NaBiO3 / Bi2O2CO3 heterojunction catalyst as well as preparation method and application thereof
By in situ growing Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3/Bi2O2CO3 heterojunction catalyst, the problems of high photogenerated carrier recombination rate and narrow light response range of existing photocatalysts are solved, and efficient photocatalytic degradation of microplastics, organic pollutants and dye-type pollutants is achieved.
Patent Information
- Application Number
- CN202510935042.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-08
- Publication Date
- 2025-10-14
AI Technical Summary
Existing photocatalysts such as TiO2, Bi2O2CO3, and NaBiO3 have defects such as high photogenerated carrier recombination rate and narrow photoresponse range. In addition, the existing heterojunction preparation methods are complex and costly, and there is a lack of effective degradation solutions for microplastics and various pollutants.
By in situ growing Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3/Bi2O2CO3 heterojunction catalyst, a photocatalytic reaction was carried out under simulated sunlight under the induction of bicarbonate, which promoted the separation of photogenerated electron-hole pairs and broadened the light response range.
It has improved photocatalytic activity and can effectively degrade microplastics, organic pollutants and dye pollutants with a degradation efficiency of 44.5% to 99%. It does not require complex preparation processes, the reaction conditions are mild, and the catalyst can be recycled.
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Figure CN120771902A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of photocatalytic materials, and in particular to a NaBiO3 / Bi2O2CO3 heterojunction catalyst, a preparation method and an application thereof. Background Art
[0002] Microplastic pollution has become a global environmental problem. Its recalcitrant nature poses a serious threat to ecosystems and human health. Traditional treatment methods (such as physical filtration and chemical oxidation) suffer from low efficiency, high cost, and secondary pollution. Photocatalytic technology has become a research hotspot due to its green and efficient characteristics. However, existing photocatalysts (such as TiO2, Bi2O2CO3, and NaBiO3) suffer from high photogenerated carrier recombination rates and narrow photoresponse ranges, limiting their practical application. Bi2O2CO3 has a layered structure and visible light responsiveness, but its photogenerated electron-hole pairs easily recombine. NaBiO3, while possessing a wide bandgap and high oxidizing ability, only responds to ultraviolet light. Heterojunctions can be constructed to optimize the band structure and improve carrier separation efficiency. However, existing heterojunction preparation methods often require complex pretreatment or high-temperature calcination, which is costly and easily degrades the material structure. Furthermore, there are few reports on in situ heterojunction construction within a reaction environment, and solutions for the degradation of microplastics and multiple pollutants are lacking. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a NaBiO3 / Bi2O2CO3 heterojunction catalyst and its preparation method and application, so as to overcome the deficiencies in the prior art.
[0004] The technical solution of the present invention to solve the above technical problems is as follows: A method for preparing a NaBiO3 / Bi2O2CO3 heterojunction catalyst comprises the following steps: NaBiO3 nanosheets were dispersed in an aqueous solution of bicarbonate and subjected to a photocatalytic reaction under simulated sunlight to induce the in-situ growth of Bi2O2CO3 on the NaBiO3 surface under the induction of bicarbonate. After the reaction, the catalyst was centrifuged and dried to obtain a NaBiO3 / Bi2O2CO3 heterojunction catalyst.
[0005] On the basis of the above technical solution, the present invention can also be improved as follows.
[0006] Furthermore, the dosage of NaBiO3 nanosheets is 0.03g / L to 0.1g / L, the bicarbonate concentration is 0.01mol / L to 0.1mol / L, the wavelength of the simulated sunlight light source is 200nm to 1000nm, and the reaction time is 2h to 30h.
[0007] Furthermore, the bicarbonate is derived from an alkali metal carbonate or an alkali metal bicarbonate.
[0008] Furthermore, one or more of sodium carbonate, potassium carbonate, sodium bicarbonate or potassium bicarbonate.
[0009] Furthermore, the simulated sunlight light source is provided by a xenon lamp or a mercury lamp.
[0010] Based on the above technical solution, the present invention also provides a NaBiO3 / Bi2O2CO3 heterojunction catalyst, which is prepared using the above preparation method.
[0011] Based on the above technical solution, the present invention also provides an application of a NaBiO3 / Bi2O2CO3 heterojunction catalyst, which is used for photocatalytic degradation of microplastics in water.
[0012] Furthermore, the microplastic is one or more of low-density polyethylene, polypropylene, polyvinyl chloride, and polystyrene.
[0013] Furthermore, the specific degradation method is as follows: NaBiO3 nanosheets are dispersed in an aqueous solution containing microplastics and bicarbonate, and a photocatalytic reaction is carried out under the irradiation of a simulated sunlight light source to promote the in situ growth of Bi2O2CO3 on the NaBiO3 surface to form a NaBiO3 / Bi2O2CO3 heterojunction, and the photocatalytic degradation reaction is continued under the irradiation of a simulated sunlight light source, using the NaBiO3 / Bi2O2CO3 heterojunction to enhance the photocatalytic activity.
[0014] Based on the above technical solution, the present invention also provides an application of a NaBiO3 / Bi2O2CO3 heterojunction catalyst, which is used for photocatalytic degradation of organic pollutants in water.
[0015] Furthermore, the organic pollutants are antibiotic pollutants, and the antibiotic pollutants are one or more of metronidazole, ciprofloxacin, and tetracycline hydrochloride.
[0016] Furthermore, the specific degradation method is as follows: NaBiO3 nanosheets are dispersed in an aqueous solution containing organic pollutants and bicarbonate ions, and a photocatalytic reaction is carried out under the irradiation of a simulated sunlight light source to promote the in situ growth of Bi2O2CO3 on the NaBiO3 surface to form a NaBiO3 / Bi2O2CO3 heterojunction, and the photocatalytic degradation reaction is continued under the irradiation of a simulated sunlight light source, using the NaBiO3 / Bi2O2CO3 heterojunction to enhance the photocatalytic activity.
[0017] Based on the above technical solution, the present invention also provides an application of a NaBiO3 / Bi2O2CO3 heterojunction catalyst, which is used for photocatalytic degradation of dye pollutants in water.
[0018] Furthermore, the dye pollutant is one or both of rhodamine B and acid red.
[0019] Furthermore, the specific degradation method is as follows: NaBiO3 nanosheets are dispersed in an aqueous solution containing dye pollutants and bicarbonate ions, and a photocatalytic reaction is carried out under the irradiation of a simulated sunlight light source to promote the in situ growth of Bi2O2CO3 on the NaBiO3 surface to form a NaBiO3 / Bi2O2CO3 heterojunction, and the photocatalytic degradation reaction is continued under the irradiation of a simulated sunlight light source, using the NaBiO3 / Bi2O2CO3 heterojunction to enhance the photocatalytic activity.
[0020] The beneficial effects of the present invention are: through the photocatalytic reaction of bicarbonate and NaBiO3 nanosheets, Bi2O2CO3 is generated in situ on the surface of NaBiO3 nanosheets, forming a close contact heterojunction, effectively promoting the separation of photogenerated electron-hole pairs, improving photocatalytic activity, and enhancing carrier separation efficiency. The heterojunction broadens the light response range to the visible light region, and can simultaneously degrade microplastics, organic pollutants and dye pollutants. Among them, the weight loss rate of microplastics can be as high as 44.5%, the efficiency of degrading antibiotic pollutants reaches more than 99%, and the efficiency of degrading dye pollutants reaches more than 99%. It has excellent photocatalytic degradation performance, does not require complex preparation technology, has mild reaction conditions, and the catalyst can be recycled. It has broad application prospects in the field of environmental governance. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 The X-ray diffraction pattern of Bi2O2CO3 growth on the surface of NaBiO3 promoted by bicarbonate in Example 1; Figure 2 This is the effect of different concentrations of bicarbonate on the photocatalytic degradation of low-density polyethylene by NaBiO3 in Example 2; Figure 3 is the weight loss rate of the photocatalytic degradation of various microplastics by NaBiO3 with bicarbonate in Example 3; Figure 4 Schematic diagram of the effect of bicarbonate on the photocatalytic degradation of organic pollutants and dye pollutants by NaBiO3 in Examples 4, 5, 6, 7, and 8. DETAILED DESCRIPTION
[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0023] Example 1 like Figure 1 As shown, a method for preparing a NaBiO3 / Bi2O2CO3 heterojunction catalyst comprises the following steps: 0.05 g of NaBiO3 nanosheets were dispersed in 100 mL of deionized water, and 0.05 mol / L of sodium bicarbonate was added. The photocatalytic reaction was carried out under the irradiation of a simulated sunlight light source. The wavelength of the simulated sunlight light source was 200 nm to 1000 nm, and the reaction time was 2 h to 30 h, preferably 2 h, so as to promote the in-situ growth of Bi2O2CO3 on the surface of NaBiO3 under the induction of bicarbonate. After the reaction, the catalyst was centrifuged and dried to obtain a NaBiO3 / Bi2O2CO3 heterojunction catalyst, which was characterized by X-ray diffractometer (XRD). Figure 1 It shows that Bi2O2CO3 was successfully grown in the product, and its characteristic diffraction peaks are consistent with the standard card (JCPDS No.41-1488).
[0024] Example 2 like Figure 2 As shown, 0.05 g of NaBiO3 nanosheets were dispersed in 100 mL of an aqueous solution containing 50 mg / L low-density polyethylene (the addition of low-density polyethylene did not affect the in situ growth of Bi2O2CO3 on the surface of the NaBiO3 nanosheets, as was the case in subsequent examples). 0.01 mol / L, 0.03 mol / L, 0.05 mol / L, and 0.07 mol / L of sodium bicarbonate were added, respectively. The mixture was reacted for 20 h under simulated sunlight with a wavelength of 200 nm to 1000 nm, promoting the in situ growth of Bi2O2CO3 on the surface of the NaBiO3 nanosheets to form a NaBiO3 / Bi2O2CO3 heterojunction. The light irradiation reaction was then continued, utilizing the efficient photocatalytic activity of the heterojunction to degrade the low-density polyethylene. The results showed that the degradation rate of the low-density polyethylene increased significantly with increasing bicarbonate concentration, reaching a maximum at 0.05 mol / L bicarbonate.
[0025] Example 3 like Figure 3As shown, 0.05g NaBiO3 nanosheets were dispersed in 100mL of an aqueous solution containing 50mg / L of different microplastics (low-density polyethylene, polypropylene, polyvinyl chloride, polystyrene), and 0.05mol / L sodium bicarbonate was added. The reaction was allowed to proceed for 20h under simulated sunlight light source with a wavelength of 200nm~1000nm, which promoted the in situ growth of Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3 / Bi2O2CO3 heterojunction. Then, the light reaction was continued, and the efficient photocatalytic activity of the heterojunction was used to degrade microplastics. The results showed that the introduction of bicarbonate can realize the photocatalytic degradation of various microplastics by NaBiO3.
[0026] Example 4 like Figure 4 As shown, 0.05g NaBiO3 nanosheets were dispersed in 100mL of a 10mg / L metronidazole solution, 0.05mol / L sodium bicarbonate was added, and the mixture was reacted for 2h under simulated sunlight light source with a wavelength of 200nm~1000nm, which promoted the in situ growth of Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3 / Bi2O2CO3 heterojunction. Then, the light reaction was continued, and the efficient photocatalytic activity of the heterojunction was utilized to degrade metronidazole. The experimental results showed that the introduction of bicarbonate can achieve a photocatalytic degradation efficiency of metronidazole of NaBiO3 of more than 99%.
[0027] Example 5 like Figure 4 As shown, 0.05g NaBiO3 nanosheets were dispersed in 100mL of 10mg / L ciprofloxacin solution, 0.05mol / L sodium bicarbonate was added, and the reaction was carried out under simulated sunlight light source for 2h. The wavelength of the simulated sunlight light source was 200nm~1000nm, which promoted the in situ growth of Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3 / Bi2O2CO3 heterojunction. Then, the light reaction was continued, and the efficient photocatalytic activity of the heterojunction was used to degrade ciprofloxacin. The experimental results showed that the introduction of bicarbonate can achieve a photocatalytic degradation efficiency of ciprofloxacin of NaBiO3 nanosheets of more than 99%.
[0028] Example 6 like Figure 4As shown, 0.05g NaBiO3 nanosheets were dispersed in 100mL of an aqueous solution containing 10mg / L tetracycline, and 0.05mol / L sodium bicarbonate was added. The reaction was allowed to react for 2h under simulated sunlight light source with a wavelength of 200nm~1000nm, which promoted the in situ growth of Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3 / Bi2O2CO3 heterojunction. Then, the light reaction was continued, and the efficient photocatalytic activity of the heterojunction was used to degrade tetracycline. The experimental results showed that the introduction of bicarbonate can achieve a photocatalytic degradation efficiency of tetracycline of NaBiO3 of more than 99%.
[0029] Example 7 like Figure 4 As shown, 0.05g NaBiO3 nanosheets were dispersed in 100mL of a solution containing 10mg / L rhodamine B, 0.05mol / L sodium bicarbonate was added, and the reaction was carried out under simulated sunlight for 2h. The wavelength of the simulated sunlight light source was 200nm~1000nm, which promoted the in situ growth of Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3 / Bi2O2CO3 heterojunction. Then, the light reaction was continued, and the efficient photocatalytic activity of the heterojunction was used to degrade rhodamine B. The experimental results showed that the introduction of bicarbonate can achieve a photocatalytic degradation efficiency of rhodamine B of NaBiO3 of more than 99%.
[0030] Example 8 like Figure 4 As shown, 0.05g NaBiO3 nanosheets were dispersed in 100mL of a 10mg / L acid red solution, 0.05mol / L sodium bicarbonate was added, and the mixture was reacted for 2h under simulated sunlight light source with a wavelength of 200nm~1000nm, which promoted the in situ growth of Bi2O2CO3 on the surface of NaBiO3 nanosheets to form a NaBiO3 / Bi2O2CO3 heterojunction. Then, the light reaction was continued, and the efficient photocatalytic activity of the heterojunction was used to degrade acid red. The experimental results showed that the introduction of bicarbonate can achieve a photocatalytic degradation efficiency of acid red of NaBiO3 of more than 99%.
[0031] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.
Claims
1. A method for preparing a NaBiO3 / Bi2O2CO3 heterojunction catalyst, characterized in that: The steps include: NaBiO3 nanosheets were dispersed in an aqueous solution of bicarbonate and subjected to a photocatalytic reaction under simulated sunlight to induce the in-situ growth of Bi2O2CO3 on the NaBiO3 surface under the induction of bicarbonate. After the reaction, the catalyst was centrifuged and dried to obtain a NaBiO3 / Bi2O2CO3 heterojunction catalyst.
2. The method according to claim 1, characterized in that The dosage of NaBiO3 nanosheets is 0.03g / L to 0.1g / L, the bicarbonate concentration is 0.01mol / L to 0.1mol / L, the wavelength of the simulated sunlight light source is 200nm to 1000nm, and the reaction time is 2h to 30h.
3. The preparation method according to claim 1 or 2, characterized in that The bicarbonate is derived from an alkali metal carbonate or an alkali metal bicarbonate.
4. A NaBiO3 / Bi2O2CO3 heterojunction catalyst, characterized in that: The method is as claimed in any one of claims 1 to 3.
5. A NaBiO3 / Bi2O2CO3 heterojunction catalyst prepared by the method according to any one of claims 1 to 3 or a use of the NaBiO3 / Bi2O2CO3 heterojunction catalyst according to claim 4, characterized in that: NaBiO3 / Bi2O2CO3 heterojunction catalyst is used for photocatalytic degradation of microplastics in water.
6. The use according to claim 5, characterized in that Microplastics are one or more of low-density polyethylene, polypropylene, polyvinyl chloride, and polystyrene.
7. A NaBiO3 / Bi2O2CO3 heterojunction catalyst prepared by the method according to any one of claims 1 to 3 or a use of the NaBiO3 / Bi2O2CO3 heterojunction catalyst according to claim 4, characterized in that: NaBiO3 / Bi2O2CO3 heterojunction catalysts are used for photocatalytic degradation of organic pollutants in water.
8. The use according to claim 7, characterized in that The organic pollutants are antibiotic pollutants, and the antibiotic pollutants are one or more of metronidazole, ciprofloxacin, and tetracycline hydrochloride.
9. A use of a NaBiO3 / Bi2O2CO3 heterojunction catalyst prepared by the method according to any one of claims 1 to 3 or a NaBiO3 / Bi2O2CO3 heterojunction catalyst according to claim 4, characterized in that: NaBiO3 / Bi2O2CO3 heterojunction catalyst is used for photocatalytic degradation of dye pollutants in water.
10. The use according to claim 9, characterized in that The dye pollutants are one or both of rhodamine B and acid red.