Composite mesoporous catalytic material for treating organic pollutants in water body and preparation method and application thereof
阅读说明：本技术 一种处理水体中有机污染物的复合介孔催化材料及其制备方法和用途 (Composite mesoporous catalytic material for treating organic pollutants in water body and preparation method and application thereof ) 是由 葛家利 刘明杰 王星皓 李剑峰 季遥 王晓 汪昱昆 于 2021-07-20 设计创作，主要内容包括：本发明提供一种处理水体中有机污染物的复合介孔催化材料及其制备方法和用途,所述复合介孔催化材料以MWCNTs-Ox为骨架,以Co-(3)O-(4)颗粒为分散相,Co-(3)O-(4)颗粒之间形成有丰富的介孔空隙结构,其中,Co-(3)O-(4)颗粒的粒径为0.5～1μm。上述所述复合介孔催化材料能够显著地提高PMS/PDS的活化效率以及对污染物的降解能力,对污染物的去除具有更广泛的适用性。(The invention provides a composite mesoporous catalytic material for treating organic pollutants in water and a preparation method thereofThe composite mesoporous catalytic material takes MWCNTs-Ox as a framework and Co as 3 O 4 The particles being in the disperse phase, Co 3 O 4 Rich mesoporous gap structure is formed between the particles, wherein, Co 3 O 4 The particle size of the particles is 0.5 to 1 μm. The composite mesoporous catalytic material can remarkably improve the activation efficiency of PMS/PDS and the degradation capability of pollutants, and has wider applicability to the removal of pollutants.)
1. The composite mesoporous catalytic material for treating organic pollutants in water is characterized by taking MWCNTs-Ox as a framework and Co as3O4The particles being in the disperse phase, Co3O4Rich mesoporous gap structure is formed between the particles, wherein, Co3O4The particle size of the particles is 0.5 to 1 μm.
2. The composite mesoporous catalytic material according to claim 1, having a mesh structure of a regular 12-sided body.
3. The composite mesoporous catalytic material according to claim 1, wherein the particle size of the composite mesoporous catalytic material is 0.5-2 μm.
4. The composite mesoporous catalytic material according to claim 1, wherein the mass ratio of carbon to cobalt in the composite mesoporous catalytic material is 1: (2-5).
5. The composite mesoporous catalytic material of claim 1, wherein the MWCNTs-Ox has an outer diameter of 50-100nm and a length of 5-10 μm.
6. The preparation method of the composite mesoporous catalytic material as set forth in any one of claims 1 to 5, comprising the steps of:
MWCNTs-Ox, Co (NO)3)2·6H2Adding O and PVP into methanol to be mixed to form a black colloidal solution;
mixing a solution of 2-methylimidazole with the black colloidal solution and standing for self-assembly;
separating out solid and roasting to obtain the composite mesoporous catalytic material.
7. The preparation method according to claim 6, wherein the amount of MWCNTs-Ox added is 0.64 to 1.6g/L based on the volume of methanol; and/or the Co (NO) is based on the volume of the methanol3)2The dosage of the compound is 0.02-0.1 mol/L; and/or the addition amount of the PVP is 0.05-0.1 g/L based on the volume of the methanol.
8. The method according to claim 6, wherein the solvent in the solution of 2-methylimidazole is methanol; and/or the concentration of the solution of the 2-methylimidazole is 0.4-0.6 mol/L; and/or the mass ratio of the 2-methylimidazole solution to the black colloid solution is 1 (0.5-3).
9. The method according to claim 6, wherein the calcination temperature is 300 to 400 ℃.
10. Use of the composite mesoporous material according to any of claims 1 to 5 as a catalyst in advanced oxidation technologies based on persulfates or hydrogen persulfates.
Technical Field
The invention relates to the field of catalytic materials, in particular to a composite mesoporous catalytic material for treating organic pollutants in water and a preparation method and application thereof.
Background
In recent years, the technology of advanced oxidation technologies (SR-AOPs) based on persulfate or peroxodisulfate (PMS/PDS) has been increasingly applied to the removal of organic pollutants in soil, groundwater, surface water and sediments. Traditional researches find that PMS/PDS can generate sulfate radical (SO) after being activated by metal materials4 -) And hydroxyl radicals (. OH),. SO4 -Having a better oxidizing power (E)0，·SO4 -/SO4 -＝2.5-3.1V>E0，·OH/OH-1.9-2.7V), longer lifetime, and wider pH applicability (2.0-9.0),so that the organic pollution can be removed effectively. In addition, the research in recent days also finds that PMS/PDS can generate a large amount of singlet oxygen in an activation system of non-metal materials (such as hydroquinone, polyaniline, carbon nano materials and the like) ((R))1O2)，1O2The higher electrophilic effect has stronger advantages in the response of removing phenolic pollutants (such as medicines, personal care products PPCPs, pesticide intermediates and the like) in water, so that the SR-AOPs technology has wider applicability and better application prospect.
The activation of PMS/PDS in SR-AOPs is the key of the technology, and light, heat, electricity, ultrasound and transition metal (Co) are found in the past research2+、Fe2+、Cu2+、Mn2+) The PMS/PDS can be activated in various ways, but the light, heat, electricity, ultrasound and other ways limit the application of the PMS/PDS due to the defect of high energy consumption, so more research is focused on transition metals and oxides thereof. Cobalt and its oxide have the best catalytic effect and are the hot spots of research, in 2005, Dionysiou et al first studied the system of CoO catalyzing PMS to degrade pollutants and found that Co dissolved in aqueous solution2+And CoO, which has a dominant effect on activation of PMS, but also faces a new environmental problem in that excessive cobalt ions leaked out of water may have toxicity and carcinogenicity, thereby causing serious health problems, for example, excessive cobalt in drinking water may cause various symptoms such as asthma, pneumonia and cardiomyopathy in human beings. Therefore how to limit Co2+Becomes the key to this type of catalytic technology, and subsequently Anipsitakis et al proposed Co3O4Structure, CoO and Co2O3Staggered net-shaped arrangement greatly limits Co2+Leakage of (2); and Yu et al also found Co3O4Co leaking in the structure2+Will react with Co after participating in homogeneous oxidation3+Precipitated back to Co3O4In the lattice, the loss of cobalt is also reduced, and is therefore based on Co3O4The SR-AOPs of (5) have been extensively studied. In this connection, a new round of Co has also been developed3O4Discussion of preparation techniques, e.g. thermal decomposition, combustion of polymers, hydrothermal treatment, solsGels, etc. by means of different precursors and treatment methods, controlling reaction time and reaction temperature, adding surfactants, microwave assistance, etc., nano-scale Co in various forms (rod-like, cubic, sheet-like, spherical, and porous) can be synthesized3O4All the materials show better activation effect. But due to the nanometer Co3O4Higher surface energies, often with inevitable agglomeration effects during operation, lead to a reduction in catalytic activity.
To reduce nano Co3O4Agglomeration effect and further reduction of Co2+The diffusion of (2) nano Co is selected by many scholars3O4Supported on other materials, Co3O4The new physical and chemical properties generated by the interaction between the material and the carrier can provide the catalyst with higher catalytic activity and stability, and the material comprises a metal oxide carrier (TiO)2,MgO,Al2O3,SiO2,MnO2And ZnO, etc.), molecular sieve carriers (zeolite material ZSM-5, mesoporous materials SBA-15 and MCM-41, etc.) and carbon material carriers (activated carbon fibers ACFs, multi-walled carbon nanotubes MWCNTs, graphene G, graphene oxide GO and graphite phase carbon nitride G-C3N4Etc.). Wherein Co3O4The composite material prepared from the carbon nano material has stronger adsorption capacity and excellent electron transfer capability, so that the activation energy for exciting the PMS/PDS is obviously lower than that of other materials, the catalytic effect is obviously improved, in addition, the carbon-based material can enable Reactive Oxygen Species (ROS) in a PMS/PDS system to have diversity, and the composite material has more applicability in removing pollutants. At present Co3O4And the carbon nanomaterial support method is usually a method such as impregnation, coprecipitation, thermal decomposition, etc., but these methods cannot support Co3O4Nano Co dispersed homogeneously on carbon material and with high density and high density3O4The particles may also mask the specificity of the carbon material or fail to bind strongly to the carbon material to fully develop catalytic properties.
Disclosure of Invention
In view of the prior art mentioned aboveThe invention aims to provide a composite mesoporous catalytic material for treating organic pollutants in water, a preparation method and application thereof, which remarkably improve the activation efficiency of PMS/PDS, increase the ROS species in an activation system, further increase the pollutant degradation capability of the activated system, and solve the problem of nano Co3O4The binding capacity of the MWCNTs material is fully exerted3O4And the synergistic effect of MWCNTs, the dimension of the catalyst is improved while the mesoporous structure is maintained, and the problem of nano Co is solved3O4Low recovery rate.
To achieve the above objects and other related objects, the present invention is achieved by the following technical solutions.
The invention provides a composite mesoporous catalytic material for treating organic pollutants in water, which takes MWCNTs-Ox as a framework and Co as3O4The particles being in the disperse phase, Co3O4Rich mesoporous gap structure is formed between the particles, wherein, Co3O4The particle size of the particles is 0.5 to 1 μm.
Preferably, the composite mesoporous catalytic material has a net structure of a regular 12-sided body.
Preferably, the particle size of the composite mesoporous material is 0.5-2 μm.
Preferably, in the composite mesoporous material, the mass ratio of carbon to cobalt is 1: (2-5).
Preferably, the MWCNTs-Ox has an outer diameter of 50-100nm and a length of 5-10 μm.
The application also provides a preparation method of the composite mesoporous catalytic material, which comprises the following steps:
MWCNTs-Ox, Co (NO)3)2·6H2Adding O and PVP into methanol to be mixed to form a black colloidal solution;
mixing a solution of 2-methylimidazole with the black colloidal solution and standing for self-assembly;
separating out solid and roasting to obtain the composite mesoporous catalytic material.
MWCNTs-Ox in the present application is an oxide of MWCNTs.
Preferably, the preparation method of MWCNTs-Ox comprises the following steps: and (3) adding the MWCNTs into a mixed solution of concentrated hydrochloric acid and concentrated sulfuric acid for oxidation treatment. More preferably, the temperature of the oxidation treatment is 60 to 90 ℃. More preferably, the oxidation treatment process is accompanied by ultrasound, and further preferably, the ultrasound intensity is 1.2-1.5W/cm2. Preferably, the time of the oxidation treatment is 3 to 15 hours. More preferably, the concentrated hydrochloric acid refers to hydrochloric acid with the concentration of more than 20 wt%, and the concentrated sulfuric acid refers to a sulfuric acid aqueous solution with the mass fraction of more than or equal to 70 wt%.
Preferably, the addition amount of the MWCNTs-Ox is 0.64-1.6 g/L based on the volume of methanol.
Preferably, the Co (NO) is based on the volume of methanol3)2The amount of the additive is 0.02-0.1 mol/L.
Preferably, the addition amount of the PVP is 0.05-0.1 g/L based on the volume of the methanol.
Preferably, the mass ratio of C to cobalt in the black colloidal solution is 1: (2-5).
Preferably, the solvent in the solution of 2-methylimidazole is methanol.
Preferably, the concentration of the 2-methylimidazole solution is 0.4-0.6 mol/L.
Preferably, the mass ratio of the 2-methylimidazole solution to the black colloid solution is 1 (0.5-3). .
Preferably, the firing atmosphere is air.
Preferably, the roasting temperature is 300-400 ℃.
The invention also discloses the application of the composite mesoporous catalytic material as a catalyst in an advanced oxidation technology based on persulfate or hydrogen persulfate.
Preferably, the catalyst is used to improve the activation efficiency of PMS/PDS and the degradation capability of organic pollutants.
Preferably, the organic pollutants in the organic polluted water body comprise medicines and personal skin care products, phenolic pesticides and intermediates, and partial persistent organic pollutants.
Preferably, the organic contaminants include one or more of 2-hydroxy-4-methoxybenzophenone (abbreviated as BP-3), ibuprofen (abbreviated as IBU), triclosan (abbreviated as TCS), sulfamethizole (abbreviated as SMX), atrazine (abbreviated as ATZ), benzylchlorophenol (abbreviated as CP) and parachlorophenol (abbreviated as 4-CP).
Compared with the prior art, the technical scheme of the invention has the following advantages:
1) the invention provides a composite mesoporous material, which improves nano Co3O4Combining with MWCNTs material, skillfully inserting the MWCNTs into Co3O4In the net structure, the dimension of the catalyst is improved while the mesoporous structure is maintained, and the nano Co is solved3O4Low recovery rate.
2) The catalytic material fully exerts the nanometer Co3O4And the synergistic effect of the MWCNTs not only gives full play to the adsorbability and the conductivity of the MWCNTs, but also solves the problem of nano Co3O4Agglomeration effect, increase of nano Co3O4The specific surface area of the catalyst increases the reaction active sites, and enlarges Co in the micro-interface limited area environment3O4The activating ability of (c).
3) When the composite mesoporous material is used as a catalyst, the composite mesoporous material has diversity in the mechanism of activating PMS/PDS, and can activate PMS/PS to generate SO4 -And OH, and can also activate PMS/PS production1O2Therefore, the composite mesoporous material can remarkably improve the activation efficiency of PMS/PDS and the degradation capability of pollutants, and has wider applicability to the removal of pollutants.
Drawings
FIGS. 1 (a) and (b) are Co-MOFs/MWCNTs-Ox and Co in example 13O4The scanning electron microscope image of the MWCNTs-Ox @0.1C type mesoporous material, the spectrogram 1 and the spectrogram 3 respectively correspond to EDS energy spectrum images of the two materials.
FIGS. 2 (a) and (b) are high power transmission electron micrographs (HRTEM) of Co-MOF/MWCNTs-Ox in example 1.
In FIG. 3, (a) and (b) are examplesCo in example 13O4High power transmission electron micrograph (HRTEM) of MWCNTs-Ox @0.1C type mesoporous material.
FIG. 4 shows Co in example 13O4MWCNTs-Ox @0.1C type mesoporous material nitrogen adsorption-desorption curve.
FIG. 5 is the Co-MOF/MWCNTs-Ox, Co of example 23O4MWCNTs-Ox @0.2C type mesoporous material, nano Co in comparative example 13O4Concentration curves for MWCNTs-Ox activated PMS/PDS degraded BP-3 in comparative example 2.
FIG. 6 is a diagram for investigating Co in example 23O4The concentration decay curve of the MWCNTs-Ox @0.2C type mesoporous material activated PMS/PDS degradation BP-3 mechanism after various active oxygen species quenchers are added.
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.
Before the present embodiments are further described, it is to be understood that the scope of the invention is not limited to the particular embodiments described below; it is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Test methods in which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the respective manufacturers.
When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition to the specific methods, devices, and materials used in the examples, any methods, devices, and materials similar or equivalent to those described in the examples may be used in the practice of the invention in addition to the specific methods, devices, and materials used in the examples, in keeping with the knowledge of one skilled in the art and with the description of the invention.
In order to improve the removal capability of persulfate or persulfate advanced oxidation technologies (SR-AOPs) to organic pollutants, the applicant particularly provides a composite mesoporous catalytic material with a specific structure, which takes MWCNTs-Ox as a framework and Co as3O4The particles being in the disperse phase, Co3O4Rich mesoporous gap structure is formed between the particles, wherein, Co3O4The particle size of the particles is 0.5 to 1 μm.
In a preferred embodiment, the composite mesoporous material has a network structure having a regular 12-sided body.
In a preferred embodiment, the particle size of the composite mesoporous material is 0.5 to 2 μm.
In a preferred embodiment, in the composite mesoporous material, the mass ratio of carbon to cobalt is 1: (2-5).
The application also provides a preparation method of the composite mesoporous catalytic material, which comprises the following steps:
MWCNTs-Ox, Co (NO)3)2·6H2Adding O and PVP into methanol to be mixed to form a black colloidal solution;
mixing a solution of 2-methylimidazole with the black colloidal solution and standing for self-assembly;
separating out solid and roasting to obtain the composite mesoporous material.
In a preferred embodiment, the MWCNTs-Ox has an outer diameter of 50 to 100nm and a length of 5 to 10 μm.
In a preferred embodiment, the MWCNTs-Ox preparation method is: and (3) adding the MWCNTs into a mixed solution of concentrated hydrochloric acid and concentrated sulfuric acid for oxidation treatment. In the application, the concentrated hydrochloric acid refers to hydrochloric acid with the concentration of more than 20 wt%, and the concentrated sulfuric acid refers to a sulfuric acid aqueous solution with the mass fraction of more than or equal to 70 wt%. More preferably, the temperature of the oxidation treatment is 60 to 90 ℃. More preferably, the oxidation treatment process is accompanied by ultrasound, and further preferably, the ultrasound intensity is 1.2-1.5W/cm2. Preferably, the time of the oxidation treatment is 3 to 15 hours.
In a preferred embodiment, the MWCNTs-Ox is added in an amount of 0.64 to 1.6g/L based on the volume of methanol.
In a preferred embodiment, the Co (NO) is based on the volume of methanol3)2The amount of the additive is 0.02-0.1 mol/L.
In a preferred embodiment, the PVP is added in an amount of 0.05-0.1 g/L based on the volume of methanol.
In a preferred embodiment, the mass ratio of C to cobalt in the black colloidal solution is 1: (2-5).
In a preferred embodiment, the solvent of the solution of 2-methylimidazole is methanol.
In a preferred embodiment, the concentration of the solution of 2-methylimidazole is 0.4 to 0.6 mol/L.
In a preferred embodiment, the mass ratio of the solution of 2-methylimidazole to the black colloid solution is 1 (0.5-3).
In a preferred embodiment, the firing atmosphere is air.
In a preferred embodiment, the calcination temperature is 300 to 400 ℃.
MWCNTs-Ox in the present application is an oxide of MWCNTs. The preparation method of the carbon nanotube oxide (MWCNTs-Ox) used in this example is: weighing 0.50g of MWCNTs with the outer diameter of 50-100nm and the length of 5-10 mu m, and putting the MWCNTs into 200mL of concentrated HCl and concentrated H with the volume ratio of 2.5:12SO4In the solution, the solution is ultrasonically heated (80 ℃) for 8 hours, and carbon dioxide nanotubes (MWCNTs-Ox) are prepared by filtering and repeatedly washing through a membrane with the aperture of 0.22 mu m.
The composite mesoporous catalytic material skillfully inserts MWCNTs into Co3O4In the net structure, the dimension of the catalyst is improved while the mesoporous structure is maintained, and the problem of nano Co is solved3O4The recovery rate is low, and the structure can fully exert the nanometer Co3O4And the synergistic effect of the MWCNTs not only fully exerts the adsorbability and the electric conduction of the MWCNTsProperty and solve the problem of nano Co3O4Agglomeration effect, increase of nano Co3O4The specific surface area of the catalyst increases the reaction active sites, and enlarges Co in the micro-interface limited area environment3O4The activating ability of (c).
In addition, the proportion and the material size of each substance in the composite mesoporous catalytic material are not randomly selected, and the factors can influence the catalytic performance of the composite mesoporous catalytic material. The factors such as self-assembly time, roasting temperature and the like in the preparation method of the composite mesoporous catalytic material are not randomly selected, and the catalytic performance of the composite mesoporous catalytic material is influenced.
When the composite mesoporous material is used as a catalyst, the activation efficiency of PNS/PDS and the degradation capability of the PNS/PDS on organic pollutants can be obviously improved, PMS/PDS can be obviously activated, and both PMS/PS can be activated to generate SO4 -And OH, and can also activate PMS/PS production1O2And thus has wider applicability to contaminant removal.
The technical solutions and technical effects in the present application are further verified and explained by the following embodiments.
Example 1
In this embodiment, a Co is provided3O4The preparation method of the MWCNTs-Ox @0.1C type mesoporous material comprises the following steps:
1) weighing 0.16g MWCNTs-Ox, 2.50g Co (NO)3)2·6H2O and 1.00g of PVP are sequentially added into 150mL of methanol solution and stirred for 2 hours under the condition of ultrasonic treatment to prepare a colloidal solution M with the mass ratio of MWCNTs-Ox to Co being 1: 3;
2) weighing 3.8g of 2-methylimidazole, and dissolving in 125mL of methanol solution to obtain clear solution N; within 30min, dropwise adding the solution N into the solution M while slowly stirring, and standing for 24 h; then repeatedly precipitating the solution and washing the membrane to obtain a Co-MOF/MWCNTs-Ox intermediate product;
3) then drying the prepared material in a drying box at 105 ℃, transferring the material to a muffle furnace, heating the material to 380 ℃ at 5 ℃/min, roasting the material for 2h, and keeping the atmosphere emptyGas to obtain Co3O4MWCNTs-Ox @0.1C mesoporous material.
FIGS. 1 (a) and (b) are Co-MOF/MWCNTs-Ox and Co in example 13O4An SEM image of/MWCNTs-Ox @0.1C type mesoporous material, a spectrogram 1 and a spectrogram 3 respectively correspond to EDS energy spectrum images of the two materials, and the Co-MOF/MWCNTs-Ox has a shape of a regular 12-sided body, the particle size is 0.5-2 mu m, and Co generated after roasting3O4The MWCNTs-Ox @0.1C material still keeps the shape of a regular 12-sided body, the particle size is slightly reduced by 0.5-1 mu m, and the MWCNTs-Ox @0.1C material has a net structure.
Table 1 Co in example 13O4Element proportion table (EDS) before and after baking/MWCNTs-Ox @0.1C mesoporous material
FIGS. 2 (a) and (b) are high power transmission electron micrographs (HRTEM) of Co-MOF/MWCNTs-Ox in example 1. In FIG. 3, (a) and (b) represent Co in example 13O4High power transmission electron microscopy (HRTEM) of/MWCNTs-Ox @0.1C type mesoporous material can find that Co is contained3O4The MWCNTs are interpenetrated in the strip-shaped particles to play a supporting role.
FIG. 4 shows Co in example 13O4The nitrogen adsorption-desorption curve of the MWCNTs-Ox @0.1C type mesoporous material shows that the type is the mesoporous material, the IV type curve is shown, and the specific surface area is 28.23m2/g。
Example 2
This example provides a highly efficient Co activation of PMS/PDS3O4MWCNTs-Ox @0.2C type mesoporous material:
1) 0.24g of MWCNTs-Ox, 2.50g of Co (NO) were weighed out3)2·6H2O and 1.00g of PVP are sequentially added into 150mL of methanol solution and stirred for 2 hours under ultrasonic condition to prepare a colloidal solution M with the mass ratio of MWCNTs-Ox to Co being 1: 2;
2) weighing 3.8g of 2-methylimidazole, and dissolving in 125mL of methanol solution to obtain clear solution N; within 30min, dropwise adding the solution N into the solution M while slowly stirring, and standing for 8 h; then repeatedly precipitating the solution and washing the membrane to obtain a Co-MOF/MWCNTs-Ox intermediate product;
3) then drying the prepared material in a drying box at 105 ℃, transferring the material to a muffle furnace, heating the material to 350 ℃ at 2 ℃/min, roasting the material for 2h in the atmosphere of air to obtain Co3O4MWCNTs-Ox @0.2C mesoporous material.
Table 2 example 2 Co3O4Element proportion table (EDS) before and after baking of MWCNTs-Ox @0.2C mesoporous material
Comparative example 1
The comparative example provides a method for preparing nano Co through a Co-MOFs self-assembly process3O4Co as a comparative catalyst3O4The manufacturing method of the/NPs does not comprise the addition of MWCNTs-Ox, and the other steps are consistent with those of the embodiment 1 and the embodiment 2, and the specific steps are as follows:
weighing 2.50g Co (NO)3)2·6H2Adding O into 150mL of methanol solution, stirring and dissolving to prepare Co (NO)3)2A solution; weighing 3.8g of 2-methylimidazole, and dissolving in 125mL of methanol solution; adding Co (NO) dropwise into 2-methylimidazole solution while slowly stirring within 30min3)2Standing the solution for 24 hours; then repeatedly precipitating and washing the solution by a membrane to obtain a Co-MOFs intermediate product; then drying the prepared material in a drying box at 105 ℃, transferring the dried material to a muffle furnace, heating the material to 380 ℃ at the speed of 5 ℃/min, roasting the material for 2 hours in the atmosphere of air, cooling the material to room temperature, and grinding the material to obtain the nano Co3O4A material.
The implementation method of the catalyst for catalyzing PMS/PDS to degrade BP-3 is the same as the steps in the example 3, and the degradation effect is shown in figure 4.
Comparative example 2
This comparative example provides a carbon nanotube oxide (MWCNTs-O)x) As a comparative catalyst, the procedure was followed for MWCNTs-O in example 1 and example 2xThe preparation method is consistent, and comprises the following specific steps:
weighing 0.50g of MWCNTs with outer diameter of 50-100nm and length of 5-10 μm, and putting into 200mL of concentrated HCl and concentrated H with volume ratio of 2.5:12SO4In the solution, the solution is ultrasonically heated (80 ℃) for 8 hours, and carbon dioxide nanotubes (MWCNTs-Ox) are prepared by filtering and repeatedly washing through a membrane with the aperture of 0.22 mu m.
Example 3
This example provides Co from example 23O4Application of MWCNTs-Ox @0.2C type mesoporous catalytic material to activation of PMS/PDS to degradation of cosmetic additive BP-3 in water environment. Adding 2 mu M BP-3, 20 mu M PMS/PDS and 50mg/L catalyst into 100mL of aqueous solution, reacting at room temperature with the rotation speed of a shaking table of 60r/min, sampling 1mL at set time intervals, and adding 0.05mL of methanol and 0.05mL of 1mol/L Na into the sample2SO4The reaction was quenched. The degradation rate was calculated by monitoring the change in the concentration of the contaminants by HPLC (FIG. 5), and the quenching curves for various active species are shown in FIG. 6.
FIG. 5 is the Co-MOF/MWCNTs-Ox, Co of example 23O4MWCNTs-Ox @0.2C type mesoporous material, nano Co in comparative example 13O4Concentration curves for MWCNTs-Ox activated PMS/PDS degraded BP-3 in comparative example 2. The experimental conditions were: the initial concentration of 2-hydroxy-4-methoxybenzophenone (abbreviated as BP-3) was 2. mu.M, the initial concentration of persulfate was 20. mu.M, and the amount of the catalyst was 50 mg/L. Can find Co3O4Compared with other materials, the MWCNTs-Ox @0.2C catalyst has the best catalytic efficiency, the degradation efficiency of 30min under the same condition reaches 95 percent, and is far higher than that of the nano Co in the comparative example 13O4(62%), MWCNTs-Ox from comparative example 2 (28%).
FIG. 6 is a diagram for investigating Co in example 23O4The concentration decay curve of the MWCNTs-Ox @0.2C type mesoporous material activated PMS/PDS degradation BP-3 mechanism after various active oxygen species quenchers are added. The experimental conditions are as follows: the initial concentration of 2-hydroxy-4-methoxybenzophenone was 2. mu.M, the initial concentration of persulfate was 20. mu.M, the amount of catalyst used was 50mg/L and the initial concentration of quencher was 2 mM. Can find SO4 -And OH quenchers methanol (MeOH) and tert-butyl alcohol (TBA) are not used for completely quenching the reaction, and the quenching effects of the MeOH and the TBA are greatly different, which indicates that the two free radicals exist in an activation system, and the furfuryl alcohol (FFA) almost completely inhibits the reaction, and according to the reaction activity and the structural characteristics of the FFA and various ROS, the existence of the FFA and the ROS in the reaction system can be inferred1O2And the catalyst has strong adsorbability to hydrophobic pollutants.
Example 4
This example provides Co from example 13O4The MWCNTs-Ox @0.1C and the Co3O4/MWCNTs-Ox @0.2C mesoporous material in the example 2 activate PMS/PDS to degrade a plurality of typical organic pollutants in water environment, wherein the pollutants comprise PPCPs (BP-3, ibuprofen IBU, triclosan TCS, sulfamethoxazole SMX), pesticides and intermediates (atrazine ATZ, benzyl chlorophenol CP, p-chlorophenol 4-CP).
The degradation procedure was the same as in example 3: adding 2 μ M of target pollutant, 20 μ M of PMS/PDS and 50mg/L of catalyst into 100mL of aqueous solution, reacting at room temperature with the rotation speed of a shaking table of 60r/min, sampling 1mL at set time intervals, and adding 0.05mL of methanol and 0.05mL of 1mol/L of Na into the sample2SO4The reaction was quenched. And monitoring the change of the concentration of the pollutants by using high performance liquid chromatography, and respectively calculating the degradation rates of the pollutants.
The interpretation curves of several typical organic pollutants in the environment are shown in table 3.
TABLE 3 removal rates (30min) of several typical organic contaminants in the PMS/PDS systems activated with the materials of examples 1 and 2, respectively
The implementation method of the catalyst for catalyzing PMS/PDS to degrade BP-3 is the same as the steps in the example 3, and the degradation effect is shown in figure 4.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.