Preparation method and application of Yb and Er co-doped S-type heterojunction

Abstract

The application discloses a preparation method and application of Yb and Er co-doped S-type heterojunction, and the Yb and Er co-doped S-type heterojunction is synthesized by using indium nitrate, silver nitrate and thioacetamide as raw materials, through a hydrothermal method, AgIn5S8 is synthesized by etching Ti3AlC2 through HF, Ti3C2T x MXene. Bismuth nitrate and potassium chloride are used as raw materials, a certain amount of ytterbium nitrate, erbium nitrate, AgIn5S8 and MXene are added, then a Yb and Er co-doped BiOCl / MXene / AgIn5S8 composite material is synthesized through an in-situ hydrothermal growth method, and the catalyst is applied to degradation of wastewater containing tetracycline hydrochloride, can realize effective degradation of antibiotic wastewater under visible light and near-infrared light respectively. Meanwhile, the catalyst has full-spectrum response performance, can fully utilize clean energy solar energy, and realizes efficient purification of water pollutants.

Description

Technical Field

[0001] This invention belongs to the field of water treatment antibiotic degradation technology, specifically relating to a method for preparing and applying a Yb and Er co-doped S-type heterojunction. Background Technology

[0002] Water resources are the material foundation for human society's production and development, and are an irreplaceable resource. Photocatalysis technology can effectively and rapidly degrade water pollutants (such as antibiotics), mineralizing them into non-toxic inorganic small molecules.

[0003] Currently, common wastewater treatment methods include adsorption, membrane separation, photocatalysis, electrochemical methods, and biological treatment. Among these, adsorption has advantages such as wide applicability and good treatment effect, providing an effective method for solving the long-term difficult-to-treat, low-concentration, highly toxic, and recalcitrant organic pollutants in wastewater. However, it also has problems such as the difficulty in green treatment of adsorbed antibiotics and the difficulty in regenerating adsorbents. Photocatalysis technology can directly utilize green, clean, and renewable energy—solar energy—to excite semiconductor materials, generating photogenerated electrons and holes in their conduction band (CB) and valence band (VB), respectively, subsequently forming surface-reactive oxygen species (ROS), including superoxide radicals (·O2). - It degrades antibiotics into small molecules such as CO2 and H2O by generating free radicals such as hydroxyl radicals (·OH), and has the characteristics of low price, easy large-scale production, and no secondary pollution.

[0004] In view of the above factors, a method for preparing and applying a Yb and Er co-doped S-type heterojunction has been developed. This invention can effectively degrade tetracycline hydrochloride in water under visible light conditions, and can make full use of clean energy such as solar energy. The method is simple to operate, low in cost, and mild in reaction conditions. It can achieve efficient purification of polluted water bodies. The catalyst is non-toxic and harmless, environmentally friendly, and causes little secondary pollution to the water environment. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing and applying a Yb and Er co-doped S-type heterojunction, in order to solve the problems mentioned in the background art.

[0006] The objective of this invention is achieved through the following technical solution: a method for preparing a Yb and Er co-doped S-type heterojunction, comprising using rare earth Yb... 3+ Er 3+ Doping with BiOCl improves light absorption and utilization efficiency through the upconversion effect, broadening its light absorption range to the NIR region and achieving a full-spectrum response; introducing MXene (Ti3C2T) further enhances this effect. xYbEr-BiOCl / MXene / AgIn5S8 S-type heterojunction was constructed using AgIn5S8 to improve the separation efficiency of photogenerated carriers and enhance the photocatalytic performance of BiOCl. The S-type heterojunction was then applied to the degradation of tetracycline hydrochloride in water.

[0007] The method for preparing a Yb and Er co-doped S-type heterojunction includes the following steps:

[0008] Step 1: Prepare AgIn5S8 using a hydrothermal method;

[0009] AgIn5S8 was prepared using a one-step hydrothermal method. In(NO3)3·4.5H2O and AgNO3 were dissolved in a mixed solution of anhydrous ethanol and deionized water, and stirred to form a clear solution (solution A). Thioacetamide was dissolved in anhydrous ethanol (solution B), and solution B was added dropwise to solution A. The mixture was stirred for 30 min, and then the turbid solution was transferred to an autoclave and heated in an oven at 180 °C for 15–24 h. The solution was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C for 12–24 h and designated as AgIn5S8.

[0010] Step 2, Preparation of exfoliated Ti3C2T x MXene nanosheets;

[0011] Add LiF (2-3.2g) to HCl (20-40mL) solution and react at 40-50°C for 10-20min. Then add Ti3AlC2 (1-2g), set the water bath temperature to 40-50°C, and stir for 24-48h. After etching, wash the precipitate several times with hydrochloric acid and water by centrifugation. Add water to the precipitate and sonicate for 0.5-3h. After sonication, centrifuge at 3500 rpm for 5-60min and collect the supernatant, which is denoted as MXene.

[0012] Step 3: Prepare a Yb and Er co-doped BiOCl / MXene / AgIn5S82D / 2D / 0D S-type heterojunction;

[0013] Bismuth nitrate, potassium chloride, and certain amounts of erbium nitrate and ytterbium nitrate were dissolved in a mixed solution of anhydrous ethanol and deionized water (V:V = 3:1). The solution was sonicated for 30-60 min, then stirred for 2-3 h. AgIn5S8 (15-40 mg) and MXene (10-20 mg) obtained in steps 1 and 2 were added to the solution, and the mixture was stirred for 1-2 h. The pH was adjusted to approximately 6 with ammonia water, and the solution was transferred to an autoclave and heated in a 160°C oven for 12-24 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60°C for 12-24 h and designated as YbEr-BiOCl / MXene / AgIn5S8.

[0014] An application of a method for preparing a Yb and Er co-doped S-type heterojunction involves combining Yb and Er co-doped BiOCl / MXene / AgIn5S8 to form a 2D / 2D / 0D S-type heterojunction composite material, which is then used to degrade wastewater containing tetracycline hydrochloride under visible and near-infrared light using a photocatalyst.

[0015] Furthermore, the steps for degrading tetracycline hydrochloride using an S-type heterojunction under visible and near-infrared light include:

[0016] I. Prepare a tetracycline hydrochloride solution of a certain concentration;

[0017] II. Measure a certain volume of the tetracycline hydrochloride solution from step I and place it in the reaction vessel;

[0018] III. Add the YbEr-BiOCl / MXene / AgIn5S8 photocatalyst to the solution in step II;

[0019] IV. Place the solution from step III in a dark environment and stir for 10-60 minutes to reach adsorption-desorption equilibrium;

[0020] V. After step IV is completed, turn on the light source and carry out the reaction at 15-35℃. Take samples at regular intervals and use a UV-Vis spectrophotometer to determine the remaining amount of tetracycline hydrochloride.

[0021] Furthermore, in step IV, 3 mL of solution is taken every 10 minutes; in step V, 3 mL of solution is taken every 5 minutes, for a total of 30 minutes.

[0022] Furthermore, in step V, the light source used is a 300W xenon lamp, and a cutoff filter is used to obtain visible light with a wavelength greater than 420nm and near-infrared light with a wavelength of 980nm.

[0023] The application of the method for preparing Yb and Er co-doped S-type heterojunctions includes the following steps;

[0024] 0.97 g of bismuth nitrate, 0.149 g of potassium chloride, and a certain amount of 8.867 mg of erbium nitrate and 59.9 mg of ytterbium nitrate were dissolved in 80 mL of a mixture of anhydrous ethanol and deionized water (V:V = 3:1). After sonication for 30 min, the mixture was stirred for 2 h. AgIn5S8 (26 mg) and MXene (15 mg) obtained in steps 1 and 2 were added to the above solution and stirred for 1 h. The pH was adjusted to about 6 with ammonia water. The mixture was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C under vacuum for 12 h and labeled as BMA5. After grinding, the sample was ready for use.

[0025] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and then 20 mg of photocatalyst was added. The mixture was stirred for 30 min in the dark under constant temperature circulating water at 25 °C to reach adsorption-desorption equilibrium. Subsequently, a xenon lamp source was turned on, and visible light with a wavelength greater than 420 nm was obtained using a 420 nm cutoff filter to carry out the photocatalytic degradation reaction for 30 min. 3 mL of solution was taken every 5 min. After centrifugation at 10,000 rpm, the supernatant was collected, and the remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer. The degradation efficiency of tetracycline hydrochloride by this method within 30 min was 92%.

[0026] The application of the method for preparing Yb and Er co-doped S-type heterojunctions includes the following steps;

[0027] 0.97 g of bismuth nitrate, 0.149 g of potassium chloride, and a certain amount of 8.867 mg of erbium nitrate and 59.9 mg of ytterbium nitrate were dissolved in 80 mL of a mixture of anhydrous ethanol and deionized water (V:V = 3:1). After sonication for 30 min, the mixture was stirred for 2 h. AgIn5S8 (26 mg) and MXene (15 mg) obtained in steps 1 and 2 were added to the above solution and stirred for 1 h. The pH was adjusted to about 6 with ammonia water. The mixture was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C under vacuum for 12 h and labeled as BMA5. After grinding, the sample was ready for use.

[0028] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and then 20 mg of photocatalyst was added. The mixture was stirred for 30 min in the dark under constant temperature circulating water at 25 °C to reach adsorption-desorption equilibrium. Subsequently, a xenon lamp source was turned on, and near-infrared light at 980 nm was used to carry out the photocatalytic degradation reaction for 120 min. 3 mL of solution was taken every 30 min. After centrifugation at 10,000 rpm, the supernatant was collected, and the remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer. The degradation efficiency of tetracycline hydrochloride by this method within 120 min was 55.8%.

[0029] This invention utilizes rare earth Yb 3+ Er 3+ Doping with BiOCl improves light absorption and utilization efficiency through the upconversion effect, broadening its light absorption range to the NIR region and achieving a full-spectrum response; introducing MXene (Ti3C2T) further enhances this effect. xYbEr-BiOCl / MXene / AgIn5S8S-type heterojunction was constructed using AgIn5S8 to improve the separation efficiency of photogenerated carriers and enhance the photocatalytic performance of BiOCl. This heterojunction was then applied to the degradation of tetracycline hydrochloride in water.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] This invention effectively degrades tetracycline hydrochloride in water under visible and near-infrared light conditions, enabling full utilization of clean energy such as solar power.

[0032] The method of the present invention is simple to operate, low in cost, and has mild reaction conditions, and can achieve efficient purification of polluted water bodies.

[0033] The catalyst used in this invention has low cost, readily available raw materials, low energy consumption, high catalytic degradation efficiency, is non-toxic and harmless, environmentally friendly, and causes little secondary pollution to the aquatic environment.

[0034] Preparation of rare earth Yb by in-situ solvothermal method 3+ Er 3+ Doping with BiOCl improves light absorption and utilization efficiency through the upconversion effect, broadens its light absorption range to the NIR region, and achieves a full-spectrum response.

[0035] Construct Yb 3+ Er 3+ An S-type heterojunction doped with BiOCl / MXene / AgIn5S82D / 2D / 0D was used to investigate the ability of semiconductor heterojunction catalysts to adsorb and degrade antibiotics. Attached Figure Description

[0036] Figure 1 The XRD images of the AgIn5S8, MXene, BiOCl, YbEr-BiOCl, YbEr-BiOCl / MXene, and YbEr-BiOCl / MXene / AgIn5S8 photocatalysts prepared in the examples are named AIS, MXene, BiOCl, EYB, BM15, and BMA15.

[0037] Figure 2 Here is a SEM image of the pure BiOCl prepared in the examples;

[0038] Figure 3 Here is a SEM image of the pure MXene prepared in the examples;

[0039] Figure 4 Here is a SEM image of the pure AgIn5S8 prepared in the examples;

[0040] Figure 5Here is a SEM image of the BMA5 photocatalyst prepared in the examples;

[0041] Figure 6 The image shows a TEM image of the BMA5 photocatalyst prepared in the examples.

[0042] Figure 7 The image shows a TEM image of the BMA5 photocatalyst prepared in the examples.

[0043] Figure 8 The image shows a TEM image of the BMA5 photocatalyst prepared in the examples.

[0044] Figure 9 The image shows the degradation of tetracycline hydrochloride by the AIS, MXene, BiOCl, EYB, BM15, and BMA5 photocatalysts prepared in the examples under visible light.

[0045] Figure 10 The degradation diagram of tetracycline hydrochloride by the AIS, MXene, BiOCl, EYB, BM15, and BMA5 photocatalysts prepared in the examples under near-infrared light is shown.

[0046] Figure 11 The image shows the UC emission spectra of the YEB and BMA5 photocatalysts prepared in the examples.

[0047] Figure 12 The images shown are EIS images of AIS, EYB, and BMA5 prepared in the examples.

[0048] Figure 13 The photocurrent diagrams of AIS, EYB, and BMA5 prepared in the examples are shown.

[0049] Figure 14 The effect of different concentrations of tetracycline hydrochloride on the photocatalytic degradation of BMA5 is illustrated in the examples.

[0050] Figure 15 The examples illustrate the effect of different coexisting ions on the degradation of tetracycline hydrochloride by BMA5 photocatalyst.

[0051] Figure 16 The effect of different amounts of catalyst on the degradation of tetracycline hydrochloride by BMA5 photocatalyst in the examples;

[0052] Figure 17 The effect of different pH environments on the degradation of tetracycline hydrochloride by BMA5 photocatalyst is shown in the examples. Detailed Implementation

[0053] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0054] like Figure 1-17 As shown, the visible light catalytic degradation method for tetracycline hydrochloride in water provided by the present invention includes two steps: preparation of a Yb and Er co-doped BiOCl / MXene / AgIn5S82D / 2D / 0D S-type heterojunction and its use for photocatalytic degradation of tetracycline hydrochloride under visible light.

[0055] The preparation steps of the Yb and Er co-doped BiOCl / MXene / AgIn5S82D / 2D / 0D S-type heterojunction include:

[0056] The first step was to prepare pure BiOCl using a hydrothermal method.

[0057] 0.97 g Bi(NO3)3·5H2O and 0.149 g KCl were dissolved in a mixed solution of 60 mL anhydrous ethanol and 20 mL deionized water. After sonication for 30 min, the mixture was stirred for 2 h. The pH was adjusted to approximately 6 with ammonia water, and the solution was transferred to an autoclave and heated in an oven at 160 °C for 12 h. The solution was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain BiOCl, which was named BiOCl.

[0058] The second step involves preparing AgIn5S8 using a hydrothermal method.

[0059] 601.66 mg In(NO3)3·4.5H2O and 67.95 mg AgNO3 were dissolved in a mixture of 40 mL anhydrous ethanol and deionized water (V:V = 1:1), and the solution was continuously stirred magnetically for 30 min to form a clear solution (solution A). 601.04 mg thioacetamide was dissolved in 20 mL anhydrous ethanol (solution B), and solution B was added dropwise to solution A. The mixture was stirred magnetically for 30 min, and then the turbid solution was transferred to an autoclave and heated in an oven at 180 °C for 15 h. The solution was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C for 12 h to obtain AgIn5S8, which was named AIS.

[0060] The third step is to prepare Ti3C2T. x MXene

[0061] Add 40 mL of 12 M HCl to a PTFE autoclave, then slowly add 3.2 g of LiF. Place the autoclave in an ice-water bath and stir at 500 rpm until completely dissolved. Weigh 2.0 g of Ti3AlC2 using a plastic spoon and add it to the etching reagent in small amounts several times. After complete addition, cover the autoclave, leaving a vent hole. Set the water bath temperature to 40°C and stir for 48 hours. After etching, centrifuge the resulting black solution at 3500 rpm, collect the bottom precipitate, add 1 M dilute hydrochloric acid to redissolve it, and continue washing to remove excess LiF and other impurities. Repeat washing three times, then centrifuge three times with deionized water. The upper solution gradually becomes turbid and separates into layers. At this point, set the speed to 7800 rpm and continue centrifuging until pH = 6. Collect the precipitate. Add water to the precipitate and sonicate for 2 hours. During sonication, an inert gas must be introduced and the system sealed. Sonication should be performed in an ice-water bath. After sonication, centrifuge at 3500 r / min for 30 min, collect the supernatant liquid to obtain MXene, and name it MXene;

[0062] The fourth step involves preparing Yb and Er co-doped BiOCl using a hydrothermal method.

[0063] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixed solution of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 2 h, and the pH was adjusted to approximately 6 with ammonia. The solution was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain YbEr-BiOCl, named EYB.

[0064] The fifth step involves preparing Yb and Er co-doped BiOCl / MXene using a hydrothermal method.

[0065] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. After sonication for 30 min and stirring for 1 h, 15 mg MXene was added, and the mixture was sonicated for 30 min. The pH was adjusted to approximately 6 with ammonia, and the mixture was stirred for 30 min. The mixture was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain YbEr-BiOCl / MXene, which was named BM15.

[0066] Step 6: Prepare Yb and Er co-doped BiOCl / MXene / AgIn5S8 using a hydrothermal method.

[0067] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 1 h, and then 15 mg MXene was added. The mixture was sonicated for another 30 min, followed by the addition of 26 mg AgIn5S8. The mixture was stirred for 30 min, and the pH was adjusted to approximately 6 with ammonia. After stirring for another 30 min, the solution was transferred to an autoclave and heated in a 160 °C oven for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain YbEr-BiOCl / MXene / AgIn5S8, which was named BMA5.

[0068] The steps for photocatalytic degradation of tetracycline hydrochloride under visible light using a photocatalyst include:

[0069] First, measure 100 mL of a 10 mg / L tetracycline hydrochloride solution and place it in a reaction vessel, then add 20 mg of photocatalyst.

[0070] The second step is to stir the mixture solution in a constant temperature circulating water environment at 25°C for 30 minutes in the dark to reach adsorption-desorption equilibrium.

[0071] The third step is to turn on the light source to carry out the photocatalytic degradation reaction for 30 minutes, and take 3 mL of solution every 5 minutes.

[0072] The fourth step involves centrifuging the sample at 10,000 rpm, taking the supernatant, and measuring the remaining tetracycline hydrochloride using a UV-8000, Metalash, China spectrophotometer.

[0073] In this invention, the light source used in step 3 of photocatalytic degradation of tetracycline hydrochloride under visible light using a photocatalyst is a xenon lamp (PLS-SXE300, Perfectlight, China), and a 420nm cutoff filter is used to obtain visible light with a wavelength greater than 420nm. Specific Implementation Example 1:

[0075] 0.97 g Bi(NO3)3·5H2O and 0.149 g KCl were dissolved in a mixed solution of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 2 h, and the pH was adjusted to approximately 6 with ammonia. The solution was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain BiOCl, which was named BiOCl and ground for later use.

[0076] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 30 min, with 3 mL of solution taken every 5 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 30 min was 41.24%. Specific Implementation Example 2:

[0078] 601.66 mg In(NO3)3·4.5H2O and 67.95 mg AgNO3 were dissolved in a mixture of 40 mL anhydrous ethanol and deionized water (V:V = 1:1), and the solution was continuously stirred magnetically for 30 min to form a clear solution (solution A). 601.04 mg thioacetamide was dissolved in 20 mL anhydrous ethanol (solution B), and solution B was added dropwise to solution A. The mixture was stirred magnetically for 30 min, and then the turbid solution was transferred to an autoclave and heated in an oven at 180 °C for 15 h. The solution was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C for 12 h to obtain AgIn5S8, named AIS, which was then ground and stored for later use.

[0079] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 30 min, with 3 mL of solution taken every 5 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 30 min was 46.59%. Specific Implementation Example 3:

[0081] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 2 h, and the pH was adjusted to approximately 6 with ammonia. The solution was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain YbEr-BiOCl, named EYB, which was then ground and stored for later use.

[0082] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 30 min, with 3 mL of solution taken every 5 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 30 min was 56.06%. Specific Implementation Example 4:

[0084] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. After sonication for 30 min and stirring for 1 h, 15 mg MXene was added, and the mixture was sonicated for 30 min. The pH was adjusted to approximately 6 with ammonia water, and the mixture was stirred for 30 min. The mixture was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C under vacuum for 12 h to obtain YbEr-BiOCl / MXene, named BM15, which was then ground and stored for later use.

[0085] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 30 min, with 3 mL of solution taken every 5 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). This method showed a degradation efficiency of 86% for tetracycline hydrochloride within 30 minutes. Specific Implementation Example 5:

[0087] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 1 h, and then 15 mg MXene was added. The mixture was sonicated for another 30 min, followed by the addition of 26 mg AgIn5S8. The mixture was stirred for 30 min, and the pH was adjusted to approximately 6 with ammonia. After stirring for another 30 min, the solution was transferred to an autoclave and heated in a 160 °C oven for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain YbEr-BiOCl / MXene / AgIn5S8, named BMA5, and ground for later use.

[0088] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 30 min, with 3 mL of solution taken every 5 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). This method showed a 92% degradation efficiency of tetracycline hydrochloride within 30 minutes.

[0089] The steps for photocatalytic degradation of tetracycline hydrochloride under near-infrared light using a photocatalyst include:

[0090] First, measure 100 mL of a 10 mg / L tetracycline hydrochloride solution and place it in a reaction vessel, then add 20 mg of photocatalyst.

[0091] The second step is to stir the mixture solution in a constant temperature circulating water environment at 25°C for 30 minutes in the dark to reach adsorption-desorption equilibrium.

[0092] The third step is to turn on the light source and carry out the photocatalytic degradation reaction for 120 minutes, taking 3 mL of solution every 30 minutes.

[0093] The fourth step involves centrifuging the sample at 10,000 rpm, taking the supernatant, and measuring the remaining tetracycline hydrochloride using a UV-8000, Metalash, China spectrophotometer.

[0094] In this invention, the light source used in step 3 of the photocatalytic degradation of tetracycline hydrochloride under near-infrared light is a xenon lamp (PLS-SXE300, Perfectlight, China), and a 980nm filter is used. Specific Implementation Example Six:

[0096] 0.97 g Bi(NO3)3·5H2O and 0.149 g KCl were dissolved in a mixed solution of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 2 h, and the pH was adjusted to approximately 6 with ammonia. The solution was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain BiOCl, which was named BiOCl and ground for later use.

[0097] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 120 min, with 3 mL of solution taken every 30 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 120 min was 18.67%. Specific Implementation Example 7:

[0099] 601.66 mg In(NO3)3·4.5H2O and 67.95 mg AgNO3 were dissolved in a mixture of 40 mL anhydrous ethanol and deionized water (V:V = 1:1), and the solution was continuously stirred magnetically for 30 min to form a clear solution (solution A). 601.04 mg thioacetamide was dissolved in 20 mL anhydrous ethanol (solution B), and solution B was added dropwise to solution A. The mixture was stirred magnetically for 30 min, and then the turbid solution was transferred to an autoclave and heated in an oven at 180 °C for 15 h. The solution was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C for 12 h to obtain AgIn5S8, named AIS, which was then ground and stored for later use.

[0100] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 120 min, with 3 mL of solution taken every 30 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 120 min was 17.93%. Specific Implementation Example 8:

[0102] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 2 h, and the pH was adjusted to approximately 6 with ammonia. The solution was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain YbEr-BiOCl, named EYB, which was then ground and stored for later use.

[0103] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 120 min, with 3 mL of solution taken every 30 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 120 min was 32.99%. Specific Implementation Example Nine:

[0105] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. After sonication for 30 min and stirring for 1 h, 15 mg MXene was added, and the mixture was sonicated for 30 min. The pH was adjusted to approximately 6 with ammonia water, and the mixture was stirred for 30 min. The mixture was then transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C under vacuum for 12 h to obtain YbEr-BiOCl / MXene, named BM15, which was then ground and stored for later use.

[0106] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 120 min, with 3 mL of solution taken every 30 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 120 min was 36.96%. Specific Implementation Example 10:

[0108] 0.97 g Bi(NO3)3·5H2O, 0.149 g KCl, 8.867 mg Er(NO3)3·5H2O, and 59.9 mg Yb(NO3)3·5H2O were dissolved in a mixture of 60 mL anhydrous ethanol and 20 mL deionized water. The solution was sonicated for 30 min, stirred for 1 h, and then 15 mg MXene was added. The mixture was sonicated for another 30 min, followed by the addition of 26 mg AgIn5S8. The mixture was stirred for 30 min, and the pH was adjusted to approximately 6 with ammonia. After stirring for another 30 min, the solution was transferred to an autoclave and heated in a 160 °C oven for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried under vacuum at 60 °C for 12 h to obtain YbEr-BiOCl / MXene / AgIn5S8, named BMA5, and ground for later use.

[0109] 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and 20 mg of photocatalyst was added. The mixture was stirred in the dark for 30 min under constant temperature circulating water at 25°C to reach adsorption-desorption equilibrium. Then, a xenon lamp (PLS-SXE300, Perfectlight, China) was turned on, and visible light with wavelengths greater than 420 nm was obtained using a 420 nm cutoff filter for photocatalytic degradation. The reaction time was 120 min, with 3 mL of solution taken every 30 min. The samples were centrifuged at 10,000 rpm, and the supernatant was collected. The remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer (UV-8000, Metalash, China). The degradation efficiency of this method for tetracycline hydrochloride within 120 min was 55.78%.

[0110] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0111] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing a Yb and Er co-doped S-type heterojunction, characterized in that: Including through rare earth Yb 3+ Er 3+ Doping with BiOCl improves light absorption and utilization efficiency through the upconversion effect, broadens its light absorption range to the NIR region, and achieves a full-spectrum response; by introducing Ti3C2T... x MXene and AgIn5S8 were used to construct a YbEr-BiOCl / MXene / AgIn5S8 S-type heterojunction, which improved the separation efficiency of photogenerated carriers and enhanced the photocatalytic performance of BiOCl. The S-type heterojunction was then applied to the degradation treatment of tetracycline hydrochloride in water. Specifically, the following steps are included: Step 1: Prepare AgIn5S8 using a hydrothermal method; AgIn5S8 was prepared using a one-step hydrothermal method. In(NO3)3•4.5H2O and AgNO3 were dissolved in a mixed solution of anhydrous ethanol and deionized water, and stirred to form a clear solution (solution A). Thioacetamide was dissolved in anhydrous ethanol to obtain solution B. Solution B was added dropwise to solution A, and the mixture was stirred for 30 min. The turbid solution was then transferred to an autoclave and heated in an oven at 180℃ for 15-24 h. The solution was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60℃ for 12-24 h and denoted as AgIn5S8. 8； Step 2, Preparation of exfoliated Ti3C2T x MXene nanosheets; Add 2-3.2 g LiF to 20-40 mL HCl solution and react at 40-50℃ for 10-20 min. Then add 1-2 g Ti3AlC2, set the water bath temperature to 40-50℃, and stir for 24-48 h. After etching, wash the precipitate several times with hydrochloric acid and water by centrifugation. Add water to the precipitate and sonicate for 0.5-3 h. After sonication, centrifuge at 3500 rpm for 5-60 min and collect the supernatant, which is denoted as MXene. Step 3: Prepare a Yb and Er co-doped BiOCl / MXene / AgIn5S8 2D / 2D / 0D S-type heterojunction; Bismuth nitrate, potassium chloride, erbium nitrate, and ytterbium nitrate were dissolved in a mixed solution of anhydrous ethanol and deionized water at a ratio of V:V = 3:

1. After sonication for 30-60 min, the solution was stirred for 2-3 h. 15-40 mg of AgIn5S8 and 10-20 mg of MXene obtained in steps 1 and 2 were added to the above solution and stirred for 1-2 h. The pH was adjusted to 6 with ammonia water, and the solution was transferred to an autoclave and heated in an oven at 160°C for 12-24 h. The solution was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60°C for 12-24 h and designated as YbEr-BiOCl / MXene / AgIn5S8.

2. An application of a Yb and Er co-doped S-type heterojunction obtained by the preparation method according to claim 1, characterized in that: By combining Yb and Er co-doped BiOCl / MXene / AgIn5S8 to form a 2D / 2D / 0D S-type heterojunction composite material, the degradation of wastewater containing tetracycline hydrochloride was achieved using a photocatalyst under visible and near-infrared light.

3. The application according to claim 2, characterized in that: The steps for degrading tetracycline hydrochloride using S-type heterojunctions under visible and near-infrared light include: I. Prepare a tetracycline hydrochloride solution of a certain concentration; II. Measure a certain volume of the tetracycline hydrochloride solution from step I and place it in the reaction vessel; III. Add the YbEr-BiOCl / MXene / AgIn5S8 photocatalyst to the solution from step II; IV. Place the solution from step III in a dark environment and stir for 10-60 min to reach adsorption-desorption equilibrium; V. After step IV is completed, turn on the light source and carry out the reaction at 15-35℃. Take samples at regular intervals and use a UV-Vis spectrophotometer to determine the remaining amount of tetracycline hydrochloride.

4. The application according to claim 3, characterized in that: In step IV, 3 mL of solution is taken every 10 minutes; in step V, 3 mL of solution is taken every 5 minutes for 30 minutes.

5. The application according to claim 4, characterized in that: In step V, a 300 W xenon lamp is used as the light source, and a cutoff filter is used to obtain visible light with a wavelength greater than 420 nm and near-infrared light with a wavelength of 980 nm.

6. The application according to claim 5, characterized in that: Includes the following steps; 0.97 g of bismuth nitrate, 0.149 g of potassium chloride, and a certain amount of 8.867 mg of erbium nitrate and 59.9 mg of ytterbium nitrate were dissolved in 80 mL of a mixture of anhydrous ethanol and deionized water (V:V = 3:1). After sonication for 30 min, the mixture was stirred for 2 h. 826 mg of AgIn5S and 15 mg of MXene obtained in steps 1 and 2 were added to the above solution and stirred for 1 h. The pH was adjusted to 6 with ammonia water, and the mixture was transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C under vacuum for 12 h and designated as BMA5. After grinding, the sample was ready for use. Take 100 mL of tetracycline hydrochloride solution with a concentration of 10 mg / L and place it in a reaction vessel. Then add 20 mg of photocatalyst and stir in the dark for 30 min under constant temperature circulating water at 25℃ to reach adsorption-desorption equilibrium. Then turn on the xenon lamp source and use a 420 nm cutoff filter to obtain visible light with a wavelength greater than 420 nm for photocatalytic degradation reaction for 30 min. Take 3 mL of solution every 5 min. After centrifuging the sample at 10000 rpm, take the supernatant and use a UV-Vis spectrophotometer to measure the remaining tetracycline hydrochloride. The degradation efficiency of tetracycline hydrochloride within 30 minutes is 92%.

7. The application according to claim 6, characterized in that: Includes the following steps; 0.97 g of bismuth nitrate, 0.149 g of potassium chloride, 8.867 mg of erbium nitrate, and 59.9 mg of ytterbium nitrate were dissolved in 80 mL of a mixture of anhydrous ethanol and deionized water (V:V = 3:1). After sonication for 30 min, the mixture was stirred for 2 h. 826 mg of AgIn5S and 15 mg of MXene obtained in steps 1 and 2 were added to the above solution, and the mixture was stirred for 1 h. The pH was adjusted to 6 with ammonia water, and the mixture was transferred to an autoclave and heated in an oven at 160 °C for 12 h. The sample was then washed several times with deionized water and anhydrous ethanol. Finally, the obtained sample was dried at 60 °C under vacuum for 12 h and designated as BMA5. After grinding, the sample was ready for use. 100 mL of a 10 mg / L tetracycline hydrochloride solution was placed in a reaction vessel, and then 20 mg of photocatalyst was added. The mixture was stirred for 30 min in the dark under constant temperature circulating water at 25℃ to reach adsorption-desorption equilibrium. Subsequently, the xenon lamp source was turned on, and the photocatalytic degradation reaction was carried out using 980 nm near-infrared light for 120 min. 3 mL of solution was taken every 30 min. After centrifugation at 10,000 rpm, the supernatant was collected, and the remaining tetracycline hydrochloride was measured using a UV-Vis spectrophotometer. The degradation efficiency of tetracycline hydrochloride within 120 minutes was 55.8%.

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