CN106000433B - A kind of Bi (III) metal oxygen cluster inorganic skeleton and preparation method and application - Google Patents

Abstract

The invention belongs to the technical field of photocatalysis, and in particular relates to a Bi(III)-metal oxygen cluster inorganic framework and a preparation method and application thereof, which are used in the field of photocatalytic degradation of organic dyes. The chemical formula of the inorganic framework is: {PMo ₁₂ O ₄₀ Bi ₂ (H ₂ O) ₂ }·4H ₂ O. The Bi(Ⅲ)-metal oxygen cluster inorganic framework described in the present invention is prepared by solvothermal method, the process is simple, the purity is high, and the reproducibility is good, and my country's bismuth resources are abundant, and the multi-acid raw materials are safe, non-toxic, cheap and It is easy to get, and the catalytic activity of metal oxygen clusters modified by Bi(Ⅲ) is obviously improved, so the research field of photocatalysis of bismuth-containing metal oxygen clusters has very broad prospects. Bi(Ⅲ)-metal oxygen cluster inorganic framework, without grinding, can be directly used in photocatalytic degradation experiments, and can be completely separated after simple filtration, with high recycling rate, which overcomes the difficulty of separation and activity of traditional POMs photocatalysts. The components are easily lost and the recycling rate is low, which is convenient for industrial use.

Description

A kind of Bi(Ⅲ)-metal oxide cluster inorganic framework and its preparation method and application

technical field

The invention belongs to the technical field of photocatalysis, and in particular relates to a Bi(III)-metal oxygen cluster inorganic framework and a preparation method and application thereof, which are used in the field of photocatalytic degradation of organic dyes.

Background technique

With the continuous development of industrial economy, environmental pollution has become a major problem that needs to be solved urgently in today's society. The treatment of wastewater has also become one of the important research contents of chemists. In water pollution, organic dyes have always been a major problem in wastewater treatment due to their poor biodegradability, high toxicity, not easy to fade, and complex components. Because these dyes are toxic to animals and humans, it is particularly important to seek an efficient and economical degradation method. However, traditional adsorption methods, membrane separation methods, coagulation methods and other treatment methods have unsatisfactory degradation effects on these dyes, and there are certain difficulties in the actual application process. In this context, people have a strong interest in photocatalytic technology. . This technology can use visible light or ultraviolet light to photocatalytically degrade organic dyes, and can completely mineralize toxic dyes in water into CO ₂ , H ₂ O and other small inorganic molecules or ions without secondary pollution and high efficiency. Become one of the main methods of degrading toxic dyes.

At present, photocatalysts commonly used to degrade organic dyes include semiconductor metal oxides or sulfides (such as TiO ₂ , ZnO, CdS, etc.), Bi-containing compounds (BiOX, X=Cl, Br or I; BiPO ₄ ) and multi-metal Oxygenates (POMs). Among them, _TiO2 has attracted much attention due to its stable chemical properties, high catalytic activity, safety and non-toxicity. However, its application in practice is limited by factors such as difficult curing and separation, narrow absorption wavelength range, high carrier recombination rate, and easy loss of photocatalyst. POMs have been attracting much attention in the field of photocatalysis due to their high reactivity, strong stability, diverse structures, controllable properties, strong oxidation-reduction properties, safety and non-toxicity, etc., and a large number of literatures have proved that POMs are an effective Photocatalysts, whose photochemical activity comes from their unique cage structure (see: Wang SS, Yang G Y. Recent Advances in Polyoxometalate-Catalyzed Reactions [J]. Chemical reviews, 2015, 115(11): 4893-4962.). However, due to the high water solubility and wide bandgap between HOMO-LUMO of traditional polyoxometalates, most polyacids have low recycling efficiency and poor photocatalytic activity, which limits their wide application as catalysts. In recent years, people have modified traditional heteropolyacids by loading polyacids on solid materials with large specific surface areas (such as: TiO ₂ , ZrO ₂ , SiO ₂ , etc.) or introducing dispersed organic ligands, organometallic components, etc. Modification, and then change the electronic structure of polyacid to improve its photocatalytic activity. At present, the introduced modification units are mainly concentrated on the fragments of organic complexes of various transition metals or rare earth ions (see: Zheng ST, Yang G Y. Recent advances in paramagnetic-TM-substituted polyoxometalates (TM = Mn, Fe, Co, Ni, Cu)[J].Chemical Society Reviews,2012,41(22):7623-7646, Dolbecq A,Mialane P,Secheresse F,et al.Functionalized polyoxometalates with covalently linkedbisphosphonate,N-donor or carboxylate ligands:from electrocatalytic tooptical properties [J].Chemical Communications, 2012,48(67):8299-8316.), and there are few compounds prepared by the reaction of bismuth and metal oxygen clusters. Because Bi(III) contains a pair of lone electrons, it can have a stereochemical effect on the formation of the target compound, which is helpful to construct a novel topology; and bismuth-containing compounds have narrow orbital hybridization due to Bi ^6s and O ^2p Band gap and high catalytic activity; finally, China's bismuth resources are relatively rich, accounting for 84% of the world's total reserves, so the preparation of bismuth-containing metal oxygen cluster photocatalytic materials has a certain research value and is of great importance for the development of China's bismuth resources. significance.

Contents of the invention

Aiming at the above current situation, the present invention provides a Bi(III)-metal oxide cluster inorganic framework and its preparation method and application. It was found that the bismuth-containing metal oxygen clusters were used to photocatalytically degrade nitrogen-containing organic dyes such as methyl orange (MO), methylene blue (MB), and rhodamine B (RhB), and the degradation rate could reach 90% within 1 h. The above, and can be completely separated after simple filtration, and the recycling rate is high, which overcomes the shortcomings of traditional POMs photocatalysts such as difficult separation, easy loss of active components, and low recycling rate. The technical method is simple, economical and easy for industrial use. Through photocatalytic performance experiments, it was found that the bismuth-containing metal oxygen clusters have high adsorption performance for cationic nitrogen-containing organic dyes such as methylene blue (MB) and rhodamine B (RhB).

In order to achieve the purpose of the above invention, the present invention is achieved through the following technical scheme: a Bi(III)-metal oxide cluster inorganic framework, whose chemical formula is: {PMo ₁₂ O ₄₀ Bi ₂ (H ₂ O) ₂ }·4H ₂ O, its crystal system belongs to the triclinic system, the space group is P-1, and the unit cell parameters are: α=106.5111°, β=100.8001°, γ=111.9686°.

In addition, the present invention provides the preparation method of the inorganic skeleton, namely: accurately weigh Bi(NO ₃ ) ₃ 5H ₂ O, H ₃ PMo ₁₂ O ₄₀ and dissolve in absolute ethanol to form 0.005mol/L Bi(NO ₃ ) A mixed solution of ₃ and 0.004mol/L H ₃ PMo ₁₂ O ₄₀ , then add a 1.0 mol/L HNO ₃ solution with a volume of 3:10 with the mixed solution, and magnetically stir for 15 min at room temperature; then the The mixed solution was transferred to a reaction kettle, reacted at 150°C for 3 days, and finally cooled to room temperature at 5°C/hour to obtain black rod-shaped or small particle crystals, which were filtered, washed and collected to obtain an inorganic framework compound.

The bismuth-containing metal oxygen cluster prepared above has relatively high stability and strong photocatalytic activity. According to the analysis of ultraviolet-visible spectrum (see Figure 2), the compound has a relatively obvious absorption peak in the ultraviolet region, and the calculated band gap is about 2.88ev, which lays the foundation for the study of its photocatalytic performance (see Figure 3).

Further, the present invention provides the application of the Bi(III)-metal oxide cluster inorganic framework in ultraviolet photocatalytic degradation of nitrogen-containing organic dyes. During specific implementation, the operation method of the application is: add _HNO3 solution to the nitrogen-containing organic dye solution to adjust the pH to 2.5, add an inorganic framework, and stir magnetically under dark conditions; then place it under ultraviolet light and continue to stir, Realize the degradation of nitrogen-containing organic dyes.

Finally, the present invention provides the application of the Bi(III)-metal oxide cluster inorganic framework in the adsorption of cationic nitrogen-containing organic dyes. During specific implementation, the operation method of the application is: add an inorganic framework to the cationic nitrogen-containing organic dye, and stir magnetically under dark conditions to realize the adsorption of the cationic nitrogen-containing organic dye.

Compared with the prior art, the Bi(Ⅲ)-metal oxide cluster inorganic framework and its preparation method and application provided by the present invention have the following advantages and effects:

(1) At present, most of the reported Bi(Ⅲ)-modified metal oxygen cluster crystals are vacancy-type structures, and the compounds based on Keggin-type {PMo ₁₂ } units have not yet appeared, and this is the first one for The example of photocatalytic degradation of nitrogen-containing organic dyes has certain innovative significance and research value.

(2) The Bi(Ⅲ)-metal oxide cluster inorganic framework of the present invention is prepared by solvothermal method, the process is simple, the purity is high, and the reproducibility is good, and my country's bismuth resources are abundant, and the multi-acid raw materials are safe and non-toxic , cheap and easy to obtain, and the catalytic activity of metal oxygen clusters modified by Bi(Ⅲ) has been significantly improved, so bismuth-containing metal oxygen clusters have broad prospects for the research field of photocatalysis.

(3) The Bi(Ⅲ)-metal oxide cluster inorganic framework described in the present invention has a very high degradation rate to nitrogen-containing organic dyes such as methyl orange (MO), methylene blue (MB), and rhodamine B (RhB) within 1 h. High, up to more than 90%, it proves that as a photocatalyst, it has a wide selectivity to degradation substrates, has universal applicability in this field, and is helpful for practical applications.

(4) The Bi(Ⅲ)-metal oxygen cluster inorganic framework described in the present invention can be directly used in photocatalytic degradation experiments without grinding, and can be completely separated through simple filtration, and has a high recycling rate, which overcomes the traditional The POMs photocatalyst is difficult to separate, the active components are easy to lose, and the recycling rate is low, which is convenient for industrial use.

(5) The Bi(Ⅲ)-metal oxygen cluster inorganic framework described in the present invention has strong adsorption capacity for cationic nitrogen-containing organic dyes (methylene blue (MB), rhodamine B (RhB)), and can be used for adsorption and degradation dye this field.

Description of drawings

Figure 1 is a structural diagram of the inorganic framework of Bi(Ⅲ)-metal oxide clusters (PM ₁₂ O ₄₀ ) (see reference materials for substantive examination for color pictures).

Fig. 2 is the ultraviolet-visible spectrum diagram of Bi(Ⅲ)-metal oxygen cluster (PM ₁₂ O ₄₀ ) inorganic framework.

Fig. 3 is a calculated diagram of the band gap of (αhν) ^1/2 of the Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework as a function of energy (hν).

Fig. 4 is the ultraviolet-visible spectrum of the degradation of methyl orange (MO) by the Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework.

Fig. 5 is a graph showing the change of methyl orange (MO) C/C ₀ with the reaction time between the blank and the skeleton material.

Fig. 6 is an ultraviolet-visible spectrum diagram of degradation of methylene blue (MB) by Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework.

Figure 7 is a graph showing the change of methylene blue (MB) C/C ₀ with the reaction time between the blank and the skeleton material.

Fig. 8 is an ultraviolet-visible spectrum diagram of degradation of Rhodamine B (RhB) by Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework.

Fig. 9 is a diagram showing the change of rhodamine B (RhB) C/C ₀ with the reaction time after the blank and the skeleton material are added.

Fig. 10 is a histogram of recycling of methyl orange (MO) degraded by Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework.

Fig. 11 is a PXRD pattern of Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework. 1 in the figure shows the peak shape of the inorganic framework after 3 cycles, 2 shows the peak shape of the inorganic framework prepared in the experiment, and 3 shows the simulated peak shape of the inorganic framework single crystal.

Figure 12 is a standard curve diagram of absorbance of different concentrations of methylene blue (MB).

Figure 13 is a linear fitting graph of the absorbance of methylene blue (MB) as a function of concentration.

Fig. 14 is a standard curve diagram of absorbance of Rhodamine B (RhB) at different concentrations.

Figure 15 is a linear fitting graph of the absorbance of Rhodamine B (RhB) changing with the concentration.

Fig. 16 is the ultraviolet-visible spectrum of the adsorption of methylene blue (MB) (no pH adjustment) on the inorganic framework of Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ).

Fig. 17 is the ultraviolet-visible spectrum of the adsorption of methylene blue (MB) (pH=2.5) on the inorganic framework of Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ).

Fig. 18 is an ultraviolet-visible spectrum diagram of Bi(III)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbing Rhodamine B (RhB) (no pH adjustment).

Fig. 19 is an ultraviolet-visible spectrum diagram of Bi(III)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbing rhodamine B (RhB) (pH=2.5).

Fig. 20 is the ultraviolet-visible spectrum of Bi(III)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbing methyl orange (MO) (no pH adjustment).

Fig. 21 is an ultraviolet-visible spectrum diagram of Bi(III)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbing methyl orange (MO) (pH=2.5).

Figure 22 is a comparison of the colors of the dye solution when Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbs methylene blue (MB) (without adjusting the pH) for 0h and 3h (see reference materials for substantive review).

Figure 23 is a comparison of the colors of the dye solution when the Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbs methylene blue (MB) (pH=2.5) for 0h and 3h (see reference materials for substantive examination for the color picture).

Figure 24 is the color comparison diagram of the dye solution when Rhodamine B (RhB) is adsorbed on Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework (without adjusting the pH) for 0h and 3h (see reference materials for substantive examination for the color picture) .

Figure 25 is a color comparison diagram of the dye solution when Rhodamine B (RhB) (pH=2.5) is adsorbed on the inorganic framework of Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) for 0h and 3h (see the reference materials for substantive examination for the color picture) .

Figure 26 is a color comparison diagram of the dye solution when Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbs methyl orange (MO) (without adjusting the pH) for 0h and 3h (see the reference materials for substantive examination for the color picture) .

Figure 27 is a color comparison diagram of the dye solution when Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework adsorbs methyl orange (MO) (pH=2.5) for 0h and 3h (see the reference materials for substantive examination for the color picture) .

Detailed ways

In order to make the technical solutions, advantages and objectives of the present invention clearer, it will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1, Preparation of Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework:

Accurately weigh 0.0243g (0.05mmol) of Bi(NO ₃ ) ₃ 5H ₂ O, 0.07301g (0.04mmol) of H ₃ PMo ₁₂ O ₄₀ , mix and dissolve in 10ml of absolute ethanol solvent, add 3ml, The HNO ₃ solution with a concentration of 1.0 mol/L was magnetically stirred at room temperature for 15 min. The mixture was transferred to a 20ml reaction kettle, reacted at 150°C for 3 days, and finally cooled to room temperature at 5°C/hour, washed with distilled water and absolute ethanol, filtered, and dried to obtain black rod-shaped or small particle crystals.

Example 2, Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework crystallographic structure parameters

The crystal structure of the Bi(Ⅲ)-metal oxide cluster (PM12O40) inorganic framework obtained in Example 1 was determined as follows: a single crystal with a suitable size was selected under a microscope for X-ray single crystal structure analysis. The X-ray diffraction data of crystals were collected by German Bruker Smart-Apex CCD surface detection X-ray single crystal diffractometer, using Mo-Kα target, measured at room temperature. Data reduction and structural elucidation were performed using the SHELXTL-97 program. The main crystallographic data of the inorganic framework are listed in Table 1.

Table 1. Crystallographic structural parameters of the inorganic framework

Embodiment 3, experimental operation of photocatalytic degradation of nitrogen-containing organic dyes:

(1) First prepare nitrogen-containing organic dye solutions such as methyl orange MO (6.5466mg), methylene blue MB (7.4780mg), rhodamine B or RhB (9.5802mg) with a concentration of 2×10 ^-5 mol/L, ready for use.

(2) Degradation experiment after adding the Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework: pipette 100ml of the above prepared organic dye solution into a large beaker, add 1.0mol/L HNO ₃ Adjust the pH of the solution to 2.5, add a weighed 20 mg sample, and stir magnetically for 30 minutes in a dark environment to ensure the adsorption balance between the organic dye and the sample. Then put it under a 30W ultraviolet lamp for a certain period of time, and keep stirring, take 3ml of the solution every 10min for ultraviolet-visible photometric analysis, so as to determine its degradation rate.

(3) Blank experiment: pipette 100ml of the above prepared organic dye solution into a large beaker, adjust the pH to 2.5 with 1.0mol/L _HNO3 solution, stir magnetically for 30min in a dark environment, and then place it in Irradiate under 30W ultraviolet light for a certain period of time, and keep stirring, take 3ml solution every 10min for ultraviolet-visible photometric analysis, so as to determine its degradation rate. It can be seen from Figures 5, 7 and 9 that under the irradiation of ultraviolet light, the degradation rate of the blank degraded organic dyes (methyl orange MO, methylene blue MB, rhodamine B or RhB) is less than 10% within 1 hour, while the degradation rate of the organic dyes after adding the inorganic framework is less than 10%. The degradation rate can reach more than 90% within 1 hour, so it can be concluded that the inorganic framework has a certain catalytic effect on degrading the three organic dyes.

(4) The recycling experiment of the Bi(Ⅲ)-metal oxide cluster (PM ₁₂ O ₄₀ ) inorganic framework: After the above step (2), that is, after the dye is completely degraded, the bismuth-containing metal oxide cluster is collected by filtration and washing. cluster. Then pipette 100ml of the above-mentioned prepared organic dye solution into a large beaker, adjust the pH to 2.5 with 1.0mol/L _HNO3 solution, and add 20mg of collected bismuth-containing metal oxygen clusters into the beaker. , and magnetically stirred for 30 minutes to ensure the adsorption balance between the organic dye and the sample. Then put it under a 30W ultraviolet lamp for a certain period of time, and keep stirring, take 3ml of the solution every 10min for ultraviolet-visible photometric analysis, so as to determine its degradation rate. By analogy, cycle 3 times to determine its stability. It can be seen from Figure 10 that after 3 cycles, the photocatalytic activity of the inorganic framework to degrade organic dyes has no obvious loss; the peak shape after 3 cycles in the PXRD figure (Figure 11) is roughly consistent with the peak shape of the single crystal simulation, It can be concluded that the inorganic framework has a complete structure and is a relatively stable photocatalyst for degrading organic dyes.

Embodiment 4, the experimental operation of adsorption nitrogen-containing organic dye:

(1) First prepare nitrogen-containing organic dye solutions such as methyl orange MO (6.5466mg), methylene blue MB (7.4780mg), rhodamine B or RhB (9.5802mg) with a concentration of 2×10 ^-5 mol/L, ready for use.

(2) Pipette 25ml of the above prepared organic dye solution into a beaker, add a weighed 5.0mg sample, continue magnetic stirring for 3h in a dark environment, take 3ml of the solution for UV-visible photometric analysis, and initially determine its Adsorption size. From Figures 16, 18, 20, 22, 24 and 26, it can be seen that the inorganic framework has a large adsorption capacity for cationic nitrogen-containing organic dyes (methylene blue (MB), rhodamine B (RhB)), while for anionic The nitrogen-containing organic dye (methyl orange (MO)) has almost zero adsorption.

(3) Drawing of standard curve: For dyes with large adsorption capacity, namely methylene blue (MB) and rhodamine B (RhB), different concentrations (2, 4, 6, 8, 10, 12, 14 mg/L) were prepared respectively solution, measure the absorbance at its maximum absorption wavelength, and obtain the linear relationship between concentration and absorbance, and finally according to the formula Q _e =V(C ₀ -C _e )/m(Q _e : adsorption amount; V: dye solution volume; C ₀ : the initial concentration of the dye solution; C _e : the concentration of the dye solution after 3 hours; m: the mass of the adsorbent) to obtain the adsorption amount. It can be seen from Figures 12 to 15 that the adsorption amount of the inorganic framework to methylene blue (MB) is 42.79 mg·g ^-1 , and the adsorption amount to rhodamine B (RhB) is 43.84 mg·g ^-1 .

(4) Experiment of the influence of pH value on the adsorption amount: Pipette 25ml of the above-mentioned prepared organic dye solution into a beaker, adjust the pH to 2.5 with 1.0mol/L _HNO3 solution, and add a weighed 5.0mg sample , continuously magnetically stirred for 3 hours in a dark environment, took 3ml of the solution for UV-Vis spectrophotometric analysis, and finally studied the effect of pH on the amount of adsorption. It can be seen from Figures 16 to 27 that pH has little effect on the adsorption capacity of methyl orange (MO) and rhodamine B (RhB), while for methylene blue (MB), at pH=2.5, it can only adsorb 17.80%, which is far from It is lower than the adsorption amount when the pH is not adjusted (ie pH=7.0).

Claims (6)

1. A Bi(Ⅲ)-metal oxide cluster inorganic framework, characterized in that its chemical formula is: {PMo ₁₂ O ₄₀ Bi ₂ (H ₂ O) ₂ }·4H ₂ O, and its crystal system belongs to the triclinic system , the space group is P-1, and the unit cell parameters are: a = 9.7857Å, b = 10.6361Å, c = 12.2790Å, α = 106.5111º, β = 100.8001º, γ = 111.9686º; the preparation of the inorganic framework method is implemented through the following steps: Accurately weigh Bi(NO ₃ ) ₃ ·5H ₂ O, H ₃ PMo ₁₂ O ₄₀ and dissolve in absolute ethanol to form 0.005mol/L Bi(NO ₃ ) ₃ and 0.004mol/L H ₃ PMo ₁₂ O ₄₀ mixed solution, then add the mixed solution volume 3:10 concentration of 1.0mol/LHNO ₃ solution, magnetically stir at room temperature for 15min; then transfer the mixed solution to the reaction kettle, react at 150°C for 3 days , and finally lowered to room temperature at 5°C/hour to obtain black rod-shaped or small-grained crystals, which were filtered, washed and collected to obtain an inorganic framework compound. 2. A preparation method of Bi(Ⅲ)-metal oxide cluster inorganic framework, what it prepares is the inorganic framework as claimed in claim 1, is characterized in that, is realized by the following steps: Accurately weigh Bi(NO ₃ ) ₃ ·5H ₂ O, H ₃ PMo ₁₂ O ₄₀ and dissolve in absolute ethanol to form 0.005mol/L Bi(NO ₃ ) ₃ and 0.004mol/L H ₃ PMo ₁₂ O ₄₀ mixed solution, then add the mixed solution volume 3:10 concentration of 1.0mol/LHNO ₃ solution, magnetically stir at room temperature for 15min; then transfer the mixed solution to the reaction kettle, react at 150°C for 3 days , and finally lowered to room temperature at 5°C/hour to obtain black rod-shaped or small-grained crystals, which were filtered, washed and collected to obtain an inorganic framework compound. 3. The application of the Bi(III)-metal oxide cluster inorganic framework according to claim 1 or 2 in the ultraviolet photocatalytic degradation of nitrogen-containing organic dyes. 4. The application according to claim 3, wherein the operation method of the application is: Add HNO ₃ solution to the nitrogen-containing organic dye solution to adjust the pH to 2.5, add the inorganic framework, and stir magnetically under dark conditions; then put it under ultraviolet light irradiation and keep stirring to realize the degradation of the nitrogen-containing organic dye. 5. The application of the Bi(III)-metal oxide cluster inorganic framework according to claim 1 or 2 in the adsorption of cationic nitrogen-containing organic dyes. 6. The application according to claim 5, wherein the operation method of the application is: The cationic nitrogen-containing organic dye is added with an inorganic framework, and magnetically stirred under dark conditions to realize the adsorption of the cationic nitrogen-containing organic dye.