Preparation method of biochar-bimetallic material for efficiently producing superoxide radicals
The biocarbon@bimetallic material enhances superoxide radical generation and BPF degradation efficiency by five times, addressing inefficiencies and costs in current materials, using agricultural waste as a resource.
Patent Information
- Application Number
- CN202510438721.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-15
AI Technical Summary
Current materials for producing superoxide radicals in environmental pollution treatment are inefficient, unstable, and costly, with issues such as low efficiency, high catalyst dosage, narrow pH applicability, and high production costs, particularly in the degradation of bisphenol F (BPF).
A method for preparing a biocarbon@bimetallic material by loading cobalt-doped copper oxide on biocarbon, using specific parameters for mixing, sonication, and hydrothermal treatment to enhance superoxide radical generation and stability, utilizing agricultural waste as a resource.
The method significantly increases superoxide radical generation efficiency and BPF degradation by five times, providing a cost-effective and stable solution for environmental pollutant degradation.
Smart Images
Figure CN120305966A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of new materials, and specifically relates to a preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals. Background Art
[0002] Bisphenol F (BPF) is a common new substitute for bisphenol A (BPA) and is currently widely used in industrial production. Unfortunately, recent studies have shown that the toxicity of BPF is comparable to or even higher than that of BPA. Given that these two new bisphenol pollutants are still commonly used raw materials for epoxy resins worldwide, there is an urgent need to deeply explore technologies for efficiently removing new bisphenol pollutants in the environment.
[0003] Currently, in the field of environmental pollutant treatment, especially in the process of applying superoxide radicals to degrade environmental pollutants, there are problems such as high energy consumption, low efficiency, large dosage of catalysts, and narrow pH application range in the generation of superoxide radicals. However, the current materials have the following problems:
[0004] 1) Low efficiency: The activation of the single cobalt-doped copper oxide material is limited in the generation of superoxide radicals, and the degradation efficiency of pollutants in environmental applications is low. By adding only 0.1 g of biochar to the preparation process of the cobalt-doped copper oxide material, the generation efficiency of superoxide radicals is increased by 170.7%, and the degradation efficiency of the model pollutant bisphenol F is increased by five times. 99% of BPF (5 ppm) can be degraded within 15 minutes.
[0005] 2) Poor stability: The cobalt-doped copper oxide material is prone to agglomeration, and biochar can be used as a carrier material to solve the agglomeration problem of the cobalt-doped copper oxide material.
[0006] 3) High cost: The use of some precious metals increases the preparation cost. Summary of the Invention
[0007] To solve the above technical problems, the present invention provides a preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals.
[0008] The technical solution of the present invention is: A preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals, comprising the following steps:
[0009] Step 1: Dissolve copper nitrate trihydrate and cobalt nitrate hexahydrate in deionized water, ultrasonicate for 3 - 8 min, add biochar, ultrasonicate for 3 - 8 min to obtain a mixed solution, and then dropwise add 0.4 M sodium hydroxide solution to the mixed solution until the pH value of the mixed solution is 4.3 ± 0.5;
[0010] Among them, the amounts of copper nitrate trihydrate, copper nitrate hexahydrate, and biochar added to deionized water are respectively: 90-100 g / L, 110-125 g / L, 3-5 g / L;
[0011] Step 2: Put the mixed solution into an ultrasonic cleaner and purge it with nitrogen for 10-20 min to remove carbon dioxide in the suspension, obtaining a treated mixed solution;
[0012] Step 3: Transfer the treated mixed solution into a polytetrafluoroethylene hydrothermal reaction liner and seal it in a stainless steel autoclave. Perform hydrothermal reaction at 120-140 °C in an oven for 4-6 h. Subsequently, naturally cool the obtained product to room temperature. After washing, drying, grinding, and calcining the product in sequence, a cobalt-doped copper oxide@biochar material is obtained.
[0013] As a technical solution of the present invention, the synthesis method of the biochar is as follows: First, crush the biomass raw material, then place it in a crucible, and place the sealed crucible in a muffle furnace. Heat it to 450-550 °C at a heating rate of 3-6 °C / min and maintain it at 450-550 °C for 1.5-3 h; After cooling, grind it through an 80-120 mesh sieve and rinse it with anhydrous ethanol and deionized water to remove the ash generated by pyrolysis; Finally, place the obtained sludge biochar in an oven and dry it at 50-70 °C for 10-15 h to obtain biochar.
[0014] Note: Prepared from renewable resources such as agricultural waste, it can effectively solve the problem of waste accumulation. By adopting the above synthesis method of biochar, a biochar carrier for cobalt-doped copper oxide loading can be effectively synthesized, thereby providing a good basic raw material for the preparation of cobalt-doped copper oxide@biochar materials and improving the degradation efficiency of the doped copper oxide@biochar materials for environmental pollutants.
[0015] Furthermore, the biomass raw material is any one of corn straw, wheat straw, sludge, and bamboo.
[0016] Note: Using the above raw materials as biomass raw materials can make full use of these renewable resources. It can not only provide high-quality raw materials for biochar synthesis but also solve the problem of waste accumulation, achieving "turning waste into treasure".
[0017] Furthermore, the ultrasonic frequency of the ultrasonic cleaner is 30-50 KHz and the ultrasonic power is 180-240 W.
[0018] Note: By adopting the working parameters of the above ultrasonic cleaner, carbon dioxide in the suspension can be fully removed, avoiding the influence of carbon dioxide on the effect of subsequent hydrothermal reactions.
[0019] Further, the washing is to wash the product with anhydrous ethanol several times; the drying is to dry the product at 60-70 °C for 10-15 h; the grinding is to grind the product through an 80-120 mesh sieve; the calcination is to calcine the product in a muffle furnace at 400-500 °C for 2-4 h.
[0020] Note: By washing the product with anhydrous ethanol, impurities on the surface and in the pores of the product can be dissolved, enhancing the pore connectivity, thereby improving the performance of the biochar material; and by calcining with the above parameters, the biochar material can be further carbonized, enhancing its mechanical strength and chemical stability, thereby obtaining a cobalt-doped copper oxide@biochar material with better performance.
[0021] As another technical solution of the present invention, the synthesis method of the biochar is as follows:
[0022] 1) Crush the biomass raw material to make the moisture content of the biomass raw material <5%, put the biomass raw material into a dielectric barrier discharge plasma reactor, and the parameters are: power density 180-220 W / m 2 , the gas environment is a mixed gas of argon and oxygen, the gas flow rate is 1.5-3 L / min, at normal pressure, treat for 10-15 min to obtain pretreated biomass;
[0023] 2) Mix 0.1 M cobalt nitrate and 0.4 M 2-methylimidazole in a volume ratio of 1:3-5, add the pretreated biomass, the solid-liquid ratio is 1:8-12, after ultrasonic-assisted impregnation, let it stand for 12 h, and control the MOF loading amount at 8-12 wt% to obtain the product;
[0024] 3) Heat the product in an air environment to 180±5 °C at a heating rate of 4-6 °C / min and keep it warm for 50-70 min; then heat it to 270±5 °C at a heating rate of 2-4 °C / min in a nitrogen environment and keep it warm for 80-100 min; then heat it to 320±5 °C at a heating rate of 1-3 °C / min in a CO2 environment and keep it warm for 20-40 min, where the flow rate of CO2 is 40-60 mL / min to obtain the carbonized product;
[0025] 4) Subsequently, soak the carbonized product with 1 M HCl for 5-8 h, adjust the pH to 7-8 with ammonia water, and dry it under vacuum at 110-120 °C to obtain biochar.
[0026] Description: The above synthesis method of biochar generates ·OH radicals through oxygen plasma, etches lignin to form 20 - 50 nm pores, and forms nano-scale pore channels, thereby improving the carbonization efficiency. The CoO generated by the decomposition of ZIF-67 can promote the cleavage of C=O bonds to generate hybrid carbon. Then, through the introduction of CO2, it reacts with these hybrid carbons at temperatures above 300 °C, further expanding the pore channels of the product, and thus preparing a biochar material with better performance, providing a good basic raw material for the preparation of cobalt-doped copper oxide @ biochar material, and further improving the degradation efficiency of the doped copper oxide @ biochar material for environmental pollutants.
[0027] Furthermore, the oxygen content in the mixed gas is 5 - 15%, and the oxygen content in the mixed gas is periodically adjusted with the treatment time. The periodic adjustment is that the oxygen content reciprocates between 5% and 15%, and the change rate of the reciprocating adjustment is 2 - 10% / min.
[0028] Description: By dynamically adjusting the oxygen content during the oxygen plasma etching treatment, the etching effect of lignin can be further enhanced, forming hierarchical pores with more nano-scale pore channels, and improving the performance of the biochar material.
[0029] Furthermore, the ultrasonic frequency of the ultrasonic-assisted impregnation is 30 - 50 kHz, the ultrasonic power is 180 - 240 W, and the treatment time is 25 - 35 min.
[0030] Description: By using the working parameters of the above ultrasonic-assisted impregnation, the impregnation treatment requirements of this preparation method can be met, so that the MOF is uniformly dispersed, improving the activation and pore expansion treatment in the subsequent carbonization stage, ensuring the pore expansion effect of the product pores, and preparing a biochar material with better performance.
[0031] The beneficial effects of the present invention are:
[0032] The preparation method of the biochar @ bimetallic material of the present invention can increase the generation efficiency of superoxide radicals of the cobalt-doped copper oxide material by loading the cobalt-doped copper oxide material on the biochar, and improve the degradation performance of BPF by at least five times, thereby providing an efficient, economical and stable method for generating superoxide radicals to promote the efficient degradation of environmental pollutants. Brief Description of the Drawings
[0033] Figure 1 is the specific surface area of the cobalt-doped copper oxide @ biochar material (CoCuO@BC) of the present invention.
[0034] Figure 2 is the detection result of superoxide radicals of the cobalt-doped copper oxide @ biochar material (CoCuO@BC) of the present invention.
[0035] Figure 3 These are the quantitative results of superoxide radicals of the cobalt-doped copper oxide@biochar material (CoCuO@BC) of the present invention.
[0036] Figure 4 These are the degradation effects of the cobalt-doped copper oxide@biochar material (CoCuO@BC) of the present invention on bisphenol pollutants. Detailed implementation manners
[0037] The present invention will be further described in more detail below in conjunction with the specific implementation manners to better reflect the advantages of the present invention.
[0038] Example 1: A preparation method of biochar@bimetallic material for efficiently producing superoxide radicals, comprising the following steps:
[0039] Step 1: Dissolve 2.42 g of copper nitrate trihydrate and 2.92 g of cobalt nitrate hexahydrate (Cu:Co = 1:1) in 25 mL of deionized water, ultrasonicate for 5 min, add 0.1 g of biochar, ultrasonicate for 5 min to obtain a mixed solution, and then dropwise add 0.4 M sodium hydroxide solution to the mixed solution until the pH value of the mixed solution is 4.3;
[0040] Among them, the synthesis method of the biochar is as follows: First, crush the biomass raw material, the biomass raw material is corn straw, then place it in a crucible, and place the sealed crucible in a muffle furnace, heat to 500 °C, the heating rate is 5 °C / min, and keep it at 500 °C for 2 h; after cooling, grind it through a 100-mesh sieve, and wash it with absolute ethanol and deionized water to remove the ash generated by pyrolysis; finally, place the obtained sludge biochar in an oven and dry it at 60 °C for 12 h to obtain biochar;
[0041] Step 2: Put the mixed solution into an ultrasonic cleaner and purge it with nitrogen for 15 min to remove carbon dioxide in the suspension to obtain a treated mixed solution, wherein the ultrasonic frequency of the ultrasonic cleaner is 40 KHz and the ultrasonic power is 200 W;
[0042] Step 3: Transfer the treated mixed solution into a 100 mL polytetrafluoroethylene hydrothermal reaction liner and seal it in a stainless steel autoclave, carry out hydrothermal reaction at 130 °C in an oven for 5 h, then naturally cool the obtained product to room temperature, wash the product three times with absolute ethanol, then dry the product at 65 °C for 12 h, grind the product through a 100-mesh sieve, and finally calcine the product in a muffle furnace at 450 °C for 3 h to obtain the cobalt-doped copper oxide@biochar material.
[0043] Now, the above-mentioned preparation method of biochar@bimetallic materials is adopted to prepare cobalt-doped copper oxide@biochar materials. Among them, the corn straw is from Lianyungang, Jiangsu. Now, the cobalt-doped copper oxide@biochar materials are measured, and the characterization results are as follows:
[0044] 1) The specific surface area of the cobalt-doped copper oxide@biochar materials is as Figure 1 shown. It can be seen that the cobalt-doped copper oxide@biochar materials prepared by using the preparation method of the biochar@bimetallic materials of the present invention have a high specific surface area and strong adsorption performance.
[0045] 2) The detection results of superoxide radicals of the cobalt-doped copper oxide@biochar materials are as Figure 2 shown. After adding PMS, the cobalt-doped copper oxide@biochar materials generate more superoxide radicals than the control cobalt-doped copper oxide materials, which is beneficial to the degradation of pollutants.
[0046] 3) The quantitative results of superoxide radicals of the cobalt-doped copper oxide@biochar materials are as Figure 3 shown. After adding PMS, the generation efficiency of the cobalt-doped copper oxide@biochar materials is increased by 170.7% compared with the control cobalt-doped copper oxide materials, which is beneficial to the degradation of pollutants.
[0047] 4) As Figure 4 shown, adding 5 mg of cobalt-doped copper oxide@biochar materials and 5 mg of PMS can degrade about 99% of bisphenol pollutants (pollutant concentration 5 mg / L). Compared with cobalt-doped copper oxide, the degradation rate of BPF is increased by five times, showing good application prospects.
[0048] Example 2: The difference between this example and Example 1 is that 2.25 g of copper nitrate trihydrate and 2.75 g of cobalt nitrate hexahydrate are dissolved in 25 mL of deionized water, sonicated for 5 min, 0.075 g of biochar is added, and sonicated for 5 min to obtain a mixed solution.
[0049] Example 3: The difference between this example and Example 1 is that 2.5 g of copper nitrate trihydrate and 3.125 g of cobalt nitrate hexahydrate are dissolved in 25 mL of deionized water, sonicated for 5 min, 0.125 g of biochar is added, and sonicated for 5 min to obtain a mixed solution.
[0050] Example 4: The difference between this example and Example 1 is that 2.42 g of copper nitrate trihydrate and 2.92 g of cobalt nitrate hexahydrate are dissolved in 25 mL of deionized water, sonicated for 3 min, 0.1 g of biochar is added, and sonicated for 3 min to obtain a mixed solution.
[0051] Example 5: The difference between this example and Example 1 is that 2.42 g of copper nitrate trihydrate and 2.92 g of cobalt nitrate hexahydrate are dissolved in 25 mL of deionized water, sonicated for 8 min, 0.1 g of biochar is added, and sonicated for 8 min to obtain a mixed solution.
[0052] Example 6: The difference between this example and Example 1 is that 0.4 M sodium hydroxide solution is added dropwise to the mixed solution until the pH value of the mixed solution is 3.8.
[0053] Example 7: The difference between this example and Example 1 is that 0.4 M sodium hydroxide solution is added dropwise to the mixed solution until the pH value of the mixed solution is 4.8.
[0054] Example 8: The difference between this example and Example 1 is that the synthesis method of the biochar is as follows: First, the biomass raw material is crushed. The biomass raw material is corn straw. Then it is placed in a crucible, and the sealed crucible is placed in a muffle furnace, heated to 450 °C at a heating rate of 6 °C / min, and maintained at 450 °C for 1.5 h; after cooling, it is ground through an 80-mesh sieve, and rinsed with anhydrous ethanol and deionized water to remove the ash generated by pyrolysis; finally, the obtained sludge biochar is placed in an oven and dried at 50 °C for 10 h to obtain biochar.
[0055] Example 9: The difference between this example and Example 1 is that the synthesis method of the biochar is as follows: First, the biomass raw material is crushed. The biomass raw material is corn straw. Then it is placed in a crucible, and the sealed crucible is placed in a muffle furnace, heated to 550 °C at a heating rate of 3 °C / min, and maintained at 550 °C for 3 h; after cooling, it is ground through a 120-mesh sieve, and rinsed with anhydrous ethanol and deionized water to remove the ash generated by pyrolysis; finally, the obtained sludge biochar is placed in an oven and dried at 70 °C for 15 h to obtain biochar.
[0056] Example 10: The difference between this example and Example 1 is that the mixed solution is placed in an ultrasonic cleaner and purged with nitrogen for 10 min to remove carbon dioxide in the suspension to obtain a treated mixed solution. Among them, the ultrasonic frequency of the ultrasonic cleaner is 30 KHz and the ultrasonic power is 180 W.
[0057] Example 11: The difference between this example and Example 1 is that the mixed solution is placed in an ultrasonic cleaner and purged with nitrogen for 20 min to remove carbon dioxide in the suspension to obtain a treated mixed solution. Among them, the ultrasonic frequency of the ultrasonic cleaner is 50 KHz and the ultrasonic power is 240 W.
[0058] Example 12: The difference between this example and Example 1 is that a hydrothermal reaction is carried out at 120 °C for 4 h in an oven.
[0059] Example 13: The difference between this example and Example 1 is that a hydrothermal reaction is carried out at 140 °C for 6 h in an oven.
[0060] Example 14: The difference between this example and Example 1 is that the product is dried at 60 °C for 10 h, then the product is ground through an 80-mesh sieve, and finally the product is calcined in a muffle furnace at 400 °C for 2 h to obtain the cobalt-doped copper oxide@biochar material.
[0061] Example 15: The difference between this example and Example 1 is that the product is dried at 70 °C for 15 h, then the product is ground through a 120-mesh sieve, and finally the product is calcined in a muffle furnace at 500 °C for 4 h to obtain the cobalt-doped copper oxide@biochar material.
[0062] Example 16: The difference between this example and Example 1 is that the synthesis method of the biochar is as follows:
[0063] 1) The biomass raw material is crushed to make the moisture content of the biomass raw material < 5%, and the biomass raw material is put into a dielectric barrier discharge plasma reactor with the following parameters: power density 200 W / m 2 , the gas environment is a mixed gas of argon and oxygen, the oxygen content in the mixed gas is 10%, the gas flow rate is 2 L / min, at normal pressure, and it is treated for 12 min to obtain the pretreated biomass; among them, the biomass raw material is corn straw;
[0064] 2) 0.1 M cobalt nitrate and 0.4 M 2-methylimidazole are mixed at a volume ratio of 1:4, and the pretreated biomass is added, with a solid-liquid ratio of 1:10. After ultrasonic-assisted impregnation, it is left standing for 12 h, and the MOF loading is controlled at 10 wt% to obtain the product; among them, the ultrasonic frequency of the ultrasonic-assisted impregnation is 40 kHz, the ultrasonic power is 220 W, and the treatment time is 30 min;
[0065] 3) The product is heated to 180 ± 5 °C at a heating rate of 5 °C / min in an air environment and kept warm for 60 min; then it is heated to 270 ± 5 °C at a heating rate of 3 °C / min in a nitrogen environment and kept warm for 90 min; then it is heated to 320 ± 5 °C at a heating rate of 2 °C / min in a CO2 environment and kept warm for 30 min, where the flow rate of CO2 is 50 mL / min, to obtain the carbonized product;
[0066] 4) Subsequently, the carbonized product is soaked in 1 M HCl for 7 h, the pH is adjusted to 7.5 with ammonia water, and it is dried in vacuum at 115 °C to obtain the biochar.
[0067] Example 17: The difference between this example and Example 16 is that the biomass raw material is put into a dielectric barrier discharge plasma reactor with the following parameters: power density 180 W / m 2 , the gas environment is a mixture of argon and oxygen, the oxygen content in the mixture is 5%, the gas flow rate is 1.5 L / min, at atmospheric pressure, and it is treated for 10 min to obtain pretreated biomass.
[0068] Example 18: The difference between this example and Example 16 is that the biomass raw material is put into a dielectric barrier discharge plasma reactor with the following parameters: power density 220 W / m 2 , the gas environment is a mixture of argon and oxygen, the oxygen content in the mixture is 15%, the gas flow rate is 3 L / min, at atmospheric pressure, and it is treated for 15 min to obtain pretreated biomass.
[0069] Example 19: The difference between this example and Example 16 is that 0.1 M cobalt nitrate and 0.4 M 2-methylimidazole are mixed at a volume ratio of 1:3, and the pretreated biomass is added. The solid-liquid ratio is 1:8. After ultrasonic-assisted impregnation, it is left standing for 12 h, and the MOF loading is controlled at 8 wt% to obtain the product.
[0070] Example 20: The difference between this example and Example 16 is that 0.1 M cobalt nitrate and 0.4 M 2-methylimidazole are mixed at a volume ratio of 1:5, and the pretreated biomass is added. The solid-liquid ratio is 1:12. After ultrasonic-assisted impregnation, it is left standing for 12 h, and the MOF loading is controlled at 12 wt% to obtain the product.
[0071] Example 21: The difference between this example and Example 16 is that the ultrasonic frequency of the ultrasonic-assisted impregnation is 30 kHz, the ultrasonic power is 180 W, and the treatment time is 25 min.
[0072] Example 22: The difference between this example and Example 16 is that the ultrasonic frequency of the ultrasonic-assisted impregnation is 50 kHz, the ultrasonic power is 240 W, and the treatment time is 35 min.
[0073] Example 23: The difference between this example and Example 16 is that the product is heated to 180 ± 5 °C at a heating rate of 4 °C / min in an air environment and kept at this temperature for 50 min; then it is heated to 270 ± 5 °C at a heating rate of 2 °C / min in a nitrogen environment and kept at this temperature for 80 min; and then it is heated to 320 ± 5 °C at a heating rate of 1 °C / min in a CO2 environment and kept at this temperature for 20 min, where the flow rate of CO2 is 40 mL / min, to obtain the carbonized product.
[0074] Example 24: The difference between this example and Example 16 is that the product is heated to 180 ± 5 °C at a heating rate of 6 °C / min in an air environment and held for 70 min; then it is heated to 270 ± 5 °C at a heating rate of 4 °C / min in a nitrogen environment and held for 100 min; and then it is heated to 320 ± 5 °C at a heating rate of 3 °C / min in a CO2 environment and held for 40 min, where the flow rate of CO2 is 60 mL / min, and the product after carbonization.
[0075] Example 25: The difference between this example and Example 16 is that the carbonized product is soaked in 1M HCl for 5 h, the pH is adjusted to 7 with ammonia water, and it is dried in vacuum at 110 °C to obtain biochar.
[0076] Example 26: The difference between this example and Example 16 is that the carbonized product is soaked in 1M HCl for 8 h, the pH is adjusted to 8 with ammonia water, and it is dried in vacuum at 120 °C to obtain biochar.
[0077] Example 27: The difference between this example and Example 16 is that the oxygen content in the mixed gas is periodically adjusted with the treatment time, and the periodic adjustment is that the oxygen content reciprocates between 5% and 15%, and the change rate of the reciprocating adjustment is 5% / min.
[0078] Example 28: The difference between this example and Example 27 is that the change rate of the reciprocating adjustment is 2% / min.
[0079] Example 29: The difference between this example and Example 27 is that the change rate of the reciprocating adjustment is 10% / min.
[0080] To further verify the influence of the parameters of the preparation method and the synthesis method of biochar on the performance of the prepared cobalt-doped copper oxide@biochar material, the superoxide radicals of the cobalt-doped copper oxide@biochar materials prepared in each example were quantified, and the improvement ratios of the generation efficiency compared with the control cobalt-doped copper oxide material were calculated respectively. The results are shown in the following table:
[0081]
[0082]
[0083] As can be seen from the results in the above table, there are some influences on the performance of the prepared cobalt-doped copper oxide@biochar material under different parameters of the preparation method or the synthesis method of biochar. The improvement ratios of the cobalt-doped copper oxide@biochar materials in each example to generate more superoxide radicals than the control cobalt-doped copper oxide material are different. The specific analysis is as follows:
[0084] Analysis 1: In Examples 2-7 and Examples 10-15, some parameters of the preparation method were adjusted. There are some differences in the performance of the cobalt-doped copper oxide@biochar materials prepared by them and the cobalt-doped copper oxide@biochar materials of Example 1 as follows:
[0085] 1) In Step 1, by comparing Example 2, Example 3, Example 4, Example 5, Example 6, Example 7 with Example 1, it is found that after using different ratios of copper nitrate trihydrate, cobalt nitrate hexahydrate and biochar, ultrasonic treatment time, and pH adjustment value, there are differences in the performance of the prepared cobalt-doped copper oxide@biochar materials. Among them, the performance of the cobalt-doped copper oxide@biochar material of Example 5 is the best, but the difference between Example 5 and Example 1 is not obvious. And Example 5 uses a longer treatment time, so the economy is poor. Therefore, the preparation method parameters of Example 1 are relatively better;
[0086] 2) In Step 2, by comparing Example 10 and Example 11 with Example 1, it is found that after using different ultrasonic cleaning parameters, there are differences in the performance of the prepared cobalt-doped copper oxide@biochar materials. Among them, the performance of the cobalt-doped copper oxide@biochar material of Example 11 is the best, but the difference between Example 11 and Example 1 is not obvious. And Example 11 uses a longer ultrasonic cleaning time and power, so the economy is poor. Therefore, the preparation method parameters of Example 1 are relatively better;
[0087] 3) In Step 3, by comparing Example 12, Example 13, Example 14, Example 15 with Example 1, it is found that after using different hydrothermal reaction temperatures and times, drying and calcination temperatures, there are differences in the performance of the prepared cobalt-doped copper oxide@biochar materials. Among them, the preparation parameters of Example 1 are relatively the best.
[0088] Analysis 2: In Examples 8, 9, and Examples 16-29, the synthesis method of biochar was adjusted. There are some differences in the performance of the cobalt-doped copper oxide@biochar materials prepared using the synthesized biochar and the cobalt-doped copper oxide@biochar materials of Example 1 as follows:
[0089] 1) In the first biochar synthesis method, by comparing Example 8 and Example 9 with Example 1, it is found that under different biochar synthesis parameters, there are differences in the use effects of the synthesized biochar as raw materials. Among them, the use effect of the biochar synthesized in Example 9 is the best, but the difference between Example 9 and Example 1 is not obvious. And the synthesis time and energy consumption of Example 9 are higher, so the economy is poor. Therefore, the synthesis parameters of Example 1 are relatively better;
[0090] 2) In the second method for synthesizing biochar, it was found by comparing Example 16 with Example 1 that under different biochar synthesis methods, there are differences in the usage effects of the synthesized biochar as a raw material, and the usage effect of the biochar synthesized in Example 16 is the best;
[0091] 3) In the second method for synthesizing biochar, it was found by comparing Example 17, Example 18, Example 19, Example 20, Example 21, Example 22, Example 23, Example 24, Example 25, Example 26 with Example 1 that after adjusting the parameters of the biochar synthesis method of Example 16, there are differences in the usage effects of the synthesized biochar as a raw material, and the usage effect of the biochar synthesized in Example 22 is the best. However, the difference between Example 22 and Example 16 is not obvious, and the synthesis time and energy consumption of Example 22 are higher, with poor economy. Therefore, the synthesis parameters of Example 16 are relatively more optimal;
[0092] 4) In the second method for synthesizing biochar, it was found by comparing Example 27, Example 28, Example 29 with Example 16 that after optimizing the method of oxygen plasma etching treatment, the usage effect of the synthesized biochar was further improved. At the same time, it was found by comparing Example 28, Example 29 with Example 27 that different reciprocating transfer change rates have differences in the usage effects of the synthesized biochar as a raw material, and the reciprocating transfer change rate parameter of Example 27 is relatively the most optimal.
Claims
1. A preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals, characterized in that, It includes the following steps: Step 1: Dissolve copper nitrate trihydrate and cobalt nitrate hexahydrate in deionized water, ultrasonicate for 3 - 8 min, add biochar, and ultrasonicate for another 3 - 8 min to obtain a mixed solution. Then, gradually add 0.4 M sodium hydroxide solution to the mixed solution until the pH value of the mixed solution is 4.3 ± 0.5; Among them, the amounts of copper nitrate trihydrate, copper nitrate hexahydrate, and biochar added in deionized water are respectively: 90 - 100 g / L, 110 - 125 g / L, and 3 - 5 g / L; Step 2: Place the mixed solution in an ultrasonic cleaner and purge with nitrogen for 10 - 20 min to obtain a treated mixed solution; Step 3: Transfer the treated mixed solution into a polytetrafluoroethylene hydrothermal reaction liner and seal it in a stainless - steel autoclave. Carry out hydrothermal reaction at 120 - 140 °C in an oven for 4 - 6 h. Subsequently, naturally cool the obtained product to room temperature. After washing, drying, grinding, and calcining the product in sequence, a cobalt - doped copper oxide @ biochar material is obtained.
2. The preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals according to claim 1, characterized in that, The synthesis method of the biochar is as follows: First, crush the biomass raw material, then place it in a crucible, and place the sealed crucible in a muffle furnace. Heat it to 450 - 550 °C at a heating rate of 3 - 6 °C / min and maintain it at 450 - 550 °C for 1.5 - 3 h; After cooling, grind it through an 80 - 120 - mesh sieve, and rinse it with anhydrous ethanol and deionized water to remove the ash generated by pyrolysis; Finally, place the obtained sludge biochar in an oven and dry it at 50 - 70 °C for 10 - 15 h to obtain biochar.
3. The preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals according to claim 2, characterized in that, The biomass raw material is any one of corn straw, wheat straw, sludge, and bamboo.
4. The preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals according to claim 1, characterized in that, The mixed solution is washed in an ultrasonic cleaner for 10 - 20 min, and the ultrasonic frequency of the ultrasonic cleaner is 30 - 50 KHz and the ultrasonic power is 180 - 240 W.
5. The preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals as described in claim 1, characterized in that, The washing is to wash the product with anhydrous ethanol several times; the drying is to dry the product at 60 - 70 °C for 10 - 15 h; the grinding is to grind the product through an 80 - 120 - mesh sieve; the calcining is to calcine the product in a muffle furnace at 400 - 500 °C for 2 - 4 h.
6. The preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals according to claim 1, characterized in that, The synthesis method of the biochar is as follows: 1) Crush the biomass raw material to make the moisture content of the biomass raw material < 5%, and put the biomass raw material into a dielectric barrier discharge plasma reactor with the following parameters: power density 180 - 220 W / m 2 , the gas environment is a mixture of argon and oxygen, the gas flow rate is 1.5 - 3 L / min, at atmospheric pressure, and treat for 10 - 15 min to obtain pretreated biomass; 2) Mix 0.1 M cobalt nitrate and 0.4 M 2 - methylimidazole at a volume ratio of 1:3 - 5, add the pretreated biomass, with a solid - liquid ratio of 1:8 - 12, carry out ultrasonic - assisted impregnation and then let it stand for 12 h, and control the MOF loading amount at 8 - 12 wt% to obtain a product; 3) Heat the product in an air environment to 180 ± 5 °C at a heating rate of 4 - 6 °C / min and keep it warm for 50 - 70 min; then, in a nitrogen environment, heat it to 270 ± 5 °C at a heating rate of 2 - 4 °C / min and keep it warm for 80 - 100 min; then, in a CO2 environment, heat it to 320 ± 5 °C at a heating rate of 1 - 3 °C / min and keep it warm for 20 - 40 min, where the flow rate of CO2 is 40 - 60 mL / min, to obtain a carbonized product; 4) Subsequently, the carbonized product is soaked in 1M HCl for 5 - 8 h, the pH is adjusted to 7 - 8 with ammonia water, and vacuum dried at 110 - 120 °C to obtain biochar.
7. The preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals according to claim 6, characterized in that, The oxygen content in the mixed gas is 5 - 15%, and the oxygen content in the mixed gas is periodically adjusted with the treatment time. The periodic adjustment is that the oxygen content reciprocally adjusts between 5 - 15%, and the change rate of the reciprocal adjustment is 2 - 10% / min.
8. The preparation method of a biochar@bimetallic material for efficiently producing superoxide radicals as described in claim 6, wherein, The ultrasonic frequency of the ultrasonic-assisted impregnation is 30 - 50 kHz, the ultrasonic power is 180 - 240 W, and the treatment time is 25 - 35 min.