Microwave-assisted prepared seaweed-like HxPy-Cz carbon material catalyst for efficiently degrading organic pollutants

Abstract

According to the method, the HxPy Cz (X = 0.1, 0.3, 0.5, 0.7 and 0.9, Y = 0.9, 0.7, 0.5, 0.3 and 0.1, and Z = 0.5, 1, 2 and 3) seaweed-like carbon material is prepared by taking citrus peel as a carbon source, natural pyrite and hematite as metal precursors and NaOH as a microwave absorbent, and simple and ultrafast solid-state synthesis of the biochar material derived from the waste biomass through microwave mediation is realized. Rapid microwave treatment not only is beneficial to construction of a seaweed-shaped structure and formation and exposure of more active sites, but also can accelerate mass transfer in the catalytic process. FeS and large specific surface area in H0. 3P0. 7atC1 can promote activation of peroxymonosulfate (PMS) to form free radicals (SO4, OH and O2) and non-free radicals (1O2) so as to degrade organic pollutants. The H0. 3P0. 7atC1 / PMS system shows excellent catalytic performance in the process of catalytically activating PMS and degrading tetracycline hydrochloride (TCH), and tetracycline hydrochloride can be completely removed within 10 minutes. In addition, in the degradation test of other pollutants, the H0. 3P0. 7atC1 / PMS system also shows wide applicability.

Description

Technical Field

[0001] Microwave-assisted prepared seaweed-like H x P y @C z carbon material catalyst for efficient degradation of organic pollutants Background Art

[0002] In recent years, antibiotics have been widely used in the medical and livestock industries. Their accumulation in natural water bodies has led to the gradual emergence of antibiotic-resistant bacteria and viruses. Tetracycline hydrochloride (TCH) is the second most commonly used antibiotic globally. Due to the stable structure of tetracycline hydrochloride, its degradation in the natural state is minimal, so it is often detected in drinking water, posing a serious threat to human health. It is imperative to solve this pollution problem. Currently, technologies such as physical adsorption, biodegradation, and chemical redox have been used to remove organic pollutants such as tetracycline hydrochloride. Among them, the chemical redox method has received extensive attention because it can completely degrade organic pollutants.

[0003] Advanced oxidation processes (AOPs) provide an efficient and economical solution for oxidizing antibiotics into harmless substances. Their active species include hydroxyl radicals (·OH), sulfate radicals (SO 4 ·− ), superoxide radicals (O 2 ·− ), and singlet oxygen ( 1 O 2 ), etc. These active species with strong oxidation ability can effectively mineralize target pollutants into carbon dioxide and water. However, unfortunately, the kinetic oxidation rate of PMS itself is very limited. Methods such as ultrasonic waves, heating, ultraviolet irradiation, and transition metal catalysis have been used to activate PMS and have shown significant effects. However, problems such as the high pH dependence in thermal activation and the high energy consumption of activation still exist. Therefore, there is an urgent need to develop efficient and green catalytic technologies to achieve water pollution control. The introduction of a carrier can increase the interaction between the functional groups on the catalyst and the carrier material, which is beneficial to the dispersion of the catalyst and the exposure of more active sites to improve catalytic activity. Carbon-based materials are widely used as carriers for various catalysts due to their excellent adsorption capacity, chemical stability, and large specific surface area. Summary of the Invention

[0004] The present invention discloses a microwave-assisted prepared seaweed-like H x P y @C zCarbon material catalyst, characterized in that, through a simple and ultrafast microwave-assisted one-pot solid-phase synthesis method, the rapid preparation of a seaweed-like catalytic material from citrus peel, hematite and pyrite is successfully achieved. During the microwave reaction process, hematite and pyrite are efficiently converted into FeS active species, and during the rapid heating process, a large number of defects are successfully introduced into the carbon material; H x P y @C z The preparation steps of the catalytic material are as follows: Weigh 0.5 g of citrus peel, 0.35 g of pyrite, 0.15 g of hematite and 0.12 g of NaOH, and mix them well in a ceramic mortar. Subsequently, place the mixture in a 25 mL crucible and pyrolyze it in a commercial microwave oven at 750 W for 8 minutes. After cooling, the carbon catalytic material H 0.3 P 0.7 @C 1 is washed with water / ethanol and dried in vacuo; When the fixed mass of citrus peel is 0.5 g and the total mass of hematite and pyrite is also 0.5 g, the catalysts prepared by varying the mass ratio of hematite and pyrite are labeled as H x P y @C 1 , where x + y = 1, when x = 0.1, 0.3, 0.5, 0.7, 0.9, y = 0.9, 0.7, 0.5, 0.3, 0.1, and the corresponding mass ratios of hematite and pyrite in the catalytic material are 1:9, 3:7, 1:1, 7:3, 9:1 respectively; When the mass of hematite is 0.15 g and the mass of pyrite is 0.35 g, the prepared catalyst is labeled as H 0.3 P 0.7 @C z , where z = 0.5, 1, 2, 3, and the corresponding masses of citrus peel are 0.25 g, 0.5 g, 1.0 g and 1.5 g respectively; Catalyst activation of peroxymonosulfate PMS for the degradation of organic pollutants: At room temperature, add 0.10 g / L of the catalyst to a 100 mL round-bottom flask containing 50 mL of an aqueous solution with 20 mg / L of organic pollutants and a pH of 6.6. Add PMS with a set concentration of 0.3 g / L to the reactor to initiate the degradation process. At set 1-minute intervals, withdraw 1 mL of the reaction solution, filter it through a 0.22 µm microporous membrane, and squeeze it into a centrifuge tube containing 2 mL of methanol. Then, measure the concentration of the organic pollutant at a specific wavelength using a UV-visible spectrophotometer; When H 0.3 P 0.7 @C 1 is used as the catalyst, 100% removal efficiency of tetracycline hydrochloride can be achieved within 10 min, and the rate constant is 0.5048 min −1 .

[0005] The above-mentioned microwave-assisted prepared seaweed-like H x P y @C z carbon material catalyst, characterized in that: when H 0.3 P 0.7 @C 1 is the catalyst, the removal efficiencies of oxytetracycline hydrochloride, ciprofloxacin, rhodamine B, carbamazepine and methyl orange can reach 100.0%, 94.9%, 96.1%, 100.0% and 96.9% within 10 min.

[0006] The above-mentioned microwave-assisted prepared seaweed-like H x P y @C z carbon material catalyst, characterized in that: compared with the traditional pyrolysis method, the microwave reaction has successfully realized the rapid carbonization of the biomass waste citrus peel, and the generated carbon material has an elongated and intertwined seaweed-like structure, which can provide better adsorption capacity in the pollutant degradation reaction. At the same time, the FeS active species can be evenly dispersed on the surface of the carrier, thus facilitating the provision of more active sites. Description of the Drawings

[0007] Figure 1 In (a) is the SEM image of H 0.3 P 0.7 @C 1 ; (b) is the elemental mapping diagram of H 0.3 P 0.7 @C 1 ; (c) is the TEM and particle size distribution image of H 0.3 P 0.7 @C 1 ; (d) is the HRTEM image of H 0.3 P 0.7 @C 1 .

[0008] Figure 2 In (a) are the catalysts H 0.9 P 0.1 @C 1 , H 0.7 P 0.3 @C 1 , H 0.5 P 0.5 @C 1 , H 0.3 P 0.7 @C 1 , H 0.1 P 0.9 @C 1 and H 0.3 P 0.7 @C600 (b) XRD pattern of catalyst H 0.3 P 0.7 @C 3 , H 0.3 P 0.7 @C 2 , H 0.3 P 0.7 @C 1 and H 0.3 P 0.7 @C 0.5 (c) is the XRD pattern of H 0.3 P 0.7 @C 1 and H 0.3 P 0.7 @C 600 Raman spectrum of H 0.3 P 0.7 @C 1 and H 0.3 P 0.7 @C 600 N 2 Adsorption–desorption isotherms.

[0009] Figure 3 Where (a) is the catalyst H 0.3 P 0.7 @C 1 and H 0.3 P 0.7 @C 600 Full XPS spectrum of . (b) is the Fe 2p spectrum, (c) is the S2p spectrum, (d) is the C 1s spectrum, and (e) is the O 1s spectrum. DETAILED DESCRIPTION

[0010] The present invention is described in detail below with reference to specific implementation cases.

[0011] Implementation Case 1: H x P y @C z Specific preparation steps of catalytic materials: H x P y @C z Synthesis of: In a convenient and rapid manner, 0.5 g of citrus peel, 0.35 g of pyrite, 0.15 g of hematite, and 0.12 g of NaOH (0.3 mmol) were weighed and mixed thoroughly in a ceramic mortar. Subsequently, the mixture was placed in a 25 mL crucible and pyrolyzed in a commercial microwave oven at 750 W for 8 min. After cooling, the carbon catalytic material H 0.3 P 0.7 @C 1Wash with water / ethanol and dry under vacuum. When the fixed mass of citrus peel is 0.5 g and the total mass of hematite and pyrite is also 0.5 g, the catalysts prepared by varying the mass ratio of hematite to pyrite are labeled as H x P y @C 1 (x + y = 1; when x = 0.1, 0.3, 0.5, 0.7, 0.9, y = 0.9, 0.7, 0.5, 0.3, 0.1, and the corresponding mass ratios of hematite to pyrite in the catalytic material are 1:9, 3:7, 1:1, 7:3, 9:1). When the mass of hematite is 0.15 g and the mass of pyrite is 0.35 g, the prepared catalyst is labeled H 0.3 P 0.7 @C z (z = 0.5, 1, 2, 3, corresponding to the masses of citrus peel being 0.25 g, 0.5 g, 1.0 g, and 1.5 g respectively).

[0012] The structure and morphology of the obtained sample H 0.3 P 0.7 @C 1 were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM): Figure 1 (a) is the SEM image of H 0.3 P 0.7 @C 1 . Figure 1 (b) is the elemental mapping diagram of H 0.3 P 0.7 @C 1 ; Figure 1 (c) is the TEM and particle size distribution images of H 0.3 P 0.7 @C 1 . Figure 1 (d) is the high-resolution transmission electron microscopy (HRTEM) image of H 0.3 P 0.7 @C 1 . The H 0.3 P 0.7 @C 1 composite catalytic material presents an elongated intertwined seaweed-like structure. The transmission electron microscopy image of the H 0.3 P 0.7 @C 1 sample also shows its seaweed-like structure, and metal nanoparticles are evenly dispersed on the carbon material. As Figure 1 shown in (d), lattice fringes of 0.260 nm appear in the HRTEM image, which correspond to the (110) crystal plane of FeS.

[0013] X-ray diffraction (XRD) was used to observe the effect of changing the mass ratio of pyrite to hematite or the mass ratio of citrus peel to ore on the crystal structure of the catalytic material, as Figure 2 shown. All catalytic materials showed a series of peaks around 29.9°, 33.9°, 36.6°, 39.8°, 43.9°, 48.3°, 53.2°, 57.1°, 64.2°, 65.2°, 71.4°, 73.3° and 79.0°, which were consistent with the crystal structure of FeS (#PDF 02-1041). In addition to the peaks of FeS, diffraction peaks corresponding to FeOOH were also detected at 11.8° and 17.0° in the XRD of H 0.9 P 0.1 @C 1 、H 0.7 P 0.3 @C 1 and H 0.5 P 0.5 @C 1 ( Figure 2 (a)). As the proportion of hematite decreased, the peak intensity of the by-product FeOOH gradually weakened. Excessive hematite would lead to the formation of the by-product FeOOH. When the ratio of hematite to pyrite was too high or too low, a large number of hematite (#PDF 24-0072) and pyrite (#PDF 26-0801) peaks were observed. Adjusting the mass ratio of hematite to pyrite showed that when the mass ratio of hematite to pyrite was 3:7, it was most favorable for the formation of FeS. Figure 2 (b) further optimized the ratio of citrus peel to ore. Too much citrus peel was not conducive to the formation of FeS. When the mass ratio of citrus peel to ore was 1:1, the peak intensity of FeS was the highest. As the mass of citrus peel further decreased, the intensity of the FeS peak also decreased. Therefore, too much or too little citrus peel was not conducive to providing sufficient energy for the conversion of pyrite and hematite to FeS. Figure 2 (c) Raman spectroscopy was used to characterize the defects in the carbon materials. The G band (1588 cm 0.3 P 0.7 @C 1 and H 0.3 P 0.7 @C 600 observed in the samples of -1 and D band (1352 cm -1 ), respectively, indicated the presence of graphite carbon and defective carbon structures. The I D / I G intensity ratio was an important parameter for evaluating the degree of defects in the carbon materials. The I 0.3 P 0.7 @C 1 of I D / I GThe value (1.12) is higher than H 0.3 P 0.7 @C 600 (0.84), indicating that microwave-assisted pyrolysis can lead to more defects in the carbon structure of H 0.3 P 0.7 @C 1 . This may be due to the unique heating mechanism of microwaves, which can induce local hot spots and promote the formation of defective carbon sites. H 0.3 P 0.7 @C 1 and H 0.3 P 0.7 @C 600 's N 2 adsorption-desorption isotherms show type-IV isotherms, indicating that the material has a mesoporous structure. The mesoporous structure not only increases the specific surface area but also improves the catalytic performance of the material by providing more active sites ( Figure 2 (d)).

[0014] Figure 3 X-ray photoelectron spectroscopy (XPS) was used to determine the surface composition and elemental valence states of the catalyst. Characteristic signals of Fe, S, C, and O were observed in the full spectra of H 0.3 P 0.7 @C 1 and H 0.3 P 0.7 @C 600 composites ( Figure 3 (a)). In Figure 3 (b), the peaks at 710.9 eV for Fe 2p 3 / 2 and 724.0 eV for Fe 2p 1 / 2 are related to Fe(II), while the peaks at 712.7 eV for Fe 2p 3 / 2 and 725.7 eV for Fe 2p 1 / 2 are related to Fe(III). The XPS of H 0.3 P 0.7 @C 1 prepared by microwave pyrolysis has a higher peak intensity for divalent iron. In Figure 3 (c), the peak at 161.7 eV is attributed to S 2- , the peak at 162.9 eV belongs to S 2 2- , and the peaks at 168.6 eV and 169.7 eV correspond to surface-bound sulfite and sulfate. H 0.3 P 0.7 @C 1 material has a strong S 2- signal, while H 0.3 P 0.7@C 600 In S 2- the signal is low, H 0.3 P 0.7 @C 600 Obvious S from the raw material pyrite is also detected in 2 2- the signal. Figure 3 S 2p in (c) indicates that microwave pyrolysis is more conducive to the generation of active species FeS, which is consistent with the XRD results. Figure 3 The three fitting peaks at 284.8 eV, 285.6 eV and 288.7 eV in d are C=C, C-O and C=O respectively. The results show that microwave pyrolysis of citrus peel is more conducive to the formation of C=O, H 0.3 P 0.7 @C 1 C=O in the catalytic material will promote the activation of PMS to generate 1 O 2 ·, thus accelerating the degradation of pollutants. Figure 3 530.3 eV, 531.3 eV, 532.5 eV and 533.4 eV in e are attributed to Fe-O, C=O, C-O and -COOH respectively. In H 0.3 P 0.7 @C 600 the large presence of Fe-O means that traditional pyrolysis is not conducive to the formation of catalytically active FeS from hematite and pyrite.

[0015] Implementation Case 2 (The reaction is shown in Table 1, entry 1) At room temperature, 0.3 g / L of PMS was added to a 100 mL round-bottom flask reactor containing 50 mL of TCH aqueous solution (20 mg / L, pH = 6.6) to initiate the degradation process. At set time intervals (1 minute to take a reaction solution), 1 mL of the reaction solution was taken, filtered through a 0.22 µm microporous membrane, and squeezed into a centrifuge tube containing 2 mL of methanol. Then, the concentration of organic pollutants was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, the degradation rate of TCH by pure PMS was only 6.6%, indicating that the rate constant of PMS for TCH degradation (0.0049 min −1 ) is very small.

[0016] Implementation Case 3 (The reaction is shown in Table 1, entry 2) At room temperature, 0.10 g / L of hematite catalyst was added to a 100 mL round-bottom flask containing 50 mL of TCH aqueous solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 / L was added to the reactor to initiate the degradation process. At set time intervals (taking the reaction solution once every 1 minute), 1 mL of the reaction solution was taken, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of organic pollutants was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, the degradation rate of TCH by the hematite catalyst was found to be 7.9%, and the rate constant was 0.0061 min −1 。

[0017] Example 4 (see Table 1, entry 3 for the reaction) At room temperature, 0.10 g / L of pyrite catalyst was added to a 100 mL round-bottom flask containing 50 mL of TCH aqueous solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (taking the reaction solution once every 1 minute), 1 mL of the reaction solution was taken, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of organic pollutants was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, the degradation rate of TCH by the pyrite catalyst was found to be 12.8%, and the rate constant was 0.0101 min −1 。

[0018] Example 5 (see Table 1, entry 4 for the reaction) At room temperature, 0.10 g / L of FeS catalyst was added to a 100 mL round-bottom flask containing 50 mL of TCH aqueous solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (taking the reaction solution once every 1 minute), 1 mL of the reaction solution was taken, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of organic pollutants was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, the degradation rate of TCH by the FeS catalyst was found to be 47.9%, and the rate constant was 0.0958 min −1 。

[0019] Example 6 (see Table 1, entry 5 for the reaction) At room temperature, 0.10 g / L of H0.3 P 0.7 @C 600 Catalyst. Add PMS with a set concentration of 0.3 g / L to the reactor to initiate the degradation process. At set time intervals (take the reaction solution every 1 minute), extract 1 mL of the reaction solution, filter it through a 0.22 µm microporous membrane, and squeeze it into a centrifuge tube containing 2 mL of methanol. Then, measure the concentration of organic pollutants with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that H 0.3 P 0.7 @C 600 The degradation rate of TCH by the catalyst was 81.5%, and the rate constant was as high as 0.1858 min −1 .

[0020] Example 7 (The reaction is shown in Table 1, entry 6) At room temperature, add 0.10 g / L of H 0.3 P 0.7 @C 1 Catalyst to a 100 mL round-bottom flask containing 50 mL of an aqueous TCH solution (20 mg / L, pH = 6.6). Add PMS with a set concentration of 0.3 g / L to the reactor to initiate the degradation process. At set time intervals (take the reaction solution every 1 minute), extract 1 mL of the reaction solution, filter it through a 0.22 µm microporous membrane, and squeeze it into a centrifuge tube containing 2 mL of methanol. Then, measure the concentration of organic pollutants with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that H 0.3 P 0.7 @C 1 The degradation rate of TCH by the catalyst was 100%, and the rate constant was 0.5048 min −1 .

[0021]

[0022] Example 8 (The reaction is shown in Table 2, entry 1) At room temperature, add 0.10 g / L of H 0.9 P 0.1 @C 1Catalyst. PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken once every 1 minute), 1 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that H 0.9 P 0.1 @C 1 The degradation rate of TCH by the catalyst was 70.6%, and the rate constant was 0.1225 min −1 .

[0023] Example 9 (The reaction is shown in Table 2, entry 2) At room temperature, 0.10 g / L of H 0.7 P 0.3 @C 1 catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous TCH solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken once every 1 minute), 1 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that H 0.7 P 0.3 @C 1 The degradation rate of TCH by the catalyst was 79.2%, and the rate constant was 0.1573 min −1 .

[0024] Example 10 (The reaction is shown in Table 2, entry 3) At room temperature, 0.10 g / L of H 0.5 P 0.5 @C 1 catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous TCH solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken once every 1 minute), 1 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that H 0.5 P 0.5 @C 1The degradation rate of TCH by the catalyst was 86.5%, and the rate constant was 0.2007 min −1 .

[0025] Implementation case 11 (the reaction is shown in Table 2, entry 4) At room temperature, 0.10 g / L of H 0.1 P 0.9 @C 1 catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous TCH solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (taking the reaction solution once every 1 minute), 1 mL of the reaction solution was taken, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that H 0.9 P 0.1 @C 1 catalyst had a degradation rate of 68.9% for TCH, and the rate constant was 0.1169 min −1 .

[0026]

[0027] Implementation case 12 (degradation of TCH with 0.06 g / L of H 0.3 P 0.7 @C 1 ) At room temperature, 0.06 g / L of H 0.3 P 0.7 @C 1 catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous TCH solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (taking the reaction solution once every 1 minute), 1 mL of the reaction solution was taken, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured with a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that H 0.3 P 0.7 @C 1 catalyst had a degradation rate of 83.6% for TCH.

[0028] Implementation case 13 (degradation of TCH with 0.08 g / L of H 0.3 P 0.7 @C 1 ) At room temperature, 0.08 g / L of H 0.3 P 0.7 @C 1 catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous TCH solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured using a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that the H 0.3 P 0.7 @C 1 catalyst had a degradation rate of 91.4% for TCH.

[0029] Example 14 (Degradation of TCH with 0.12 g / L of H 0.3 P 0.7 @C 1 ) At room temperature, 0.12 g / L of H 0.3 P 0.7 @C 1 catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous TCH solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured using a UV-visible spectrophotometer at a wavelength of 275 nm. When the reaction time was 10 minutes, it was found that the H 0.3 P 0.7 @C 1 catalyst had a degradation rate of 96.5% for TCH.

[0030] Example 15 (See Table 3, Entries 1 - 5 for the reaction) At room temperature, 0.15 g / L of H 0.3 P 0.7 @C 1Catalyst, add the required amount of PMS with a concentration of 0.3 g / L into the reactor and start the degradation. At predetermined time intervals (take the reaction solution every 1 minute), withdraw 1 mL of the reaction solution, filter it using a 0.22 µm microporous membrane, and squeeze it into a centrifuge tube containing 2 mL of methanol. Then, detect the concentration of organic pollutants at 275 nm using a UV-visible spectrophotometer. When the reaction time is 10 minutes, it is found that H 0.3 P 0.7 @C 1 The degradation rate of TCH by the catalyst is 100%. When the catalyst is used for the second time after centrifugation, the TCH degradation rate is 98.4%. When the catalyst is used for the third time after centrifugation, the TCH degradation rate is 95.8%. When the catalyst is used for the fourth time after centrifugation, the TCH degradation rate is 92.5%. When the catalyst is used for the fifth time after centrifugation, the TCH degradation rate is 89.6%.

[0031]

[0032] Example 16 (The reaction is shown in Table 4, H 0.3 P 0.7 @C 1 Degradation of oxytetracycline hydrochloride (OTC) by the catalyst) At room temperature, add 0.15 g / L of H 0.3 P 0.7 @C 1 catalyst to a 100 mL round-bottom flask containing 50 mL of an oxytetracycline hydrochloride (OTC) aqueous solution (20 mg / L, pH = 6.6). Add PMS with a set concentration of 0.3 g / L to the reactor to initiate the degradation process. At the set time intervals (take the reaction solution every 1 minute), withdraw 1 mL of the reaction solution, filter it using a 0.22 µm microporous membrane, and squeeze it into a centrifuge tube containing 2 mL of methanol. Then, measure the concentration of organic pollutants at a wavelength of 360 nm using a UV-visible spectrophotometer. When the reaction time is 10 minutes, it is found that H 0.3 P 0.7 @C 1 the degradation rate of oxytetracycline hydrochloride (OTC) by the catalyst is 100.0%.

[0033] Example 17 (The reaction is shown in Table 4, H 0.3 P 0.7 @C 1 Degradation of ciprofloxacin (CIP) by the catalyst) At room temperature, add 0.15 g / L of H 0.3 P 0.7 @C 1Catalyst. PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured using a UV-visible spectrophotometer at a wavelength of 267 nm. When the reaction time was 10 minutes, it was found that H 0.3 P 0.7 @C 1 The degradation rate of the catalyst for ciprofloxacin (CIP) was 94.9%.

[0034] Example 18 (for the reaction, see Table 4, H 0.3 P 0.7 @C 1 Degradation of rhodamine B (RhB) by the catalyst) At room temperature, 0.15 g / L of H 0.3 P 0.7 @C 1 Catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous rhodamine B (RhB) solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured using a UV-visible spectrophotometer at a wavelength of 549 nm. When the reaction time was 10 minutes, it was found that H 0.3 P 0.7 @C 1 The degradation rate of the catalyst for RhB was 96.1%.

[0035] Example 19 (for the reaction, see Table 4, H 0.3 P 0.7 @C 1 Degradation of carbamazepine (CBZ) by the catalyst) At room temperature, 0.15 g / L of H 0.3 P 0.7 @C 1Catalyst. PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and squeezed into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured with a UV-visible spectrophotometer at a wavelength of 286 nm. When the reaction time was 10 minutes, it was found that H 0.3 P 0.7 @C 1 The degradation rate of the catalyst for CBZ was 100.0%.

[0036] Example 20 (The reaction is shown in Figure 4, H 0.3 P 0.7 @C 1 Degradation of methyl orange (Mo) by the catalyst) At room temperature, 0.15 g / L of H 0.3 P 0.7 @C 1 Catalyst was added to a 100 mL round-bottom flask containing 50 mL of an aqueous methyl orange (Mo) solution (20 mg / L, pH = 6.6). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At set time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and squeezed into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was measured with a UV-visible spectrophotometer at a wavelength of 390 nm. When the reaction time was 10 minutes, it was found that H 0.3 P 0.7 @C 1 The degradation rate of the catalyst for Mo was 96.9%.

[0037]

[0038] Example 21 (Effect of tert-butanol (TBA) quencher on the degradation of TCH by H 0.3 P 0.7 @C 1 catalyst) At room temperature, 0.10 g / L of H 0.3 P 0.7 @C 1The catalyst and 2 mM TBA. PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At predetermined time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and squeezed into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was detected at 275 nm using a UV-visible spectrophotometer. When the reaction time was 10 minutes, it was found that after the addition of TBA, the removal efficiency of TCH decreased to 64.9%, indicating that ·OH was involved in the degradation of TCH to a certain extent.

[0039] Example 22 (Effect of methanol quencher on the degradation of TCH by H 0.3 P 0.7 @C 1 catalyst) At room temperature, 0.10 g / L of H 0.3 P 0.7 @C 1 catalyst and 2 mM methanol were added to a reactor containing 50 mL of an aqueous TCH solution (20 mg / L). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At predetermined time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was extracted, filtered through a 0.22 µm microporous membrane, and squeezed into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was detected at 275 nm using a UV-visible spectrophotometer. When the reaction time was 10 minutes, it was found that with the addition of methanol, the removal efficiency of TCH decreased to 22.0%. The quenching results of methanol and tert-butanol showed that ·OH and SO 4 ·- were involved in the degradation of TCH. Compared with ·OH, SO 4 ·- radicals made a more important contribution to the degradation of TCH in the H 0.3 P 0.7 @C 1 system.

[0040] Example 23 (Effect of curcumin (Cur) quencher on the degradation of TCH by H 0.3 P 0.7 @C 1 catalyst) At room temperature, 0.10 g / L of H 0.3 P 0.7 @C 1A catalyst and 2 mM curcumin (Cur). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At predetermined time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was detected at 275 nm using a UV-visible spectrophotometer. When the reaction time was 10 minutes, it was found that with the addition of Cur, the removal efficiency of TCH decreased to 72.8%, indicating that 1 O 2 contributed to a certain extent to the removal process of TCH.

[0041] Example 24 (Effect of benzoquinone (BQ) quencher on the degradation of TCH by H 0.3 P 0.7 @C 1 catalyst) At room temperature, 0.10 g / L of H 0.3 P 0.7 @C 1 catalyst and 2 mM benzoquinone (BQ) were added to a reactor containing 50 mL of an aqueous TCH solution (20 mg / L). PMS with a set concentration of 0.3 g / L was added to the reactor to initiate the degradation process. At predetermined time intervals (the reaction solution was taken every 1 minute), 1 mL of the reaction solution was withdrawn, filtered through a 0.22 µm microporous membrane, and extruded into a centrifuge tube containing 2 mL of methanol. Then, the concentration of the organic pollutant was detected at 275 nm using a UV-visible spectrophotometer. When the reaction time was 10 minutes, it was found that with the addition of BQ, the removal efficiency of TCH decreased to 85.3%. The quenching results of curcumin and benzoquinone showed that in the H 0.3 P 0.7 @C 1 system 1 O 2 and O 2 ·- coexisted. Compared with O 2 ·- 1 O 2 contributed more significantly to the removal process of TCH.​

Claims

1. Microwave-assisted preparation of seaweed-like H for efficient degradation of organic pollutants x P y @C z A carbon material catalyst, characterized in that Through a simple and ultrafast microwave-assisted one-pot solid-phase synthesis method, the seaweed-like catalytic material was successfully prepared from citrus peel, hematite and pyrite. During the microwave reaction, hematite and pyrite were efficiently converted into FeS active species, and abundant defects were successfully introduced into the carbon material during the rapid heating process. H x P y @C z The preparation steps of the catalytic material are as follows: 0.5 g of citrus peel, 0.35 g of pyrite, 0.15 g of hematite and 0.12 g of NaOH were weighed and mixed thoroughly in a ceramic mortar. Subsequently, the mixture was placed in a 25 mL crucible and pyrolyzed in a 750 W commercial microwave oven for 8 minutes. After cooling, the carbon catalytic material H 0.3 P 0.7 @C1 was washed with water / ethanol and dried in vacuo; when the fixed mass of citrus peel was 0.5 g and the total mass of hematite and pyrite was also 0.5 g, the catalyst prepared by adjusting the mass ratio of hematite and pyrite was marked as H x P y @C1, where x+y=1, and y=0.9, 0.7, 0.5, 0.3, 0.1, and the mass ratios of hematite and pyrite in the corresponding catalytic materials are 1:9, 3:7, 1:1, 7:3, and 9:1, respectively; when the mass of hematite is 0.15 g and the mass of pyrite is 0.35 g, the prepared catalyst is labeled H 0.3 P 0.7 @C z , where z=0.5,1,2,3, corresponding to the masses of citrus peels of 0.25g, 0.5g, 1.0g and 1.5g respectively; Catalyst activated peroxymonosulfate PMS degradation of organic pollutants: At room temperature, 0.10 g / L of catalyst was added to a 100 mL round-bottom flask containing 50 mL of 20 mg / L organic pollutant pH = 6.6 aqueous solution. PMS with a set concentration of 0.3 g / L was added to the reactor to start the degradation process. At a set time interval of 1 minute, 1 mL of the reaction solution was extracted, filtered using a 0.22 µm microporous membrane, and squeezed into a centrifuge tube containing 2 mL of methanol. Then, the concentration of organic pollutants was measured at a specific wavelength using a UV-visible spectrophotometer; H 0.3 P 0.7 When @C1 was used as the catalyst, tetracycline hydrochloride could achieve 100% removal efficiency within 10 min, and the rate constant was 0.5048 min −1 .

2. The microwave-assisted preparation of seaweed-like H for efficient degradation of organic pollutants according to claim 1 x P y @C z A carbon material catalyst, characterized in that: H 0.3 P 0.7 When @C1 was used as the catalyst, the removal efficiencies of oxytetracycline hydrochloride, ciprofloxacin, rhodamine B, carbamazepine and methyl orange could be achieved at 100.0%, 94.9%, 96.1%, 100.0% and 96.9% within 10 min.

3. The seaweed-like H prepared by microwave-assisted method for efficient degradation of organic pollutants according to claim 1 x P y @C z A carbon material catalyst, characterized in that: Compared with the traditional pyrolysis method, microwave reaction successfully achieved the rapid carbonization of biomass waste citrus peel. The generated carbon material has a slender and interwoven seaweed-like structure, which can provide better adsorption capacity in the pollutant degradation reaction. At the same time, the FeS active species can be evenly dispersed on the carrier surface, which is conducive to providing more active sites.

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