An nh2-UiO-66 / ti3c2 / bi2wo6 nano composite photocatalyst and a preparation method and application thereof

Abstract

The application discloses an NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst and a preparation method and application thereof, and belongs to the technical field of materials. Bi2WO6 and NH2-UiO-66 are in-situ grown on Ti3C2 nanosheets through a two-step hydrothermal method, and the prepared NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst has a narrow band gap, is easy to be excited by light, has a wide spectral response range, has a smaller particle size and a larger specific surface area, can enhance adsorption, can effectively inhibit the recombination of photo-generated electron-hole pairs, and can improve the transmission efficiency of electrons. The degradation rates of the prepared NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst to TCH and LEV can both reach more than 90%, the photocatalyst has excellent photochemical stability and reusability, and has potential application value for the degradation of residual antibiotics in water.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of materials, and particularly relates to a NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst, a preparation method and application thereof. BACKGROUND

[0002] In recent years, the problem of antibiotic pollution caused by the abuse of antibiotics has seriously threatened the stability of aquatic ecosystems. At present, the main methods for removing antibiotic pollutants in water bodies include microbial degradation, adsorption removal, membrane separation, etc. However, these methods have many shortcomings, such as long cycle time of microbial degradation, difficulty in regenerating adsorbents and high cost of adsorption removal, and certain application range limitations of membrane separation.

[0003] Photocatalytic oxidation technology has been widely concerned by researchers due to its advantages such as green and efficient, economical and environmental protection, and is a water treatment technology with great application prospect. This technology usually uses high-oxidizing active species generated by semiconductors under light to degrade pollutants, and TiO2 is the most widely used semiconductor photocatalyst. However, some shortcomings of TiO2 seriously limit the practical application of the technology. For example, high band gap energy value requires more energy to achieve carrier separation, resulting in low light energy utilization rate, in addition, electrons and holes recombine with each other and the recombination rate is very fast, resulting in a decrease in the number of photo-generated ROS available for the photocatalytic process on the surface reaction site, resulting in low overall photocatalytic quantum efficiency. Therefore, seeking more efficient semiconductor photocatalytic materials has also become a research hotspot for scholars at home and abroad. In order to achieve the above purpose, the technical personnel in the field investigate semiconductor photocatalytic materials from the utilization rate of visible light, chemical stability, material cost and service life, toxicity and corrosion resistance, etc. Bi2WO6 is selected as a semiconductor photocatalytic material to replace TiO2. The main reason is that Bi2WO6 has the advantages of suitable band gap (2.7eV), high chemical stability, non-toxicity and strong visible light absorption, etc. However, the single photocatalyst has high photo-generated electron-hole recombination rate and low quantum efficiency, resulting in slow and incomplete photocatalytic degradation, and the activity of the obtained photocatalyst is not very ideal, and it cannot degrade antibiotics.

[0004] In view of the technical problems of the existing Bi2WO6 single photocatalyst, such as high photo-generated electron-hole recombination rate, low quantum efficiency, slow and incomplete photocatalytic degradation, and low photocatalyst activity, which cannot degrade antibiotics, it is urgent to modify Bi2WO6 to inhibit the recombination of photo-generated electron-hole pairs, improve the electron transport efficiency and photocatalytic degradation performance. SUMMARY

[0005] In order to overcome the above-mentioned defects of the prior art, the purpose of the present application is to provide an NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst as well as a preparation method and application thereof, so as to solve the technical problems that the existing Bi2WO6 single photocatalyst has a high photoelectron hole recombination rate, a low quantum efficiency, a slow and incomplete photodegradation, and an unsatisfactory photocatalyst activity, and cannot degrade antibiotics.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The present application discloses an NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst, which is a three-dimensional structure and comprises a Ti3C2 / Bi2WO6 composite material and NH2-UiO-66 grown on the surface of the Ti3C2 / Bi2WO6 composite material.

[0008] Preferably, the mass ratio of Ti3C2 to Bi2WO6 in the Ti3C2 / Bi2WO6 composite material is (0.02-0.05):1.

[0009] Preferably, the mass content of NH2-UiO-66 in the NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst is 4-10wt%.

[0010] The present application also discloses a preparation method of the above-mentioned NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst, which comprises the following steps:

[0011] 1) Bi(NO3)3·5H2O and Ti3C2 nanosheets are added to deionized water to obtain solution A; Na2WO4·2H2O and CTAB are dissolved in deionized water to obtain solution B; solution A is added to solution B and stirred uniformly, and then a Ti3C2 / Bi2WO6 composite material is obtained through hydrothermal reaction, washing and drying;

[0012] 2) The Ti3C2 / Bi2WO6 composite material prepared in step 1) is added to a DMF solution and stirred uniformly, ZrCl4 and 2-amino terephthalic acid are added and stirred uniformly, and then an NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst is obtained through hydrothermal reaction, washing and drying.

[0013] Preferably, in step 1), the mass ratio of Bi(NO3)3·5H2O:Ti3C2 nanosheets:Na2WO4·2H2O:CTAB is 1:(0.01-0.03):(0.3-0.4):(0.05-0.06).

[0014] Preferably, in step 1), the temperature of the hydrothermal reaction is 100-150 DEG C; the time of the hydrothermal reaction is 24-30 h.

[0015] Preferably, in step 2), the mass ratio of the Ti3C2 / Bi2WO6 composite material: ZrCl4: 2-amino terephthalic acid is 1: (0.005-0.02): (0.004-0.02).

[0016] Preferably, in step 2), the temperature of the hydrothermal reaction is 100-150 DEG C; the time of the hydrothermal reaction is 24-30 h.

[0017] Preferably, in step 2), the drying condition is: vacuum drying at 60-90 DEG C for 24-36 h.

[0018] The application further discloses an application of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst in degrading antibiotics in water.

[0019] Compared with the prior art, the application has the following beneficial effects:

[0020] The application discloses an NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst, which comprises a Ti3C2 / Bi2WO6 composite material and an NH2-UiO-66 system grown on the surface of the Ti3C2 / Bi2WO6 composite material. The NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst is a z-type heterojunction photocatalyst based on Bi2WO6 and having a solid-state electronic medium, Bi2WO6 and NH2-UiO-66 are in-situ grown on Ti3C2 nanosheets, on the surface of the Bi2WO6 nanosheet, a large number of Ti3C2 nanosheets are irregularly distributed and a large number of gaps exist, so that the composite material has a large specific surface area, and the particle size of the NH2-UiO-66 on the Ti3C2 / Bi2WO6 composite material is greatly reduced; the combination of Ti3C2 and NH2-UiO-66 improves the specific surface area and electron mobility of the Bi2WO6 photocatalyst; the larger specific surface area can increase active sites and promote the transfer of photoexcited charges, the narrower band gap is easy to be excited by light, has a wider spectral response range, and the smaller particle size and larger specific surface area enhance adsorption, can effectively inhibit the recombination of photo-generated electron-hole pairs and improve the transmission efficiency of electrons; the photo-degradation rates of TCH and LEV are both above 90%. The application solves the technical problems of the prior art Bi2WO6 single photocatalyst, such as high photo-generated electron-hole recombination rate, low quantum efficiency, slow and incomplete photo-degradation, unsatisfactory photocatalyst activity and inability to degrade antibiotics.

[0021] Further, the mass ratio of Ti3C2:Bi2WO6 in the Ti3C2 / Bi2WO6 composite material is (0.02-0.05:1); so as to ensure that Ti3C2 and Bi2WO6 are successfully compounded and have a larger specific surface area.

[0022] Further, the mass ratio of NH2-UiO-66 in the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is 4-10wt%; so as to ensure that NH2-UiO-66 and Ti3C2 / Bi2WO6 material are successfully compounded.

[0023] The application further discloses a preparation method of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst. 3+ Bi(NO3)3·5H2O and Ti3C2 nanosheets are added into deionized water, so that Bi is adsorbed on the surface of Ti2C3 to obtain solution A; Na2WO4·2H2O and CTAB are dissolved in deionized water to obtain solution B, which is used for controlling the size and dispersity of catalyst particles; solution A is added into solution B and stirred uniformly, and then hydrothermal reaction, washing and drying are performed to obtain Ti3C2 / Bi2WO6 composite material; the Ti3C2 / Bi2WO6 composite material, ZrCl4 and 2-amino terephthalic acid are added into a DMF solution and stirred uniformly, and then hydrothermal reaction, washing and drying are performed to obtain the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst. The preparation method is simple in process and easy in condition control, a z-type heterojunction photocatalyst with a solid-state electronic medium is synthesized based on Bi2WO6, that is, the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is prepared by in-situ growth of Bi2WO6 and NH2-UiO-66 on the Ti3C2 nanosheet in a two-step hydrothermal way. The NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst has a narrow band gap and is easy to be excited by light, has a wide spectral response range, and has smaller particle size and larger specific surface area, so that the adsorption is enhanced, the recombination of photo-generated electron-hole pairs is effectively inhibited, and the transmission efficiency of electrons is improved.

[0024] The application also discloses application of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst in degrading antibiotics in water bodies. -1 When used for degrading TCH, because the chemical interaction between TCH molecules and the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is the main factor affecting the degradation efficiency, under strong acidic conditions, there is strong electrostatic attraction between the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst and TCH, which continuously provides driving force for TCH molecules to overcome the mass transfer resistance from the liquid phase main body to the surface of the catalyst, accelerates the adsorption of TCH molecules, and is beneficial to the catalytic reaction. When the concentration is 20 mg / L, the photodegradation rate and the photodegradation rate reach maximum values of 0.01448 min -1 and 90.0%, respectively. When used for degrading LEV, the LEV molecule is amphoteric, when the solution pH value is lower than 6.02, the LEV molecule mainly exists in the form of LEV + , when the solution 6.02 < pH < 8.15, the LEV molecule is neutral, and when the solution pH > 8.15, the LEV molecule is protonated and mainly exists in the form of LEV - in the solution. In combination with the Zeta potential of 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6, when 2.08 < pH < 8.15, it is beneficial to the combination of the LEV molecule and the active site on the surface of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst. When the solution concentration is 10 mg / L, the apparent rate of photodegradation of the LEV solution by the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst reaches a maximum value of 0.01208 min -1 Compared with the Bi2WO6 single catalyst, the composite photocatalyst prepared in the application has increased number of active sites, improved electron transport efficiency, and has strong adsorption and photocatalytic degradation performance. Under the optimal conditions (pH = 3, C0= 20 mg / L, C 光催化剂 = 0.6 g / L and pH = 5, C0= 10 mg / L, C 光催化剂 = 0.6 g / L), the photocatalytic degradation rates of the composite photocatalyst to TCH and LEV are both more than 90%. The combination of Ti3C2 and NH2-UiO-66 improves the specific surface area and electron mobility of the Bi2WO6 photocatalyst. The photocatalytic degradation performance of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is superior to that of the single catalyst, the larger specific surface area can increase the active sites and promote the transfer of photoexcited charges, and can effectively inhibit the recombination of photo-generated electron-hole pairs. The NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst has potential application value for degrading residual antibiotics in water bodies. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A schematic diagram of the preparation process of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in the present application is shown in Figure 1.

[0026] Figure 2 XRD patterns of various materials provided in Example 1 of the present application are shown in Figure 2; wherein (a) is the XRD pattern of Ti3C2 and Ti3AlC2; (b) is the XRD pattern of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, NH2-UiO-66, Bi2WO6 and Ti3C2 / Bi2WO6 composite material;

[0027] Figure 3 XPS patterns of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Example 1 of the present application are shown in Figure 3; wherein (a) is the XPS full spectrum; (b) is the O 1s spectrum; (c) is the Bi 4f spectrum; (d) is the W 4f spectrum; (e) is the Zr 3d spectrum; (f) is the VB-XPS spectrum;

[0028] Figure 4 SEM images of the photocatalyst provided in Example 1 of the present application are shown in Figure 4; wherein (a) is the Bi2WO6 photocatalyst, and (b) is the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst;

[0029] Figure 5 TEM images of the photocatalyst provided in Example 1 of the present application are shown in Figure 5; wherein (a) is the Bi2WO6 photocatalyst, and (b) is the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst;

[0030] Figure 6 UV-Vis DRS absorption spectra of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, NH2-UiO-66, Bi2WO6 and Ti3C2 / Bi2WO6 composite material provided in Example 1 of the present application are shown in Figure 6;

[0031] Figure 7 The effect of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Example 1 of the present application on the degradation rate of TCH and LEV at different pH values is shown in Figure 7; wherein (a) is the degradation of TCH; (b) is the degradation of LEV;

[0032] Figure 8The line graph of the influence of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Embodiment 1 of the present application on the degradation rates of TCH and LEV under different initial concentrations of solution; wherein (a) is for degrading TCH; (b) is for degrading LEV;

[0033] Figure 9 The data graph of the light degradation rates and unit mass light degradation rates of TCH and LEV of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Embodiment 1 of the present application under different photocatalyst addition amounts; wherein (a) is the light degradation rate graph of TCH; (b) is the unit mass light degradation rate graph of TCH; (c) is the light degradation rate graph of LEV; (d) is the unit mass light degradation rate graph of LEV;

[0034] Figure 10 The column graph of the influence of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Embodiment 1 of the present application and the Bi2WO6 photocatalyst provided in Comparative Example 1 on the degradation rate of TCH;

[0035] Figure 11 The column graph of the influence of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Embodiment 1 of the present application and the Bi2WO6 photocatalyst provided in Comparative Example 1 on the degradation rate of LEV. DETAILED DESCRIPTION

[0036] In order to make the personnel in the art better understand the present application scheme, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should belong to the scope of protection of the present application.

[0037] It should be noted that the experimental methods in each of the following embodiments are conventional methods unless otherwise specified. The reagents and materials used, unless otherwise specified, can be purchased on the market.

[0038] The present application will be further described in detail below in conjunction with the drawings:

[0039] The application synthesizes a z-type heterojunction photocatalyst with a solid-state electronic medium based on Bi2WO6, that is, in-situ growth of Bi2WO6 and NH2-UiO-66 on Ti3C2 nanosheet by a two-step hydrothermal method to prepare an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite. The catalyst has a narrow band gap and is easy to be excited by light, has a wide spectral response range, and the smaller particle size and larger specific surface area enhance the adsorption, and at the same time can effectively inhibit the recombination of photo-generated electron-hole pairs and improve the transmission efficiency of electrons.

[0040] The first object of the application is to provide an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, which comprises a Ti3C2 / Bi2WO6 composite material, and an NH2-UiO-66 system grown on the surface of the Ti3C2 / Bi2WO6 composite material.

[0041] The NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is a three-dimensional structure.

[0042] The mass ratio of Ti3C2 to Bi2WO6 is (0.02-0.05):1.

[0043] The mass fraction of NH2-UiO-66 is 4-10wt%.

[0044] Preferably, the Ti3C2 is prepared by the following preparation method:

[0045] Preferably, the Ti3C2 / Bi2WO6 composite material is prepared by the following preparation method:

[0046] Bi(NO3)3·5H2O and Ti3C2 nanosheet are added to a deionized water solution, denoted as solution A; Na2WO4·2H2O and cetyltrimethylammonium bromide are dissolved in deionized water and stirred for 1-1.5h, denoted as solution B; solution A is added dropwise to solution B under stirring, and stirring is continued, then the precipitate is washed with deionized water and ethanol, and dried to obtain the Ti3C2 / Bi2WO6 composite material.

[0047] The preparation method of the Ti2C3 nanosheet comprises the following steps: adding LiF into a hydrochloric acid solution, stirring for 10-30 min, then adding Ti3AlC2 powder, stirring at 30-40 DEG C for 24-48 h, washing with deoxygenated water until pH>6, ultrasonic breaking with an ultrasonic breaking machine under argon protection for 2-3 h, centrifuging the solution for 30-50 min, taking supernatant, and the obtained supernatant is the Ti3C2 nanosheet solution; after filtration and drying, the mass of the obtained purple flexible film is weighed to determine the Ti3C2 content in the supernatant; and the Ti2C3 nanosheet is obtained from the multilayer Ti2C3 after ultrasonic stripping.

[0048] More preferably, the mass ratio of Bi(NO3)3.5H2O:Ti3C2 nanosheet:Na2WO4.2H2O:CTAB is 1:(0.01-0.03):(0.3-0.4):(0.05-0.06).

[0049] The second object of the application is to provide a preparation method of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst.

[0050] The Ti3C2 / Bi2WO6 composite material is provided.

[0051] The Ti3C2 / Bi2WO6 composite material is added into a dimethylformamide solution, then ZrCl4 and 2-amino terephthalic acid are added, after stirring, reaction is carried out at 100-150 DEG C for 24-30 h, and after treatment, the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is obtained.

[0052] Preferably, the mass ratio of the Ti3C2 / Bi2WO6 composite material to the ZrCl4 and 2-amino terephthalic acid is 1:(0.005-0.02):(0.004-0.02).

[0053] Preferably, after the reaction is completed, the reactants are cooled to room temperature, washed with anhydrous ethanol and deionized water for multiple times, and then vacuum drying treatment is carried out at 60-90 DEG C for 24-36 h.

[0054] The third object of the application is to provide an application of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst in antibiotic degradation.

[0055] Reference is made to Figure 1A preparation process schematic diagram of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided by the application; as can be seen from the diagram, a z-type heterojunction photocatalyst with a solid-state electronic medium is synthesized based on Bi2WO6, that is, Bi2WO6 and NH2-UiO-66 are in-situ grown on Ti3C2 nanosheets through a two-step hydrothermal method, and Ti3C2 / Bi2WO6 composite materials and NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalysts are sequentially prepared. The prepared NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is a three-dimensional structure, including Ti3C2 / Bi2WO6 composite materials and NH2-UiO-66 systems grown on the surface of the Ti3C2 / Bi2WO6 composite materials; the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst has a narrow band gap and is easy to be excited by light, has a wide spectral response range, and the smaller particle size and larger specific surface area enhance the adsorption effect, at the same time, can effectively inhibit the recombination of photo-generated electron-hole pairs and improve the transmission efficiency of electrons. The whole preparation method is simple in process and easy to control the conditions.

[0056] Example 1

[0057] A preparation method of an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, comprising the following steps:

[0058] Step 1: 1.5923g of Bi(NO3)3·5H2O and 0.0234g of Ti3C2 nanosheet are weighed and added into 40mL of deionized water, denoted as solution A; 0.5411g of Na2WO4·2H2O and 0.0821g of CTAB are dissolved in 40mL of deionized water, and stirred for 1.5h to obtain a uniform solution, denoted as solution B; solution A is added dropwise into solution B under stirring, and stirred for 1.5h; then it is transferred into a 100mL hydrothermal reaction kettle, and reacted at 120℃ for 24h; after washing with deionized water and ethanol, the product is dried to obtain Ti3C2 / Bi2WO6 composite materials;

[0059] Step 2: 1.1686g of Ti3C2 / Bi2WO6 composite materials are added into 50mL of DMF solution and stirred for 30min, then 0.0098g of ZrCl4 and 0.0076g of 2-amino terephthalic acid are added and stirred for 1.5h; the solution is transferred into a 100mL hydrothermal reaction kettle, and reacted at 120℃ for 24h; after cooling to room temperature, the residual DMF is removed by washing with anhydrous ethanol and deionized water, and then vacuum dried at 80℃ for 24h to obtain an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst.

[0060] The content of NH2-UiO-66 in the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is realized by adjusting the content of the Ti3C2 / Bi2WO6 composite material. In this embodiment 1, the content of NH2-UiO-66 is 6wt%.

[0061] Embodiment 2

[0062] A preparation method of a NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, comprising the following steps:

[0063] Step 1: weigh 2.4392g Bi(NO3)3·5H2O and 0.0358g Ti3C2 nanosheet into 40mL deionized water, and mark it as solution A; weigh 0.8299g Na2WO4·2H2O and 0.1257g CTAB into 40mL deionized water, and stir for 1.5h to obtain a uniform solution, and mark it as solution B; under stirring, drop solution A into solution B, and stir for 1.5h; move into a 100mL hydrothermal reaction kettle, and react at 100℃ for 27h; after washing with deionized water and ethanol, dry the product, and obtain the Ti3C2 / Bi2WO6 composite material;

[0064] Step 2: add 1.7902g Ti3C2 / Bi2WO6 composite material into 50mL DMF solution, and stir for 30min, then add 0.0098g ZrCl4 and 0.0076g 2-amino terephthalic acid, and stir for 1.5h; move the solution into a 100mL hydrothermal reaction kettle, and react at 100℃ for 27h; after cooling to room temperature, wash with anhydrous ethanol and deionized water to remove residual DMF, and dry at 60℃ under vacuum for 36h, and obtain the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst.

[0065] The content of NH2-UiO-66 in the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is realized by adjusting the content of the Ti3C2 / Bi2WO6 composite material. In this embodiment 2, the content of NH2-UiO-66 is 4wt%.

[0066] Embodiment 3

[0067] A preparation method of a NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, comprising the following steps:

[0068] Step 1: 1.931 g of Bi(NO3)3·5H2O and 0.0429 g of Ti3C2nanosheets were weighed into 40 mL of deionized water, denoted as solution A; 0.6562 g of Na2WO4·2H2O and 0.0995 g of CTAB were dissolved in 40 mL of deionized water, stirred for 1.5 h to obtain a uniform solution, denoted as solution B; solution A was added dropwise to solution B under stirring, and stirred for 1.5 h; then transferred into a 100 mL hydration reactor, reacted at 120℃ for 24 h, and then washed with deionized water and ethanol and dried to obtain a Ti3C2 / Bi2WO6 composite material;

[0069] Step 2: 1.4319 g of Ti3C2 / Bi2WO6 composite material was added to 50 mL of DMF solution and stirred for 30 min, then 0.0099 g of ZrCl4 and 0.0077 g of 2-amino terephthalic acid were added and stirred for 1.5 h; the solution was transferred into a 100 mL hydration reactor, reacted at 130℃ for 24 h, cooled to room temperature, washed with anhydrous ethanol and deionized water to remove residual DMF, and then vacuum dried at 90℃ for 24 h to obtain a NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst.

[0070] In the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, the content of NH2-UiO-66 is realized by adjusting the content of Ti3C2 / Bi2WO6 composite material. In this embodiment 3, the content of NH2-UiO-66 is 5 wt%.

[0071] Example 4

[0072] A preparation method of a NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, comprising the following steps:

[0073] Step 1: 1.931 g of Bi(NO3)3·5H2O and 0.0429 g of Ti3C2nanosheets were weighed into 40 mL of deionized water, denoted as solution A; 0.6562 g of Na2WO4·2H2O and 0.0995 g of CTAB were dissolved in 40 mL of deionized water, stirred for 1.5 h to obtain a uniform solution, denoted as solution B; solution A was added dropwise to solution B under stirring, and stirred for 1.5 h; then transferred into a 100 mL hydration reactor, reacted at 120℃ for 24 h, and then washed with deionized water and ethanol and dried to obtain a Ti3C2 / Bi2WO6 composite material;

[0074] Step 2: 0.991 g of Ti3C2 / Bi2WO6 composite material was added to 50 mL of DMF solution and stirred for 30 min, then 0.0098 g of ZrCl4 and 0.0076 g of 2-amino terephthalic acid were added and stirred for 1 h; the solution was transferred to a 100 mL hydration reactor and reacted at 120℃ for 30 h, cooled to room temperature, washed with anhydrous ethanol and deionized water to remove residual DMF, and then vacuum dried at 80℃ for 30 h to obtain the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst.

[0075] In the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, the content of NH2-UiO-66 is realized by adjusting the content of Ti3C2 / Bi2WO6 composite material. In this embodiment 4, the content of NH2-UiO-66 is 7wt%.

[0076] Example 5

[0077] A preparation method of an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, comprising the following steps:

[0078] Step 1: 1.1688 g of Bi(NO3)3·5H2O and 0.026 g of Ti3C2 nanosheet were weighed and added to 40 mL of deionized water, denoted as solution A; 0.3972 g of Na2WO4·2H2O and 0.0602 g of CTAB were dissolved in 40 mL of deionized water and stirred for 1 h to obtain a uniform solution, denoted as solution B; under stirring, solution A was added dropwise to solution B and stirred for 1 h; then it was transferred to a 100 mL hydration reactor and reacted at 130℃ for 30 h; the product was washed with deionized water and ethanol and then dried to obtain the Ti3C2 / Bi2WO6 composite material;

[0079] Step 2: 0.8666 g of Ti3C2 / Bi2WO6 composite material was added to 50 mL of DMF solution and stirred for 30 min, then 0.0099 g of ZrCl4 and 0.0077 g of 2-amino terephthalic acid were added and stirred for 1 h; the solution was transferred to a 100 mL hydration reactor and reacted at 130℃ for 30 h, cooled to room temperature, washed with anhydrous ethanol and deionized water to remove residual DMF, and then vacuum dried at 90℃ for 30 h to obtain the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst.

[0080] The content of NH2-UiO-66 in the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is realized by adjusting the content of the Ti3C2 / Bi2WO6 composite material. In this embodiment 5, the content of NH2-UiO-66 is 8wt%.

[0081] Embodiment 6

[0082] A preparation method of a NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, comprising the following steps:

[0083] Step 1: 0.9147g of Bi(NO3)3·5H2O and 0.0274g of Ti3C2 nanosheet are weighed and added to 40mL of deionized water, denoted as solution A; 0.3109g of Na2WO4·2H2O and 0.0471g of CTAB are dissolved in 40mL of deionized water, and stirred for 1h to obtain a uniform solution, denoted as solution B; under stirring, solution A is added dropwise to solution B, and stirred for 1h; then it is transferred into a 100mL hydration reactor, and reacted at 150℃ for 27h; after washing with deionized water and ethanol, the product is dried to obtain a Ti3C2 / Bi2WO6 composite material;

[0084] Step 2: 0.6853g of the Ti3C2 / Bi2WO6 composite material is added to 50mL of DMF solution and stirred for 30min, then 0.0099g of ZrCl4 and 0.0077g of 2-amino terephthalic acid are added and stirred for 1h; the solution is transferred into a 100mL hydration reactor, and reacted at 150℃ for 27h; after cooling to room temperature, it is washed with anhydrous ethanol and deionized water to remove residual DMF, and then vacuum dried at 90℃ for 30h to obtain a NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst.

[0085] The content of NH2-UiO-66 in the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst is realized by adjusting the content of the Ti3C2 / Bi2WO6 composite material. In this embodiment 6, the content of NH2-UiO-66 is 10wt%.

[0086] Comparative Example 1

[0087] A preparation method of a Bi2WO6 nanosheet, comprising the following steps:

[0088] 0.9701 g Bi(NO3)3·5H2O was stirred in 40 mL of deionized water for 30 min, marked as solution A; 0.3297 g Na2WO4·2H2O and 0.05 g CTAB were weighed into 40 mL of deionized water and stirred for 1 h, marked as solution B; solution A was slowly added to solution B, stirred for 1 h, and the mixed solution was transferred to a 100 mL hydration kettle, which was stored at 120℃ for 24 h. After washing with deionized water and ethanol, the Bi2WO6 nanophotocatalyst was dried for 24 h.

[0089] To illustrate the performance of the composite photocatalyst provided by the present application, the composite photocatalyst provided by Example 1 was tested for relevant performance, and Comparative Example 1 was used as a control group, as shown in Table 1. Figures 2 to 6

[0090] Figure 2 The XRD patterns of the materials provided by Example 1 of the present application are shown in Figure 1; wherein (a) is the XRD pattern of Ti3C2 and Ti3AlC2; (b) is the XRD pattern of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, NH2-UiO-66, Bi2WO6 and Ti3C2 / Bi2WO6 composite material; it can be seen from Figure 2 that in the XRD pattern of 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6, part of the diffraction peaks from NH2-UiO-66 and Ti3C2 / Bi2WO6 can be observed, indicating that NH2-UiO-66 has been successfully grown on Ti3C2 / Bi2WO6; the combination of Ti3C2 and NH2-UiO-66 does not affect the lattice structure of Bi2WO6.

[0091] Figure 3 ​​​XPS spectra of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Example 1 of this invention are shown below. (a) is the full XPS spectrum; (b) is the O1s spectrum; (c) is the Bi 4f spectrum; (d) is the W 4f spectrum; (e) is the Zr3d spectrum; and (f) is the VB-XPS spectrum. As can be seen from the figures, the Bi 4f7 / 2 and Bi 4f5 / 2 peaks shift towards higher binding energies, indicating that a close contact and strong chemical interaction are formed between Ti3C2 and Bi2WO6 after composite formation, causing electrons to migrate from Bi2WO6 to Ti3C2. Figure (d) shows the same trend as Figure (c), indicating that the built-in electric field formed after composite formation causes electron transfer, suggesting that the catalysts are not simply physically bonded but rather form a heterostructure. The spectrum of NH2-UiO-66 / Ti3C2 / Bi2WO6 can be divided into four peaks, indicating that Bi in this catalyst has two valence states: trivalent and pentavalent.

[0092] See Figure 4 SEM images of the photocatalysts provided in Example 1 of this invention are shown; where (a) is a Bi2WO6 photocatalyst, and (b) is an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst; from Figure 4 As can be seen from the above, the Bi2WO6 prepared in Comparative Example 1 has a nanoflower-like structure composed of numerous irregular nanosheets, with obvious three-dimensional hierarchy. Ti3C2 / Bi2WO6 is composed of stacked Ti3C2 and Bi2WO6 nanosheets. There are numerous Ti3C2 nanosheets irregularly distributed on the surface of Bi2WO6 nanosheets and a large number of voids, indicating that the Ti3C2 / Bi2WO6 nanocomposite has a large specific surface area. NH2-UiO-66 bulk particles are irregularly distributed on Ti3C2 / Bi2WO6. The presence of Bi2WO6 greatly reduces the particle size of NH2-UiO-66, thereby shortening the distance of charge carriers and reducing the charge carrier recombination rate.

[0093] See Figure 5 The images show TEM images of the photocatalyst provided in Example 1 of this invention; where (a) is a Bi2WO6 photocatalyst and (b) is an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst; as can be seen from the images, Bi2WO6 in Figure (a) is composed of numerous nanosheets of varying sizes stacked together, with obvious nanosheet outlines and lattice fringes. As shown in Figure (b), NH2-UiO-66 and Ti3C2 are randomly distributed and tightly bonded on the surface of Bi2WO6, indicating that NH2-UiO-66 has been successfully grown on the surface of Ti3C2 / Bi2WO6 nanosheets.

[0094] See Figure 6UV-Vis DRS absorption spectrum of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, NH2-UiO-66, Bi2WO6 and Ti3C2 / Bi2WO6 composite material provided in Example 1 of the present application; from Figure 6 It can be seen that the four catalysts have strong light absorption in the visible light region, and the light absorption edges of Bi2WO6 and Ti3C2 / Bi2WO6 are near 440 nm and 400 nm, respectively, while the light absorption edges of NH2-UiO-66 and NH2-UiO-66 / Ti3C2 / Bi2WO6 are near 460 nm. After Ti3C2 and Bi2WO6 are compounded, the light absorption in the ultraviolet light region appears a significant blue shift, and the absorption spectrum of NH2-UiO-66 / Ti3C2 / Bi2WO6 appears a significant red shift, and the introduction of NH2-UiO-66 makes the overall absorbance of NH2-UiO-66 / Ti3C2 / Bi2WO6 composite material expand to the visible light region. The existence of amino groups in NH2-UiO-66 and the effective interface interaction with Bi2WO6 can form a strong heterostructure, which has a wide spectral response range in the visible light region, and the narrow band gap of NH2-UiO-66 / Ti3C2 / Bi2WO6 composite catalyst makes it easy to be excited by light, and has strong photocatalytic activity.

[0095] In order to further illustrate the photocatalytic degradation performance of the composite photocatalyst provided by the present application, only the composite photocatalyst provided in Example 1 is subjected to photocatalytic degradation test, and Comparative Example 1 is used as a control group, as shown in Table 1. Figure 7

[0096] Among them, the determination method of the photocatalytic degradation of the photocatalyst to TCH and LEV is as follows:

[0097] A certain concentration of tetracycline hydrochloride solution (TCH) and levofloxacin solution (LEV) is taken in a 100 mL beaker, and after adjusting the pH value, a certain amount of NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Example 1 is added, mixed and stirred in the dark for 60 min for dark treatment, and after adsorption reaches equilibrium, the photocatalytic reaction is carried out under the irradiation of a 150 W xenon lamp with continuous stirring. Every 20 min, 2 mL of reaction solution is collected with a syringe, filtered with a 0.22 μm filter membrane, and the absorbance of the solution is measured at 357 nm and 287 nm, respectively, using a UV-visible spectrophotometer. The concentration C (mg / L) of tetracycline hydrochloride and levofloxacin is calculated according to the standard curve. The degradation efficiency of the photocatalytic reaction can be calculated by formula (1-1):

[0098]

[0099] ​In the formula: DE represents the photocatalytic degradation efficiency, %; C0 represents the actual initial concentration of the photodegradation reaction, mg / L; Ct represents the concentration of the solution at t time, mg / L.

[0100] Photocatalytic performance test of NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst

[0101] I. Effect of pH on the photodegradation rate

[0102] Take 50 mL of TCH and LEV solutions with a certain concentration in a 100 mL beaker, respectively, and adjust the pH value of the solution to 3.0, 5.0, 7.0, 9.0 and 11.0 with 1 mol / L HCl and NaOH solution, respectively. Add 10 mg of 6% NH2-UiO-66 / Ti3C2 / Bi2WO6 composite catalyst, and stir the solution in the dark for 1 h. Take 2 mL of the reaction solution, filter it with a 0.22 μm microporous filter, and measure the absorbance using a UV-visible spectrophotometer. Then place the beaker under a 150 W xenon lamp and continuously stir, and take samples every 20 min to measure the absorbance of the solution.

[0103] See Figure 7 The effect of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Example 1 on the degradation rate of TCH and LEV at different pH values is shown in the line graph; wherein (a) is the degradation of TCH; (b) is the degradation of LEV; as can be seen from Figure (a), when the pH value is 4 and 7, the degradation rate of TCH reaches 94.62% and 91.60%, respectively. This is because the chemical interaction between TCH molecules and the catalyst is the main factor affecting the degradation efficiency. Under acidic conditions, there is strong electrostatic attraction between the catalyst and TCH, which continuously provides driving force for TCH molecules to overcome the mass transfer resistance from the liquid phase to the catalyst surface, accelerates the adsorption of TCH molecules, and is conducive to the catalytic reaction. However, when the pH value of the TCH solution is low, the amino group of the MOF molecule will be protonated, which is not conducive to the formation of hydrogen bonds. In addition, the π-π bond interaction between organic molecules and NH2-UiO-66 is also a way for the composite catalyst to adsorb organic molecules, and the π-π bond interaction will be strengthened as the pH value increases. As can be seen from Figure (b), the degradation rate of LEV reaches a maximum value when the pH value of the solution is 5. LEV is an amphoteric substance, and when the pH value of the solution is less than 6.02, LEV mainly exists in the form of LEV Figure 7 (b), the degradation rate of LEV reaches a maximum value when the pH value of the solution is 5. LEV is an amphoteric substance, and when the pH value of the solution is less than 6.02, LEV mainly exists in the form of LEV + , when 6.02 < pH < 8.15, LEV molecules are neutral, and when the solution pH > 8.15, LEV molecules are protonated and mainly exist in the form of LEV -Formally present. The Zeta potential of 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 can be obtained, when 2.08 < pH < 8.15, it is conducive to the combination of LEV molecules and the active sites on the surface of the catalyst.

[0104] II. Effect of initial concentration of solution on photodegradation rate

[0105] 1g / L TCH and LEV solution was diluted to 10mg / L, 15mg / L, 20mg / L, 25mg / L and 30mg / L respectively. 50mL of each was added to a 100mL beaker, the pH value was adjusted to 7 and 10mg of 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 composite catalyst was added and stirred constantly. After stirring in the dark for 1h, 2mL of the reaction solution was filtered and the absorbance was measured using a UV-visible spectrophotometer to calculate the concentration after adsorption equilibrium, then the beaker was placed under a 150W xenon lamp for light irradiation and the absorbance of the solution was measured every 20min.

[0106] Referring to Figure 8 The effect of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided in Example 1 on the degradation rate of TCH and LEV under different initial concentrations of solution is shown in the line graph; (a) is for degrading TCH; (b) is for degrading LEV; as can be seen from Figure (a), the maximum photodegradation rate and photodegradation rate are 0.01448min -1 and 90.0% respectively at 20mg / L. This is because at low concentrations, increasing the concentration of the solution can enhance the adsorption of the catalyst on the TCH molecules, thereby accelerating the combination of the TCH molecules with the active sites on the surface of the catalyst, promoting the photocatalytic rate, and as the concentration increases, a large number of photons are absorbed by the TCH molecules surrounding the catalyst, and the active sites on the surface of the photocatalyst are gradually occupied by TCH and its degradation products, inhibiting the photocatalytic reaction. As can be seen from Figure (b), the photodegradation efficiency decreases continuously as the concentration increases, indicating that the active sites on the surface of the catalyst have approached saturation and gradually reached the limit of photocatalytic degradation of the catalyst. The apparent rate of photocatalytic degradation of the catalyst on the LEV solution reaches a maximum of 0.01208min -1 at a solution concentration of 10mg / L, indicating that the catalyst is suitable for lower concentration LEV solution photocatalytic degradation. Therefore, the amount of catalyst can be appropriately increased in subsequent reactions to accelerate the reaction rate.

[0107] III. Effect of photocatalyst addition amount on photodegradation rate

[0108] Take 50 mL of 20 mg / L TCH and LEV solution in a 100 mL beaker, adjust the pH value to 7, then add 10 mg, 20 mg, 30 mg, 40 mg and 50 mg of 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst respectively, and stir constantly. After 1h of adsorption in the dark, measure the absorbance and calculate the initial concentration, then place the beaker under a 150W xenon lamp for light irradiation, take samples every 20 min, measure the absorbance of the solution and calculate the solution concentration at time t.

[0109] Referring to Figure 9 The data graphs of the light degradation rate and the unit mass light degradation rate of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst provided in Example 1 of the present application under different photocatalyst addition amounts for TCH and LEV; wherein (a) is the light degradation rate graph of TCH; (b) is the unit mass light degradation rate graph of TCH; (c) is the light degradation rate graph of LEV; (d) is the unit mass light degradation rate graph of LEV; it can be seen from Figure 9 In the light degradation process of TCH and LEV, as the catalyst dosage increases, the light degradation rate increases, indicating that the increase in catalyst dosage does not affect the light degradation rate due to the decrease in light transmittance of the solution. The change in light degradation rate of the unit mass catalyst presents an opposite trend to the light degradation rate curve, and as the catalyst dosage increases, the unit mass light degradation rate of the catalyst decreases. This is because under the experimental conditions, when the catalyst dosage exceeds 10 mg, there is a certain degree of redundancy of the catalyst relative to the 50 mL 20 mg / L TCH and LEV solution, resulting in a decrease in the utilization rate of the catalyst.

[0110] IV. Effect of photocatalyst type on light degradation rate

[0111] Take 50 mL of 20 mg / L TCH and LEV solution in a 100 mL beaker, adjust the pH value to 7, then add 10 mg of Bi2WO6 and 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 respectively in the above solutions, and stir constantly. After 1h of adsorption in the dark, measure the absorbance and calculate the initial concentration, then place the beaker under a 150W xenon lamp for light irradiation, take samples every 20 min, measure the absorbance of the solution and calculate the solution concentration at time t.

[0112] Referring to Figure 10 The bar graph of the effect of the 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 nano composite photocatalyst provided in Example 1 of the present application and the composite photocatalyst Bi2WO6 provided in Comparative Example 1 on the TCH degradation rate. Referring to Figure 11The bar chart of the influence of the 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst provided for the embodiment 1 of the present application and the composite photocatalyst Bi2WO6 provided for the comparative example 1 on the degradation rate of LEV is shown in the following figure. Figure 10 As can be seen from the figure, Figure 11 It can be seen from the figure that the photo-degradation rate of Bi2WO6 on TCH and LEV is always lower than that of the 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst, which indicates that the single photocatalyst is prone to composite of photo-generated electron-hole pairs, and the slow and incomplete degradation is caused by the low quantum efficiency. The composite of Ti3C2 and NH2-UiO-66 on Bi2WO6 enhances the photocatalytic activity of the single catalyst, which is beneficial to increase the specific surface area of the catalyst, increase the number of active sites, and enhance the adsorption and degradation performance of the catalyst; on the other hand, it is beneficial to promote the transfer of photo-excited charges and inhibit the composite of photo-generated electron-hole pairs.

[0113] The experimental results show that the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst prepared by the above method has the strongest photocatalytic degradation performance on TCH under the conditions of pH=3, C0=20mg / L, C 光催化剂 =0.6g / L, adsorption in the dark for 1h, and light irradiation for 120min; has the strongest photocatalytic degradation performance on LEV under the conditions of pH=5, C0=10mg / L, C 光催化剂 =0.6g / L, adsorption in the dark for 1h, and light irradiation for 120min; under the optimal conditions, the removal rate of TCH and LEV by the 6wt% NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst can reach more than 90%, which indicates that the preparation method provided by the present application is feasible, and the photocatalyst with better catalytic performance can be obtained.

[0114] The preferred embodiments and their effects are described in the present application. However, once the basic creative concept is known to those skilled in the art, additional changes and modifications can be made to the embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0115] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

[0116] The above merely illustrates the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the present application.

Claims

1. Application of an NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst in degrading antibiotics in water bodies, characterized in that, The preparation method of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst comprises the following steps: 1) Bi(NO3)3·5H2O and Ti3C2 nanosheets are added into deionized water to obtain solution A; Na2WO4·2H2O and CTAB are dissolved in deionized water to obtain solution B; solution A is added into solution B and stirred uniformly, and then Ti3C2 / Bi2WO6 composite material is obtained through hydrothermal reaction, washing and drying; 2) the Ti3C2 / Bi2WO6 composite material prepared in step 1) is added into a DMF solution and stirred uniformly, ZrCl4 and 2-amino terephthalic acid are added and stirred uniformly, and then NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst is obtained through hydrothermal reaction, washing and drying; The NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst has a three-dimensional structure, comprising Ti3C2 / Bi2WO6 composite material and NH2-UiO-66 grown on the surface of the Ti3C2 / Bi2WO6 composite material; the mass ratio of Ti3C2 to Bi2WO6 in the Ti3C2 / Bi2WO6 composite material is (0.02-0.05):1; and the mass fraction of NH2-UiO-66 in the NH2-UiO-66 / Ti3C2 / Bi2WO6 nano-composite photocatalyst is 4-10 wt%. The antibiotic is tetracycline or levofloxacin.

2. Use of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst according to claim 1 for the degradation of antibiotics in water bodies, characterized in that, In step 1), the mass ratio of Bi(NO3)3·5H2O:Ti3C2 nanosheets:Na2WO4·2H2O:CTAB is 1:(0.01-0.03):(0.3-0.4):(0.05-0.06).

3. Use of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst according to claim 1 for the degradation of antibiotics in water bodies, characterized in that, In step 1), the temperature of the hydrothermal reaction is 100-150°C; and the time of the hydrothermal reaction is 24-30 h.

4. Use of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst according to claim 1 for the degradation of antibiotics in water bodies, characterized in that, In step 2), the mass ratio of the Ti3C2 / Bi2WO6 composite material:ZrCl4:2-amino terephthalic acid is 1:(0.005-0.02):(0.004-0.02).

5. Use of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst according to claim 1 for the degradation of antibiotics in water bodies, characterized in that, In step 2), the temperature of the hydrothermal reaction is 100-150°C; and the time of the hydrothermal reaction is 24-30 h.

6. Use of the NH2-UiO-66 / Ti3C2 / Bi2WO6 nanocomposite photocatalyst according to claim 1 for the degradation of antibiotics in water bodies, characterized in that, In step 2), the drying condition is vacuum drying at 60-90°C for 24-36 h.

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