Bi with core-shell structure2O2CO3@ rGO photocatalyst, and preparation method and application thereof
阅读说明：本技术 一种核壳结构的Bi2O2CO3@rGO光催化剂及其制备方法及应用 (Bi with core-shell structure2O2CO3@ rGO photocatalyst, and preparation method and application thereof ) 是由 谈国强 毕钰 杨迁 王敏 冯帅军 王勇 张碧鑫 任慧君 夏傲 于 2021-09-29 设计创作，主要内容包括：本发明提供一种核壳结构的Bi-(2)O-(2)CO-(3)@rGO光催化剂及其制备方法和应用,包括：取GO加入去离子水中,超声分散后得到前驱液B；取Bi-(2)O-(2)CO-(3)粉体加入到无水乙醇中,超声分散后紫外光照处理,得到前驱液C；在搅拌条件下,将前驱液B和前驱液C混合后进行紫外光照处理3～9h,所得产物洗涤干燥,得到Bi-(2)O-(2)CO-(3)@rGO光催化剂。制备的Bi-(2)O-(2)CO-(3)@rGO光催化剂光催化活性好,对抗生素有很好的降解作用。(The invention provides a Bi with a core-shell structure 2 O 2 CO 3 The @ rGO photocatalyst and the preparation method and the application thereof comprise: adding GO into deionized water, and performing ultrasonic dispersion to obtain a precursor liquid B; taking Bi 2 O 2 CO 3 Adding the powder into absolute ethyl alcohol, performing ultraviolet irradiation treatment after ultrasonic dispersion to obtain a precursor solution C; under the stirring condition, mixing the precursor liquid B and the precursor liquid C, carrying out ultraviolet irradiation treatment for 3-9 h, washing and drying the obtained product to obtain Bi 2 O 2 CO 3 @rGOA photocatalyst. Prepared Bi 2 O 2 CO 3 The @ rGO photocatalyst has good photocatalytic activity and has good degradation effect on antibiotics.)
1. Bi with core-shell structure2O2CO3@ rGO photocatalyst, characterized in that it is Bi2O2CO3Is an inner core, rGO is wrapped in Bi2O2CO3Of (2) is provided.
2. The core-shell structure of claim 1 Bi2O2CO3A preparation method of a @ rGO photocatalyst is characterized by comprising the following steps:
adding GO into deionized water, and performing ultrasonic dispersion to obtain a precursor liquid B;
taking Bi2O2CO3Adding the powder into absolute ethyl alcohol, and performing ultraviolet irradiation after ultrasonic dispersionPerforming illumination treatment to obtain a precursor solution C;
under the stirring condition, mixing the precursor liquid B and the precursor liquid C, carrying out ultraviolet irradiation treatment for 3-9 h, washing and drying the obtained product to obtain Bi2O2CO3@ rGO photocatalyst.
3. Bi of the core-shell structure according to claim 22O2CO3The preparation method of the @ rGO photocatalyst is characterized in that Bi2O2CO3The preparation method of the powder comprises the following steps:
step 1: mixing Na3C6H5O7·2H2O and Bi (NO)3)3·5H2O dissolved in HNO3Stirring the solution for 30-90 min, adjusting the pH value of the solution by using a NaOH solution, and stirring the solution for 30-90 min to obtain a precursor solution A;
step 2: carrying out hydrothermal reaction on the precursor solution A, washing and drying the obtained product to obtain Bi2O2CO3And (3) powder.
4. Bi of the core-shell structure according to claim 32O2CO3The preparation method of the @ rGO photocatalyst is characterized in that in the step 1, Na is added3C6H5O7·2H2O and Bi (NO)3)3·5H2The molar ratio of O is 1: 2; in the step 2, the hydrothermal reaction temperature is 180 ℃, and the reaction time is 18-20 h.
5. Bi of the core-shell structure according to claim 22O2CO3The preparation method of the @ rGO photocatalyst is characterized in that GO and Bi2O2CO3The mass ratio of (1) to (25-50).
6. Bi of the core-shell structure according to claim 22O2CO3The preparation method of the @ rGO photocatalyst is characterized in that in the preparation process of the precursor liquid B and the precursor liquid C, the ultrasonic time is 20-90 min.
7. Bi of the core-shell structure according to claim 22O2CO3The preparation method of the @ rGO photocatalyst is characterized in that in the preparation process of the precursor liquid C, the illumination power for ultraviolet illumination treatment is 200-500W, and the illumination time is 20-60 min.
8. Bi of the core-shell structure according to claim 22O2CO3The preparation method of the @ rGO photocatalyst is characterized in that the illumination power for ultraviolet illumination treatment after the precursor liquid B and the precursor liquid C are mixed is 200-500W, and the illumination time is 3-8 h.
9. The core-shell structure of claim 1 Bi2O2CO3Application of a @ rGO photocatalyst in degrading antibiotics.
10. The use of claim 9, wherein the antibiotic is ciprofloxacin.
Technical Field
The invention belongs to the field of environment-friendly functional materials, and particularly relates to Bi with a core-shell structure2O2CO3A @ rGO photocatalyst, a preparation method and application thereof.
Background
The rapid development of the industry causes the air pollution to be more serious, and the sustainable development of the human society and the physical health of people are seriously influenced. The photocatalysis technology can be used for treating air pollution, has good effect, takes sunlight as a driving force, has low cost and has obvious advantages.
Bi2O2CO3The photocatalyst has been widely noticed and researched as a semiconductor photocatalyst having unique crystal and electronic structure and excellent activity. However, Bi alone2O2CO3Due to the defects of large forbidden band width (about 3.2eV), narrow photoresponse range and the like, the photocatalytic activity of the material is reduced, and the practical application is limited.
Disclosure of Invention
The invention aims to provide Bi with a core-shell structure2O2CO3@ rGO photocatalyst, preparation method and application thereof, and prepared Bi2O2CO3The @ rGO photocatalyst has good photocatalytic activity and has good degradation effect on antibiotics.
The invention is realized by the following technical scheme:
bi with core-shell structure2O2CO3@ rGO photocatalyst in the form of Bi2O2CO3Is an inner core, rGO is wrapped in Bi2O2CO3Of (2) is provided.
The Bi of the core-shell structure2O2CO3A preparation method of a @ rGO photocatalyst comprises the following steps:
adding GO into deionized water, and performing ultrasonic dispersion to obtain a precursor liquid B;
taking Bi2O2CO3Adding the powder into absolute ethyl alcohol, performing ultraviolet irradiation treatment after ultrasonic dispersion to obtain a precursor solution C;
under the stirring condition, mixing the precursor liquid B and the precursor liquid C, carrying out ultraviolet irradiation treatment for 3-9 h, washing and drying the obtained product to obtain Bi2O2CO3@ rGO photocatalyst.
Preferably, Bi2O2CO3The preparation method of the powder comprises the following steps:
step 1: mixing Na3C6H5O7·2H2O and Bi (NO)3)3·5H2O dissolved in HNO3Stirring the solution for 30-90 min, adjusting the pH value of the solution by using a NaOH solution, and stirring the solution for 30-90 min to obtain a precursor solution A;
step 2: carrying out hydrothermal reaction on the precursor solution A, washing and drying the obtained product to obtain Bi2O2CO3And (3) powder.
Preferably, in step 1, Na3C6H5O7·2H2O and Bi (NO)3)3·5H2The molar ratio of O is 1: 2; in the step 2, the hydrothermal reaction temperature is 180 ℃, and the reaction time is 18-20 h.
Preferably, GO and Bi2O2CO3The mass ratio of (1) to (25-50).
Preferably, the ultrasonic time is 20-90 min in the preparation process of the precursor liquid B and the precursor liquid C.
Preferably, in the preparation process of the precursor liquid C, the illumination power for the ultraviolet illumination treatment is 200-500W, and the illumination time is 20-60 min.
Preferably, the illumination power for the ultraviolet illumination treatment after the precursor liquid B and the precursor liquid C are mixed is 200-500W, and the illumination time is 3-8 h.
The coreBi of shell structure2O2CO3Application of a @ rGO photocatalyst in degrading antibiotics.
Preferably, the antibiotic is ciprofloxacin.
Compared with the prior art, the invention has the following beneficial technical effects:
the present invention provides Bi of a core-shell structure2O2CO3@ rGO photocatalyst, high electron transfer capability of graphene, no influence of temperature change, and Bi2O2CO3The semiconductor material is compounded, and has a strong inhibiting effect on the recombination of a photo-generated electron-hole pair. Meanwhile, graphene has a specific surface area larger than a general area (2630 m)2g-1) Easily interacts with functional groups of macromolecular organic matters to form a stable compound, thereby increasing the adsorption capacity to pollutant molecules, and therefore, the Bi with a core-shell structure2O2CO3The @ rGO photocatalyst has better photocatalytic activity, increases the degradation capability of the photocatalyst on ciprofloxacin, and can be used for the treatment of antibiotics.
The invention uses Bi2O2CO3GO is used as a raw material, an in-situ ultraviolet illumination reduction method is adopted, and photoproduction electrons are adsorbed on Bi2O2CO3Reduction of GO to rGO at the surface to form Bi2O2CO3@ rGO core-shell structure. The method has the advantages of simple flow, simple operation, short reaction time and mild reaction conditions.
Bi of the invention2O2CO3The @ rGO photocatalyst can realize the efficient degradation of antibiotics such as ciprofloxacin under sunlight, and has excellent photocatalytic stability.
Drawings
FIG. 1 shows Bi prepared according to the present invention2O2CO3And Bi2O2CO3The XRD pattern of a @ rGO photocatalyst;
FIG. 2 shows Bi prepared according to the present invention2O2CO3Raman plots for @ rGO photocatalysts;
FIG. 3 is a graph showing the removal curve of ciprofloxacin from the catalyst powder prepared according to the present invention under solar irradiation;
FIG. 4 shows Bi prepared by the present invention2O2CO3The circulating degradation curve of @ rGO photocatalyst for ciprofloxacin.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
The preparation method of the invention comprises the following steps:
step 1: mixing Na3C6H5O7·2H2O and Bi (NO)3)3·5H2O dissolved in HNO3Stirring the solution for 30-90 min, adjusting the pH value of the solution by using NaOH solution, and stirring the solution for 30-90 min to obtain precursor solution A, wherein Na is contained in the precursor solution A3C6H5O7·2H2O and Bi (NO)3)3·5H2The molar ratio of O is 1:2, and Bi in the precursor liquid A3+The concentration of (A) is 0.05-0.2 mol/L;
step 2: placing the precursor solution A in a hydrothermal reaction kettle with a reaction filling ratio of about 80%, heating from room temperature to reaction temperature, keeping the temperature for a period of time, finishing the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol respectively, and drying at constant temperature to obtain Bi2O2CO3A photocatalyst;
and step 3: adding GO into deionized water, and performing ultrasonic dispersion to obtain a precursor liquid B; in the precursor liquid B, the ratio of GO to deionized water is 0.01 g: (20-70) mL.
And 4, step 4: taking Bi2O2CO3Adding the powder into 20-70 mL of absolute ethanol, and performing ultraviolet irradiation treatment after ultrasonic dispersion to obtain a precursor solution C; in the precursor solution C, Bi2O2CO3The ratio of the powder to the absolute ethyl alcohol is 0.5 g: (20-70) mL.
And 5: under the condition of stirring, mixing the precursor liquid B and the precursor liquid C, carrying out ultraviolet irradiation treatment for 3-9 h, and finally washing and drying to obtain Bi2O2CO3@ rGO composite photocatalyst. Wherein, GO and Bi2O2CO3The mass ratio of (1) to (25-50).
And the time of the ultrasonic reaction in the steps 3 and 4 is 20-90 min.
In the step 4, the power of a mercury lamp used for ultraviolet illumination is 200-500W, and the illumination time is 20-60 min.
In the step 5, the power of a mercury lamp used for ultraviolet illumination is 200-500W, and the illumination time is 3-8 h.
Prepared Bi2O2CO3The @ rGO composite photocatalyst has better photocatalytic performance under simulated sunlight.
Comparative example 1:
step 1: 1.2g of Na3C6H5O7·2H2O and 3.88g Bi (NO)3)3·5H2O dissolved in 60mL of 1mol/L HNO3Stirring the solution for 60min, adjusting the pH value of the solution to 5.4 by using a 3mol/L NaOH solution, and then stirring the solution for 60min to obtain a precursor solution A;
step 2: placing the precursor solution A in a hydrothermal reaction kettle with a reaction filling ratio of about 80%, heating to 180 ℃ from room temperature after 60min, preserving heat for 18h to finish the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol for 3 times respectively, and drying at a constant temperature of 70 ℃ for 12h to obtain Bi2O2CO3A photocatalyst.
Example 1:
step 1: 1.2g of Na3C6H5O7·2H2O and 3.88g Bi (NO)3)3·5H2O dissolved in 60mL of 1mol/L HNO3Stirring the solution for 60min, adjusting the pH value of the solution to 5.4 by using a 3mol/L NaOH solution, and then stirring the solution for 60min to obtain a precursor solution A;
step 2: placing the precursor solution A in a hydrothermal reaction kettle with a reaction filling ratio of about 80%, heating to 180 ℃ from room temperature after 60min, preserving heat for 18h to finish the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol for 3 times respectively, and drying at a constant temperature of 70 ℃ for 12h to obtain Bi2O2CO3A photocatalyst;
and step 3: adding 0.01g of GO into 40mL of deionized water, and performing ultrasonic dispersion for 60min to obtain a precursor solution B;
and 4, step 4: 0.5g of Bi is taken2O2CO3Adding the powder into 40mL of absolute ethyl alcohol, performing ultrasonic dispersion for 30min, and performing ultraviolet light treatment for 30min under a 300W mercury lamp to obtain a precursor solution C;
and 5: under the condition of stirring, mixing the precursor solution B and the precursor solution C according to the volume ratio of 1:1, carrying out ultraviolet irradiation treatment for 5 hours under a 300W mercury lamp, and finally washing and drying to obtain Bi2O2CO3@ rGO photocatalyst.
Example 2:
step 1: 1.2g of Na3C6H5O7·2H2O and 3.88g Bi (NO)3)3·5H2O dissolved in 60mL of 1mol/L HNO3Stirring the solution for 60min, adjusting the pH value of the solution to 5.4 by using a 3mol/L NaOH solution, and then stirring the solution for 60min to obtain a precursor solution A;
step 2: placing the precursor solution A in a hydrothermal reaction kettle with a reaction filling ratio of about 80%, heating to 180 ℃ from room temperature after 60min, preserving heat for 18h to finish the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol for 3 times respectively, and drying at a constant temperature of 70 ℃ for 12h to obtain Bi2O2CO3A photocatalyst;
and step 3: adding 0.01g of GO into 40mL of deionized water, and performing ultrasonic dispersion for 60min to obtain a precursor solution B;
and 4, step 4: 0.5g of Bi is taken2O2CO3Adding the powder into 40mL of absolute ethyl alcohol, performing ultrasonic dispersion for 30min, and performing ultraviolet light treatment for 60min under a 300W mercury lamp to obtain a precursor solution C;
and 5: under the condition of stirring, mixing the precursor solution B and the precursor solution C according to the volume ratio of 1:1, carrying out ultraviolet irradiation treatment for 5 hours under a 300W mercury lamp, and finally washing and drying to obtain Bi2O2CO3@ rGO photocatalyst.
Example 3:
step 1: 1.2g of Na3C6H5O7·2H2O and 3.88g Bi (NO)3)3·5H2O dissolved in 60mL of 1 mol-HNO of L3Stirring the solution for 60min, adjusting the pH value of the solution to 5.4 by using a 3mol/L NaOH solution, and then stirring the solution for 60min to obtain a precursor solution A;
step 2: placing the precursor solution A in a hydrothermal reaction kettle with a reaction filling ratio of about 80%, heating to 180 ℃ from room temperature after 60min, preserving heat for 18h to finish the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol for 3 times respectively, and drying at a constant temperature of 70 ℃ for 12h to obtain Bi2O2CO3A photocatalyst;
and step 3: adding 0.01g of GO into 40mL of deionized water, and performing ultrasonic dispersion for 60min to obtain a precursor solution B;
and 4, step 4: 0.5g of Bi is taken2O2CO3Adding the powder into 40mL of absolute ethyl alcohol, performing ultrasonic dispersion for 30min, and performing ultraviolet irradiation treatment for 90min under a 300W mercury lamp to obtain a precursor solution C;
and 5: under the condition of stirring, mixing the precursor solution B and the precursor solution C according to the volume ratio of 1:1, carrying out ultraviolet irradiation treatment for 5 hours under a 300W mercury lamp, and finally washing and drying to obtain Bi2O2CO3@ rGO photocatalyst.
Example 4:
step 1: 1.2g of Na3C6H5O7·2H2O and 3.88g Bi (NO)3)3·5H2O dissolved in 60mL of 1mol/L HNO3Stirring the solution for 60min, adjusting the pH value of the solution to 5.4 by using a 3mol/L NaOH solution, and then stirring the solution for 60min to obtain a precursor solution A;
step 2: placing the precursor solution A in a hydrothermal reaction kettle with a reaction filling ratio of about 80%, heating to 180 ℃ from room temperature after 60min, preserving heat for 18h to finish the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol for 3 times respectively, and drying at a constant temperature of 70 ℃ for 12h to obtain Bi2O2CO3A photocatalyst;
and step 3: adding 0.01g of GO into 40mL of deionized water, and performing ultrasonic dispersion for 60min to obtain a precursor solution B;
and 4, step 4: 0.5g of Bi is taken2O2CO3Adding the powder into 40mL of absolute ethyl alcohol, and performing ultrasonic dispersion for 30minPerforming ultraviolet irradiation treatment for 120min under a 300W mercury lamp to obtain a precursor solution C;
and 5: under the condition of stirring, mixing the precursor solution B and the precursor solution C according to the volume ratio of 1:1, carrying out ultraviolet irradiation treatment for 5 hours under a 300W mercury lamp, and finally washing and drying to obtain Bi2O2CO3@ rGO photocatalyst
Example 5:
step 1: 1.2g of Na3C6H5O7·2H2O and 3.88g Bi (NO)3)3·5H2O dissolved in 60mL of 1mol/L HNO3Stirring the solution for 60min, adjusting the pH value of the solution to 5.4 by using a 3mol/L NaOH solution, and then stirring the solution for 60min to obtain a precursor solution A;
step 2: placing the precursor solution A in a hydrothermal reaction kettle with a reaction filling ratio of about 80%, heating to 180 ℃ from room temperature after 60min, preserving heat for 19h to finish the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol for 3 times respectively, and drying at a constant temperature of 70 ℃ for 12h to obtain Bi2O2CO3A photocatalyst;
and step 3: adding 0.01g of GO into 40mL of deionized water, and performing ultrasonic dispersion for 60min to obtain a precursor solution B;
and 4, step 4: 0.5g of Bi is taken2O2CO3Adding the powder into 40mL of absolute ethyl alcohol, performing ultrasonic dispersion for 30min, and performing ultraviolet light treatment for 30min under a 300W mercury lamp to obtain a precursor solution C;
and 5: under the condition of stirring, mixing the precursor solution B and the precursor solution C according to the volume ratio of 1:1, carrying out ultraviolet irradiation treatment for 5 hours under a 300W mercury lamp, and finally washing and drying to obtain Bi2O2CO3@ rGO photocatalyst
Example 6:
step 1: 1.2g of Na3C6H5O7·2H2O and 3.88g Bi (NO)3)3·5H2O dissolved in 60mL of 1mol/L HNO3Stirring the solution for 60min, adjusting the pH value of the solution to 5.4 by using a 3mol/L NaOH solution, and then stirring the solution for 60min to obtain a precursor solution A;
step 2: placing the precursor solution A into a hydrothermal reaction kettle with a reaction filling ratio ofHeating to 180 ℃ from room temperature after 60min, keeping the temperature for 20h to finish the reaction, naturally cooling to room temperature, washing the obtained precipitate with deionized water and absolute ethyl alcohol for 3 times respectively, and drying at the constant temperature of 70 ℃ for 12h to obtain Bi2O2CO3A photocatalyst;
and step 3: adding 0.01g of GO into 40mL of deionized water, and performing ultrasonic dispersion for 60min to obtain a precursor solution B;
and 4, step 4: 0.5g of Bi is taken2O2CO3Adding the powder into 40mL of absolute ethyl alcohol, performing ultrasonic dispersion for 30min, and performing ultraviolet light treatment for 30min under a 300W mercury lamp to obtain a precursor solution C;
and 5: under the condition of stirring, mixing the precursor solution B and the precursor solution C according to the volume ratio of 1:1, carrying out ultraviolet irradiation treatment for 5 hours under a 300W mercury lamp, and finally washing and drying to obtain Bi2O2CO3@ rGO photocatalyst.
FIG. 1 shows Bi2O2CO3And Bi2O2CO3The XRD patterns of the @ rGO photocatalyst are shown as a and b in the XRD patterns of the powders prepared in comparative example 1 and example 1 respectively. Bi can be observed from the XRD pattern2O2CO3Diffraction peak of (3), tetragonal phase Bi after introduction of rGO2O2CO3The crystallinity of (3) is reduced, indicating that rGO is wrapped in Bi2O2CO3And forming a core-shell structure on the surface.
FIG. 2 shows Bi prepared in example 12O2CO3Raman spectra of @ rGO photocatalyst at 1355cm-1At position 1585cm-1D peak and G peak are respectively appeared, the D peak is caused by lattice defect of C atom and sp3Hybridization results, 1585cm-1The G peak at (A) is due to the C atom sp2Hybrid in-plane stretching vibration. I of pure phase GOD/IGA value of about 0.42, and Bi2O2CO3@ rGO composite catalyst ID/IGThe value is about 0.947. The above results clearly show that GO is reduced to rGO during in situ UV reduction, confirming that Bi is present2O2CO3The composite photocatalyst has rGO in the @ rGO composite photocatalyst.
FIG. 3 is a ciprofloxacin removal curve of the catalyst powder prepared by the invention under sunlight irradiation, wherein a and b are the ciprofloxacin removal curves of the powder prepared by the comparative example 1 and the powder prepared by the example 1 respectively, and C/C of ordinate0Is the ratio of the concentration of ciprofloxacin after degradation to its initial concentration. As seen from the figure, prepared Bi of core-shell structure2O2CO3The @ rGO photocatalyst shows that the photocatalyst is obviously higher than pure phase Bi2O2CO3The photocatalytic performance of the catalyst. Bi prepared after 120min of sunlight irradiation2O2CO3The removal rate of the @ rGO photocatalyst to ciprofloxacin can reach 89%.
FIG. 4 shows Bi2O2CO3The circulating degradation curve of the @ rGO photocatalyst to ciprofloxacin after four times of sunlight circulating degradation experiments2O2CO3The photocatalytic activity of the @ rGO photocatalyst is not obviously reduced, which shows that the photocatalyst has excellent photocatalytic stability under simulated sunlight.
The above description is only one embodiment of the present invention, and not all or only one embodiment, and any equivalent alterations to the technical solutions of the present invention, which are made by those skilled in the art through reading the present specification, are covered by the claims of the present invention.