阅读说明：本技术 用于去除废水中四环素的三元复合催化材料及其制备方法 (Ternary composite catalytic material for removing tetracycline in wastewater and preparation method thereof ) 是由 李育珍 霍浩浩 夏云生 石建惠 谭思洋 于 2021-09-24 设计创作，主要内容包括：本发明公开了一种用于去除废水中四环素的三元复合催化材料及其制备方法,包括：(1)制备g-C-(3)N-(4)；(2)制备Bi-(12)O-(15)Cl-(6)；(3)制备Bi-(12)O-(15)Cl-(6)/g-C-(3)N-(4)二元复合材料；(4)制备AgCl/Bi-(12)O-(15)Cl-(6)/g-C-(3)N-(4)三元复合催化材料。制备的三元复合催化材料可用于可见光条件下对四环素的降解。本发明通过湿式浸渍法合成了三元光催化剂,具有操作方法简单,易实施的特点。通过将AgCl和Bi-(12)O-(15)Cl-(6)掺杂到g-C-(3)N-(4)上,有效地提高g-C-(3)N-(4)对可见光的利用率,促进了其光生载流子的分离效率,进而提高其可见光催化效率；此工艺流程简单,便于操作,在污水治理方面有很大的应用前景。(The invention discloses a ternary composite catalytic material for removing tetracycline in wastewater and a preparation method thereof, wherein the preparation method comprises the following steps: (1) preparation of g-C 3 N 4 (ii) a (2) Preparation of Bi 12 O 15 Cl 6 (ii) a (3) Preparation of Bi 12 O 15 Cl 6 /g‑C 3 N 4 A binary composite material; (4) preparation of AgCl/Bi 12 O 15 Cl 6 /g‑C 3 N 4 Ternary elementA composite catalytic material. The prepared ternary composite catalytic material can be used for degrading tetracycline under the condition of visible light. The invention synthesizes the ternary photocatalyst by a wet impregnation method, and has the characteristics of simple operation method and easy implementation. By mixing AgCl and Bi 12 O 15 Cl 6 Doping to g-C 3 N 4 Effectively increase g-C 3 N 4 The separation efficiency of photon-generated carriers of the visible light is promoted by the utilization rate of the visible light, so that the visible light catalysis efficiency is improved; the process is simple, convenient to operate and has a great application prospect in the aspect of sewage treatment.)

1. A ternary composite catalytic material for removing tetracycline from waste water is characterized in that the composite material is AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄In the composite material Bi₁₂O₁₅Cl₆/g-C₃N₄The mass ratio of the AgCl to the water is 20: 1-10: 3; in the composite material, Bi₁₂O₁₅Cl₆And g-C₃N₄The mass ratio of (A) to (B) is 1: 2.

2. The three-way composite catalytic material for removing tetracycline from wastewater according to claim 1, wherein Bi is₁₂O₁₅Cl₆/g-C₃N₄The mass ratio of the catalyst to AgCl is 20: 3.

3. A method for preparing the three-way composite catalytic material for removing tetracycline from wastewater according to claim 1 or 2, characterized by comprising the steps of:

（1）g-C₃N₄the preparation of (1):

weighing 10-30 g of urea, placing the urea in an alumina crucible with a cover, heating the urea to 550 ℃ in an electric furnace at the speed of 5 ℃/min, and keeping the temperature for 4 hours; cooling to room temperature after the reaction is finished, grinding the obtained light yellow powder and collecting to obtain g-C₃N₄A sample;

（2）Bi₁₂O₁₅Cl₆the preparation of (1):

weigh 1 mmol of Bi (NO)₃)₃•5H₂O, dissolved to 10 mL under vigorous stirringForming a uniform solution A in ethylene glycol; simultaneously weigh 0.33 mmol of NH₄Cl, which is dissolved in 35 mL of distilled water to form a solution B; slowly adding the solution A into the solution B under vigorous stirring, and stirring for 1 h at room temperature; after stirring, transferring the mixture into an autoclave, and heating the mixture for 12 hours at 160 ℃; after the reaction is finished, cooling the high-pressure kettle to room temperature, washing the obtained precipitate with ethanol and distilled water for three times, and drying at 60 ℃ overnight; then, calcining the obtained white solid powder in an electric furnace at 400 ℃ for 5 h, wherein the heating rate is 2 ℃/min; after the reaction is finished, light yellow Bi is obtained₁₂O₁₅Cl₆Grinding and collecting the powder for later use, and marking the powder as BOCl;

（3）Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a binary composite material:

weigh 0.5g of g-C₃N₄Measuring 30mL of methanol in a 150 mL beaker, and performing ultrasonic treatment for 30 min; further weigh Bi in an amount of 0.25g₁₂O₁₅Cl₆Dissolving it in g-C₃N₄Continuing to perform ultrasonic treatment for 30 min in the solution; then continuously stirring in a fume hood for 24 hours; after evaporation of the methanol, the resulting product was collected and dried at 60 ℃ overnight to obtain Bi₁₂O₁₅Cl₆/g-C₃N₄Binary composite material marked as BOCl/CN;

（4）AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a ternary composite catalytic material:

weighing 0.5g of Bi prepared by the method₁₂O₁₅Cl₆/g-C₃N₄Dissolving the binary composite material into 30mL of deionized water, and then performing ultrasonic dispersion;

secondly, placing 0.17-0.85 mmol of chlorine source in the solution of the first step, and stirring at room temperature to obtain a suspension;

③ AgNO₃Dropwise adding the solution into the suspension obtained in the step II, and continuously stirring for 4-8 hours at room temperature; adding AgNO₃The molar quantity of the chlorine source is the same as that of the chlorine source in the step II;

collecting the precipitateCentrifuging and washing the substance for 3-6 times by using absolute ethyl alcohol and distilled water, wherein the centrifugal rotating speed is 8000-10000 r/min, the centrifugal time is 5-10 min, collecting a product, dispersing the product into a culture dish containing the absolute ethyl alcohol, and then placing the culture dish into an oven for drying to obtain AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The ternary composite catalytic material is marked as A/BOCl/CN.

4. The preparation method of the ternary composite catalytic material for removing tetracycline in wastewater according to claim 3, wherein Bi in step (4) and (r)₁₂O₁₅Cl₆/g-C₃N₄The ultrasonic time of the binary composite material at room temperature is 30-60 min.

5. The preparation method of the ternary composite catalytic material for removing tetracycline from wastewater according to claim 3, wherein the chlorine source in the step (4) and the step (II) is one of potassium chloride or sodium chloride; stirring for 30-60 min at room temperature.

6. Use of the ternary composite catalytic material of claim 1 or 2 in the removal of tetracycline from wastewater under visible light conditions.

7. Use according to claim 6, characterized in that: AgCl/Bi in photocatalytic degradation process₁₂O₁₅Cl₆/g-C₃N₄The dosage of the ternary composite catalytic material is 0.2-1.0 g/L of wastewater, and the concentration of tetracycline in the wastewater is 10-30 mg/L.

8. Use according to claim 7, characterized in that: 250 mL of tetracycline solution with the concentration of 20 mg/L is prepared, and then 0.05g of AgCl/Bi is weighed₁₂O₁₅Cl₆/g-C₃N₄Adding the ternary composite catalytic material into a tetracycline solution, carrying out ultrasonic treatment for 15 min under a dark condition to uniformly disperse the catalyst, and then carrying out magnetic stirring for 40 min to enable the solution to reach adsorption-desorption balance; then adopt and carryPerforming photocatalytic reaction with a 300W xenon lamp with a 420 nm filter as a visible light source, wherein the total time of the photocatalytic reaction is 80min, taking a sample every 20 min, performing secondary centrifugal separation on the obtained solution at 10000 rpm, centrifuging for 5 min each time, and filtering the supernatant with a 0.45-micrometer filter membrane; finally, testing the absorbance of the filtered clear liquid on an ultraviolet visible spectrophotometer; the absorbance of the filtrate was measured at a wavelength of 357 nm.

Technical Field

The invention relates to AgCl/Bi for removing tetracycline in wastewater₁₂O₁₅Cl₆/g-C₃N₄A ternary composite catalytic material and a preparation method thereof belong to the technical field of catalyst preparation and application.

Background

Technological progress and social development have promoted the rapid development of the pharmaceutical industry, but accompanying the rapid development of the pharmaceutical industry are the abuse of antibiotic drugs and the rapid increase of the discharge amount of pharmaceutical wastewater. In the face of the increasingly serious problem of medical wastewater pollution, the traditional treatment method is difficult to remove efficiently. In recent years, the photocatalytic technology is rapidly started due to the characteristics of environmental protection, no secondary pollution and the like. The photocatalytic reaction is an advanced oxidation technology taking a semiconductor photocatalyst as a core. In the photocatalytic reaction process, a photocatalyst plays an important role.

Graphite phase g-C₃N₄Is a mid-gap semiconductor (-2.7 eV) with good visible light response. The graphite phase carbon nitride has the characteristics of excellent thermal stability and chemical stability, no toxicity, low raw material price, easy preparation, good biocompatibility and the like. These characteristics indicate that g-C₃N₄Has great advantages in the field of environmental purification.

But in the photocatalytic process, g-C₃N₄It is difficult to exhibit high photocatalytic activity due to its inherent defects. First, g-C₃N₄The band gap is wider (2.7 eV), the sunlight utilization efficiency is limited, and the generated photon-generated carriers are generatedLess and ultimately has an effect on its photocatalytic activity. Second, due to the g-C prepared₃N₄The specific surface area is low, so the number of active sites of the photocatalyst in the photoreaction process is small, and the photocatalytic efficiency is influenced. Finally, due to the inherent defects of the structure, the recombination rate of photoinduced electron holes is high, and the inhibition effect is finally generated on the photocatalytic activity of the material. Therefore, it is necessary to search for how to reduce the recombination rate of photoelectron-hole pairs and improve the photocatalytic efficiency. The semiconductor and semiconductor heterojunction structure can promote the separation of photogenerated electrons and holes, thereby improving the photocatalytic performance of the semiconductor photocatalyst.

Disclosure of Invention

The invention aims to provide AgCl/Bi for removing tetracycline in wastewater₁₂O₁₅Cl₆/g-C₃N₄Ternary composite catalytic material and preparation method thereof, and application of Bi₁₂O₁₅Cl₆Co-modified with AgCl to form g-C₃N₄To improve its photocatalytic efficiency.

In the invention, Bi₁₂O₁₅Cl₆And g-C₃N₄In combination, g-C can be reduced by band matching₃N₄The forbidden band width of the crystal is increased, and g-C is improved₃N₄The response range to visible light is further enhanced₃N₄Photocatalytic activity of (a); however, Bi₁₂O₁₅Cl₆/g-C₃N₄The period of the binary catalyst for degrading pollutants is longer, which affects the large-scale application of the binary catalyst, so that AgCl is doped into Bi₁₂O₁₅Cl₆/g-C₃N₄In the above way, a double electron transfer mechanism is formed, and the recombination rate of photo-generated electrons and holes is further reduced, so that the catalytic activity of the catalyst is increased.

The invention provides AgCl/Bi prepared by a wet impregnation method₁₂O₁₅Cl₆/g-C₃N₄Composite material of Bi₁₂O₁₅Cl₆And g-C₃N₄In a mass ratio of 1:2, Bi₁₂O₁₅Cl₆/g-C₃N₄The mass ratio of the AgCl to the water is 20: 1-10: 3.

The invention provides the AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The preparation method of the ternary composite catalytic material comprises the following steps:

（1）g-C₃N₄the preparation of (1):

20 g of urea were weighed, placed in a covered alumina crucible, heated to 550 ℃ in an electric furnace at a rate of 5 ℃/min, and held for 4 h. Cooling to room temperature after the reaction is finished, grinding the obtained light yellow powder and collecting to obtain g-C₃N₄A sample;

（2）Bi₁₂O₁₅Cl₆the preparation of (1):

weigh 1 mmol of Bi (NO)₃)₃•5H₂O, which was dissolved in 10 mL of ethylene glycol with vigorous stirring to form a homogeneous solution A. Simultaneously weigh 0.33 mmol of NH₄Cl, dissolved in 35 mL of distilled water to form solution B. The solution A was slowly added to the solution B with vigorous stirring and stirred at room temperature for 1 h. After the stirring was completed, it was transferred to an autoclave and heated at 160 ℃ for 12 hours. After the reaction was completed, the autoclave was cooled to room temperature and the resulting precipitate was washed three times with ethanol and distilled water and dried at 60 ℃ overnight. Then, the obtained white solid powder was calcined in an electric furnace at 400 ℃ for 5 hours at a heating rate of 2 ℃/min. After the reaction is finished, light yellow Bi is obtained₁₂O₁₅Cl₆Grinding and collecting the powder for later use, and marking the powder as BOCl;

（3）Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a binary composite material:

weigh 0.5g of g-C₃N₄In a 150 mL beaker, 30mL of methanol was measured and sonicated for 30 min. Further weigh 0.25g of Bi₁₂O₁₅Cl₆Dissolving it in g-C₃N₄Continuing to perform ultrasonic treatment for 30 min. After which stirring was continued in a fume hood for 24 h. After evaporation of the methanol, the resulting product was collected and dried at 60 ℃ overnight to obtain Bi₁₂O₁₅Cl₆/g-C₃N₄Binary composite materialMaterial, marked as BOCl/CN;

（4）AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a ternary composite catalytic material:

weighing 0.5g of Bi prepared by the method₁₂O₁₅Cl₆/g-C₃N₄Dissolving the binary composite material into 30mL of deionized water, and then carrying out ultrasonic dispersion for 30-60 min;

secondly, placing 0.17-0.85 mmol of chlorine source in the solution, and then stirring for 30-60 min at room temperature to obtain suspension;

③ AgNO₃And (4) dropwise adding the solution into the suspension obtained in the step (II), and continuously stirring at room temperature for 4-8 hours. Adding AgNO₃The molar quantity of the chlorine source is the same as that of the chlorine source in the step II;

collecting the precipitate, centrifugally washing the precipitate for 3-6 times by using absolute ethyl alcohol and distilled water, wherein the centrifugal rotating speed is 8000-10000 r/min, the centrifugal time is 5-10 min, collecting the product, dispersing the product into a culture dish containing the absolute ethyl alcohol, and then placing the culture dish into an oven to obtain AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The ternary composite catalytic material is marked as A/BOCl/CN.

The AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The preparation method of the ternary composite catalytic material comprises the step (4) and the chlorine source is one of potassium chloride or sodium chloride.

The AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The preparation method of the ternary composite catalytic material comprises the step (4) and the step (II), wherein the ultrasonic dispersion time of the chlorine source in the ultrapure water is preferably 30 min.

The invention provides the AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The application of the ternary composite catalytic material in catalytic degradation of antibiotics in wastewater under the condition of visible light.

In the above application, the antibiotic is tetracycline; AgCl/Bi in photocatalytic degradation process₁₂O₁₅Cl₆/g-C₃N₄Adding of ternary composite catalytic materialThe amount of the tetracycline in the wastewater is 0.2-1.0 g/L, and the concentration of the tetracycline in the wastewater is 10-30 mg/L.

In the above application, 250 mL of tetracycline solution with a concentration of 20 mg/L was prepared, and then 0.05g of AgCl/Bi was weighed₁₂O₁₅Cl₆/g-C₃N₄Adding the ternary composite catalytic material into a tetracycline solution, performing ultrasonic treatment for 15 min under a dark condition to uniformly disperse the catalyst, and then performing magnetic stirring for 40 min under the dark condition to ensure that the solution achieves adsorption-desorption balance; then, a 300W xenon lamp with a 420 nm optical filter is used as a visible light source for carrying out photocatalytic reaction, the total time of the photocatalytic reaction is 80min, samples are taken every 20 min, supernatant liquid is taken after centrifugal separation to measure the absorbance, and the maximum absorption wavelength of tetracycline is 357 nm.

The invention has the beneficial effects that:

(1) the invention firstly utilizes a wet impregnation method to prepare AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The three-way catalyst has the advantages of simple and convenient preparation method, simple operation, cheap and easily obtained raw materials and the like

(2) AgCl/Bi prepared by the invention₁₂O₁₅Cl₆/g-C₃N₄The three-way catalyst is a photocatalyst with efficient photocatalytic performance under visible light. Using oxygen-enriched bismuth oxyhalide Bi₁₂O₁₅Cl₆And AgCl pair g-C capable of generating surface plasma resonance effect₃N₄Is modified to increase g-C₃N₄The adsorption capacity and the separation efficiency of the photo-generated electron hole pairs under the irradiation of visible light, and further the photocatalytic performance of the photo-generated electron hole pairs is improved.

(3) The novel AgCl/Bi prepared by the invention₁₂O₁₅Cl₆/g-C₃N₄The three-way catalyst has better photocatalytic performance and adsorption capacity than g-C₃N₄The method is improved, and the prepared photocatalyst shows higher stability.

(4) Using the prepared novel AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄Three-way catalyst for degrading tetracycline under irradiation of lightAnd after 80min, the degradation effect of more than 75.4 percent can be achieved, and excellent photocatalytic performance is shown.

Drawings

FIG. 1 is a graph of g-C prepared in example 1 of the present invention₃N₄、Bi₁₂O₁₅Cl₆The X-ray diffraction patterns of the BOCl/CN and 15A/BOCl/CN ternary composite catalysts;

FIG. 2 is an SEM photograph of a 15A/BOCl/CN ternary composite catalyst prepared in example 1 of the present invention;

FIG. 3 is a graph of g-C prepared in example 1 of the present invention₃N₄、Bi₁₂O₁₅Cl₆Ultraviolet-visible diffuse reflection spectrograms of the BOCl/CN and 15A/BOCl/CN ternary composite catalysts;

FIG. 4 shows g-C prepared in example 1 of the present invention₃N₄、Bi₁₂O₁₅Cl₆Band gap diagrams of the BOCl/CN and 15A/BOCl/CN ternary composite catalysts;

FIG. 5 shows g-C prepared in example 1 of the present invention₃N₄、Bi₁₂O₁₅Cl₆And the degradation effect of the BOCl/CN and 15A/BOCl/CN ternary composite catalysts on 20 mg/L tetracycline is shown.

Detailed Description

The present invention is further illustrated by, but is not limited to, the following examples.

Example 1:

this example provides an AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The preparation method and the application of the ternary composite catalytic material are as follows:

（1）g-C₃N₄the preparation of (1):

20 g of urea were weighed, placed in a covered alumina crucible, heated to 550 ℃ in an electric furnace at a rate of 5 ℃/min, and held for 4 h. Cooling to room temperature after the reaction is finished, grinding the obtained light yellow powder and collecting to obtain g-C₃N₄A sample;

（2）Bi₁₂O₁₅Cl₆the preparation of (1):

weigh 1 mmol of Bi (NO)₃)₃•5H₂O, which was dissolved in 10 mL of ethylene glycol with vigorous stirring to form a homogeneous solution A. Simultaneously weigh 0.33 mmol of NH₄Cl, dissolved in 35 mL of distilled water to form solution B. The solution A was slowly added to the solution B with vigorous stirring and stirred at room temperature for 1 h. After the stirring was completed, it was transferred to an autoclave and heated at 160 ℃ for 12 hours. After the reaction was completed, the autoclave was cooled to room temperature and the resulting precipitate was washed three times with ethanol and distilled water and dried at 60 ℃ overnight. Then, the obtained white solid powder was calcined in an electric furnace at 400 ℃ for 5 hours at a heating rate of 2 ℃/min. After the reaction is finished, light yellow Bi is obtained₁₂O₁₅Cl₆Grinding and collecting the powder for later use, and marking the powder as BOCl;

（3）Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a binary composite material:

weigh 0.5g of g-C₃N₄In a 150 mL beaker, 30mL of methanol was measured and sonicated for 30 min. Further weigh 0.25g of Bi₁₂O₁₅Cl₆Dissolving it in g-C₃N₄Continuing to perform ultrasonic treatment for 30 min. After which stirring was continued in a fume hood for 24 h. After evaporation of the methanol, the resulting product was collected and dried at 60 ℃ overnight to obtain Bi₁₂O₁₅Cl₆/g-C₃N₄Binary composite material marked as BOCl/CN;

（4）AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a ternary composite catalytic material:

weighing 0.5g of Bi prepared by the method₁₂O₁₅Cl₆/g-C₃N₄Dissolving the binary composite material into 30mL of deionized water, and then carrying out ultrasonic dispersion for 30 min;

② placing 0.52 mmol potassium chloride in the solution, then continuing stirring for 30 min at room temperature to obtain suspension;

③ AgNO₃The solution was added drop by drop to the suspension from step 2 and stirring was continued at room temperature for 4 h. Adding AgNO₃Molar amount of (2) and chlorine in step (ii)The molar amount of the source is the same.

Collecting the precipitate, centrifugally washing the precipitate for 6 times by using absolute ethyl alcohol and distilled water, collecting the product, dispersing the product into a culture dish containing the absolute ethyl alcohol, placing the culture dish into an oven, and drying the culture dish at 60 ℃ for 12 hours to obtain 15% AgCl/Bi, wherein the centrifugal speed is 8000 r/min and the centrifugal time is 5 min₁₂O₁₅Cl₆/g-C₃N₄The ternary composite catalytic material is marked as 15A/BOCl/CN.

Three 250 mL tetracycline solutions with a concentration of 20 mg/L were prepared, and 0.05 g-C was added separately₃N₄BOCl/CN and 15A/BOCl/CN. The photocatalyst is uniformly dispersed by ultrasonic treatment for 15 min under the dark condition, and then the solution is stirred by magnetic force for 40 min under the dark condition to reach the adsorption-desorption balance; then, a 300W xenon lamp with a 420 nm optical filter is used as a visible light source for carrying out photocatalytic reaction, the total time of the photocatalytic reaction is 80min, samples are taken every 20 min, supernatant liquid is taken after centrifugal separation to measure the absorbance, and the maximum absorption wavelength of tetracycline is 357 nm. Then, the time (t) is used as an abscissa, and the concentration ratio of tetracycline at t is used as an ordinate to draw a curve, the degradation performance of the three-way catalyst is tested (see figure 5), and the degradation rate of the catalyst prepared by the method to tetracycline can reach 75.4% within 80 min.

FIG. 1 is an XRD pattern (a: g-C) of the sample prepared in example 1₃N₄, b: Bi₁₂O₁₅Cl₆And c: BOCl/CN and 15A/BOCl/CN). As can be seen from the figure, the sample was clearly observed to have good crystal phase growth and a strong and sharp diffraction peak. Monomers g to C₃N₄The diffraction peaks at 13.04 ° and 27.40 ° correspond to the (001) and (002) crystal planes, respectively, corresponding to the standard card JCPDS number 87-1526. In the ternary complex 15A/BOCl/CN, it can be seen that it is classified as g-C₃N₄、Bi₁₂O₁₅Cl₆And characteristic peaks of AgCl which respectively correspond to cards JCPDS number 87-1526, JCPDS No.70-0249 and JCPDS No.85-1355, and illustrate that Bi₁₂O₁₅Cl₆And AgCl was successfully loaded to g-C₃N₄The above.

FIG. 2 isSEM image of 15A/BOCl/CN ternary composite catalyst prepared in example 1, and it can be seen that Bi appears in a needle-leaf shape₁₂O₁₅Cl₆And AgCl in particulate form to g-C₃N₄And (4) nano-chips.

FIG. 3 is g-C prepared in example 1₃N₄、Bi₁₂O₁₅Cl₆The ultraviolet-visible diffuse reflection spectrogram of the BOCl/CN and 15A/BOCl/CN ternary composite catalyst can be known as g-C₃N₄Has a light absorption edge of 470 nm, a light absorption edge of 500 nm and a light absorption edge of 510 nm for BOCl/CN and 15A/BOCl/CN, respectively, compared with the monomer g-C₃N₄All have red shifts, which indicate that Bi₁₂O₁₅Cl₆Incorporation of AgCl increases g-C₃N₄Utilization ratio of visible light.

FIG. 4 is g-C prepared in example 1₃N₄、Bi₁₂O₁₅Cl₆The band gap diagrams of the BOCl/CN and 15A/BOCl/CN ternary composite catalysts are shown in the figure, g-C₃N₄、Bi₁₂O₁₅Cl₆The band gap values of the BOCl/CN and 15A/BOCl/CN ternary composite catalysts are 2.74 eV, 2.36 eV, 2.67 eV and 2.63 eV, respectively, which shows that Bi₁₂O₁₅Cl₆And loading of AgCl to g-C₃N₄The band gap is narrowed, the separation of the photo-generated electron hole pairs is promoted, and the utilization rate of visible light is improved.

FIG. 5 is g-C prepared in example 1₃N₄、Bi₁₂O₁₅Cl₆And the degradation effect of the BOCl/CN and 15A/BOCl/CN ternary composite catalysts on 20 mg/L tetracycline is shown. g-C after 80min of visible light irradiation₃N₄、Bi₁₂O₁₅Cl₆、Bi₁₂O₁₅Cl₆/g-C₃N₄And AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The degradation rates of the ternary composite material to 20 mg/L tetracycline are respectively 30.7%, 63% and 75.4%, which shows that Bi₁₂O₁₅Cl₆Incorporation of AgCl increases g-C₃N₄The photocatalytic ability of (c).

Example 2:

this example provides an AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The preparation method and the application of the ternary composite catalytic material are as follows:

（1）g-C₃N₄the preparation of (1):

20 g of urea were weighed, placed in a covered alumina crucible, heated to 550 ℃ in an electric furnace at a rate of 5 ℃/min, and held for 4 h. Cooling to room temperature after the reaction is finished, grinding the obtained light yellow powder and collecting to obtain g-C₃N₄A sample;

（2）Bi₁₂O₁₅Cl₆the preparation of (1):

weigh 1 mmol of Bi (NO)₃)₃•5H₂O, which was dissolved in 10 mL of ethylene glycol with vigorous stirring to form a homogeneous solution A. Simultaneously weigh 0.33 mmol of NH₄Cl, dissolved in 35 mL of distilled water to form solution B. The solution A was slowly added to the solution B with vigorous stirring and stirred at room temperature for 1 h. After the stirring was completed, it was transferred to an autoclave and heated at 160 ℃ for 12 hours. After the reaction was completed, the autoclave was cooled to room temperature and the resulting precipitate was washed three times with ethanol and distilled water and dried at 60 ℃ overnight. Then, the obtained white solid powder was calcined in an electric furnace at 400 ℃ for 5 hours at a heating rate of 2 ℃/min. After the reaction is finished, light yellow Bi is obtained₁₂O₁₅Cl₆Grinding and collecting the powder for later use, and marking the powder as BOCl;

（3）Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a binary composite material:

weigh 0.5g of g-C₃N₄In a 150 mL beaker, 30mL of methanol was measured and sonicated for 30 min. Further weigh 0.25g of Bi₁₂O₁₅Cl₆Dissolving it in g-C₃N₄Continuing to perform ultrasonic treatment for 30 min. After which stirring was continued in a fume hood for 24 h. After evaporation of the methanol, the resulting product was collected and dried at 60 ℃ overnight to yield Bi₁₂O₁₅Cl₆/g-C₃N₄Binary composite material marked as BOCl/CN;

（4）AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a ternary composite catalytic material:

weighing 0.5g of Bi prepared by the method₁₂O₁₅Cl₆/g-C₃N₄Dissolving the binary composite material into 30mL of deionized water, and then performing ultrasonic dispersion for 40 min;

② placing 0.17 mmol sodium chloride in the solution, then continuing stirring for 40 min at room temperature to obtain suspension;

③ AgNO₃The solution was added drop by drop to the suspension from step 2 and stirring was continued at room temperature for 5 h. Adding AgNO₃The molar amount of (a) is the same as the molar amount of the chlorine source in the step (ii).

Collecting precipitate, centrifugally washing the precipitate for 5 times with absolute ethyl alcohol and distilled water at 9000 r/min for 7 min, collecting the product, dispersing the product into a culture dish containing absolute ethyl alcohol, placing the culture dish into an oven, and drying the culture dish at 60 ℃ for 12 h to obtain 5% AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄A three-way composite catalytic material.

Three 250 mL tetracycline solutions with a concentration of 20 mg/L were prepared, and 0.05 g-C was added separately₃N₄、Bi₁₂O₁₅Cl₆/g-C₃N₄And 5% AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The photocatalyst is uniformly dispersed by ultrasonic treatment for 15 min under the dark condition, and then the solution is stirred by magnetic force for 40 min under the dark condition to reach the adsorption-desorption balance; then, a 300W xenon lamp with a 420 nm optical filter is used as a visible light source for carrying out photocatalytic reaction, the total time of the photocatalytic reaction is 80min, samples are taken every 20 min, supernatant liquid is taken after centrifugal separation to measure the absorbance, and the maximum absorption wavelength of tetracycline is 357 nm. And then, drawing a curve by taking time (t) as an abscissa and taking the concentration ratio of tetracycline at t as an ordinate, and testing the degradation performance of the three-way catalyst. The test shows that the 5% AgCl/Bi of the example₁₂O₁₅Cl₆/g-C₃N₄The degradation rate of tetracycline is 73 percent, which shows that Bi₁₂O₁₅Cl₆Incorporation of AgCl increases g-C₃N₄The photocatalytic ability of (c).

Example 3:

this example provides an AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The preparation method and the application of the ternary composite catalytic material are as follows:

（1）g-C₃N₄the preparation of (1):

20 g of urea were weighed, placed in a covered alumina crucible, heated to 550 ℃ in an electric furnace at a rate of 5 ℃/min, and held for 4 h. Cooling to room temperature after the reaction is finished, grinding the obtained light yellow powder and collecting to obtain g-C₃N₄A sample;

（2）Bi₁₂O₁₅Cl₆the preparation of (1):

weigh 1 mmol of Bi (NO)₃)₃•5H₂O, which was dissolved in 10 mL of ethylene glycol with vigorous stirring to form a homogeneous solution A. Simultaneously weigh 0.33 mmol of NH₄Cl, dissolved in 35 mL of distilled water to form solution B. The solution A was slowly added to the solution B with vigorous stirring and stirred at room temperature for 1 h. After the stirring was completed, it was transferred to an autoclave and heated at 160 ℃ for 12 hours. After the reaction was completed, the autoclave was cooled to room temperature and the resulting precipitate was washed three times with ethanol and distilled water and dried at 60 ℃ overnight. Then, the obtained white solid powder was calcined in an electric furnace at 400 ℃ for 5 hours at a heating rate of 2 ℃/min. After the reaction is finished, light yellow Bi is obtained₁₂O₁₅Cl₆Grinding and collecting the powder for later use, and marking the powder as BOCl;

（3）Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a binary composite material:

weigh 0.5g of g-C₃N₄In a 150 mL beaker, 30mL of methanol was measured and sonicated for 30 min. Further weigh 0.25g of Bi₁₂O₁₅Cl₆Dissolving it in g-C₃N₄Solutions ofAnd continuing to perform ultrasonic treatment for 30 min. After which stirring was continued in a fume hood for 24 h. After evaporation of the methanol, the resulting product was collected and dried at 60 ℃ overnight to yield Bi₁₂O₁₅Cl₆/g-C₃N₄Binary composite material marked as BOCl/CN;

（4）AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄preparing a ternary composite catalytic material:

weighing 0.5g of Bi prepared by the method₁₂O₁₅Cl₆/g-C₃N₄Dissolving the binary composite material into 30mL of deionized water, and then carrying out ultrasonic dispersion for 60 min;

② placing 0.34 mmol sodium chloride in the solution, then continuing stirring for 50 min at room temperature to obtain suspension;

③ AgNO₃The solution was added drop by drop to the suspension from step (ii) and stirring was continued at room temperature for 6 h. Adding AgNO₃The molar amount of (a) is the same as the molar amount of the chlorine source in the step (ii).

Collecting the precipitate, centrifugally washing the precipitate for 4 times by using absolute ethyl alcohol and distilled water, collecting the product, dispersing the product into a culture dish containing the absolute ethyl alcohol, placing the culture dish into an oven, and drying the culture dish for 12 hours at the temperature of 60 ℃ to obtain 10% AgCl/Bi, wherein the centrifugal speed is 10000 r/min and the centrifugal time is 5 min₁₂O₁₅Cl₆/g-C₃N₄A three-way composite catalytic material.

Three 250 mL tetracycline solutions with a concentration of 20 mg/L were prepared, and 0.05 g-C was added separately₃N₄、Bi₁₂O₁₅Cl₆/g-C₃N₄And 10% AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The photocatalyst is uniformly dispersed by ultrasonic treatment for 15 min under the dark condition, and then the solution is stirred by magnetic force for 40 min under the dark condition to reach the adsorption-desorption balance; then, a 300W xenon lamp with a 420 nm optical filter is used as a visible light source for carrying out photocatalytic reaction, the total time of the photocatalytic reaction is 80min, samples are taken every 20 min, a supernatant is taken after centrifugal separation to measure the absorbance, and the maximum absorption wavelength of tetracycline is measured357 nm. And then, drawing a curve by taking time (t) as an abscissa and taking the concentration ratio of tetracycline at t as an ordinate, and testing the degradation performance of the three-way catalyst. By detection, this example is 10% AgCl/Bi₁₂O₁₅Cl₆/g-C₃N₄The degradation rate of tetracycline is 72.5%, which shows that Bi₁₂O₁₅Cl₆Incorporation of AgCl increases g-C₃N₄The photocatalytic ability of (c).