阅读说明：本技术 一种光催化剂及其制备方法和应用 (Photocatalyst and preparation method and application thereof ) 是由 宋志国 彭进才 王齐 彭跃红 王田慧 李永进 邱建备 杨正文 尹兆益 韩缙 于 2021-10-14 设计创作，主要内容包括：本发明属于光催化技术领域,具体涉及一种光催化剂及其制备方法和应用。本发明提供了一种光催化剂,所述光催化剂的化学组成为MBi-(1-)-(y)RE-(y)O-(2)X；所述M包括Ca、Sr、Ba、Pb和Cd中的一种或几种；所述RE为稀土元素；所述X为卤族元素；所述y＝0.001～0.9。本发明通过稀土元素掺杂,能够使得到的光催化剂产生氧空位和/或杂质能级,捕获光生电子,提高光生载流子的分离效率,产生宽光谱响应,实现对紫外光、可见光和近红外光的吸收,提高光的利用率以及光催化剂的活性,进一步提高光催化性能。(The invention belongs to the technical field of photocatalysis, and particularly relates to a photocatalyst as well as a preparation method and application thereof. The invention provides a photocatalyst, the chemical composition of which is MBi 1‑ y RE y O 2 X; the M comprises one or more of Ca, Sr, Ba, Pb and Cd; the RE is a rare earth element; the X is a halogen element; and y is 0.001-0.9. By doping rare earth elements, the obtained photocatalyst can generate oxygen vacancies and/or impurity energy levels, capture photo-generated electrons, improve the separation efficiency of photo-generated carriers, generate wide-spectrum response, realize the absorption of ultraviolet light, visible light and near infrared light, improve the utilization rate of light and the activity of the photocatalystAnd the photocatalytic performance is further improved.)

1. A photocatalyst is characterized in that the chemical composition of the photocatalyst is MBi_1-yRE_yO₂X；

The M comprises one or more of Ca, Sr, Ba, Pb and Cd;

the RE is a rare earth element;

the X is a halogen element;

and y is 0.001-0.9.

2. The photocatalyst of claim 1, wherein RE comprises one or more of Er, Tb, Ce and Tm.

3. The method for preparing the photocatalyst according to claim 1 or 2, characterized by comprising the steps of:

according to the following M: bi: RE: o: x is 1: (1-y): y: 2: 1, mixing the M compound, the bismuth source, the rare earth compound and the halide to obtain a premix; wherein y is 0.001-0.9;

and sintering the premix or treating the premix under a supercritical condition to obtain the photocatalyst.

4. The method according to claim 3, wherein the premix is subjected to the sintering treatment when the M compound comprises an M-containing oxide, an M-containing halide or an M-containing carbonate, the bismuth source comprises bismuth oxide or bismuth oxyhalide, the rare earth compound comprises a rare earth oxide or rare earth nitrate, and the halide comprises ammonium halide or bismuth oxyhalide.

5. The preparation method according to claim 4, wherein the sintering temperature is 300-1500 ℃ and the sintering time is 1-40 h.

6. The method of claim 3, wherein the premix further comprises a solvent, and the premix is treated under supercritical conditions when the solvent is contained therein;

the solvent comprises one or more of water, an alcohol solvent and an ester solvent.

7. The method of claim 6, wherein the M compound comprises a nitrate containing M or a halide containing M when the premix is treated under supercritical conditions; the bismuth source comprises bismuth nitrate; the rare earth compound comprises a rare earth nitrate; the halide comprises an alkali metal halide, an ammonium halide, a M-containing halide, or a halogen-containing ionic liquid;

the concentration of the premix is 0.063-0.125 mol/L.

8. The method according to claim 7, wherein the treatment under supercritical conditions is carried out at a temperature of 110 to 250 ℃ for 1 to 40 hours.

9. The method according to any one of claims 6 to 8, further comprising, after the premix is subjected to the supercritical treatment: carrying out heat treatment on the obtained product;

the temperature of the heat treatment is 200-1200 ℃, and the time is 0.5-6 h.

10. The photocatalyst according to claim 1 or 2 or the photocatalyst prepared by the preparation method according to any one of claims 3 to 9 for pollutant purification, photocatalytic decomposition of water and CO₂Application in the field of photocatalytic reduction.

Technical Field

The invention belongs to the technical field of photocatalysis, and particularly relates to a photocatalyst as well as a preparation method and application thereof.

Background

The photocatalysis technology is a technology for converting solar energy into chemical energy to drive a series of chemical reactions, and is widely concerned and deeply researched by domestic and foreign scholars at present due to the advantages of economic feasibility, no toxicity, resource saving, environmental friendliness and the like.

Bismuth-based material MBiO₂The layered structure of X (where X is Ca, Sr, Ba, Pb or Cd and X is a halogen) is advantageously in [ MBiO ]₂]⁺And a built-in electric field is formed between the photo-induced charge carrier and the halogen layer, and the recombination of the photo-induced charge carriers is inhibited, so that the charge separation efficiency is improved, and therefore, the photo-induced charge carrier has great research and application potential in the field of photocatalysis. However, MBiO₂The band gap of X is large, which is not beneficial to the effective separation and rapid transfer of photon-generated carriers, only can absorb and utilize ultraviolet light and a small part of visible light, but does not respond to most of visible light and near infrared light, and the absorption utilization rate is low, thereby limiting the practical application of the X.

Disclosure of Invention

The invention aims to provide a photocatalyst and a preparation method thereof, and the photocatalyst provided by the invention can absorb ultraviolet light, visible light and near infrared light.

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

the invention provides a photocatalyst, the chemical composition of which is MBi_1-yRE_yO₂X；

The M comprises one or more of Ca, Sr, Ba, Pb and Cd;

the RE is a rare earth element;

the X is a halogen element;

and y is 0.001-0.9.

Preferably, the RE comprises one or more of Er, Tb, Ce and Tm.

The invention also provides a preparation method of the photocatalyst, which comprises the following steps:

according to the following M: bi: RE: o: x is 1: (1-y): y: 2: 1, mixing the M compound, the bismuth source, the rare earth compound and the halide to obtain a premix; wherein y is 0.001-0.9;

and sintering the premix or treating the premix under a supercritical condition to obtain the photocatalyst.

Preferably, when the M compound comprises an M-containing oxide, an M-containing halide, or an M-containing carbonate, the bismuth source comprises bismuth oxide or bismuth oxyhalide, the rare earth compound comprises a rare earth oxide or rare earth nitrate, and the halide comprises an ammonium halide or bismuth oxyhalide, the pre-mix is subjected to a sintering process.

Preferably, the sintering temperature is 300-1500 ℃, and the time is 1-40 h.

Preferably, the premix further comprises a solvent, and when the premix contains the solvent, the premix is treated under supercritical conditions;

the solvent comprises one or more of water, an alcohol solvent and an ester solvent.

Preferably, when the premix is treated under supercritical conditions, the M compound comprises a nitrate containing M or a halide containing M; the bismuth source comprises bismuth nitrate; the rare earth compound comprises a rare earth nitrate; the halide comprises an alkali metal halide, an ammonium halide, a M-containing halide, or a halogen-containing ionic liquid;

the concentration of the premix is 0.063-0.125 mol/L;

preferably, the temperature for processing under the supercritical condition is 110-250 ℃ and the time is 1-40 h.

Preferably, the premix further comprises, after the treatment under supercritical conditions: carrying out heat treatment on the obtained product;

the temperature of the heat treatment is 200-1200 ℃, and the time is 0.5-6 h.

The invention also provides the photocatalyst prepared by the technical scheme or the photocatalyst prepared by the preparation method in the aspects of pollutant purification, photocatalytic decomposition of water and CO₂Application in the field of photocatalytic reduction.

The invention provides a photocatalyst, the chemical formula of which is MBi_1-yRE_yO₂X; the M comprises one or more of Ca, Sr, Ba, Pb and Cd; the RE is a rare earth element; the X is a halogen element; and y is 0.001-0.9. According to the invention, by doping rare earth elements, the obtained photocatalyst can generate oxygen vacancies and/or impurity energy levels, the energy band gap is reduced, photo-generated electrons are captured, the separation efficiency of photo-generated carriers is improved, a wide spectrum response is generated, the absorption of ultraviolet light-visible light-near infrared light is realized, the light utilization rate and the activity of the photocatalyst are improved, and the photocatalytic performance is further improved.

Drawings

FIG. 1 is an X-ray diffraction pattern of the photocatalysts obtained in example 1 and comparative example 1;

FIG. 2 is an absorption spectrum of the photocatalysts obtained in example 1 and comparative example 1;

FIG. 3 is a catalytic degradation spectrum of the photocatalyst obtained in example 1 and comparative example 1 on rhodamine B;

FIG. 4 is a graph of a dynamic curve of the photocatalyst obtained in example 1 and comparative example 1 for rhodamine B;

FIG. 5 is an X-ray diffraction pattern of the photocatalysts obtained in example 2 and comparative example 2;

FIG. 6 is an absorption spectrum of the photocatalysts obtained in example 2 and comparative example 2;

FIG. 7 is a catalytic degradation spectrum of the photocatalyst obtained in example 2 and comparative example 2 on rhodamine B;

FIG. 8 is a graph of the dynamic curve of the photocatalyst for rhodamine B obtained in example 2 and comparative example 2.

Detailed Description

The invention provides a photocatalyst, the chemical composition of which is MBi_1-yRE_yO₂X；

The M comprises one or more of Ca, Sr, Ba, Pb and Cd;

the RE is a rare earth element;

the X is a halogen element;

and y is 0.001-0.9.

In the present invention, the chemical composition of the photocatalyst is MBi_1-yRE_yO₂X。

In the present invention, the M includes one or more of Ca, Sr, Ba, Pb and Cd, and when the M is two or more of the above specific choices, the ratio of the specific elements in the present invention is not particularly limited, and those skilled in the art can easily understand the ratio.

In the invention, the RE is a rare earth element, and further preferably comprises one or more of Er, Tb, Ce and Tm, and when the RE is more than two of the above specific choices, the proportion of the rare earth element is not particularly required, and the RE can be mixed according to any proportion.

In the invention, the X is a halogen element, and further preferably comprises one or more of F, Cl, Br and I, and when the X is more than two of the above specific choices, the proportion of the specific elements in the invention has no special requirement, and the specific elements can be mixed according to any proportion.

In the present invention, y is 0.001 to 0.9, more preferably 0.05 to 0.85, and still more preferably 0.1 to 0.8.

The invention also provides a preparation method of the photocatalyst in the technical scheme, which comprises the following steps:

according to the following M: bi: RE: o: x is 1: (1-y): y: 2: 1, mixing the M compound, the bismuth source, the rare earth compound and the halide to obtain a premix; wherein y is 0.001-0.9;

and sintering the premix or treating the premix under a supercritical condition to obtain the photocatalyst.

In the present invention, when the photocatalyst is prepared by a sintering method:

the preparation method of the photocatalyst comprises the following steps:

according to the following M: bi: RE: o: x is 1: (1-y): y: 2: 1, mixing the M compound, the bismuth source, the rare earth compound and the halide to obtain a premix; wherein y is 0.001-0.9;

and sintering the premix to obtain the photocatalyst.

The invention is characterized in that according to M: bi: RE: o: x is 1: (1-y): y: 2: 1, mixing the M compound, the bismuth source, the rare earth compound and the halide to obtain a premix; wherein y is 0.001 to 0.9.

In the present invention, the value of y is the same as the value of y in the above technical solution, and is not described herein again.

In the present invention, the M compound preferably includes an oxide, halide or carbonate containing M. In the present invention, M is the same as M in the above technical solution, and is not described herein again. In a particular embodiment of the invention, the M compound is in particular SrO or BaCO₃. In the present invention, the bismuth source preferably comprises bismuth oxide or bismuth oxyhalide. In the present invention, the rare earth compound preferably includes a rare earth oxide or a rare earth nitrate. In a particular embodiment of the invention, the rare earth compound is in particular Er₂O₃Or Tb₄O₇. In the present invention, the halide preferably comprises ammonium halide or bismuth oxyhalide. In a particular embodiment of the invention, the halide is in particular NH₄Cl。

In the present invention, the mixing is preferably performed by grinding. The invention has no special limitation on the grinding process and the grain diameter after grinding, and can be mixed uniformly.

After obtaining the premix, the invention sinters the premix to obtain the photocatalyst.

In the invention, the sintering temperature is preferably 300-1500 ℃, more preferably 400-1400 ℃, and more preferably 500-1300 ℃; the time is preferably 1 to 40 hours, more preferably 2 to 38 hours, and still more preferably 3 to 25 hours. In the invention, the heating rate of the sintering is preferably 3-5 ℃/min, and more preferably 4 ℃/min. In the present invention, the sintering is preferably performed under an air atmosphere. In the present invention, the specific embodiment of the sintering is preferably: and (3) putting the premix into a crucible, covering the crucible, and then putting the crucible into a muffle furnace for sintering.

After the sintering is completed, the invention also preferably comprises furnace cooling the crucible to room temperature.

In the present invention, when the photocatalyst is prepared under supercritical conditions:

the preparation method of the photocatalyst comprises the following steps:

according to the following M: bi: RE: o: x is 1: (1-y): y: 2: 1, mixing the M compound, the bismuth source, the rare earth compound, the halide and the solvent to obtain a premix; wherein y is 0.001-0.9;

and treating the premix under a supercritical condition to obtain the photocatalyst.

In the present invention, the M compound preferably includes a nitrate containing M or a halide containing M. In a particular embodiment of the invention, the M compound is in particular Ca (NO)₃)₂Or Cd (NO)₃)₂. In the present invention, the bismuth source includes bismuth nitrate. In a particular embodiment of the invention, the bismuth source is in particular Bi (NO)₃)₃·5H₂And O. In the present invention, the rare earth compound preferably includes a rare earth nitrate. In a particular embodiment of the invention, the rare earth compound is in particular Ce (NO)₃)₃Or Tm (NO)₃)₃. In the present invention, the halide preferably includes an alkali metal halide, ammonium halide, M-containing halideA halide or a halogen-containing ionic liquid, the alkali metal halide further preferably comprising a potassium halide or a sodium halide; the ionic liquid containing the halogen further preferably comprises one or more of hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl imidazole chloride. In a particular embodiment of the invention, the halide is in particular cetyltrimethylammonium chloride or KI.

In the present invention, the solvent preferably includes one or more of water, an alcohol solvent and an ester solvent; the alcohol solvent is preferably one or more of methanol, ethanol and glycol; the lipid solvent preferably comprises ethyl acetate; when the solvent is two or more selected from the above specific choices, the ratio of the specific substances in the present invention is not particularly limited, and those known to those skilled in the art may be used.

In the present invention, the mixing preferably comprises: according to the following M: bi: RE: o: x is 1: (1-y): y: 2: 1, mixing the M compound, the bismuth source, the rare earth compound and the halide for the first time, and then mixing the mixture with a solvent to obtain the premix.

In the present invention, the first mixing method is preferably grinding. The invention has no special limitation on the grinding process and the grain diameter after grinding, and can be mixed uniformly. The present invention does not have any particular limitation on the mixing with the solvent, and the mixing is carried out by a process well known to those skilled in the art and the mixing is ensured to be uniform.

In the invention, the concentration of the premix is preferably 0.063-0.125 mol/L, more preferably 0.065-0.120 mol/L, and even more preferably 0.070-0.115 mol/L.

In the present invention, it is also preferable to include adding polyvinylpyrrolidone to the premix before the treatment under the supercritical conditions. In the invention, the mass ratio of the polyvinylpyrrolidone to the M compound is preferably 0.1-1.0: 1, more preferably 1 to 9: 1, more preferably 2 to 8: 1. in the invention, the polyvinylpyrrolidone can modify the morphology of the photocatalyst, further increase the specific surface area of the photocatalyst and increase the active sites of the photocatalyst; meanwhile, the built-in electric field can be enhanced, and the separation of photon-generated carriers is facilitated.

In the invention, after the polyvinylpyrrolidone is added, the pH value is preferably adjusted, and the adjusted pH value is preferably 8-14, more preferably 9-13, and even more preferably 10-12. In the present invention, the solution used for the pH adjustment preferably includes a hydrochloric acid solution, a nitric acid solution, ammonia water, a sodium hydroxide solution, or a potassium hydroxide solution. In the present invention, the concentration and the amount of the solution to be used are not particularly limited, and the reaction solution may be adjusted to a desired pH.

In the invention, the temperature when the treatment is carried out under the supercritical condition is preferably 110-250 ℃, more preferably 120-240 ℃, and more preferably 130-230 ℃; the time is preferably 1 to 40 hours, more preferably 3 to 38 hours, and still more preferably 5 to 35 hours. In the present invention, the treatment under supercritical conditions is preferably carried out in a hydrothermal reaction vessel with a polytetrafluoroethylene inner liner. In the invention, the volume ratio of the premix to the polytetrafluoroethylene lining is preferably 0.4-0.8: 1, more preferably 0.5 to 0.7: 1, more preferably 0.6: 1.

after the treatment under the supercritical condition is finished, the invention preferably carries out post-treatment on the obtained product; the post-treatment preferably comprises filtration, washing and drying in that order.

The present invention is not particularly limited to the specific embodiments of the filtration, and those skilled in the art will be familiar with the present invention. In the present invention, the washing is preferably performed using deionized water and ethanol. The number of washes and the specific embodiment of the wash are not specifically required by the present invention and may be those well known to those skilled in the art. In the invention, the drying temperature is preferably 60-100 ℃, more preferably 70-90 ℃, and more preferably 75-85 ℃; the time is preferably 3 to 24 hours, more preferably 5 to 22 hours, and even more preferably 6 to 20 hours. The present invention does not require any special embodiment for the drying, and a dried sample can be obtained.

After the drying is completed, the invention also preferably carries out heat treatment on the product obtained by drying. In the invention, the heat treatment temperature is preferably 200-1200 ℃, more preferably 300-1100 ℃, and more preferably 400-1000 ℃; the time is preferably 0.5 to 6 hours, more preferably 1 to 5 hours, and even more preferably 2 to 4 hours. The present invention is not particularly limited to the specific embodiment of the heat treatment, and those known to those skilled in the art can be used. The heat treatment under the above conditions can further improve the crystallinity of the photocatalyst.

The invention also provides the photocatalyst prepared by the technical scheme and the photocatalyst prepared by the preparation method of the technical scheme, which are used for purifying pollutants, decomposing water and CO through photocatalysis₂Application in the field of photocatalytic reduction. The present invention is not particularly limited to the specific embodiments for the applications, and those skilled in the art will be familiar with the application.

In order to further illustrate the present invention, the following detailed description of a photocatalyst provided by the present invention, its preparation method and application are provided in conjunction with the accompanying drawings and examples, which should not be construed as limiting the scope of the present invention.

Example 1

According to Sr: bi: er: o: cl ═ 1: 0.9: 0.1: 2: 1 molar ratio of 1.0484g of Bi₂O₃、0.0956g Er₂O₃0.5181g SrO and 0.3209gNH₄Mixing Cl, and grinding to obtain a premix;

and putting the premix into a crucible and covering, then putting the crucible into a muffle furnace, heating to 700 ℃, preserving heat for 20 hours, and then cooling to room temperature along with the furnace to obtain the photocatalyst.

The chemical formula of the photocatalyst obtained in the example is SrBi_0.9Er_0.1O₂Cl。

Example 2

According to the weight ratio of Ba: bi: tb: o: cl ═ 1: 0.8: 0.2: 2: 1 molar ratio of 0.9319g of Bi₂O₃、0.1869g Tb₄O₇、0.9867g BaCO₃And 0.3209gNH₄Mixing Cl, and grinding to obtain a premix;

and putting the premix into a crucible and covering, then putting the crucible into a muffle furnace, heating to 900 ℃, preserving heat for 24 hours, and then cooling to room temperature along with the furnace to obtain the photocatalyst.

The chemical formula of the photocatalyst obtained in this example is BaBi_0.8Tb_0.2O₂Cl。

Example 3

According to the Ca: bi: ce: o: cl ═ 1: 0.85: 0.15: 2: 1, 2.0615g of Bi (NO)₃)₃·5H₂O、0.2446g Ce(NO₃)₃、0.8205g Ca(NO₃)₂And 1.6000g of hexadecyl trimethyl ammonium chloride are dissolved in 60mL of ethanol, and then ammonia water is added to adjust the pH value to 13 to obtain a premix; then the premix is put into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, and the volume ratio of the premix to the polytetrafluoroethylene lining is 0.6: 1; then heating to 160 ℃, and preserving heat for 20 hours;

and after the reaction is finished, filtering the reaction solution, washing the filtered material with deionized water and ethanol for multiple times respectively, and drying at 60 ℃ to obtain the photocatalyst.

The chemical formula of the photocatalyst obtained in this example is CaBi_0.85Ce_0.15O₂Cl。

Example 4

According to Cd: bi: tm: o: 1: 0.8: 0.2: 2: 1, 1.9403g of Bi (NO)₃)₃·5H₂O、0.3550g Tm(NO₃)₃、1.1821g Cd(NO₃)₂0.8300g of KI is dissolved in 70mL of deionized water, and then NaOH solution is added to adjust the pH value to 12 to obtain premix; then the premix is put into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, and the volume ratio of the premix to the polytetrafluoroethylene lining is 0.7: 1; then heating to 180 ℃, and preserving heat for 16 h;

and after the reaction is finished, filtering the reaction solution, washing the filtered material with deionized water and ethanol for multiple times respectively, and drying at 80 ℃ to obtain the photocatalyst.

The chemical formula of the photocatalyst obtained in the example is CdBi_0.8Tm_0.2O₂I。

Example 5

According to the Ca: bi: ce: o: cl ═ 1: 0.85: 0.15: 2: 1, 2.0615g of Bi (NO)₃)₃·5H₂O、0.2446g Ce(NO₃)₃、0.8205g Ca(NO₃)₂And 1.6000g of hexadecyl trimethyl ammonium chloride are dissolved in 60mL of ethanol, and then ammonia water is added to adjust the pH value to 13 to obtain a premix; then the premix is put into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, and the volume ratio of the premix to the polytetrafluoroethylene lining is 0.6: 1; then heating to 160 ℃, and preserving heat for 20 hours;

and after the reaction is finished, filtering the reaction solution, washing the filtered material with deionized water and ethanol for multiple times respectively, drying at 60 ℃, and then carrying out heat treatment at 500 ℃ for 6 hours to obtain the photocatalyst.

The chemical formula of the photocatalyst obtained in this example is CaBi_0.85Ce_0.15O₂Cl。

Example 6

According to the Ca: bi: ce: o: cl ═ 1: 0.85: 0.15: 2: 1, 2.0615g of Bi (NO)₃)₃·5H₂O、0.2446g Ce(NO₃)₃、0.8205g Ca(NO₃)₂Dissolving 1.6000g of hexadecyl trimethyl ammonium chloride and 1.0308g of polyvinylpyrrolidone in 60mL of ethanol, and adding ammonia water to adjust the pH value to 13 to obtain a premix; then the premix is put into a hydrothermal reaction kettle with a polytetrafluoroethylene lining, and the volume ratio of the premix to the polytetrafluoroethylene lining is 0.6: 1; then heating to 160 ℃, and preserving heat for 20 hours;

and after the reaction is finished, filtering the reaction solution, washing the filtered material with deionized water and ethanol for multiple times respectively, drying at 60 ℃, and then carrying out heat treatment at 500 ℃ for 6 hours to obtain the photocatalyst.

The chemical formula of the photocatalyst obtained in this example is CaBi_0.85Ce_0.15O₂Cl。

Comparative example 1

A photocatalyst was prepared by referring to the method of example 1 except that Er was not added₂O₃The chemical formula of the obtained photocatalyst is SrBiO₂Cl。

Comparative example 2

A photocatalyst was prepared by referring to the procedure of example 2 except that Tb was not added₄O₇The chemical formula of the obtained photocatalyst is BaBiO₂Cl。

Performance testing

Test example 1

The photocatalysts obtained in examples 1-2 and comparative examples 1-2 were subjected to an X-ray diffraction test in the following manner (test conditions): the test range is 10-80 degrees, the voltage is 40KV, the current is 30mA, the step width is 0.02 degree, and the sampling time is 0.1 s. Wherein the test results of example 1 and comparative example 1 are shown in FIG. 1, it can be seen from FIG. 1 that pure-phase SrBiO was successfully prepared₂Cl and SrBi_0.9Er_0.1O₂Cl; the test results of example 2 and comparative example 2 are shown in fig. 5, and it can be seen from fig. 5 that pure phase BaBiO was successfully prepared₂Cl and BaBi_0.8Tb_0.2O₂Cl。

Test example 2

The photocatalysts obtained in the examples 1-2 and the comparative examples 1-2 are subjected to an absorption spectrogram test, and the test method (conditions) are as follows: the test range is 200-2000 nm, the step width is 1nm, and the test speed is 600 nm/min. The test results of the example 1 and the comparative example 1 are shown in FIG. 2, and it can be seen from FIG. 2 that the doping of the rare earth element Er enhances the absorption of the photocatalyst in the ultraviolet-visible light; the test results of example 2 and comparative example 2 are shown in fig. 6, and it can be seen from fig. 6 that the incorporation of the rare earth element Tb significantly enhances the absorption of the photocatalyst in uv-vis-nir.

Test example 3

The photocatalysts obtained in the embodiments 1-2 and the comparative examples 1-2 are used for carrying out a catalytic degradation test on rhodamine B, and the test method comprises the following steps: the xenon lamp power is 500W, the concentration of rhodamine B is 10mg/L, the dosage is 50mL, and the photocatalyst is 50 mg. Wherein, FIG. 3 is a catalytic degradation diagram of the photocatalyst obtained in example 1 and comparative example 1 for rhodamine B under ultraviolet-visible-near infrared lightSpectrum, as can be seen from FIG. 3, SrBiO was observed after two hours of light irradiation₂The degradation rate of Cl on rhodamine B is 45.5 percent, and SrBi_0.9Er_0.1O₂The degradation rate of Cl on rhodamine B is 81.3 percent; FIG. 4 is a graph of a kinetic curve of the photocatalyst obtained in example 1 and comparative example 1 on rhodamine B under ultraviolet-visible-near infrared light, and from FIG. 4, SrBi can be seen_0.9Er_0.1O₂The degradation rate of Cl is SrBiO₂2.55 times of Cl; FIG. 7 shows the catalytic degradation spectrum of the photocatalysts obtained in example 2 and comparative example 2 on rhodamine B under ultraviolet-visible-near infrared light, and it can be seen from FIG. 7 that BaBiO is formed after two hours of light irradiation₂The degradation rate of Cl on rhodamine B is 49.5 percent, and BaBi_0.8Tb_0.2O₂The degradation rate of Cl on rhodamine B is 89.1%; FIG. 8 is a graph of a kinetic curve of the photocatalyst obtained in example 2 and comparative example 2 on rhodamine B under ultraviolet-visible-near infrared light, and BaBi can be seen from FIG. 8_0.8Tb_0.2O₂The degradation rate of Cl is BaBiO₂3.26 times of Cl.

Although the above embodiments have been described in detail, they are only a part of the embodiments of the present invention, not all of the embodiments, and other embodiments can be obtained without inventive step according to the embodiments, and all of the embodiments belong to the protection scope of the present invention.