阅读说明：本技术 一种改性活性炭复合材料的制备 (Preparation of modified activated carbon composite material ) 是由 苏春彦 贾苗静 訾曼莉 于 2021-10-08 设计创作，主要内容包括：本发明提供了一种改性活性炭复合材料的制备。制备步骤如下：1)将一定量的铁源和硫源先后溶解于去离子水中,搅拌充分溶解,再将含有一定量的抗坏血酸水溶液缓慢滴入其中,得前驱体溶液；2)将一定量活性炭粉末加入前驱体溶液中,充分搅拌,超声分散,得悬浊液；3)将悬浊液置于密封不锈钢高压反应釜中,然后将反应釜放入恒温烘箱中高温反应一定时间；4)将反应釜中的产物清洗干净,真空干燥,获得复合材料。本发明的显著特点：采用一步水热合成法,方法简单、成本低；活性炭粉末作为载体,使该复合材料易于稳定,有利于还原反应的进行,且易于回收重复利用。(The invention provides a preparation method of a modified activated carbon composite material. The preparation steps are as follows: 1) dissolving a certain amount of iron source and a certain amount of sulfur source in deionized water in sequence, stirring and fully dissolving, and slowly dripping a certain amount of ascorbic acid-containing water solution into the solution to obtain a precursor solution; 2) adding a certain amount of activated carbon powder into the precursor solution, fully stirring, and performing ultrasonic dispersion to obtain a suspension; 3) placing the suspension in a sealed stainless steel high-pressure reaction kettle, and then placing the reaction kettle in a constant-temperature oven for high-temperature reaction for a certain time; 4) and cleaning the product in the reaction kettle, and drying in vacuum to obtain the composite material. The invention has the remarkable characteristics that: a one-step hydrothermal synthesis method is adopted, so that the method is simple and low in cost; the active carbon powder is used as a carrier, so that the composite material is easy to stabilize, is beneficial to the reduction reaction and is easy to recycle.)

1. The preparation method of the modified activated carbon composite material is characterized in that ferrous disulfide is used as a reduction active component, activated carbon powder is used as a carrier material, and the ferrous disulfide is stably dispersed on the activated carbon powder, and the preparation method comprises the following steps:

1) dissolving a certain amount of iron source and sulfur source in 40 mL of deionized water in sequence, and stirring by magnetic force to fully dissolve the iron source and the sulfur source;

2) dissolving a certain amount of ascorbic acid in 10 mL of deionized water, and slowly dripping the ascorbic acid into the mixed solution obtained in the step 1) after magnetic stirring to obtain a precursor solution;

3) adding a certain amount of activated carbon powder into the precursor solution obtained in the step 2), fully stirring, and uniformly dispersing in ultrasonic waves to obtain a suspension;

4) placing the suspension obtained in the step 3) into a reaction kettle, and reacting for a certain time at a certain temperature;

5) and (3) naturally cooling the reaction kettle in the step 4) to room temperature, taking out a reaction product in the kettle, sequentially washing the reaction product with absolute ethyl alcohol and deionized water for 3 times, and carrying out vacuum drying at 60 ℃ for 10 hours to obtain the ferrous disulfide modified activated carbon material.

2. The method of claim 1, wherein: in the step 1), the iron source is ferric trichloride hexahydrate, ferric nitrate nonahydrate or ferric sulfate nonahydrate, and the amount of the substance is 1-3 mmol.

3. The method of claim 1, wherein: in the step 1), the sulfur source is L-cysteine, thiourea or thioacetamide.

4. The method of claim 1, wherein: the ratio of the amounts of the sulfur source and the iron source in the step 1) is (0.9-3): 1.

5. the method of claim 1, wherein: the quantity ratio of the ascorbic acid in the step 2) to the iron source in the step 1) is (0.1-2): 1.

6. the method of claim 1, wherein: the mass of the activated carbon powder in the step 3) is 0.3-0.5 g.

7. The method of claim 1, wherein: the reaction temperature of the reaction kettle in the step 4) is 160-200 ℃, and the heating reaction time is 8-15 h.

Technical Field

The invention relates to preparation of a modified activated carbon composite material, and belongs to the technical field of water treatment.

Background

With the rapid development of economic society, the problem of treating and removing heavy metal pollution in wastewater is not easy. Hexavalent chromium in wastewater has high toxicity and strong carcinogenicity, and is easy to dissolve and migrate, so that the environmental safety of soil and underground water and the health of human bodies are threatened, and therefore, the wastewater needs to be detoxified urgently. Trivalent chromium is less toxic in most environmental systems, unlike hexavalent chromium, and thus, chemical reduction methods are often used to treat hexavalent chromium in wastewater. The iron-sulfur compound is considered to be a high-efficiency hexavalent chromium reducing agent, and on one hand, low-valence sulfur shows strong electron donating capability; on the other hand, iron can form stable coprecipitation with chromium, and meanwhile, reduction of hexavalent chromium by sulfur can be promoted. Ferrous disulfide is a common transition metal sulfide, exists in the form of pyrite in nature, has good environmental compatibility, abundant reserves, higher stability and excellent reducibility, and has wide application prospects in the fields of reduction, photocatalysis, lithium ion battery electrode materials and the like. However, ferrous disulfide particles tend to agglomerate during synthesis or storage to form crystals of larger particles, resulting in a decrease in specific surface area and dispersibility, and thus a decrease in activity. Therefore, by loading a proper carrier, the high-dispersity ferrous disulfide crystals are prepared, and the performance of the original material is improved. The activated carbon is a carbon with a special microcrystalline structure, and has a series of advantages: the catalyst has the advantages of low price, acid and alkali resistance, stable property, developed pore structure, huge specific surface area and excellent electron transmission capacity, so that the activated carbon is widely applied as a catalyst carrier.

Ferrous disulfide has better reducibility, and the activated carbon powder is used as a carrier, thereby being beneficial to the stability and dispersion of nano particles, increasing active sites for reaction, being beneficial to the implementation of redox reaction and being easy to recycle. In a word, the ferrous disulfide is loaded on the activated carbon powder, so that the redox performance and the reusability are improved.

Disclosure of Invention

The invention aims to provide a preparation method of a reducing composite material, which solves the problems of high cost, difficult reutilization and low degradation efficiency of deep purification of heavy metal pollutants in the existing wastewater. The composite material adopts a one-step hydrothermal synthesis method, and has the advantages of simple preparation method, low cost, higher removal effect and reusability.

The preparation method of the composite reducing material is characterized by comprising the following steps of:

1) dissolving a certain amount of iron source and sulfur source in 40 mL of deionized water in sequence, and stirring by magnetic force to fully dissolve the iron source and the sulfur source;

2) dissolving a certain amount of ascorbic acid in 10 mL of deionized water, and slowly dripping the ascorbic acid into the mixed solution obtained in the step 1) after magnetic stirring to obtain a precursor solution;

3) adding a certain amount of activated carbon powder into the precursor solution obtained in the step 2), fully stirring, and uniformly dispersing in ultrasonic waves to obtain a suspension;

4) placing the suspension obtained in the step 3) into a reaction kettle, and reacting for a certain time at a certain temperature;

5) and (3) naturally cooling the reaction kettle in the step 4) to room temperature, taking out a reaction product in the kettle, sequentially washing the reaction product with absolute ethyl alcohol and deionized water for 3 times, and carrying out vacuum drying at 60 ℃ for 10 hours to obtain the ferrous disulfide modified activated carbon material.

According to the scheme, the iron source is ferric chloride hexahydrate, ferric nitrate nonahydrate or ferric sulfate nonahydrate, and the amount of substances is 1-3 mmol.

According to the scheme, the sulfur source is L-cysteine, thiourea or thioacetamide.

According to the scheme, the ratio of the sulfur source to the iron source is (0.9-3): 1.

according to the scheme, the ratio of the ascorbic acid to the iron source substance is (0.1-2): 1.

according to the scheme, the mass of the activated carbon powder is 0.3-0.5 g.

According to the scheme, the reaction temperature of the reaction kettle is 160-200 ℃, and the heating reaction time is 8-15 hours.

The working principle of the invention is as follows: the novel stable reducing material is obtained by taking activated carbon powder as a carrier and loading and reducing ferrous disulfide serving as an active component, and the activated carbon is favorable for the stability and dispersion of nano particles, is favorable for the oxidation-reduction reaction and is easy to recycle.

The invention has the following beneficial effects:

the invention is synthesized by a one-step hydrothermal synthesis method, has simple operation, cheap and easily obtained raw materials and low cost, and the prepared material has better reduction performance and can be recycled. Has wide application prospect in the fields of environmental protection and material chemistry.

Drawings

FIG. 1 is a Scanning Electron Microscope (SEM) image and an X-ray energy spectrum analysis (EDS) image of a ferrous disulfide-modified activated carbon material prepared in example 1;

FIG. 2 is an X-ray powder diffraction (XRD) pattern of the ferrous disulfide modified activated carbon material prepared in example 1;

FIG. 3 is an X-ray photoelectron spectroscopy (XPS) spectrum of the ferrous disulfide-modified activated carbon material prepared in example 1;

FIG. 4 shows a ferrous disulfide modified activated carbon material (denoted as CL-FeS) prepared in example 1₂) And the hexavalent chromium removing efficiency of the activated carbon powder is changed along with the change of the reaction time.

Detailed Description

The technical solution of the present invention is not limited to the following specific embodiments, but includes any combination of the specific embodiments.

Example 1:

1) dissolving 1 mmol ferric chloride hexahydrate and 1.1 mmol L-cysteine in 40 mL deionized water successively, and magnetically stirring for 1 h to make them fully dissolved;

2) dissolving 0.1 mmol of ascorbic acid in 10 mL of deionized water, slowly dripping the ascorbic acid into the mixed solution obtained in the step 1) after magnetic stirring to obtain a precursor solution;

3) adding 0.5g of activated carbon powder into the precursor solution obtained in the step 2), fully stirring, and uniformly dispersing in ultrasonic waves to obtain a suspension;

4) placing the suspension liquid obtained in the step 3) in a reaction kettle, and heating for 10 hours at 180 ℃;

5) and (3) naturally cooling the reaction kettle in the step 4) to room temperature, taking out a reaction product in the kettle, sequentially washing the reaction product with absolute ethyl alcohol and deionized water for 3 times, and carrying out vacuum drying at 60 ℃ for 10 hours to obtain the ferrous disulfide modified activated carbon material.

Example 2:

this example differs from example 1 in that: adding 1 mmol of ferric nitrate nonahydrate into the step 1). The rest is the same as in embodiment 1.

Example 3:

this example differs from example 1 in that: 2 mmol of ascorbic acid were added in step 2). The rest is the same as in embodiment 1.

Example 4:

this example differs from example 1 in that: 3mmol of L-cysteine was added in step 1). The rest is the same as in embodiment 1.

Example 5:

this example differs from example 1 in that: 1 mmol of thioacetamide was added in step 1). The rest is the same as in embodiment 1.

Example 6:

this example differs from example 1 in that: 1 mmol of thiourea was added in step 1). The rest is the same as in embodiment 1.

Example 7:

this example differs from example 1 in that: the reaction temperature of the reaction kettle in the step 3) is 170 ℃, and the heating reaction time is 13 h. The rest is the same as in embodiment 1.

Example 8:

this example differs from example 1 in that: adding 0.9 mmol of L-cysteine into the step 1); step 2) 1.5 mmol of ascorbic acid were added. The rest is the same as in embodiment 1.

Example 9:

this example differs from example 1 in that: adding 2.5 mmol of thiourea into the step 1), and heating the reaction kettle in the step 3) at the reaction temperature of 160 ℃ for 15 h. The rest is the same as in embodiment 1.

Example 10:

this example differs from example 1 in that: adding 1.5 mmol of L-cysteine into the step 1); adding 2 mmol of ascorbic acid in the step 2); the reaction temperature of the reaction kettle in the step 3) is 200 ℃, and the heating reaction time is 10 h. The rest is the same as in embodiment 1.