 times of that of the Cu-BDC/PMS system.

And detecting PMS in Cu-BDC + PMS and Cu_xDecomposition efficiency in O-350+ PMS system, as shown in FIG. 3. The Cu-BDC + PMS can decompose about 63.7 percent of PMS and Cu in 60min_xO-350+ PMS can decompose about 100% of PMS in 60min, which shows that PMS is taken as a pro-oxidant and contains Cu_xNo residue exists in the reaction system of O, and no secondary pollution is caused.

In one aspect, Cu_xO has a larger surface area than Cu-BDC, meaning that Cu_xMore active sites in O. On the other hand, Cu_xThe mixed valence Cu of O and oxygen vacancies may promote the rapid generation of free radicals or non-free radicals in large quantities. For this purpose, the catalysts Cu prepared in example 1 at different calcination temperatures were used_xO and the catalytic performance of degrading TC was evaluated as shown in fig. 4a, b, c. And Cu_xO-350 phase vs, Cu_xThe characteristic diffraction peak of CuO in O-400 has no Cu₂Characteristic diffraction peak of O. Cu_xThe characteristic diffraction peaks of CuO also appear in O-300, and some weaker Cu appears at 36.4 DEG and 42.3 DEG₂O characteristic diffraction peak. The degradation efficiency and k value of TC are sequentially Cu_xO-400<Cu_xO-300<Cu_xO-350, indicating Cu_xThe mixed valence of Cu in O-350 plays an important role in PMS activation. The degradation efficiency of the PMS system alone on TC was 41.5% (FIG. 5), by electrochemistryImpedance Spectroscopy (EIS) measures the charge transfer resistance of the catalyst. Generally, in the EIS nyquist diagram, the smaller the arc radius, the smaller the charge transfer resistance. Therefore, as can be seen from FIG. 4d, the magnitude sequence of the arcs in the EIS Nyquist plot is Cu-BDC>Cu_xO-400>Cu_xO-300≈Cu_xAnd O-350, which shows that the electron transfer efficiency of the CuxO-350 surface is higher, and the activation of PMS and the degradation of TC are facilitated.

In practical applications, reuse is an important indicator of heterogeneous catalysts. To evaluate Cu_xReusability of O, 4 cycles of experiments were performed under the same conditions. As can be seen from FIG. 6, in the first experiment, Cu was present after 60min_xThe degradation efficiency of the O-350+ PMS system on TC can reach 100%, the degradation rate after the second circulation can still reach 98%, and after 4 circulation experiments in total, Cu is obtained_xThe degradation efficiency of the O-350+ PMS system on TC is still kept above 90%. Further indicates Cu_xO-350 has good stability. XRD and FTIR analysis also confirmed this conclusion. Used Cu as shown in FIGS. 6b and c_xO-350 for Cu₂Characteristic peaks of O and CuO and unused Cu_xThe characteristic peak of O is well matched, which shows that Cu is obtained after four times of cycle experiments_xThe crystal structure and surface groups of O-350 were unchanged. Thus, these results indicate that Cu-BDC derived Cu_xO is the best heterogeneous catalyst for controlling organic contaminants.

To evaluate Cu_xThe actual application capability and the prospect of the O-350+ PMS system are that TC degradation experiments are respectively carried out on tap water and river water under the same experimental conditions as the deionized water. River water for this study was taken from the Zhujiang basin, Guangzhou City. The degradation efficiency of TC in different water resources is shown in fig. 7. After the experiment is carried out for 55min, the degradation rate of TC in the deionized water can reach 100%, and the degradation efficiency of TC in tap water and river water is slightly lower than that of the deionized water. Considering the coexistence of impurities (such as Cl) in the water resource^-、NO₃ ^-Natural organics, etc.) inhibit the degradation of TC by various means, but the Cu produced_xThe O material still exhibits excellent catalytic performance. Evidence of Cu_xThe O + PMS system can effectively degrade actual water resourcesThe TC has strong practical application potential.

Claims (10)

1. Cu_xA method for producing an O material, characterized in that the Cu_xThe O material is mixed valence copper oxide, and comprises the following steps:

1) dissolving a copper oxide and an organic compound in an organic solvent, and heating for reaction for 10-14h at the temperature of 100-130 ℃, wherein the copper oxide is selected from copper nitrate, copper acetate and copper sulfate, and the organic compound is selected from terephthalic acid, triisopropanolamine and trimesic acid; the molar ratio of copper oxide to organic compound is 1: 0.8-1.2;

2) after the reaction is finished, centrifuging to obtain a solid material, washing and drying;

3) calcining the dried solid material for 1.5-3h at the temperature of 300-400 ℃ under the aerobic condition, and cooling to obtain the catalyst.

2. The method of claim 1, wherein: in the step 2), the organic solvent, ethanol and deionized water in the step 1) are adopted for washing in sequence, and preferably, each detergent is used for washing for 3 times.

3. The method of claim 1, wherein: calcining in a muffle furnace in the step 3), wherein the temperature rise program is 4-6 ℃/min, preferably 5 ℃/min, and calcining for 2 h; the calcination temperature is 300-380 ℃.

4. The method of claim 3, wherein: the calcination temperature is 300-370 ℃, 320-370 ℃, 330-360 ℃ or 350 ℃.

5. The method of claim 1, wherein: in the step 1), the copper oxide and the organic compound react for 12 hours at 120 ℃; the copper oxide is copper nitrate, the organic compound is terephthalic acid, and the organic solvent is dimethylformamide; the preferred molar ratio of copper nitrate to terephthalic acid is 1: 1.

6. Cu produced by the production method according to any one of claims 1 to 5_xThe application of the O material in degrading antibiotics.

7. The use of claim 6, wherein: the antibiotic is tetracycline.

8. Use according to claim 6 or 7, characterized in that: the application method is to mix Cu_xThe O material is added into the solution containing the antibiotics, and after the adsorption-desorption balance is achieved, the activated peroxymonosulfate is added for degradation reaction.

9. The use of claim 8, wherein:

the concentration of the antibiotic is 10-25mg/L, preferably 20 mg/L;

Cu_xthe adding amount of the O material is 0.05-0.15g/L, preferably 0.1 g/L;

the amount of activated peroxymonosulfate added is between 0.25 and 2mmol/L, preferably 0.75 mmol/L.

10. The use of claim 8, wherein: the degradation reaction time is 50 minutes or more, preferably 55 or 60 minutes or more.

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