阅读说明：本技术 一种氯氧化铋碳基复合材料的原位合成方法及其应用 (In-situ synthesis method and application of bismuth oxychloride carbon-based composite material ) 是由 兰东辉 李代光 易兵 沈静 邓人杰 陈镇 伍水生 区泽堂 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种氯氧化铋碳基复合材料的原位合成方法,包括如下步骤：(1)将铋源溶于醇溶液后加入碳材料超声分散,得分散液A；(2)将维生素B1盐酸盐溶于水中,随后在搅拌下滴加至分散液A中,反应后洗涤、干燥即得氯氧化铋碳基复合材料。本发明的制备过程避免使用酸、碱以及表面活性剂,通过简单的液相合成方法即能得到均一的花瓣状结构的氯氧化铋碳基复合材料,在可见光条件下,可高效催化染料和易挥发有机污染物(VOCs)降解,且复合材料多次循环使用后活性几乎不变。(The invention discloses an in-situ synthesis method of a bismuth oxychloride carbon-based composite material, which comprises the following steps: (1) dissolving a bismuth source in an alcohol solution, adding a carbon material, and performing ultrasonic dispersion to obtain a dispersion liquid A; (2) dissolving vitamin B1 hydrochloride in water, then dropwise adding the solution into the dispersion liquid A under stirring, washing and drying after reaction to obtain the bismuth oxychloride carbon-based composite material. According to the preparation method, acid, alkali and surfactant are avoided, the uniform petal-shaped bismuth oxychloride carbon-based composite material can be obtained by a simple liquid phase synthesis method, the dye and volatile organic pollutants (VOCs) can be efficiently catalyzed to degrade under the condition of visible light, and the activity of the composite material is almost unchanged after the composite material is recycled for many times.)

1. An in-situ synthesis method of a bismuth oxychloride carbon-based composite material is characterized by comprising the following steps:

(1) dissolving a bismuth source in an alcohol solution, adding a carbon material, and performing ultrasonic dispersion to obtain a dispersion liquid A;

(2) dissolving vitamin B1 hydrochloride in water, then dropwise adding the solution into the dispersion liquid A under stirring, washing and drying after reaction to obtain the bismuth oxychloride carbon-based composite material.

2. The in-situ synthesis method of the bismuth oxychloride carbon-based composite material according to claim 1, characterized in that: in the step (1), the bismuth source is selected from one of bismuth nitrate pentahydrate and bismuth chloride, and the concentration of the bismuth source is 10-40 g/L.

3. The in-situ synthesis method of the bismuth oxychloride carbon-based composite material according to claim 1, characterized in that: in the step (1), the alcohol solution is a mixed solution of alcohol and water, and the volume ratio of the alcohol to the water is 0.5-4: 1; the alcohol is selected from one of methanol, ethanol, isopropanol, ethylene glycol and glycerol.

4. The in-situ synthesis method of the bismuth oxychloride carbon-based composite material according to claim 1, characterized in that: in the step (1), the carbon material is selected from one of graphene, graphene oxide, carbon nanotubes and carbon trinitrogen, and the mass ratio of the bismuth source to the carbon material is 10-100: 1.

5. the in-situ synthesis method of the bismuth oxychloride carbon-based composite material according to claim 1, characterized in that: in the step (2), the molar ratio of the vitamin B1 hydrochloride to the bismuth source is 0.5-5: 1.

6. the in-situ synthesis method of the bismuth oxychloride carbon-based composite material according to claim 1, characterized in that: in the step (2), the concentration of the vitamin B1 hydrochloride is 0.05-0.5 mol/L.

7. The in-situ synthesis method of the bismuth oxychloride carbon-based composite material according to claim 1, characterized in that: in the step (2), the reaction temperature is room temperature, and the reaction time is 1-6 h.

8. The use of the bismuth oxychloride carbon-based composite material obtained by the in-situ synthesis method according to any one of claims 1 to 7, wherein: the photocatalyst is used for degrading dyes or VOCs under visible light;

the method comprises the following specific steps: adding the bismuth oxychloride carbon-based composite material into water with dye concentration of 15-150mg/L or gas with VOCs concentration of 10-100mg/L at room temperature, and reacting for 0.1-12 h.

9. Use of a bismuth oxychloride carbon-based composite material according to claim 8, wherein: the dye is selected from one or more of methyl orange, rhodamine B and methylene blue, and the mass ratio of the bismuth oxychloride carbon-based composite material to the dye is 1: 0.01-0.5.

10. Use of a bismuth oxychloride carbon-based composite material according to claim 8, wherein: the VOCs are selected from one or more of formaldehyde, toluene, benzene and xylene, and the mass ratio of the bismuth oxychloride carbon-based composite material to the VOCs is 1: 0.005-0.1.

Technical Field

The invention belongs to the technical field of bismuth oxychloride preparation, and particularly relates to an in-situ synthesis method of a bismuth oxychloride carbon-based composite material and application of the bismuth oxychloride carbon-based composite material in visible light catalytic dye and volatile organic matter degradation.

Background

The visible light catalysis technology can directly convert solar energy into chemical energy or electric energy through a semiconductor photocatalysis material, can realize complete mineralization and degradation of toxic and harmful organic pollutants in the environment, is a low-cost green common technology, and has application prospects in the directions of environmental management, solar energy conversion, self-cleaning and the like. The key of the visible light catalysis technology is the development of high-efficiency and stable semiconductor catalysts. The BiOCl material has a layered structure and a smaller band gap width (<2.62eV), is easy to regulate and control energy band, shows good photocatalytic activity and stability, and is one of hot spots of research in the field of photocatalysis. Researchers often compound BiOCl with other materials to improve their visible photocatalytic performance.

At present, BiOCl composite materials are synthesized by preparing BiOCl by a hydrolysis method, a hydrothermal (solvent) method, an alcoholic thermal method, a sol-gel method, a soft template method, a low-temperature chemical vapor method, a high-temperature solid phase method, a reverse microemulsion method and the like, and then compounding the BiOCl with other materials, wherein the synthesis process is complex, and acid or alkali and a surfactant are generally required to be added.

The hydrolysis method is to dissociate hydrogen ions from water or solvent and react hydroxyl ions with ions dissociated from salt to generate weak electrolyte molecules, and precipitate BiOCl particles by changing reaction conditions such as acidity or alkalinity, etc., usually adjusting the pH of the solution with hydrochloric acid, and employing Bi (NO) as a carrier₃)₃、BiCl₃And Bi₂O₃The BiOCl prepared by the method is simple to operate and short in reaction time, but acid is needed, the dispersibility is poor, and uniform micro-nano BiOCl materials are difficult to form.

The solvent thermal method is that in a closed container such as a high-pressure reaction kettle, under the condition of changing reaction temperature and pressure, the dissolubility and the reaction activity of the reaction are improved, the chemical reaction is promoted to be carried out, and substances which are difficult to react at normal temperature and normal pressure can be reacted.

The alcohol thermal method is generally to add bismuth nitrate or bismuth chloride into alcohol solvents such as ethanol and ethylene glycol, and obtain BiOCl samples through subsequent procedures such as ultrasonic or hydrothermal technology, cooling, washing, grinding and the like.

The sol-gel method generally comprises the steps of uniformly stirring bismuth metal alkoxide in an organic solution to dissolve bismuth metal alkoxide to form a precursor, carrying out hydrolysis and condensation compound reaction to form a transparent sol system with stable dispersion in the solution, then reacting the transparent sol system in a solvent losing fluidity, slowly polymerizing the sol in colloidal particles to further form gel with a three-dimensional network structure, and drying, sintering and curing to prepare the nano-structure material.

Disclosure of Invention

In order to solve the problems existing in the synthesis process of the existing BiOCl composite material, the invention aims to provide the in-situ synthesis method of the bismuth oxychloride carbon-based composite material, which has the advantages of mild conditions, simple process, environmental protection, and the like.

The invention also aims to provide the application of the bismuth oxychloride carbon-based composite material, which can efficiently catalyze the degradation of dyes and volatile organic pollutants (VOCs) under the condition of visible light, and the activity of the composite material is almost unchanged after the composite material is recycled for many times.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

an in-situ synthesis method of a bismuth oxychloride carbon-based composite material comprises the following steps:

(1) dissolving a bismuth source in an alcohol solution, adding a carbon material, and performing ultrasonic dispersion to obtain a dispersion liquid A;

(2) dissolving vitamin B1 hydrochloride in water, then dropwise adding the solution into the dispersion liquid A under stirring, washing and drying after reaction to obtain the bismuth oxychloride carbon-based composite material.

Preferably, in the step (1), the bismuth source is selected from one of bismuth nitrate pentahydrate and bismuth chloride, and the concentration of the bismuth source is 10-40 g/L.

Preferably, in the step (1), the alcohol solution is a mixed solution of alcohol and water, and the volume ratio of the alcohol to the water is 0.5-4: 1; the alcohol is selected from one of methanol, ethanol, isopropanol, ethylene glycol and glycerol.

Preferably, in the step (1), the carbon material is selected from one of graphene, graphene oxide, carbon nanotubes and carbon triazo, and the mass ratio of the bismuth source to the carbon material is 10-100: 1.

preferably, in the step (2), the molar ratio of the vitamin B1 hydrochloride to the bismuth source is 0.5-5: 1.

preferably, in the step (2), the concentration of the vitamin B1 hydrochloride is 0.05-0.5 mol/L.

Preferably, in the step (2), the reaction temperature is room temperature, and the reaction time is 1-6 h.

The invention also provides an application of the prepared bismuth oxychloride carbon-based composite material, which is used as a photocatalyst for degrading dyes or VOCs under visible light, and comprises the following specific steps: adding the bismuth oxychloride carbon-based composite material into water with dye concentration of 15-150mg/L or gas with VOCs concentration of 10-100mg/L at room temperature, and reacting for 0.1-12 h.

Preferably, the dye is selected from one or more of methyl orange, rhodamine B and methylene blue, and the mass ratio of the bismuth oxychloride carbon-based composite material to the dye is 1: 0.01 to 0.5.

Preferably, the VOCs are selected from one or more of formaldehyde, toluene, benzene and xylene, and the mass ratio of the bismuth oxychloride carbon-based composite material to the VOCs is 1: 0.005-0.1.

Compared with the prior art, the invention has the technical effects that:

1. vitamin B in the invention₁The hydrochloride is used as a chlorine source and a surfactant, so that a uniform structure is formed, acid, alkali and the surfactant are avoided, the condition is mild, the process is simple, and the environment is protected.

2. The method adopts the in-situ preparation technology, and adds the carbon material before generating the bismuth oxychloride, so that the method is favorable for inhibiting the agglomeration of the carbon-based material and forming the composite material with a uniform petal-shaped structure.

3. According to the invention, the carbon-based material is compounded with the bismuth oxychloride, so that the method is favorable for improving the light absorption rate of the material, regulating and controlling the structure and catalytic performance of the material, and is favorable for accurately constructing the efficient visible light photocatalyst.

4. The bismuth oxychloride carbon-based composite material prepared by the invention has a nano size and a porous structure, can efficiently degrade dyes in water or VOCs in air under visible light, and can be recycled for multiple times.

Drawings

FIG. 1 is an XRD spectrum of the material prepared in example 1;

FIG. 2 is an SEM photograph of the material prepared in example 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

Weighing 1.2g of bismuth nitrate pentahydrate at room temperature, dissolving in 60mL of ethylene glycol solution, and then adding 30mg of graphene oxide for ultrasonic dispersion to obtain a dispersion liquid A; dissolving 1.6g of vitamin B1 hydrochloride in 20mL of water, slowly dropwise adding the solution into the dispersion A under stirring, placing the solution at room temperature, stirring for 2 hours, washing and drying to obtain the BiOCl @ GO composite material. As shown in fig. 1 and fig. 2, the structure of BiOCl is not changed by the addition of graphene oxide, and the BiOCl @ GO composite material has a uniform petal-like morphology.

Example 2

Weighing 1.2g of bismuth nitrate pentahydrate at room temperature, dissolving in 30mL of methanol solution, and adding 12mg of carbon nanotubes for ultrasonic dispersion to obtain a dispersion liquid A; mixing 3.7g vitamin B₁And dissolving hydrochloride in 50mL of water, slowly dropwise adding the hydrochloride into the dispersion liquid A under stirring, placing the dispersion liquid A at room temperature, stirring the dispersion liquid A for 1 hour, and washing and drying the dispersion liquid A to obtain the BiOCl @ CNTs composite material.

Example 3

1.2g of bismuth nitrate pentahydrate are weighed out at room temperature and dissolved in 120mL of glycerol solution, followed by addition of 120mg of C₃N₄Performing ultrasonic dispersion to obtain a dispersion liquid A; dissolving 0.74g of vitamin B1 hydrochloride in 50mL of water, slowly dropwise adding the solution into the dispersion liquid A under stirring, placing the solution at room temperature, stirring for 6 hours, washing and drying to obtain the BiOCl @ C₃N₄A composite material.

Comparative example 1

Weighing 1.2g of bismuth nitrate pentahydrate at room temperature, and dissolving in 60mL of glycol solution to obtain a dispersion A; mixing 1.6g vitamin B₁And dissolving the hydrochloride in 20mL of water, slowly dropwise adding the solution into the dispersion liquid A under stirring, reacting at room temperature for 2 hours, and washing and drying to obtain the BiOCl.

Comparative example 2

At room temperature, 1.2g of nitric acid pentahydrate are weighedDissolving bismuth in 60mL of glycol solution to obtain a dispersion A; mixing 1.6g vitamin B₁Dissolving hydrochloride in 20mL of water, slowly dropwise adding the hydrochloride into the dispersion liquid A under stirring, reacting at room temperature for 2 hours, and washing and drying to obtain the bismuth oxychloride; and weighing 30mg of graphene oxide, ultrasonically dispersing the graphene oxide in 60mL of water, adding the prepared bismuth oxychloride, stirring for 2 hours, washing and drying to obtain the BiOCl @ GO composite material.

Comparative example 3

Weighing 1.2g of bismuth nitrate pentahydrate and 0.1g of lysine, dissolving in 5mL of hydrochloric acid (the concentration is 36.5%), adding 20mL of deionized water, stirring rapidly while generating a white precipitate, adjusting the pH value to 9 by using 5 wt.% of ammonia water solution, stirring continuously for 10min, and washing and drying the obtained precipitate to obtain the BiOCl.

(1) Degradation of dye:

at room temperature, respectively adding 30mg of the materials prepared in examples 1-3 and comparative examples 1-3 into 30mL of 45mg/L rhodamine B aqueous solution, carrying out dark ultrasonic dispersion for 15min, carrying out dark reaction for 30min, turning on a 300W xenon lamp light source, carrying out reaction for 30min, filtering to remove the catalyst, detecting the residual concentration, and calculating the degradation rate as shown in Table 1:

TABLE 1 rhodamine B degradation Rate data sheet

TABLE 2 example 1 BiOCl @ GO photocatalytic initial concentration of 45mg/L rhodamine B degradation cycle performance

	Circulating for 1 time	Circulating for 2 times	Circulating for 3 times	Circulating for 4 times	Circulating for 5 times
						Degradation Rate (%)	99.1	99.0	98.7	98.8	98.5

Note: after the single use, the product is filtered, washed and dried for repeated use.

(2) And (3) degrading VOCs:

100mg of each of the materials prepared in examples 1 to 3 and comparative examples 1 to 3 was added to 250mL of 30mg/L formaldehyde gas at room temperature, a 300W xenon lamp was turned on, and after 6 hours of reaction, the residual concentration was measured by sampling with a gas sampler, and the degradation rate was calculated as shown in Table 3:

TABLE 3 Formaldehyde degradation Rate data Table

TABLE 4 example 1 BiOCl @ GO photocatalytic initial concentration of 30mg/L formaldehyde gas degradation cycling performance

	Circulating for 1 time	Circulating for 2 times	Circulating for 3 times	Circulating for 4 times	Circulating for 5 times
						Degradation Rate (%)	98.5	98.3	98.3	98.2	98.0

Note: after the single use, the product can be directly reused.