阅读说明：本技术 利用改性炭黑负载的镍-金双金属纳米催化剂处理硝基芳香烃类物质的方法 (Method for treating nitroaromatic substances by using modified carbon black loaded nickel-gold bimetallic nano-catalyst ) 是由 陈亮 秦蕾 赖萃 曾光明 符玉葵 李必胜 柳诗语 易欢 张明明 于 2019-04-23 设计创作，主要内容包括：本发明公开了一种利用改性炭黑负载的镍-金双金属纳米催化剂处理硝基芳香烃类物质的方法,该方法是采用改性炭黑负载的镍-金双金属纳米催化剂对硝基芳香烃类物质进行处理,其中改性炭黑负载的镍-金双金属纳米催化剂包括改性炭黑、纳米镍和纳米金颗粒,纳米镍和纳米金颗粒共同负载在改性炭黑表面,改性炭黑由炭黑经浓硝酸改性后制得。本发明利用改性炭黑负载的镍-金双金属纳米催化剂处理硝基芳香烃类物质的方法,具有操作简单、反应迅速、催化剂稳定且易回收利用、经济等优点,是一种可以广泛应用于处理硝基芳香烃物质的方法,有着很好的应用价值和应用前景。(The invention discloses a method for treating nitro-aromatic substances by using a modified carbon black loaded nickel-gold bimetallic nano-catalyst, which is used for treating the nitro-aromatic substances by using the modified carbon black loaded nickel-gold bimetallic nano-catalyst, wherein the modified carbon black loaded nickel-gold bimetallic nano-catalyst comprises modified carbon black, nano nickel and nano gold particles, the nano nickel and the nano gold particles are loaded on the surface of the modified carbon black together, and the modified carbon black is prepared by modifying the carbon black by concentrated nitric acid. The method for treating the nitroaromatic substances by using the modified carbon black loaded nickel-gold bimetallic nano-catalyst has the advantages of simple operation, rapid reaction, stable catalyst, easy recycling, economy and the like, can be widely applied to treating the nitroaromatic substances, and has good application value and application prospect.)

1. A method for processing nitro-aromatic hydrocarbon substances by using a modified carbon black loaded nickel-gold bimetallic nano-catalyst is characterized in that the method is to process the nitro-aromatic hydrocarbon substances by using the modified carbon black loaded nickel-gold bimetallic nano-catalyst; the nickel-gold bimetallic nano-catalyst loaded by the modified carbon black comprises modified carbon black, nano nickel and nano gold particles, wherein the nano nickel and the nano gold particles are loaded on the surface of the modified carbon black together; the modified carbon black is prepared by modifying carbon black with concentrated nitric acid.

2. The method of claim 1, wherein the modified carbon black supported nickel-gold bimetallic nanocatalyst contains 5.73-20.11 wt% of nano nickel and 0.21-0.61 wt% of nano gold particles; the molar ratio of the nano nickel to the nano gold particles is 2: 1-10: 1; the modified carbon black is nanosphere particles, and the average particle size is 20-40 nm; the nano nickel is spheroidal, and the average particle size is 76 nm-127 nm; the average grain diameter of the nano gold particles is 8 nm-10 nm.

3. The method of claim 2, wherein the preparation method of the modified carbon black supported nickel-gold bimetallic nanocatalyst comprises the following steps:

s1, mixing the modified carbon black with glycol, performing ultrasonic treatment, and adding glycol-Ni²⁺Stirring the solution to obtain modified carbon black-Ni²⁺A dispersion liquid;

s2, modifying the carbon black-Ni obtained in the step S1²⁺Mixing the dispersion liquid, a NaOH solution and a hydrazine hydrate solution for reduction reaction to obtain a modified carbon black loaded monometallic nickel nano catalyst;

s3, loading the modified carbon black obtained in the step S2 with monometallic nickel nano-particlesMixing the catalyst with ethylene glycol, performing ultrasonic treatment, and adding Au³⁺And carrying out reduction reaction on the solution and a hydrazine hydrate solution to obtain the modified carbon black loaded nickel-gold bimetallic nano-catalyst.

4. The method according to claim 3, wherein in step S1, the modified carbon black is prepared by a method comprising the steps of:

(1) mixing carbon black and concentrated nitric acid according to the ratio of 1g to 100-150 mL, and stirring at the rotating speed of 400-1500 r/min for 10-30 min to obtain a mixed solution of the carbon black and the concentrated nitric acid;

(2) and (2) heating the mixed solution of the carbon black and the concentrated nitric acid obtained in the step (1) to 75-90 ℃, stirring, filtering, cleaning and drying to obtain the modified carbon black.

5. The method of claim 3, wherein in step S1, the ratio of the modified carbon black to the ethylene glycol is 200 mg: 75 mL; the ultrasound is carried out at the temperature of 5-40 ℃; the ultrasonic time is 30-60 min; the modified carbon black and ethylene glycol-Ni²⁺The ratio of the solution is 200 mg: 1 mL-5 mL; the ethylene glycol-Ni²⁺Ni in solution²⁺Is 24.26 mM; the rotating speed of the stirring is 400 r/min-600 r/min; the stirring time is 15 min;

in the step S2, the modified carbon black-Ni²⁺The volume ratio of the dispersion liquid to the NaOH solution to the hydrazine hydrate solution is 76-80: 25: 5; the concentration of the NaOH solution is 1M; the mass percentage content of the hydrazine hydrate solution is 85 percent; the reduction reaction is carried out under the stirring condition with the rotating speed of 400 r/min-600 r/min; the temperature of the reduction reaction is 80-90 ℃; the time of the reduction reaction is 2-4 h;

in the step S3, the ratio of the modified carbon black-supported monometallic nickel nanocatalyst to ethylene glycol is 200 mg: 100 mL; the ultrasound is carried out at the temperature of 5-40 ℃; the ultrasonic time is 30-60 min; the temperature of the reduction reaction is 85-95 ℃; the time of the reduction reaction is 3 to 5 hours(ii) a The modified carbon black loaded single metal nickel nano catalyst and Au³⁺The ratio of the solution to the hydrazine hydrate solution is 200 mg: 0.5 mL: 200 muL; the reduction reaction is carried out under the stirring condition with the rotating speed of 400 r/min-600 r/min; the Au layer³⁺The solution is chloroauric acid solution; the concentration of the chloroauric acid solution is 8 g/L-12 g/L; the mass percentage of the hydrazine hydrate solution is 85%.

6. The method as claimed in any one of claims 1 to 5, wherein the method is used for treating the nitroaromatic substances in the water body by using the modified carbon black loaded nickel-gold bimetallic nano-catalyst, and comprises the following steps: mixing the modified carbon black loaded nickel-gold bimetallic nano-catalyst with a water body containing the nitro-aromatic hydrocarbon substances for adsorption, adding borohydride for catalytic reduction reaction, and finishing the treatment of the nitro-aromatic hydrocarbon substances in the water body.

7. The method according to claim 6, wherein the addition amount of the modified carbon black loaded nickel-gold bimetallic nano-catalyst is 100mg per liter of water containing the nitro aromatic hydrocarbon substances; the ratio of the water containing the nitro aromatic hydrocarbon substance to the borohydride is 50 mL: 0.034 g.

8. The method according to claim 7, wherein the concentration of the nitroaromatic substances in the nitroaromatic substance-containing water body is 0.2-1.0 g/L; the borohydride salt is sodium borohydride.

9. The method according to claim 8, wherein the nitroaromatic substances in the nitroaromatic-containing water body are at least one of 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, congo red, methyl orange and chrome black T.

10. The method according to claim 6, wherein the adsorption is carried out under stirring conditions at a rotation speed of 400r/min to 600 r/min; the adsorption time is 20 min-60 min; the time of the catalytic reduction reaction is 3min to 30 min.

Technical Field

The invention belongs to the field of reduction treatment of nitroaromatic substances, relates to a method for treating the nitroaromatic substances, and particularly relates to a method for treating the nitroaromatic substances by using a modified carbon black loaded nickel-gold bimetallic nano catalyst.

Background

Nitroaromatic hydrocarbon substances are those in which one or more hydrogen atoms in the hydrocarbon molecule are replaced by nitro groups (-NO) in the molecule containing multiple benzene rings₂) Nitro compounds generated after substitution, such as 2-nitrophenol, 4-nitrophenol, 2, 4-nitrophenol, azo dyes, and the like. They are the main chemical raw materials in chemical industry production and are widely applied to the aspects of pesticide production, printing and dyeing industry, explosives, medicines and the like. The aniline and nitrobenzene compounds emitted into the environment worldwide are about 1 and 3 million tons per year. With the increasing development of chemical industry, the demand of such chemicals is gradually rising, and the amount of the chemicals discharged into the environment is higher and higher. These substances are concentrated in the environment and gradually accumulate in the human body. High doses of nitroaromatics are absorbed by the human skin or from the respiratory tract and can cause poisoning and even death. Therefore, the temperature of the molten metal is controlled,how to reduce the pollution of nitroaromatic substances to the environment and prevent the substances from harming human and animals attracts people's attention.

At present, the treatment of nitroaromatic wastewater at home and abroad mainly comprises physical, chemical, biological and other methods, which mainly comprise physical and chemical adsorption, oxidation, biodegradation and the like, but the nitroaromatic structure is very stable, so that the methods are difficult to completely degrade the nitroaromatic in the wastewater, and the final product can generate secondary pollution if the nitroaromatic is not completely degraded, and the methods are complex in operation, time-consuming, low in efficiency and require a large amount of energy to be input.

The nano gold and the nano nickel are used as two important nano materials, have the advantages of wide application, easy synthesis, large specific surface area, biocompatibility, no toxicity and the like, and have unique dielectric properties and excellent catalytic action, so that the nano gold and the nano nickel can be widely applied to the fields of medicine, chemistry, environment and the like. Especially, both can reduce the nitroaromatic hydrocarbon, and the highly toxic nitroaromatic hydrocarbon substances are reduced into corresponding amines under the action of the catalyst, so that on one hand, the toxicity of the nitroaromatic hydrocarbon is reduced, and the pollution to the environment is reduced; on the other hand, the amines can be used as chemical raw materials to carry out industrial production, and have certain economic value. Therefore, the method for reducing the nitroaromatic substances by using the nano gold and nano nickel catalysts has good application prospect and has important significance for reducing environmental pollution and maintaining human health.

The nano-sized colloidal gold has better catalytic action, can quickly reduce specific nitroaromatic hydrocarbon, and has further enhanced catalytic activity along with the reduction of the particle size, but the smaller the particle size is, the larger the surface energy of the colloidal gold is caused by the size effect, and the colloidal gold is easy to be affected by the outside to generate plasma resonance so as to be easy to precipitate. The precipitated colloidal gold has larger particle size, fewer active sites and reduced catalytic activity, and meanwhile, the colloidal gold nanoparticles exist in the solution and cannot be well recycled, so that resource waste is easily caused. Meanwhile, the raw materials for preparing the nano gold are expensive, and the green economic development is not met. The nickel is rich in the earth crust, the price is relatively low, and the nano nickel has magnetism, which is beneficial to separating from the solution, but the catalytic activity is poor, and a large amount of nickel is needed to achieve the satisfactory catalytic activity. Therefore, how to utilize the advantages of the nano nickel and nano gold catalysts to mutually make up the weaknesses of the nano nickel and nano gold catalysts to obtain the economic bimetallic nano catalyst which has good economic benefit, good stability, high catalytic activity, good recycling performance and easy recycling, and has very important significance for expanding the application field of the metal nano catalyst.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art and provide the method for economically treating the nitroaromatic substances by using the nickel-gold bimetallic nano-catalyst loaded by the modified carbon black, which has the advantages of simple operation, quick reaction, stable catalyst and easy recycling.

In order to solve the technical problems, the invention adopts the technical scheme that:

a method for processing nitro-aromatic hydrocarbon substances by using a modified carbon black loaded nickel-gold bimetallic nano-catalyst is characterized in that the nitro-aromatic hydrocarbon substances are processed by using the modified carbon black loaded nickel-gold bimetallic nano-catalyst; the nickel-gold bimetallic nano-catalyst loaded by the modified carbon black comprises modified carbon black, nano nickel and nano gold particles, wherein the nano nickel and the nano gold particles are loaded on the surface of the modified carbon black together; the modified carbon black is prepared by modifying carbon black with concentrated nitric acid.

In the method, the content of nano nickel in the modified carbon black loaded nickel-gold bimetallic nano catalyst is 5.73 to 20.11 weight percent, and the content of nano gold particles is 0.21 to 0.61 weight percent; the molar ratio of the nano nickel to the nano gold particles is 2: 1-10: 1; the modified carbon black is nanosphere particles, and the average particle size is 20-40 nm; the nano nickel is spheroidal, and the average particle size is 76 nm-127 nm; the average grain diameter of the nano gold particles is 8 nm-10 nm.

In the method, the further improvement is that the preparation method of the modified carbon black supported nickel-gold bimetallic nano-catalyst comprises the following steps:

s1, mixing the modified carbon black with glycol, performing ultrasonic treatment, and adding glycol-Ni²⁺Stirring the solution to obtain modified carbon black-Ni²⁺A dispersion liquid;

s2, modifying the carbon black-Ni obtained in the step S1²⁺Mixing the dispersion liquid, a NaOH solution and a hydrazine hydrate solution for reduction reaction to obtain a modified carbon black loaded monometallic nickel nano catalyst;

s3, mixing the modified carbon black loaded monometallic nickel nano catalyst obtained in the step S2 with ethylene glycol, performing ultrasonic treatment, and adding Au³⁺And carrying out reduction reaction on the solution and a hydrazine hydrate solution to obtain the modified carbon black loaded nickel-gold bimetallic nano-catalyst.

In a further improvement of the above method, in step S1, the method for preparing the modified carbon black comprises the following steps:

(1) mixing carbon black and concentrated nitric acid according to the ratio of 1g to 100-150 mL, and stirring at the rotating speed of 400-1500 r/min for 10-30 min to obtain a mixed solution of the carbon black and the concentrated nitric acid;

(2) and (2) heating the mixed solution of the carbon black and the concentrated nitric acid obtained in the step (1) to 75-90 ℃, stirring, filtering, cleaning and drying to obtain the modified carbon black.

In a further improvement of the above method, in step S1, the ratio of the modified carbon black to the ethylene glycol is 200 mg: 75 mL; the ultrasound is carried out at the temperature of 5-40 ℃; the ultrasonic time is 30-60 min; the modified carbon black and ethylene glycol-Ni²⁺The ratio of the solution is 200 mg: 1 mL-5 mL; the ethylene glycol-Ni²⁺Ni in solution²⁺Is 24.26 mM; the rotating speed of the stirring is 400 r/min-600 r/min; the stirring time is 15 min;

in the step S2, the modified carbon black-Ni²⁺The volume ratio of the dispersion liquid to the NaOH solution to the hydrazine hydrate solution is 76-80: 25: 5; the concentration of the NaOH solution is 1M; the mass percentage content of the hydrazine hydrate solution is 85 percent; the reduction reaction is carried out under the stirring condition with the rotating speed of 400 r/min-600 r/min; what is needed isThe temperature of the reduction reaction is 80-90 ℃; the time of the reduction reaction is 2-4 h;

in the step S3, the ratio of the modified carbon black-supported monometallic nickel nanocatalyst to ethylene glycol is 200 mg: 100 mL; the ultrasound is carried out at the temperature of 5-40 ℃; the ultrasonic time is 30-60 min; the temperature of the reduction reaction is 85-95 ℃; the time of the reduction reaction is 3-5 h; the modified carbon black loaded single metal nickel nano catalyst and Au³⁺The ratio of the solution to the hydrazine hydrate solution is 200 mg: 0.5 mL: 200 muL; the reduction reaction is carried out under the stirring condition with the rotating speed of 400 r/min-600 r/min; the Au layer³⁺The solution is chloroauric acid solution; the concentration of the chloroauric acid solution is 8 g/L-12 g/L; the mass percentage of the hydrazine hydrate solution is 85%.

In a further improvement of the method, the method is to use the modified carbon black loaded nickel-gold bimetallic nano-catalyst to treat the nitroaromatic substances in the water body, and comprises the following steps: mixing the modified carbon black loaded nickel-gold bimetallic nano-catalyst with a water body containing the nitro-aromatic hydrocarbon substances for adsorption, adding borohydride for catalytic reduction reaction, and finishing the treatment of the nitro-aromatic hydrocarbon substances in the water body.

In the method, the addition amount of the modified carbon black loaded nickel-gold bimetallic nano-catalyst is 100mg per liter of water containing the nitro aromatic hydrocarbon substances; the ratio of the water containing the nitro aromatic hydrocarbon substance to the borohydride is 50 mL: 0.034 g.

In the method, the concentration of the nitroaromatic substances in the water body containing the nitroaromatic substances is further improved to be 0.2-1.0 g/L; the borohydride salt is sodium borohydride.

In the method, the nitroaromatic substance in the nitroaromatic substance-containing water body is at least one of 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, congo red, methyl orange and chrome black T.

The method is further improved, and the adsorption is carried out under the stirring condition with the rotating speed of 400 r/min-600 r/min; the adsorption time is 20 min-60 min; the time of the catalytic reduction reaction is 3min to 30 min.

Compared with the prior art, the invention has the advantages that:

(1) the invention provides a method for treating nitroaromatic substances by using a modified carbon black loaded nickel-gold bimetallic nano catalyst. Taking 4-nitrophenol as an example, under the condition of existence of a small amount of sodium borohydride, the catalytic action of nano nickel and nano gold in the modified carbon black loaded nickel-gold bimetallic nano catalyst is activated, and at the moment, the sodium borohydride generates active hydrogen (H) under the condition of existence of water molecules₂) Active hydrogen is absorbed to the surface of the nano nickel and the nano gold to form Ni-H and Au-H intermediates with the nano gold, and meanwhile, the nano gold becomes a hydride transfer medium. When the target substance (4-NP) exists, the target substance can be diffused and adsorbed to the surfaces of the nano nickel and the nano gold, active hydrogen on the surfaces of the nano nickel and the nano gold is transferred to the target substance under the pushing action of the nano gold to form a hydrogenation reaction with the target substance, the target substance is reduced by the hydrogen to gradually form nitrosophenol and hydroxylamine, and finally, the p-nitroamine is formed, so that the purpose of degradation is achieved. In the process, the modified carbon black and a target substance (4-NP) have a strong pi-pi stacking effect, so that the adsorption of the catalyst on the 4-NP is promoted, the mass transfer process is accelerated, the contact of the 4-NP with active sites of nano nickel and nano particles is facilitated, and the catalytic efficiency of the catalyst is further promoted. The modified carbon black loaded nickel-gold bimetallic nano-catalyst shows good stability when used for treating nitroaromatic substances, can be repeatedly utilized for many times, has a removal rate of 95 percent after being repeatedly used for 8 times, is favorable for reducing the treatment cost, shows good catalytic activity, and can completely remove pollutants in a short time, for example, 4-nitrophenol can be removed from a water body within 3 min. The invention utilizes the nickel-gold bimetallic nano-catalyst loaded by modified carbon black to treat the nitroaromatic substancesThe method has the advantages of simple operation, rapid reaction, stable catalyst, easy recycling, economy and the like, can be widely applied to the treatment of the nitroaromatic substances, and has good application value and application prospect.

(2) The nickel-gold bimetallic nano-catalyst loaded by the modified carbon black comprises the modified carbon black, nano nickel and nano gold particles, wherein the nano nickel and the nano gold particles are loaded on the surface of the modified carbon black together; the modified carbon black is prepared by modifying carbon black with acid. In the invention, the modified carbon black is prepared by acid modification of carbon black, because the carbon black contains rich pore channel structures, the anchoring of nano nickel and nano gold particles is facilitated, and the oxygen content in the acid-modified carbon black is increased and a small amount of nitrogen is introduced for doping, so that oxygen-containing groups and nitrogen-containing groups on the surface of the modified carbon black, such as carboxyl (-COOH), hydroxyl (-OH), amino (-NH), are introduced₂) And the groups can further anchor nano nickel and nano gold particles and fix the nano nickel and nano gold particles on the surface of carbon black to form the nickel-gold bimetallic nano catalyst taking acid modified carbon black as a carrier. In the invention, the nano nickel and nano gold particles are fixed on the surface of the modified carbon black, which is beneficial to improving the content of the nano nickel and nano gold particles, thereby enhancing the catalytic performance of the material. Meanwhile, the modified carbon black has a mixed layer and a porous structure, so that the modified carbon black has better electron transfer capacity and adsorption capacity, and can further promote electron transfer after the nano nickel and the nano gold are triggered to obtain active hydrogen, so that more active hydrogen and target substances can be adsorbed, and the reaction of the hydrogen and the target substances is promoted, thereby accelerating the reaction; due to the abundant pore structure and graphene-like properties, strong pi-pi stacking effect is generated between the carbon black and the target substance, adsorption of the target substance is further promoted, the active hydrogen transfer distance of the nano nickel and the nano gold is shortened, the target substance is favorably close to a catalyst, mass transfer can be promoted, reaction is further promoted, and the catalytic efficiency is improved. In addition, the modified carbon black has the advantages of large specific surface area, wide contact with a target substance and the like, and is beneficial to realizing catalytic reduction of the target substance in practical application. Compared with nano gold colloid catalyst, the modified carbon black of the invention is loadedThe nickel-gold bimetallic nano-catalyst has the advantages of good economic benefit, good stability, high catalytic activity, good recycling performance, easy recycling and the like, is an economic bimetallic nano-catalyst which can be widely used, can efficiently degrade and remove organic pollutants in the environment, particularly can reduce high-toxicity nitroaromatic substances into corresponding low-toxicity amines, and has good application value and application range.

(3) In the invention, the adopted modified carbon black loaded nickel-gold bimetallic nano-catalyst comprises nano nickel and nano gold, the nano nickel has relatively low price and magnetism and is beneficial to separation from a solution, but the catalytic activity of the nano nickel is poor, and a large amount of nickel is needed to achieve satisfactory catalytic activity. The nano gold as a noble metal has better catalytic activity, but is expensive and not beneficial to wide preparation. Therefore, the modified carbon black loaded nickel-gold bimetallic nano-catalyst combines the advantages of nano nickel and nano gold, and avoids the disadvantages of the nano nickel and the nano gold; and because of the energy contained on the surface of the nano nickel and the overflow effect, when the nano nickel exists, the nano gold particles with smaller particle size and more regular spherical shape can be formed; meanwhile, when the nano nickel exists, more nano gold tends to grow on the nano nickel, so that more active sites are increased, namely the catalytic activity of the bimetallic nano catalyst prepared by the method is further improved through the synergistic effect of the nano nickel and the nano gold.

(4) In the invention, in the adopted modified carbon black loaded nickel-gold bimetallic nano-catalyst, the content of nano nickel and nano gold particles has important influence on improving the performance of the catalyst. When the content of the nano nickel is too low (e.g. less than 5.73 wt%), less nano nickel is not beneficial to forming the nano gold particles with smaller particle size and more regular spherical shape, so that the loading of the nano gold particles is lower, and the photocatalytic activity is still poor; when the content of the nano nickel is too high (for example, higher than 20.11 wt%), the excessive nano nickel occupies the anchoring sites on the surface of the carbon black, so that the loading amount of the nano gold is reduced, the catalytic activity of the catalyst is reduced, the nano nickel is easier to precipitate due to the existence of the excessive nano nickel, the particles are larger, the catalytic efficiency is influenced, and meanwhile, the excessive nano nickel also blocks the pore channels of the modified carbon black, the specific surface area is reduced, the mass transfer process is not facilitated, and the catalytic efficiency is reduced. In addition, when the content of the nano-gold particles is too low (e.g., less than 0.21 wt%), less nano-gold particles are not favorable for improving the catalytic activity of the catalyst; when the content of the gold nanoparticles is too high (e.g., higher than 0.61 wt%), it is not favorable for reducing the material cost, and it is difficult to meet the actual requirement. Therefore, in the application, the content of the nano nickel is 5.73-20.11 wt%, the content of the nano gold particles is 0.21-0.61 wt%, and the molar ratio of the nano nickel to the nano gold particles is 2: 1-10: 1, so that the adsorption performance and the catalytic performance of the catalyst are improved, and the material cost can be reduced, thereby obtaining the modified carbon black loaded nickel-gold bimetallic nano catalyst with good adsorption performance, high catalytic activity and low cost.

(5) The nickel-gold bimetallic nano-catalyst loaded by the modified carbon black is prepared by a two-step synthesis method by taking the modified carbon black as a carrier, a hydrazine hydrate solution as a reducing agent and ethylene glycol as a dispersing agent. In the invention, because the modified carbon black has rich pore channel structures and the existence of oxygen-containing groups and nitrogen-containing groups on the surface, the modified carbon black is beneficial to the Ni²⁺And Au³⁺Adsorbed on the surface of carbon black, these Ni²⁺And Au³⁺Reducing the nickel into nano nickel and nano gold under the reducing action of hydrazine hydrate; meanwhile, the surface energy and the overflow phenomenon of the nano nickel enable the nano gold to tend to grow around the nano nickel, the particle size of the nano gold is reduced, and the modified carbon black loaded nickel-gold bimetallic nano catalyst with good stability and high catalytic activity is formed. In the preparation method, the existence of the nano nickel is beneficial to the formation of the nano gold, and the formed nano gold particles are uniform and have smaller particle size, thereby being beneficial to improving the catalytic activity of the catalyst. In addition, the carbon black has wide source and low price, can further control the cost of the bimetallic nano-catalyst, and accords with economic development. Therefore, the preparation method of the modified carbon black loaded nickel-gold bimetallic nano-catalyst has the advantages of wide raw material source, low cost, no need of special equipment and the like, is suitable for large-scale preparation, and is beneficial to industrial production.

(6) In the preparation method of the modified carbon black loaded nickel-gold bimetallic nano-catalyst, the NaOH solution is easy to obtain and cheap, and no impurity element is introduced when the NaOH solution is adopted. In the invention, the purpose of modifying the carbon black by using concentrated nitric acid is to increase the oxygen content and introduce N, if concentrated nitric acid is used, the oxygen content may be increased and S element is introduced, but the concentrated sulfuric acid has higher danger, and concentrated hydrochloric acid cannot increase the oxygen content and introduce other elements.

Drawings

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

FIG. 1 shows a modified carbon black-supported nickel-gold bimetallic nanocatalyst (HCB-Ni) prepared in example 1 of the present invention₍₆₎-Au₍₁₎) A TEM image of (a).

FIG. 2 shows a modified carbon black-supported nickel-gold bimetallic nanocatalyst (HCB-Ni) prepared in example 1 of the present invention₍₆₎-Au₍₁₎) Energy spectrum of (2).

FIG. 3 shows a modified carbon black supported Ni-Au bimetallic nanocatalyst (HCB-Ni) prepared in example 1 of the present invention₍₆₎-Au₍₁₎) XPS comparison of unmodified Carbon Black (CB) and modified carbon black (HCB).

FIG. 4 shows a modified carbon black-supported nickel-gold bimetallic nanocatalyst (HCB-Ni) prepared in example 1 of the present invention₍₆₎-Au₍₁₎) The high resolution XPS chart of (a) is Ni and (b) is Au.

FIG. 5 shows a modified carbon black-supported nickel-gold bimetallic nanocatalyst (HCB-Ni) prepared in example 1 of the present invention₍₆₎-Au₍₁₎) Adsorption-desorption isotherms of unmodified Carbon Black (CB) and modified carbon black (HCB).

FIG. 6 shows a modified carbon black-supported nickel-gold bimetallic nanocatalyst (HCB-Ni) prepared in example 1 of the present invention₍₆₎-Au₍₁₎) Pore diameter distribution diagrams of unmodified Carbon Black (CB) and modified carbon black (HCB).

FIG. 7 is a graph showing the degradation effect of different modified carbon black-loaded Ni-Au bimetallic nanocatalysts on 4-nitrophenol (4-NP) in example 1 of the present invention.

FIG. 8 is a graph comparing the kinetic constants for the degradation of 4-nitrophenol (4-NP) by different modified carbon black loaded nickel-gold bimetallic nanocatalysts in example 1 of the present invention.

FIG. 9 shows modified carbon black-supported nickel-gold bimetallic nanocatalyst (HCB-Ni) in example 1 of the present invention₍₆₎-Au₍₁₎) Corresponding UV spectrograms when 4-nitrophenol (4-NP) is degraded at different reaction times.

FIG. 10 is a graph showing the effect of the modified carbon black supported Ni-Au bimetallic nanocatalyst on the cyclic degradation of 4-nitrophenol (4-NP) in example 2 of the present invention.

FIG. 11 shows modified carbon black-loaded nickel-gold bimetallic nanocatalysts (HCB-Ni) before and after reaction in example 2 of the present invention₍₆₎-Au₍₁₎) XRD pattern of (a).

FIG. 12 shows modified carbon black loaded Ni-Au bimetallic nanocatalysts (HCB-Ni) before and after reaction in example 2 of the present invention₍₆₎-Au₍₁₎) XPS survey spectrum of (1).

FIG. 13 shows modified carbon black loaded Ni-Au bimetallic nanocatalysts (HCB-Ni) before and after reaction in example 2 of the present invention₍₆₎-Au₍₁₎) The high resolution XPS chart of (a) is Ni and (b) is Au.

FIG. 14 shows modified carbon black-supported nickel-gold bimetallic nanocatalyst (HCB-Ni) in example 3 of the present invention₍₆₎-Au₍₁₎) Ultraviolet spectrograms of different nitroaromatic substances under different reaction times.

FIG. 15 shows modified carbon black supported Ni-Au bimetallic nanocatalyst (HCB-Ni) in example 3 of the present invention₍₆₎-Au₍₁₎) And (3) corresponding kinetic constant graphs when different nitroaromatic substances are degraded.

FIG. 16 is a graph comparing the kinetic constants for the decomposition of 4-nitrophenol (4-NP) at different initial pH for the modified carbon black supported nickel-gold bimetallic nanocatalyst of example 4 of the present invention.

FIG. 17 is a graph showing the comparison of the kinetic constants of the modified carbon black loaded Ni-Au bimetallic nanocatalyst of the present invention for degrading 4-nitrophenol (4-NP) in different water bodies in example 5.

Detailed Description

The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention.

In the examples of the present invention, the raw materials and instruments used were all commercially available. If not stated otherwise, the process adopted is a conventional process, the equipment adopted is conventional equipment, and the obtained data are average values of more than three repeated experiments.