CN108997441B

CN108997441B - Polyacid-based metal organic hybrid material and preparation method and application thereof

Info

Publication number: CN108997441B
Application number: CN201810791035.XA
Authority: CN
Inventors: 谢景力; 宫春华; 徐昊; 曾祥华; 张俊勇; 郭海洋
Original assignee: Anhui Weixiang New Material Co Ltd; Jiaxing University
Current assignee: Anhui Weixiang New Material Co., Ltd; Jiaxing University
Priority date: 2018-07-18
Filing date: 2018-07-18
Publication date: 2020-09-22
Anticipated expiration: 2038-07-18
Also published as: CN108997441A

Abstract

The invention discloses a polyacid-based metal-organic hybrid material and a preparation method and application thereof, wherein the polyacid-based metal-organic hybrid material is synthesized by utilizing an evaporation reflux method and/or a hydrothermal synthesis method through metal salt, ammonium molybdate and an organic ligand; or, synthesizing the polyacid-based metal-organic hybrid material by using ammonium molybdate and an organic ligand through an evaporation reflux method; wherein the metal salt is copper salt or cobalt salt, and the organic ligand is tris-pyridylmethylene amine and/or 1- (tetrazol-5-yl) -3- (triazol-1-yl) benzene; the terpyridyl methylamine is abbreviated as TPMA, and the 1- (tetrazole-5-yl) -3- (triazole-1-yl) benzene is abbreviated as 1, 3-ttb. The invention has the function of degrading organic dye with the photocatalytic material.

Description

Polyacid-based metal organic hybrid material and preparation method and application thereof

Technical Field

The invention relates to the field of polyacid-based metal organic hybrid materials. More specifically, the invention relates to a polyacid-based metal organic hybrid material, and a preparation method and application thereof.

Background

The polyacid is known as polyoxometallate and is a polynuclear complex in which the main metal elements constituting the polyacid are molybdenum and tungsten. Polyoxometallate complexes have been developed in the field of inorganic chemistry for over two hundred years. Since the first polyacid was synthesized, researchers have discovered and synthesized six common structures in succession, namely: keggin, Anderson, Silverton, Lindqvist, Dawson, Waugh.

With the continuous and intensive research on polyacid, good chemoselectivity and high catalytic efficiency under mild conditions are gradually shown. In addition, many breakthroughs in the application of polyacids are available, for example: nanotechnology, medical drugs, biochemistry, material chemistry, surface science, and the like. The progress of polyoxometallate in the aspects is benefited by the changeable structure, high porosity, adjustable specific surface area and pore size, post-modification, convenient synthesis and the like.

Disclosure of Invention

The invention aims to provide a polyacid-based metal organic hybrid material, and a preparation method and application thereof.

To achieve these objects and other advantages in accordance with the purpose of the invention, there is provided a nitrogen-containing ligand-induced polyacid-based metal-organic hybrid material,

synthesizing the polyacid-based metal-organic hybrid material by using metal salt, ammonium molybdate and organic ligand through an evaporation reflux method and/or a hydrothermal synthesis method; or, synthesizing the polyacid-based metal-organic hybrid material by using ammonium molybdate and an organic ligand through an evaporation reflux method;

wherein the metal salt is copper salt or cobalt salt, and the organic ligand is tris-pyridylmethylene amine and/or 1- (tetrazol-5-yl) -3- (triazol-1-yl) benzene; the terpyridyl methylamine is abbreviated as TPMA, and the 1- (tetrazole-5-yl) -3- (triazole-1-yl) benzene is abbreviated as 1, 3-ttb.

Preferably, the polyacid-based metal organic hybrid material is MoO₃(TPMA)、2[Cu(TPMA)(H₂O)]·(Mo₈O₂₆)·4H₂O、[Co₂(TPMA)₂(β-Mo₈O₂₆)]Or [ Cu ]₂(TPMA)₂₍1,3-ttb)(β-Mo₈O₂₆)]·2H₂O。

Preferably, the MoO is₃The synthesis method of (TPMA) comprises the following steps: mixing 0.1mmol TPMA, 0.1mmol ammonium molybdate, 0.45mmol hydrochloric acid and 30mL water, putting into a container, evaporating and refluxing at 110 ℃ for 5 days, cooling, filtering to obtain a yellow brown turbid solution, filtering to obtain a light yellow clear solution, placing the solution in a beaker, standing and volatilizing to obtain light yellow cuboid crystals, and thus obtaining the crystal.

Preferably, 2[ Cu (TPMA) (H)₂O)]·(Mo₈O₂₆)·4H₂The synthesis method of O comprises the following steps: adding 0.02mmol MoO₃(TPMA), 0.1mmol of blue vitriod and 10mL of water are put into a high-pressure stainless steel reaction kettle with a polytetrafluoroethylene lining, the pH value is adjusted to 2.35 by nitric acid solution, the reaction kettle is sealed and then put into a drying oven to react for 3 days at 160 ℃, and the temperature is reducedObtaining a blue clear solution, standing and volatilizing to obtain a light blue diamond crystal, and obtaining the product.

Preferably, [ Co ]₂(TPMA)₂(β-Mo₈O₂₆)]The synthesis method comprises the following steps: putting 0.1mmol of cobalt nitrate hexahydrate, 0.1mmol of TPMA, 0.1mmol of 1,3-ttb, 0.1mmol of ammonium molybdate and 10mL of water into a polytetrafluoroethylene-lined high-pressure stainless steel reaction kettle, adjusting the pH to 2.52 by using a nitric acid solution, sealing, putting the reaction kettle into an oven, reacting for 3 days at 160 ℃, and carrying out programmed cooling to obtain wine red blocky crystals.

Preferably, [ Cu ]₂(TPMA)₂(1,3-ttb)(β-Mo₈O₂₆)]·2H₂The synthesis method of O comprises the following steps: putting 0.1mmol of copper nitrate trihydrate, 0.1mmol of TPMA, 0.1mmol of 1,3-ttb, 0.1mmol of ammonium molybdate and 10mL of water into a polytetrafluoroethylene-lined high-pressure stainless steel reaction kettle, adjusting the pH to 2.35 by using a hydrochloric acid solution, sealing, putting the reaction kettle into an oven, reacting for 3 days at 160 ℃, and carrying out programmed cooling to obtain blue diamond crystals.

The invention also provides application of the nitrogen-containing ligand induced polyacid-based metal-organic hybrid material as a photocatalytic material to degrade organic dyes.

The invention also provides application of the nitrogen-containing ligand induced polyacid-based metal organic hybrid material as an inhibitor for bauxite desilication.

The invention at least comprises the following beneficial effects: when the hydrothermal synthesis method is used, metal salt, polyacid, organic ligand and solvent are added into a reaction kettle, and the evaporation reflux method is to add the metal salt, the polyacid, the organic ligand and the solvent into a round-bottom flask and heat reflux the mixture. Because the polyacid anion has coordination sites of terminal oxygen and bridge oxygen atoms, the metal cation can be well coordinated with the polyacid. And then an organic ligand (N and O atoms in the organic ligand have lone pair electrons) is utilized to easily form a metal bond, so that a compound with rich structure and high dimension is obtained in an extending way.

Copper and cobalt act as transition metal ions due to their flexible coordination patterns and their readily variable valency. The ligands selected were tris-pyridinylmethylene amine (TPMA) and 1- (tetrazol-5-yl) -3- (triazol-1-yl) benzene (1,3-ttb ligand), the tris-pyridinylmethylene amine (TPMA) source being selected as: TPMA has four potential coordination sites, has rich bridging modes, has a basis for obtaining a multi-dimensional and high-core structure, and has fewer reports on the existing polyacid-based metal organic hybrid materials related to TPMA; the 1,3-ttb has six potential coordination sites, which makes it easy to coordinate with metal and obtain abundant geometrical configuration, and the ligand has rigid skeleton, so that the structure of the synthesized MOFs is relatively stable, and two nitrogen-containing functional groups exist in the 1,3-ttb ligand, so that the coordination possibility exists more. For the reasons mentioned above, TPMA and 1,3-ttb were chosen to try to synthesize polyacid-based metal-organic hybrid materials with novel structures.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

FIG. 1 is an infrared spectrum of Compound 1;

FIG. 2 is an infrared spectrum of Compound 2;

FIG. 3 is an infrared spectrum of Compound 3;

FIG. 4 is an infrared spectrum of Compound 4;

FIG. 5 is a cyclic voltammogram of Compound 1;

FIG. 6 is a cyclic voltammogram of Compound 3;

FIG. 7 is a cyclic voltammogram of Compound 4;

FIG. 8 is a graph of Compound 4 vs. NaNO₂The catalytic properties of (a);

FIG. 9 is Compound 4 vs. H₂O₂The catalytic properties of (a);

FIG. 10 is the photocatalytic effect of Compound 1 on methylene blue solution;

FIG. 11 is the photocatalytic effect of Compound 3 on methylene blue solution;

FIG. 12 is the photocatalytic effect of Compound 4 on methylene blue solution;

FIG. 13 shows the photocatalytic effect of compound 1 on rhodamine b solutions;

FIG. 14 shows the photocatalytic effect of compound 3 on rhodamine b solutions;

FIG. 15 shows the photocatalytic effect of compound 4 on rhodamine b solutions;

FIG. 16 is an X-ray diffraction pattern of Compound 1;

FIG. 17 is an X-ray diffraction pattern of Compound 2;

FIG. 18 is an X-ray diffraction pattern of Compound 3;

FIG. 19 is an X-ray diffraction pattern of Compound 4;

FIG. 20 is a molecular structure diagram of Compound 1;

FIG. 21 is a molecular structure diagram of Compound 2;

FIG. 22 is a molecular structure diagram of Compound 3;

FIG. 23 is a one-dimensional chain scheme of Compound 3;

FIG. 24 is a molecular structure diagram of Compound 4;

FIG. 25 is a two-dimensional block diagram of Compound 2;

figure 26 is a schematic of a two-dimensional layer of compound 2.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

The TPMA synthesis method comprises the steps of adding 2-methylamino pyridine, 2-chloromethyl pyridine hydrochloride, potassium carbonate and acetonitrile into a round-bottom flask, heating and refluxing for three days at the temperature of 80 ℃, and passing through a column to obtain a yellow-brown solid.

Example 1

Compound 1: MoO₃Synthesis of (TPMA)

MoO₃The synthesis method of (TPMA) comprises the following steps: mixing 0.1mmol TPMA, 0.1mmol ammonium molybdate, 0.45mmol hydrochloric acid and 30mL water, putting into a container, evaporating and refluxing at 110 ℃ for 5 days, cooling, filtering to obtain a yellow brown turbid solution, filtering to obtain a light yellow clear solution, placing the solution in a beaker, standing and volatilizing to obtain light yellow cuboid crystals, and thus obtaining the crystal.

Example 2

Compound 2:2[Cu(TPMA)(H₂O)]·(Mo₈O₂₆)·4H₂O

2[Cu(TPMA)(H₂O)]·(Mo₈O₂₆)·4H₂the synthesis method of O comprises the following steps: 0.02mmol of MoO₃(TPMA), 0.1mmol of blue sulfate pentahydrate and 10mL of water are put into a high-pressure stainless steel reaction kettle with a polytetrafluoroethylene lining, the pH value is adjusted to 2.35 by using a nitric acid solution, the reaction kettle is sealed and then placed into a drying oven to react for 3 days at 160 ℃, a blue clear solution is obtained after cooling, and a light blue rhombus crystal is obtained after standing and volatilizing.

Example 3

Compound 3: [ Co ] A₂(TPMA)₂(β-Mo₈O₂₆)]

[Co₂(TPMA)₂(β-Mo₈O₂₆)]The synthesis method comprises the following steps: putting 0.1mmol of cobalt nitrate hexahydrate, 0.1mmol of TPMA, 0.1mmol of 1,3-ttb, 0.1mmol of ammonium molybdate and 10mL of water into a polytetrafluoroethylene-lined high-pressure stainless steel reaction kettle, adjusting the pH to 2.52 by using a nitric acid solution, sealing, putting the reaction kettle into an oven, reacting for 3 days at 160 ℃, and carrying out programmed cooling to obtain wine red blocky crystals.

Example 4

Compound 4: [ Cu ]₂(TPMA)₂(1,3-ttb)(β-Mo₈O₂₆)]·2H₂O

[Cu₂(TPMA)₂(1,3-ttb)(β-Mo₈O₂₆)]·2H₂The synthesis method of O comprises the following steps: putting 0.1mmol of copper nitrate trihydrate, 0.1mmol of TPMA, 0.1mmol of 1,3-ttb, 0.1mmol of ammonium molybdate and 10mL of water into a polytetrafluoroethylene-lined high-pressure stainless steel reaction kettle, adjusting the pH to 2.35 by using a hydrochloric acid solution, sealing, putting the reaction kettle into an oven, reacting for 3 days at 160 ℃, and carrying out programmed cooling to obtain blue diamond crystals.

Correlation experiments

1. Determination of Crystal Structure

As shown in FIGS. 16 to 19, the single crystal X-ray diffraction data of the compounds 1 to 4 were measured by an Xcalibur, Eos, Gemini diffractometer, and crystals of appropriate size and good quality were selected under a microscope for measurementConstant room temperature at 296K, using MoK α monochromized from graphite

Radiation or Cu-K α radiation

Diffraction data were collected and empirically absorption corrected using the SADABS program. The structural data was solved and obtained by the direct method (SHELXS) and Olex2 programs. And (3) performing full matrix least square correction on all non-hydrogen atom coordinates and anisotropic parameters, calculating and determining the positions of C-H atoms according to a theoretical mode, finding O-H atoms according to a difference Fourier, performing full matrix least square correction on the hydrogen atom coordinates and the isotropic parameters, and participating in final structure refinement. Some parameters of the crystallographic diffraction point data collection and structure refinement are listed in tables 1-3.

TABLE 1 crystallographic data and structural parameters for Compounds 1-4

TABLE 2 major bond lengths of

Compounds

1,2

Key angle (o)

TABLE 3 major bond lengths of

Compounds

3,4

And key angle(o)

2. Crystal Structure analysis of Compounds 1-4

Compound 1: MoO₃(TPMA) Crystal Structure

As shown in FIG. 20, Compound 1 contains one TPMA ligand and one MoO₃The crystal is in orthorhombic Pbca, and the bond valence calculation shows that all Mo atoms are in + VI oxidation state. In order to make the structure diagram clearer, all interstitial water molecules and hydrogen atoms are omitted, and one hydrogen atom of each water molecule is also omitted in the following compounds 2-4, and detailed description is omitted.

In compound 1, Mo1 reacts with three N atoms and Mo in TPMA₈O₂₆Three O atoms in the structure are coordinated by 6 to form a double triangular pyramid structure. In the structure, the non-coordinated N and the naked O atom exist in the TPMA ligand, so the crystal is taken as a raw material, and the attempt is made to continuously introduce a second metal or ligand into a reaction system. The bond length ranges of Mo-O bond and Mo-N bond are respectively

And

compound 2: 2[ Cu (TPMA)) (H₂O)]·(Mo₈O₂₆)·4H₂O

As shown in FIG. 21, Compound 2 contains a Cu (II) ion, a TPMA ligand, and a free [ Mo ]₈O₂₆]^4-Polyacid anion (Mo for short)₈O₂₆) And five water molecules. Belongs to the monoclinic system C2₂The bond valence calculation shows that all Mo atoms are in the + VI oxidation state and all Cu atoms are in the + II oxidation state.

As shown in FIGS. 25 and 26, in Compound 2, the Cu1 ion is penta-coordinated with a TPMA ligand and a water, Mo₈O₂₆In the free state, a pentahedral structure is formed. The bond lengths of the Cu-O bond and the Cu-N bond are respectively in the range

And

compound 3: [ Co ] A₂(TPMA)₂(β-Mo₈O₂₆)]

As shown in FIG. 22, compound 3 contains two Co (II) ions, two TPMA ligands, and one β - [ Mo ]₈O₂₆]^4-Polyacid anion (Mo for short)₈O₂₆). Belonging to the monoclinic system P21/c, the bond valence calculation shows that all Mo atoms are in the + VI oxidation state and all Co atoms are in the + II oxidation state.

As shown in FIG. 23, the coordination environments of the two Co ions in the compound 3 are the same and symmetrical, Co and β -Mo₈O₂₆Is hexacoordinated to TPMA to form a distorted octahedral structure β^-[Mo₈O₂₆]^4-Units condensed by sharing two common vertices (O) to form infinite [ Mo ]₈O₂₇]_n ^4n-Chains, such octamolybdenum chains are relatively rare. The bond lengths of the Co-O bond and the Co-N bond are in the ranges

And

compound 4: [ Cu ]₂(TPMA)₂(1,3-ttb)(β-Mo₈O₂₆)]·2H₂O

As shown in FIG. 24, two Cu (II) ions, two TPMA ligands, one 1,3-ttb ligand, and one β are contained in Compound 4^-[Mo₈O₂₆]^4-Polyacid anion (Mo for short)₈O₂₆) And two water molecules. Belongs to a triclinic system P-1, and the valence calculation shows that all Mo atoms are in a + VI oxidation state, and all Cu atoms are in a + II oxidation state.

Cu1 and Cu1 in three Cu (II) ions in compound 4^#The Cu in the structure is connected with two TPMA, two 1,3-ttb ligands and one β^-[Mo₈O₂₆]^4-Coordination forms an irregular octahedral structure, three Cu (II) ions in the structure are positioned on the same plane and are tangent on the same chain, a one-dimensional chain structure is formed by coordination of the Cu (II) ions and the 1,3-ttb ligand, and β^-[Mo₈O₂₆]^4-The oxygen in (2) and Cu (II) ion coordinate link form a two-dimensional plane structure. The bond lengths of the Cu-O bond and the Cu-N bond are respectively in the range

And

3. infrared spectroscopic analysis of Compounds 1 to 4

The infrared spectrogram of the compound 1-4 is shown in figures 1-4. For infrared measurements, KBr was mixed with the compound at a ratio of 100:1 and the mixture was tableted and measured by a Varian 640 model FT-IR spectrometer. The spectrogram shows that: compound 1, 3343cm^-1The characteristic peak at (A) is O-H stretching vibration in the hydroxyl group. 1159-1643 cm^-1The characteristic peak is C-N, C ═ C stretching vibration. 549 cm to 1058cm^-1The characteristic peak of can be attributed to [ Mo ]₈O₂₆]^4-Stretching vibration of Mo-O and Mo-O-Mo in the alloy. Compound 2, 3340cm^-1The characteristic peak can be attributed to the O-H stretching vibration in water molecules and hydroxyl groups. 1153-1588 cm^-1The characteristic peak at (a) can be attributed to the stretching vibration of C-N, C ═ C. 694-1042 cm^-1The characteristic peak of can be attributed to [ Mo ]₈O₂₆]^4-Stretching vibration of Mo-O and Mo-O-Mo in the alloy. Compound 3, 3431cm^-1The characteristic peak of (A) isO-H in the hydroxyl group vibrates telescopically. 1152-1602 cm^-1The characteristic peak at (a) is the stretching vibration of C-N, C ═ C in the TPMA ligand. 610-1056 cm^-1The characteristic peak of can be attributed to [ Mo ]₈O₂₆]^4-Stretching vibration of Mo-O and Mo-O-Mo in the alloy. Compound 4, 3488cm^-1The characteristic peak at (a) can be attributed to the water molecules in the compound and the O — H stretching vibration in the hydroxyl group. 1164-1610 cm^-1Characteristic peaks at (a) are stretching vibrations of the TPMA ligand and the C-N, C ═ C and N-N bonds in 1, 3-ttb. 528-charge 1051cm^-1The characteristic peak of can be attributed to [ Mo ]₈O₂₆]^4-Stretching vibration of Mo-O and Mo-O-Mo in the alloy.

4. Analysis of electrochemical Properties of Compound 1, Compound 3 and Compound 4

Since the compound 2 is unstable in the electrolyte, the electrochemical properties of the compound 1, the compound 3 and the compound 4 are mainly studied, as shown in fig. 5 to 7. Firstly, weighing a small amount of compounds 1-4, mixing the compounds with graphite powder, grinding the mixture in an agate mortar until the mixture is uniformly mixed, stirring the mixture to be viscous by using silicone oil, filling the mixture into a glass tube, and inserting a copper wire to be detected after the mixture is completely mixed. The electrochemical workstation used for detection is CHI660E electrochemical workstation, the reference electrode used is Ag/AgCl electrode, the counter electrode is platinum electrode, the electrolyte is a mixed solution of sulfuric acid and sodium sulfate, and finally the measured cyclic voltammetry curve is shown in the figure. In the potential range of 0-500mV, compound 1 has a pair of redox peaks (E) at 200mV_1/2＝(E_pa+E_pc) [ 2 ] corresponds to Mo₈O₂₆The reduction process of (1). Compound 3 presents two pairs of redox peaks at 200mV and 350mV (E)_1/2＝(E_pa+E_pc) [ 2 ] corresponds to Mo₈O₂₆The reduction process of (1). Compound 4 has a pair of redox peaks (E) at 75mV_1/2＝(E_pa+E_pc) The/2) corresponds to the electronic oxidation-reduction process of Cu, and a pair of oxidation-reduction peaks (E) exist at 200mV_1/2＝(E_pa+E_pc) [ 2 ] corresponds to Mo₈O₂₆The reduction process of (1).

Based on the above, compound 4 was further investigatedFor NaNO₂And H₂O₂Study of catalytic properties of (2). The results are shown in FIGS. 8 to 9. According to the analysis of the change of the oxidation reduction peak, the oxidation reduction peak is along with NaNO₂And H₂O₂Is determined to have catalytic NaNO₂And H₂O₂The nature of (c).

5. Photocatalytic performance of Compounds 1-4

For the research of the photocatalytic performance, methylene blue and rhodamine B are selected as pollutants to research the degradation property of different crystals on dyes. The experimental procedure was to weigh a small amount of crystals into a beaker and add methylene blue (6 mg/L)^-1) Or rhodamine B (10 mg/L)^-1) Then, methylene blue (6 mg/L) was added to the other beaker^-1) Or rhodamine B (10 mg/L)^-1) As a blank control. The beaker is placed on a magnetic stirrer under the irradiation of an ultraviolet lamp, and a part of the reaction solution is taken out every half an hour for ultraviolet measurement.

As shown in fig. 10 to 12, after ultraviolet measurement, analysis charts show that compounds 1 to 4 have catalytic degradation effects on methylene blue, and among the four compounds, the catalytic efficiency of compound 1 is the highest, and particularly in the first half hour, compound 3 times, and the catalytic efficiencies of compound 2 and compound 4 are both very low. As shown in fig. 13 to 15, the

compounds

1,3 and 4 have higher catalytic efficiency for rhodamine B, wherein the compound 4 has a significant catalytic degradation effect for rhodamine B, and the compound 1 is inferior to the compound 4 for 3 times.

6. Application of compound 1 as inhibitor for bauxite desilication

Sodium oleate is adopted as the collecting agent.

Water glass is used as inhibitor No. 1.

The inhibitor No. 2 is prepared by mixing water glass and the compound 1 according to the mass ratio of 100:3 and then stirring for 15min at 3000r/min, wherein the stirring temperature is controlled at 20 ℃.

Al in raw bauxite₂O₃40.13% of SiO₂The content is 8.66%, and the gangue minerals in the bauxite raw ore are quartz, hydromica, chlorite, calcite and the like. Raw bauxite oreGrinding by using a ball mill, wherein the grinding fineness is-0.074 mm and accounts for 70%, the pulp concentration is 34%, performing a primary-coarse-two-sweeping process, and the dosage of a flotation reagent is as follows: adding Na as regulator in the first roughing₂CO₃1500g/t, 600g/t of inhibitor, 150g/t of collecting agent, 8g/t of collecting agent is added in both scavenging, the rough concentrate and the middlings obtained by scavenging are combined in the two concentrating processes, and the results are shown in table 1.

TABLE 1

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims

1. The polyacid-based metal-organic hybrid material induced by the nitrogen-containing ligand is characterized in that,

the polyacid-based metal-organic hybrid material is [ Cu (TPMA)) (H₂O)]₂·(Mo₈O₂₆)·4H₂O、[Co₂(TPMA)₂(β-Mo₈O₂₆)]Or [ Cu ]₂(TPMA)₂(1,3-ttb)(β-Mo₈O₂₆)]·2H₂O；

[Cu(TPMA)(H₂O)]₂·(Mo₈O₂₆)·4H₂The synthesis method of O comprises the following steps: 0.02mmol of MoO₃(TPMA), 0.1mmol of blue sulfate pentahydrate and 10mL of water are put into a high-pressure stainless steel reaction kettle with a polytetrafluoroethylene lining, the pH value is adjusted to 2.35 by using a nitric acid solution, the reaction kettle is sealed and then placed into a drying oven to react for 3 days at 160 ℃, a blue clear solution is obtained after cooling, and a light blue rhombus crystal is obtained after standing and volatilizing;

[Co₂(TPMA)₂(β-Mo₈O₂₆)]the synthesis method comprises the following steps: putting 0.1mmol of cobalt nitrate hexahydrate, 0.1mmol of TPMA, 0.1mmol of 1,3-ttb, 0.1mmol of ammonium molybdate and 10mL of water into a polytetrafluoroethylene-lined high-pressure stainless steel reaction kettle, adjusting the pH to 2.52 by using a nitric acid solution, sealing, putting the reaction kettle into an oven, reacting for 3 days at 160 ℃, and carrying out programmed cooling to obtain wine red blocky crystals; wherein TPMA is pyridine methylene amine, 1,3-ttb is 1- (tetrazole-5-yl) -3- (triazole-1-yl) benzene;

2. Use of the nitrogen-containing ligand induced polyacid-based metal-organic hybrid material of claim 1 as a photocatalytic material to degrade organic dyes.

3. Nitrogen-containing ligand induced polyacid-based metal organic hybrid material MoO₃(TPMA) use as inhibitor for desiliconization of bauxite, wherein MoO₃The synthesis method of (TPMA) comprises the following steps: mixing 0.1mmol of TPMA, 0.1mmol of ammonium molybdate, 0.45mmol of hydrochloric acid and 30mL of water, putting the mixture into a container, evaporating and refluxing the mixture for 5 days at 110 ℃, cooling the mixture, filtering the mixture to obtain a yellow brown turbid solution, filtering the yellow turbid solution to obtain a light yellow clear solution, and putting the solution into a beaker, standing and volatilizing the solution to obtain light yellow cuboid crystals.