阅读说明：本技术 一种由碳氮基光催化剂包覆的活性炭复合材料的制备方法 (Preparation method of activated carbon composite material coated by carbon-nitrogen-based photocatalyst ) 是由 余岩 严佳雯 胡邦炯 余梦丹 葛北骁 徐辰仪 杨焘键 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种由碳氮基光催化剂包覆的活性炭复合材料的制备方法,包括：1)CTF的制备；2)g-C-(3)N-(4)/CTF的制备；3)碳氮基光催化剂包覆活性炭的制备：取活性炭于水中吸水饱和；取聚乙烯醇于热水中加热溶解,冷却后稀释得2%的聚乙烯醇溶液；将饱和后的活性炭倒入2%的聚乙烯醇溶液中,加入g-C-(3)N-(4)/CTF光催化剂,得混合料；混合料于烘箱加热,得包覆g-C-(3)N-(4)/CTF薄膜的活性炭复合材料。本发明方法基于价廉易得的活性炭吸附剂与碳氮基光催化材料构建吸附-光催化双功能的复合材料,在提高饮用水中抗生素的去除效率的同时解决了活性炭再生成本高的问题,实现饮用水中低浓度抗生素彻底、高效、低能耗的去除。(The invention discloses a preparation method of an activated carbon composite material coated by a carbon-nitrogen-based photocatalyst, which comprises the following steps: 1) preparing CTF; 2) g-C 3 N 4 Preparation of/CTF; 3) carbon-nitrogen base photocatalyst coated active carbonThe preparation of (1): taking activated carbon to absorb water in water to saturate; heating polyvinyl alcohol in hot water for dissolving, cooling and diluting to obtain 2% polyvinyl alcohol solution; pouring the saturated activated carbon into 2% polyvinyl alcohol solution, adding g-C 3 N 4 the/CTF photocatalyst is used for obtaining a mixture; heating the mixture in a drying oven to obtain coated g-C 3 N 4 An activated carbon composite material of a/CTF film. The method of the invention constructs the adsorption-photocatalysis composite material based on the cheap and easily available active carbon adsorbent and the carbon-nitrogen-based photocatalysis material, improves the removal efficiency of the antibiotics in the drinking water, solves the problem of high regeneration cost of the active carbon, and realizes the thorough, efficient and low-energy consumption removal of the low-concentration antibiotics in the drinking water.)

1. A preparation method of an activated carbon composite material coated by a carbon-nitrogen-based photocatalyst is characterized by comprising the following steps:

1) preparation of CTF: weighing a proper amount of 1, 4-dicyanobenzene, placing the mixture into 25ml of trifluoromethanesulfonic acid, mixing, stirring for 1.5h at the temperature of 0 ℃, placing the mixture into a 100 ℃ oven for 20min, taking out, cooling to room temperature, carrying out centrifugal washing for a plurality of times by using ethanol, placing the mixture into a 60 ℃ oven for drying, adding a sodium hydroxide solution after drying, soaking for 5h in the 60 ℃ oven, and drying in the 60 ℃ oven after centrifugal washing to obtain CTF for later use;

2）g-C₃N₄preparation of/CTF: weighing proper amount of CTF and g-C₃N₄Putting the mixture into a 250mL beaker, adding ethanol, carrying out ultrasonic treatment for 2h, carrying out magnetic stirring at the constant temperature of 50 ℃ for 2h, and putting the centrifuged solid product into a vacuum drying oven for drying at the constant temperature overnight; taking out, placing into a vacuum/atmosphere tubular electric furnace, heating from 30 deg.C to 200 deg.C at a certain heating rate, maintaining for 120min, and cooling to room temperature at a certain cooling rate to obtain g-C₃N₄the/CTF photocatalyst is ground into powder for standby;

3) preparing carbon-nitrogen photocatalyst coated active carbon:

a) putting the activated carbon in water, stirring and absorbing water until the activated carbon is saturated to obtain saturated activated carbon for later use;

b) heating a certain amount of polyvinyl alcohol in hot water at 95 ℃ for dissolving, cooling to room temperature, and diluting to a concentration of 2% to obtain a 2% polyvinyl alcohol solution;

c) pouring the saturated activated carbon prepared in the step a) into the 2% polyvinyl alcohol solution prepared in the step b), and then adding g-C prepared in the step 2)₃N₄the/CTF photocatalyst is mixed and stirred for 10min to obtain a mixture;

d) placing the mixture obtained in the step C) in an oven at 180 ℃ for heating for 10h to obtain the coating g-C₃N₄An activated carbon composite material of a/CTF film.

2. The method for preparing an activated carbon composite coated with a carbon-nitrogen-based photocatalyst as claimed in claim 1, wherein the amount of 1, 4-dicyanobenzene added in step 1) is 0.5 to 0.6g, the concentration of the sodium hydroxide solution is 0.5mol/L, and the amount added is 50 to 70 mL.

3. The method for preparing an activated carbon composite coated with a carbon-nitrogen-based photocatalyst as claimed in claim 1, wherein appropriate amounts of CTF and g-C in the step 2)₃N₄The weight ratio of the two is 1:1, and the ratio of the total weight of the two to the addition amount of ethanol is 1g:200 mL.

4. The method according to claim 1, wherein the step 2) of drying at a constant temperature comprises a temperature of 60 ℃, a temperature increasing rate of 4-5 ℃/min, and a temperature decreasing rate of 5 ℃/min.

5. The method for preparing an activated carbon composite coated with a carbon-nitrogen-based photocatalyst as claimed in claim 1, wherein the g/mL ratio of the polyvinyl alcohol to water in step b) in step 3) is 1: 10.

6. The method according to claim 1, wherein the ratio of g/mL of the activated carbon in step C) to 2% polyvinyl alcohol in the step 3) is 4:1, g-C₃N₄The feed-liquid ratio g/mL of the/CTF photocatalyst to the 2% polyvinyl alcohol solution is 1: 10.

Technical Field

The invention belongs to the technical field of composite material preparation, and particularly relates to a preparation method of an activated carbon composite material coated by a carbon-nitrogen-based photocatalyst.

Background

Human activities and industrial processes aggravate the pollution of underground water and surface water, and the conventional treatment process (coagulation/precipitation/filtration/disinfection) of water supply plants is difficult to ensure that the quality of effluent water reaches the standard when a micro-polluted water source is used as raw water for treatment. With the improvement of water quality analysis technology, the types of trace organic pollutants measured in source water and drinking water are gradually increased, and the substances are the general names of organic pollutants with trace concentration (ng/L or mug/L) widely existing in environmental water and mainly comprise endocrine disruptors, personal care products, medicines, other emerging compounds and the like. Antibiotics and metabolites thereof have potential toxicological risks to aquatic organisms, and damage energy transfer of aquatic food chains, thereby affecting health of high-nutrition organisms and aquatic ecosystem. Another survey also showed that multiple antibiotics were detected in urine samples from children and pregnant women, some of which have been clinically banned, and antibiotic exposure has been associated with obesity, precocious puberty, and the like in children. Antibiotics can not be completely metabolized after entering human bodies and animal bodies through ways of drinking water or edible aquatic products and the like, and the intestinal flora is unbalanced due to the abuse of the antibiotics, so that the immunity is gradually reduced. With the rapid development of economy, the requirements of people on the quality of drinking water are remarkably improved, and the water quality indexes in the sanitary standards for drinking water are gradually improved, so that an effective drinking water safety guarantee system needs to be established urgently.

At present, the technology mainly adopted by China in the aspect of civil drinking water quality safety guarantee comprises the following steps: active carbon adsorption filtration technology, membrane separation technology, water softening technology and the like. The adsorption effect of the activated carbon can effectively remove chlorine, organic matters, turbidity, chromaticity, odor and the like in water, but the treatment efficiency of the activated carbon on low-concentration organic matters such as antibiotics and the like is low. The membrane separation technology is divided into microfiltration, ultrafiltration, nanofiltration, reverse osmosis and the like, can remove most of substances harmful to human bodies in water, and also removes mineral substances in the water. However, medical studies have shown that pregnant women and infants are not suitable for drinking pure water for a long period of time. The water softening technology utilizes cation exchange resin to reduce the hardness of water and improve the water quality and taste of drinking water. Nowadays, the research of advanced treatment of drinking water focuses on not only removing harmful substances in water to human body, but also retaining minerals in water which are beneficial to human health. The nano material photocatalytic oxidation technology is a novel high-efficiency, energy-saving and environment-friendly advanced oxidation technology, is favored because of high reaction speed and high treatment efficiency, and can realize thorough mineralization of pollutants, and when micro-polluted organic matters in water are treated by photocatalysis, the slow reaction kinetics problem of the photocatalytic reaction is caused by the lower adsorption capacity of the traditional photocatalytic material. Therefore, in order to overcome the defect that the existing photocatalytic material is difficult to have both strong adsorption and photocatalytic performance, the construction of a novel composite material integrating high adsorption/photocatalytic double effects is one of the research directions with application potential. Designing a high adsorption/photocatalytic activity material for an antibiotic degradation system in drinking water is an opportunity and challenge coexistence work.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a preparation method of an activated carbon composite material coated by a carbon-nitrogen photocatalyst.

The invention is realized by the following technical scheme:

the preparation method of the activated carbon composite material coated by the carbon-nitrogen-based photocatalyst is characterized by comprising the following steps of:

1) preparation of CTF: weighing a proper amount of 1, 4-dicyanobenzene, placing the mixture into 25mL of trifluoromethanesulfonic acid, mixing, stirring for 1.5h at the environment of 0 ℃, placing the mixture into a 100 ℃ oven for 20min, taking out, cooling to room temperature, carrying out centrifugal washing for a plurality of times by using ethanol, placing the mixture into a 60 ℃ oven for drying, adding a sodium hydroxide solution after drying, soaking for 5h in the 60 ℃ oven, and drying in the 60 ℃ oven after centrifugal washing to obtain CTF for later use;

2）g-C₃N₄preparation of/CTF: weighing proper amount of CTF and g-C₃N₄Putting the mixture into a 250mL beaker, adding ethanol, carrying out ultrasonic treatment for 2h, carrying out magnetic stirring at the constant temperature of 50 ℃ for 2h, and putting the centrifuged solid product into a vacuum drying oven for drying at the constant temperature overnight; taking out, placing into a vacuum/atmosphere tubular electric furnace, heating from 30 deg.C to 200 deg.C at a certain heating rate, maintaining for 120min, and cooling to room temperature at a certain cooling rate to obtain g-C₃N₄the/CTF photocatalyst is ground into powder for standby;

3) preparing carbon-nitrogen photocatalyst coated active carbon:

a) putting the activated carbon in water, stirring and absorbing water until the activated carbon is saturated to obtain saturated activated carbon for later use;

b) heating a certain amount of polyvinyl alcohol in hot water at 95 ℃ for dissolving, cooling to room temperature, and diluting to a concentration of 2% to obtain a 2% polyvinyl alcohol solution;

c) pouring the saturated activated carbon prepared in the step a) into the 2% polyvinyl alcohol solution prepared in the step b), and then adding g-C prepared in the step 2)₃N₄the/CTF photocatalyst is mixed and stirred for 10min to obtain a mixture;

d) placing the mixture obtained in the step C) in an oven at 180 ℃ for heating for 10h to obtain the coating g-C₃N₄An activated carbon composite material of a/CTF film.

Further, in the step 1), the adding amount of the 1, 4-dicyanobenzene is 0.5-0.6g, the concentration of the sodium hydroxide solution is 0.5mol/L, and the adding amount is 50-70 mL.

Further, appropriate amounts of CTF and g-C in step 2)₃N₄The weight ratio of the two is 1:1, and the ratio of the total weight of the two to the addition amount of ethanol is 1g:200 mL.

Further, the constant temperature drying in the step 2) is carried out at 60 ℃, the certain heating rate is 4-5 ℃/min, and the certain cooling rate is 5 ℃/min.

Further, the feed-liquid ratio g/mL of the polyvinyl alcohol in the step b) in the step 3) to the water is 1: 10.

Further, the feed-liquid ratio g/mL of the activated carbon in the step C) to the 2% polyvinyl alcohol solution in the step 3) is 4:1, g-C₃N₄The feed-liquid ratio g/mL of the/CTF photocatalyst to the 2% polyvinyl alcohol solution is 1: 10.

The method of the invention constructs the adsorption-photocatalysis composite material based on the cheap and easily available active carbon adsorbent and the carbon-nitrogen-based photocatalysis material, which not only can improve the removal efficiency of antibiotics in drinking water, but also solves the problem of high regeneration cost of the active carbon, and realizes the thorough, efficient and low-energy consumption removal of low-concentration antibiotics in the drinking water.

Drawings

Fig. 1 is a graph showing the effect of the test example on the removal of ofloxacin.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The present invention will be described in further detail with reference to specific examples to better understand the technical solution.

Example 1

Preparation of CTF: 0.513 g of 1, 4-Dicyanobenzene (DCB) and 25mL of trifluoromethanesulfonic acid (TFMS) are respectively mixed, stirred for 1.5h at 0 ℃ and placed in an oven at 100 ℃ for 20 min. Cooling to room temperature, washing with ethanol for several times, and drying in an oven at 60 deg.C. Then adding 60mL of 0.5mol/L NaOH solution, soaking in a 60 ℃ oven for 5h, centrifugally washing, and drying in the 60 ℃ oven for later use.

Example 2

g-C₃N₄Preparation of/CTF: weighing proper amount of CTF and g-C₃N₄Putting the mixture into a 250mL beaker, adding 200mL of ethanol, carrying out ultrasonic treatment for 2h, then carrying out magnetic stirring at the constant temperature of 50 ℃ for 2h, and putting the centrifuged solid product into a vacuum drying oven for vacuum drying at the constant temperature of 60 ℃ overnight. Placing into a vacuum/atmosphere tubular electric furnace, heating to 200 deg.C at 4-5 deg.C/min from 30 deg.C, maintaining for 120min, and cooling to room temperature at 5 deg.C/min to obtain g-C₃N₄CTF, ground to powder for use.

Example 3

Preparing activated carbon coated with a carbon-nitrogen photocatalyst:

1) adding 20mL of water into 40g of activated carbon, and stirring for 10min to obtain saturated activated carbon;

2) heating 20g of polyethylene in 200mL of 95 ℃ water for dissolving, cooling to room temperature, and diluting to a concentration of 2%;

3) pouring the saturated activated carbon into 10mL of 2% polyvinyl alcohol solution, and adding 1g g-C₃N₄the/CTF photocatalyst is stirred for 10min to obtain a mixture;

4) placing the stirred mixture in an oven at 180 ℃ for heating for 10h to obtain the coating g-C₃N₄An activated carbon composite material of a/CTF film.

Test example: removal rate of antibiotic ofloxacin

The production and the active carbon prepared in the examples 1-3 are respectively used for removing the antibiotic norfloxacin in the reaction liquid, and the specific steps are as follows: simulating sunlight with xenon lamp as light source, and measuring reaction solution (100 mL, 5 mgL)^-1Norfloxacin) was poured into the reactor, 50mg of the photocatalyst was weighed, stirred in the dark for 30min, then the xenon lamp was turned on, 1ml of the solution was extracted each time at set time intervals, filtered and injected into a liquid phase vial, and the final removal effect is shown in fig. 1. CTF/C obtainable from FIG. 1₃N₄Activated carbon, CTF, g-C₃N₄The removal efficiency of norfloxacin after 180 minutes of photocatalytic reaction with activated carbon is 99.99%, 67.93%, 64.35% and 30.7% respectively.