Preparation method of indium complex nanomaterial, obtained material and application thereof

Abstract

The application relates to the technical field of complex nanomaterials, in particular to a preparation method of an indium complex nanomaterial, the obtained material and application thereof. The application discloses a preparation method of an indium complex nanomaterial, which comprises the following steps: adding inorganic indium salt and 5-bromoisophthalic acid into N,N-dimethylformamide to obtain a transparent reaction liquid; carrying out a solvothermal reaction on the reaction liquid in a reaction kettle; cooling the reaction kettle after the solvothermal reaction, and separating to obtain a solid crude product; washing the solid crude product, drying, and obtaining the indium complex nanomaterial. The application also discloses the indium complex nanomaterial prepared by the above preparation method and application of the indium complex nanomaterial in adsorption of organic dye wastewater. The indium complex nanomaterial prepared by the application has excellent adsorption performance on Congo red dye in a water environment, and also has certain adsorption performance on rhodamine B and methyl orange, and has relatively high practical application value in treatment of organic dye wastewater containing Congo red dye.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of complex nanomaterials, in particular to a preparation method of an indium complex nanomaterial, the obtained material and application thereof. BACKGROUND

[0002] With the accelerating degree of global industrialization, environmental problems have increasingly become an important factor affecting development. Water resource purification and other issues have attracted widespread attention from people, and the large use of colorants has made them one of the main pollutants of water pollution, especially organic dyes, which are the largest class of colorants used in industry, such as commonly used Congo red, methyl orange and the like. These organic dyes are mostly toxic and even carcinogenic hazardous substances, and most of them have complex and stable molecular structures, which are difficult to remove from wastewater by chemical or biological degradation methods.

[0003] At present, the most effective method for organic dye waste liquid is adsorption. The adsorption material is crucial to the implementation effect of adsorption treatment. Some biological composite materials for adsorbing Congo red are disclosed in patents CN103464106B and CN113274983A, but these biological composite materials have insufficient adsorption capacity. Patent CN105817211B discloses a microsphere capable of adsorbing Congo red, but the preparation of the microsphere requires more raw materials and a more complex process, which brings defects in production and use cost.

[0004] In view of the related technologies in the above, the inventors believe that it is necessary to prepare a new material capable of effectively adsorbing organic dyes in waste liquid through a simple preparation process under the condition of controlling cost. SUMMARY

[0005] In order to improve the problems of the current organic dye adsorption material in adsorption capacity and production and use cost, the first object of the present application is to provide a preparation method of an indium complex nanomaterial, which can prepare an adsorption material with high Congo red dye fixation, high adsorption rate and high adsorption capacity through a simple preparation process with fewer raw materials.

[0006] The second object of the present application is to provide an adsorption material prepared by the above preparation method, which has very good thermal stability and can be widely used in various environments.

[0007] The third object of the present application is to provide an application of the above adsorption material in organic dye adsorption. The adsorption material exhibits the characteristics of chemical bond fixation, large adsorption capacity, high removal rate and fast adsorption rate when applied in Congo red dye adsorption, and also exhibits certain adsorption effect on methyl orange and rhodamine B dyes.

[0008] To achieve the first object of the present application, the present application provides a preparation method of an indium complex nanomaterial, which adopts the following technical scheme:

[0009] A preparation method of an indium complex nanomaterial, characterized in that the preparation method comprises the following steps: adding an indium salt and 5-bromoisophthalic acid into N,N-dimethylformamide, stirring uniformly at room temperature to obtain a transparent reaction liquid;

[0010] The reaction liquid is added into a reaction kettle, and the reaction kettle is kept at 120-140°C to perform a solvothermal reaction;

[0011] After the solvothermal reaction is completed, the reaction kettle is cooled to room temperature, and a solid crude product is obtained by separation;

[0012] The solid crude product is washed with a washing liquid, dried, and the final product, an indium complex nanomaterial, is obtained.

[0013] The raw materials required by the preparation method of the present application are easy to obtain, only inorganic indium salt, 5-bromoisophthalic acid and N,N-dimethylformamide (DMF) are required, without other organic solvents, surfactants and templates, the cost of raw materials is saved, and the difficulty of subsequent separation and purification is greatly reduced, and no other pollutants are generated. Under the premise of simplifying raw materials, simple equipment, easy-to-operate process and low cost, the preparation method of the present application can still obtain the target product with a yield of about 45%, and the X-ray powder diffraction pattern and infrared spectrum characterization of the target product are very high in purity, so that the preparation method of the present application is very suitable for large-scale industrial production.

[0014] Implementations can include any or all of the following features.

[0015] In another embodiment, the indium salt is inorganic indium salt, hydrated indium nitrate.

[0016] In another embodiment, the molar ratio of the hydrated indium nitrate and the 5-bromoisophthalic acid is 1.0:0.3-1.0.

[0017] The indium complex nanomaterial of the present application belongs to the complex of inorganic indium salt and 5-bromoisophthalic acid, so the amount of hydrated indium nitrate and 5-bromoisophthalic acid determines the yield of the product, the stability of the structure of the product, the spatial structure of the product, and the purity of the product. Within the selected amount ratio range of the present technical scheme, not only the raw materials are not wasted, but also the product yield and structural stability are maintained at a relatively high level, and the product has high purity and good spatial structure, which is helpful to improve the adsorption capacity and adsorption efficiency of the prepared complex nanomaterial.

[0018] In another embodiment, the N,N-dimethylformamide is used in an amount of 20 mL to 30 mL per 0.01 mol of the indium nitrate hydrate.

[0019] The N,N-dimethylformamide is an essential organic solvent in the present solvothermal reaction, and the amount thereof is required to be in a state of completely dissolving the reactants, the indium nitrate hydrate and the 5-bromoisophthalic acid, so that the solvothermal reaction can effectively occur. Too little or too much amount of the N,N-dimethylformamide can affect the efficiency of the solvothermal reaction, and finally affect the yield and purity of the target product.

[0020] In another embodiment, the reaction time of the solvothermal reaction is 18 h to 24 h.

[0021] The solvothermal reaction must reach a certain reaction time to obtain an effective target product.

[0022] In another embodiment, the washing liquid is N,N-dimethylformamide or ethanol.

[0023] Washing the crude product of the solvothermal reaction by the organic solvent can remove water-soluble impurities and alcohol-soluble impurities in the crude product, and improve the purity of the final product. The N,N-dimethylformamide and the ethanol do not chemically react with the target product.

[0024] In order to achieve the second object of the present application, the present application provides an indium complex nanomaterial, which adopts the following technical solution:

[0025] An indium complex nanomaterial, characterized in that the indium complex nanomaterial is prepared according to the preparation method of the indium complex nanomaterial.

[0026] The present indium complex nanomaterial can maintain the stability of the shape in the air and water, is easy to be stored conventionally, and exhibits the performance of chemical bond fixation, adsorption and removal of Congo red in the Congo red dye wastewater.

[0027] In order to achieve the third object of the present application, the present application provides an application of the indium complex nanomaterial in the adsorption of organic dye wastewater, which adopts the following technical solution:

[0028] An application of an indium complex nanomaterial in the adsorption of organic dye wastewater.

[0029] In another embodiment, the indium complex nanomaterial is applied to adsorb the Congo red dye, the methyl orange dye and the rhodamine B dye in the organic dye wastewater.

[0030] The indium complex nanomaterial of the present application can be used for adsorption of organic dyes in wastewater, and shows high adsorption effect and chemical bond fixation effect on Congo red dye. Compared with traditional physical adsorption, the adsorption stability of the present material on Congo red is high, and desorption is not easy to occur under changes of external physical and chemical conditions. Meanwhile, the present material also shows certain adsorption effect on methyl orange dye and rhodamine B dye.

[0031] In another embodiment, when the indium complex nanomaterial is applied to adsorb Congo red dye in the organic dye wastewater, the indium complex nanomaterial is added to wastewater containing Congo red dye, and shaken at 20-30°C and 100-200 r / min for 30 min-7 h. The initial concentration of Congo red dye in wastewater containing Congo red dye is 200-400 mg / L, and the dosage of the indium complex nanomaterial added to 100 mL wastewater containing Congo red dye is 10-30 mg.

[0032] Under the condition of room temperature shaking, the indium complex nanomaterial of the present application can produce good adsorption effect on Congo red dye in wastewater. Within the dosage range of the indium complex nanomaterial and the initial concentration range of wastewater containing Congo red dye in the preferred technical solution, the adsorption performance of the indium complex nanomaterial on Congo red dye is in the excellent range, and the application effect is better. Therefore, in actual operation, high-concentration Congo red dye waste liquid can be diluted to the concentration range of the present application to achieve more economical and effective adsorption effect.

[0033] In summary, the present application provides a preparation method of indium complex nanomaterial, the obtained material and its application, which has the following beneficial effects:

[0034] The raw materials of the preparation method of the present application are simple and easy to obtain, the equipment is simple, the process is simple and convenient, and the production cost is low. It is very suitable for large-scale industrial production, and the target product indium complex nanomaterial can be prepared at a yield of about 45%. The indium complex nanomaterial prepared has uniform and ordered morphology as shown by scanning electron microscopy. The indium complex nanomaterial obtained in the present application can produce chemical bond fixation in the adsorption of Congo red dye waste liquid, and shows excellent adsorption performance. The removal rate of Congo red dye in aqueous solution containing Congo red dye can reach 99.90%, and the maximum adsorption capacity is close to 1500 mg / g. After 2 hours of adsorption, the aqueous solution containing Congo red dye is basically colorless, indicating that the adsorption speed is very fast. Therefore, when the indium complex nanomaterial prepared by the preparation method of the present application is applied to the treatment of wastewater containing Congo red dye, the treatment cost is low and the effect is obvious, and it has relatively high practical application value in the treatment of organic dye wastewater containing Congo red dye. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 Scanning electron microscope image of the indium complex nanomaterials;

[0036] Figure 2 Scanning electron microscope image of the indium complex nanomaterials after adsorbing Congo red dye;

[0037] Figure 3 Five main element distribution map of the indium complex nanomaterials;

[0038] Figure 4 Five main element distribution map of the indium complex nanomaterials after adsorbing Congo red dye;

[0039] Figure 5 X-ray diffraction analysis spectrum of the indium complex nanomaterials before and after adsorbing Congo red, methyl orange, and rhodamine B dyes;

[0040] Figure 6 Ultraviolet-visible light absorption spectrum of the indium complex nanomaterials after adsorbing Congo red dye aqueous solution with different initial concentrations;

[0041] Figure 7 Equilibrium concentration and adsorption amount relationship diagram of the indium complex nanomaterials for different initial concentrations of Congo red dye aqueous solution;

[0042] Figure 8 Thermodynamic model fitting diagram of the indium complex nanomaterials for adsorbing Congo red in aqueous solution;

[0043] Figure 9 Ultraviolet-visible light absorption spectrum of the indium complex nanomaterials for adsorbing Congo red dye aqueous solution at different adsorption times;

[0044] Figure 10 Different adsorption time and adsorption amount relationship diagram of the indium complex nanomaterials for Congo red dye aqueous solution;

[0045] Figure 11 Kinetic model fitting diagram of the indium complex nanomaterials for adsorbing Congo red dye in aqueous solution at different adsorption times;

[0046] Figure 12 Infrared spectrum of the indium complex nanomaterials before and after adsorbing Congo red dye;

[0047] Figure 13 Thermogravimetric curve of the indium complex nanomaterials;

[0048] Figure 14 Ultraviolet-visible light absorption spectrum of the indium complex nanomaterials for adsorbing methyl orange dye;

[0049] Figure 15UV-Vis absorption spectrum of indium complex nanomaterial adsorbing rhodamine B dye is shown.

[0050] Figure 16 X-ray diffraction analysis spectrum of indium complex nanomaterials constructed by different organic ligands is shown.

[0051] Figure 17 UV-Vis absorption spectrum of indium complex nanomaterials constructed by different organic ligands adsorbing Congo red dye is shown. DETAILED DESCRIPTION

[0052] The embodiments of the present application will be further specifically described below.

[0053] The present application provides a preparation method of indium complex nanomaterial, the obtained material and its application. First, a preparation method of indium complex nanomaterial is provided, comprising the following steps:

[0054] S1: indium salt and 5-bromoisophthalic acid are added into N,N-dimethylformamide, and the mixture is stirred uniformly at room temperature to obtain a colorless transparent reaction solution;

[0055] S2: the reaction solution is added into a reaction kettle, and the reaction kettle is kept at 120-140℃ for solvothermal reaction;

[0056] S3: after the solvothermal reaction is completed, the reaction kettle is cooled to room temperature, and the solid crude product is separated and obtained;

[0057] S4: the solid crude product is washed with a washing liquid, dried, and the final product indium complex nanomaterial is obtained.

[0058] In the step S1, the indium salt is a reactant, and preferably an inorganic indium salt which is easily soluble in N,N-dimethylformamide (DMF), and further preferably hydrated indium nitrate, and more preferably In(NO3)3·4H2O. In(NO3)3·4H2O is selected to be easily soluble in N,N-dimethylformamide, so that the product yield is improved in the subsequent solvothermal reaction. Further, the molar ratio of In(NO3)3·4H2O to 5-bromoisophthalic acid is 1.0:0.3-1.0. Further, the amount of DMF used is 20-30 mL of DMF solvent per 0.01 mol of In(NO3)3·4H2O.

[0059] In step S2, the reaction kettle can be a stainless steel reaction kettle with a polytetrafluoroethylene lining. After stirring, the colorless transparent liquid is added to the reaction kettle, and the reaction kettle is sealed for solvothermal reaction. The temperature condition of the solvothermal reaction can be set by an air drying oven, for example, the reaction kettle containing the reaction liquid is sealed and placed in the air drying oven for solvothermal reaction at 120-140°C. The solvothermal reaction is a constant temperature reaction, and the reaction temperature is any temperature between 120-140°C, for example, the reaction temperature of the solvothermal reaction can be 120°C, 125°C, 130°C, 135°C, or 140°C. The reaction time of the solvothermal reaction is any time between 18-24 hours.

[0060] In step S3, the reaction kettle can be naturally cooled, and the separation can be filtration, preferably suction filtration, to remove the liquid and obtain the solid crude product.

[0061] In step S4, the washing liquid is not particularly limited and is a liquid commonly used in the art that does not react with the product and can achieve a washing effect. From the perspective of production cost, the washing liquid can preferably be DMF or ethanol. DMF can be used alone for washing, ethanol can be used alone for washing, or DMF can be used first followed by ethanol. Washing can improve the purity of the product. The number of washings is not particularly limited, but the more washings, the more unavoidable loss of product yield. The drying can be room temperature natural air drying, or preferably vacuum drying in a vacuum drying oven. The vacuum drying conditions are 60°C and 0.1 kPa, and the drying time can be 12 hours.

[0062] The application also provides an indium complex nanomaterial prepared by the above preparation method. Under a scanning electron microscope (SEM), the appearance of the indium complex nanomaterial of the application is a basically uniform honeycomb-like nanostructure morphology, and each honeycomb is about 2.0 μm in size. Further magnification of each honeycomb-like nanostructure material shows that it is composed of a large number of nanosheets, and the size of the nanosheets is about 10-20 nm.

[0063] The application also provides the use of the above indium complex nanomaterial in the adsorption of organic dye wastewater. Further, the indium complex nanomaterial is used in the adsorption of Congo red dye, methyl orange dye, and rhodamine B dye in organic dye wastewater. During adsorption, the indium complex nanomaterial is added to wastewater containing a certain concentration of Congo red dye, methyl orange dye, and rhodamine B dye to be treated. The wastewater to be treated can contain only one of the dyes, or two or more of the dyes.

[0064] Further, when the indium complex nanomaterial is applied to adsorb Congo red dye in the organic dye wastewater, the indium complex nanomaterial is added to the wastewater containing the Congo red dye, and the adsorption is performed at 20-30°C and 100-200 r / min for 30 min-7.0 h. The initial concentration of the Congo red dye in the wastewater containing the Congo red dye is 200-400 mg / L. Preferably, the adsorption treatment effect of the indium complex nanomaterial is most obvious for the wastewater with the initial concentration of the Congo red dye being 200-300 mg / L. The dosage of the indium complex nanomaterial added to 100 mL of the wastewater containing the Congo red dye is 10-30 mg.

[0065] Further, when the indium complex nanomaterial is applied to adsorb methyl orange (MO) and rhodamine B (RhB) dyes in the organic dye wastewater, the dosage of the indium complex nanomaterial added to 100 mL of the wastewater containing 20 mg / L of the methyl orange (MO) or 20 mg / L of the rhodamine B (RhB) dye is 20 mg, and the adsorption time is set to be 24.0 h at the longest.

[0066] The present application will be further described in detail below in combination with the specific embodiments, the accompanying drawings and the performance evaluation results.

[0067] Embodiment 1

[0068] A preparation method of an indium complex nanomaterial, comprising the following steps:

[0069] S1: 6.016 g (0.02 mol, analytical pure) of In(NO3)3·4H2O and 1.486 g (0.006 mol, 98% purity) of 5-bromoisophthalic acid are weighed according to a molar ratio of 1:0.3 in a 80 mL glass beaker, 40 mL of DMF is added to the beaker, and the obtained colorless transparent liquid is the reaction liquid after magnetic stirring at room temperature for 30 min;

[0070] S2: The reaction liquid obtained in S1 is transferred to a 100 mL stainless steel reaction kettle with a polytetrafluoroethylene lining and is sealed, the reaction kettle is placed in a blast drying oven for solvent thermal reaction at 120°C, and the reaction time is 18 h;

[0071] S3: After the solvent thermal reaction is completed, the reaction kettle is naturally cooled to room temperature, and the white crystalline crude product is obtained by suction filtration;

[0072] S4: The crude product is first washed once with DMF, then washed twice with ethanol, and then the obtained white crystals are dried in a 60°C vacuum drying oven for 12 h, and the vacuum drying conditions are 60°C and 0.1 kPa, to obtain the white powder crystals as the indium complex nanomaterial.

[0073] Example 2:

[0074] A preparation method of an indium complex nanomaterial, comprising the following steps:

[0075] S1: In(NO3)3·4H2O 6.016g (0.02mol, analytical pure) and 5-bromoisophthalic acid 1.968g (0.008mol, 98% purity) were weighed according to a molar ratio of 1:0.4 in an 80mL glass beaker, 40mL of DMF was added to the above beaker, and magnetic stirring was performed at room temperature for 30 minutes, and the obtained colorless transparent liquid was the reaction liquid;

[0076] S2: The reaction liquid obtained in S1 was transferred to a 100mL stainless steel reaction kettle lined with polytetrafluoroethylene and sealed, and the reaction kettle was placed in a blast drying oven for solvent thermal reaction at 120°C, and the reaction time was 18h;

[0077] S3: After the solvent thermal reaction was completed, the reaction kettle was naturally cooled to room temperature, and white crystalline crude product was obtained by suction filtration;

[0078] S4: The crude product was first washed once with DMF, then washed twice with ethanol, and then the obtained crystals were dried in a 60°C vacuum drying oven for 12 hours, and the vacuum drying conditions were 60°C and 0.1kPa, and white powder crystals were obtained as the indium complex nanomaterial.

[0079] Example 3:

[0080] A preparation method of an indium complex nanomaterial, comprising the following steps:

[0081] S1: In(NO3)3·4H2O 6.016g (0.02mol, analytical pure) and 5-bromoisophthalic acid 2.952g (0.012mol, 98% purity) were weighed according to a molar ratio of 1:0.6 in an 80mL glass beaker, 40mL of DMF was added to the above beaker, and magnetic stirring was performed at room temperature for 30 minutes, and the obtained colorless transparent liquid was the reaction liquid;

[0082] S2: The reaction liquid obtained in S1 was transferred to a 100mL stainless steel reaction kettle lined with polytetrafluoroethylene and sealed, and the reaction kettle was placed in a blast drying oven for solvent thermal reaction at 140°C, and the reaction time was 24h;

[0083] S3: After the solvent thermal reaction was completed, the reaction kettle was naturally cooled to room temperature, and white crystalline crude product was obtained by suction filtration;

[0084] S4: The crude product is first eluted with DMF once, then washed with ethanol twice, and the obtained crystals are dried in a vacuum drying oven at 60°C for 12 hours under the conditions of 60°C and 0.1 kPa, to obtain white powder crystals as the indium complex nanomaterial.

[0085] Example 4:

[0086] The application of an indium complex nanomaterial in the adsorption of organic dye wastewater, when the indium complex nanomaterial is applied to adsorb Congo red dye in the organic dye wastewater, 11 125 mL flasks are taken, and 20 mg of the indium complex nanomaterial prepared in Example 3 is weighed into each flask. 100 mL of a Congo red aqueous solution is added to each flask containing the indium complex nanomaterial, and the concentrations of the Congo red aqueous solutions corresponding to the 11 flasks are different, and are 200 mg / L, 220 mg / L, 240 mg / L, 260 mg / L, 280 mg / L, 300 mg / L, 320 mg / L, 340 mg / L, 360 mg / L, 380 mg / L, and 400 mg / L, respectively. The 11 flasks are placed in a gas bath oscillator and oscillated at 25°C and 200 r / min for 7 hours to perform the adsorption of the indium complex nanomaterial on the Congo red dye.

[0087] Example 5:

[0088] The application of an indium complex nanomaterial in the adsorption of organic dye wastewater, when the indium complex nanomaterial is applied to adsorb methyl orange (MO) dye in the organic dye wastewater, 1 125 mL flask is taken, and 20 mg of the indium complex nanomaterial prepared in Example 3 is weighed into the flask. 100 mL of a methyl orange (MO) aqueous solution with a concentration of 20 mg / L is added to the flask. The flask is placed in a gas bath oscillator and oscillated at 25°C and 200 r / min for 24 hours to perform the adsorption of the indium complex nanomaterial on the methyl orange (MO) dye, and a sample is taken and stored for liquid testing of the concentration of the methyl orange dye.

[0089] Example 6:

[0090] The application of an indium complex nanomaterial in the adsorption of organic dye wastewater, when the indium complex nanomaterial is applied to adsorb rhodamine B (RhB) dye in the organic dye wastewater, 1 125 mL flask is taken, and 20 mg of the indium complex nanomaterial prepared in Example 3 is weighed into the flask. 100 mL of a rhodamine B (RhB) aqueous solution with a concentration of 20 mg / L is added to the flask. The flask is placed in a gas bath oscillator and oscillated at 25°C and 200 r / min for 24 hours to perform the adsorption of the indium complex nanomaterial on the rhodamine B (RhB) dye, and a sample is taken and stored for liquid testing of the concentration of the methyl orange dye.

[0091] Comparative Example 1:

[0092] Application of an indium complex nanomaterial in adsorption of organic dye wastewater, when the indium complex nanomaterial is applied to adsorb Congo red dye in the organic dye wastewater, 20 mg of the indium complex nanomaterial prepared in Example 1 is weighed and added to a 125 mL Erlenmeyer flask; 100 mL of a Congo red aqueous solution with a concentration of 100 mg / L is added to the Erlenmeyer flask; the Erlenmeyer flask is placed in a gas bath shaker, and oscillation is performed at 25°C and 200 r / min for 6 hours, thereby serving as a control group for adsorption of the Congo red dye by the indium complex nanomaterial.

[0093] Comparative Example 2:

[0094] This comparative example discloses a preparation method of an indium complex nanomaterial, which is different from Example 3 only in that 2.952 g (0.012 mol, 98% purity) of 5-bromoisophthalic acid in Example 3 is replaced by 2.667 g (0.012 mol, 98% purity) of 5-tert-butylisophthalic acid.

[0095] Comparative Example 3:

[0096] This comparative example discloses a preparation method of an indium complex nanomaterial, which is different from Example 3 only in that 2.952 g (0.012 mol, 98% purity) of 5-bromoisophthalic acid in Example 3 is replaced by 2.162 g (0.012 mol, 98% purity) of 5-methylisophthalic acid.

[0097] Performance evaluation experiment:

[0098] 1. Morphology analysis of the indium complex material before adsorption of Congo red: a cold field emission scanning electron microscope (SEM) with a model number of Japan Hitachi Regulus 8100 is used to analyze the product of the indium complex nanomaterial prepared in Example 3, and the results are shown in FIG. 1. As can be seen from the figure, the indium complex nanomaterial has a honeycomb-like nanostructure morphology, and each honeycomb has a size of about 2.0 μm. Further magnification of each honeycomb-like nanostructure material shows that it is composed of a large number of nanosheets, and the nanosheets have a size of about 10-20 nm. Figure 1

[0099] 2. Morphology analysis of the indium complex material after adsorption of Congo red: a cold field emission scanning electron microscope (SEM) with a model number of Germany Zeiss SIGMA 500 is used to analyze the product of the indium complex nanomaterial prepared in Example 3 after adsorption of the Congo red dye, and the results are shown in FIG. 2. As can be seen from the figure, the indium complex nanomaterial has a honeycomb-like nanostructure morphology, and each honeycomb has a size of about 2.0 μm. Further magnification of each honeycomb-like nanostructure material shows that it is composed of a large number of nanosheets, and the nanosheets have a size of about 10-20 nm. Figure 2 Figure 1 ​​The morphology of the material before adsorption can be seen, and the product of the indium complex nanomaterial of the application after adsorbing the Congo red dye also has a honeycomb-like morphology, which does not change significantly compared with the material before adsorption. This also indicates that the material itself does not change significantly during the adsorption of the Congo red dye, and the material has high stability.

[0100] 3. Analysis of the distribution of the five main elements of the indium complex nanomaterial product: In order to further explore the composition structure of the indium complex nanomaterial prepared by the application before and after adsorbing Congo red, the element distribution of the indium complex nanomaterial of Example 3 and the product after adsorbing the Congo red dye was determined, and the results are shown in Figure 3 and 4 From the determination results, the indium complex nanomaterial and the material after adsorbing the Congo red both contain C, N, In, O and Br five elements, which also indicates that the two raw materials of the application form a stable complex structure.

[0101] 4. X-ray diffraction analysis (XRD) analysis of the indium complex nanomaterial before and after adsorbing Congo red (CR), methyl orange (MO) and rhodamine B (RhB): The powder diffraction pattern analyzer with model Japan Science Ultima IV was used to analyze the powder diffraction pattern of the indium complex nanomaterial obtained in Example 3 and the product after adsorbing the Congo red, methyl orange and rhodamine B dyes according to Examples 4-6, and the results are shown in Figure 5 It can be found that after adsorbing the Congo red dye, the powder XRD pattern of the indium complex nanomaterial changes obviously at 2θ = 22°, and a diffraction peak appears, indicating that the molecular structure of the material of the application changes to a certain extent after adsorbing the Congo red dye, and chemical adsorption is produced. At the same time, it also indicates that the material of the application has obvious and effective absorption to the Congo red dye in the Congo red aqueous solution. After the indium complex nanomaterial adsorbs the methyl orange and rhodamine B dyes, the diffraction pattern remains basically unchanged, and the diffraction intensity also remains basically unchanged, which also indicates that the adsorption of the indium complex nanomaterial to the methyl orange and rhodamine B may be only physical adsorption on the surface. By comparison, it can be seen that the adsorption material of the application has better adsorption and fixation effect on the Congo red.

[0102] 5. Performance analysis of the indium complex nanomaterial adsorbing the Congo red dye: The liquid in the 12 triangular flasks after adsorption of Example 3 and Comparative Example 1 was added into corresponding 12 15 mL centrifuge tubes, and after centrifugation at 4000 r / min for 5 min, the liquid filtered by a 0.22 μm filter membrane was taken as the detection liquid. The concentration of the Congo red dye in the filtrate was determined on a ultraviolet-visible spectrophotometer with model Japan Hitachi UH-5700, and the adsorption capacity q of the indium complex nanomaterial of Example 3 was calculated by formula (I) e (mg·g -1 ).

[0103]

[0104] In formula (I), c0and c e (mg·L -1 ) represent the concentration of Congo red solution at initial and equilibrium state respectively, V (L) represents the volume of Congo red solution, and W (g) represents the mass of indium complex nanomaterial.

[0105] The UV-Vis spectrum of the solution is shown in Figure 6 , the relationship between equilibrium concentration and adsorption capacity is shown in Figure 7 , and the thermodynamic model in the adsorption process is shown in Figure 8 From the above Figures 6-8 , it can be seen that the indium complex nanomaterial of Example 3 reached adsorption equilibrium in different concentrations of Congo red dye aqueous solution after 7 hours of oscillation. The color of the solution before and after adsorption changed obviously, the low concentration changed from red to colorless, and the high concentration became lighter. The removal rates of Congo red in the above-mentioned 12 initial concentrations of 200 mg / L, 220 mg / L, 240 mg / L, 260 mg / L, 280 mg / L were 99.04%, 98.83%, 98.64%, 98.52% and 98.29% respectively, and the maximum adsorption capacity was close to 1500 mg / g. The removal rate and adsorption capacity both exceeded the adsorption capacity of many adsorption materials in aqueous solution. The above results show that the prepared indium complex nanomaterial has very excellent adsorption performance for Congo red dye under a certain concentration of Congo red aqueous solution.

[0106] In order to further understand the kinetic properties of the indium complex nanomaterial in aqueous solution for adsorbing Congo red dye, 20 mg of the indium complex nanomaterial prepared in Example 3 was weighed in a 125 mL Erlenmeyer flask, 100 mL of Congo red aqueous solution with a concentration of 100 mg / L was added to the Erlenmeyer flask, and the Erlenmeyer flask was placed in a gas bath oscillator at 25°C and 200 r / min. The first sampling interval was 30 minutes, and then the sampling interval was 60 minutes. The sampling method was to put the liquid in the Erlenmeyer flask into a 15 mL centrifuge tube, centrifuge at 4000 r / min for 5 min, and take the filtered liquid after 0.22 μm filter as the detection sample. The color of the first sampling Congo red dye solution became obviously lighter, which also indicated that the product had fast adsorption and large adsorption capacity for Congo red in aqueous solution. The detection samples obtained at different adsorption times were characterized by UV-Vis absorption spectrum, and the results are shown in Figure 9 ; the analysis of different adsorption times and adsorption capacity is shown in Figure 10 ; and the kinetics of the indium complex nanomaterial adsorbing Congo red dye in aqueous solution at different adsorption times is shown in Figure 11 . From the above Figures 9-11The results show that the indium complex nanomaterials of the application can produce obvious adsorption of Congo red in aqueous solution within 0.5 h, and have the effects of high adsorption rate, large adsorption capacity and high removal rate.

[0107] 6. Infrared spectrum analysis of indium complex nanomaterials before and after adsorbing Congo red: The infrared spectrum of the indium complex nanomaterials of Example 3 and the product after adsorbing Congo red dye was determined by the potassium bromide tabletting method, and the infrared spectrum of the indium complex nanomaterials before and after adsorbing Congo red dye was analyzed by using a Nicolet IS10 infrared spectrometer, and the results are shown in Figure 12 The infrared spectrum shows that the position of the infrared spectrum peaks of the indium complex nanomaterials before and after adsorbing Congo red dye does not change obviously, and the product after adsorption has an absorption vibration peak at 1040 cm -1 The absorption vibration peak is attributed to the S-O stretching vibration peak in the sulfonate group of the Congo red dye, and further indicates that the product of Example 3 adsorbs the Congo red dye by chemical bond action to enrich it in the material. Compared with conventional physical adsorption, the chemical bond adsorption enrichment method of the application is more stable in fixing Congo red and is not easy to desorb under the influence of external environment.

[0108] 7. Thermogravimetric analysis of indium complex nanomaterials: In order to understand the thermal stability change of the indium complex nanomaterials of the application, the thermogravimetric curve of the product was determined under nitrogen atmosphere, and the results are shown in Figure 13 The indium complex nanomaterials always accompany with slow weight loss during the heating process, indicating that the material contains solvent molecules, and the removal of solvent molecules during the heating process also accompanies the collapse of the structure and the decomposition of the material. The material is severely weight loss at a temperature of 450°C, indicating that the structure of the material is completely decomposed, and the weight loss is not obvious during 450°C-800°C, and the final product is indium metal oxide. This result shows that the indium complex nanomaterials of the application have good thermal stability and can normally adsorb organic dye waste liquid under high temperature conditions.

[0109] 8. Performance analysis of indium complex nanomaterials adsorbing methyl orange (MO) and rhodamine B (RhB) dyes: The liquid in the triangular flask after adsorption of Example 5 and Example 6 was placed in two 15 mL centrifuge tubes, centrifuged at 4000 r / min for 5 min, and the liquid filtered by a 0.22 μm filter membrane was taken as a detection sample. The sample solutions obtained from Example 5 and Example 6 were subjected to ultraviolet-visible spectrum analysis, and the results are shown in Figure 14 and Figure 15The In complex nanomaterial prepared in the present application has a weaker adsorption effect on the above two dyes than on the Congo red dye, but still has a certain adsorption effect on methyl orange (MO) and rhodamine B (RhB) after a certain time of adsorption treatment. The removal rate of methyl orange dye with a concentration of 20 mg / L is 50%, and the removal rate of rhodamine B dye with a concentration of 20 mg / L can reach 90%.

[0110] 9. X-ray diffraction analysis (XRD) of the In complex nanomaterial prepared in Example 3 and the In complex nanomaterial prepared in Comparative Example 1 and Comparative Example 2: The In complex nanomaterial obtained in Example 3, the In complex nanomaterial obtained in Comparative Example 1, and the In complex nanomaterial obtained in Comparative Example 2 were subjected to X-ray diffraction analysis (XRD) using a powder diffraction pattern analyzer with a model of Japan Rigaku Ultima IV, and the results are shown in FIG. 3. Figure 16 As can be seen from the XRD results, Figure 16 As can be seen from the XRD results,

[0111] 10. Comparative analysis of UV-visible absorption spectra of indium complex nanomaterial prepared in Example 3 and indium complex nanomaterial prepared in Comparative Example 1 and Comparative Example 2 adsorbing Congo red dye: According to the application of Example 4, four 125 mL triangular flasks were taken, and were marked as No. 1 flask, No. 2 flask, No. 3 flask and No. 4 flask. 20 mg of indium complex nanomaterial prepared in Example 3 was weighed and added into the No. 1 flask, and 100 mL of Congo red aqueous solution with a concentration of 100 mg / L was added; 20 mg of indium complex nanomaterial prepared in Example 3 was weighed and added into the No. 2 flask, and 100 mL of Congo red aqueous solution with a concentration of 250 mg / L was added; 20 mg of indium complex nanomaterial prepared in Comparative Example 1 was weighed and added into the No. 3 flask, and 100 mL of Congo red aqueous solution with a concentration of 250 mg / L was added; 20 mg of indium complex nanomaterial prepared in Comparative Example 2 was weighed and added into the No. 4 flask, and 100 mL of Congo red aqueous solution with a concentration of 250 mg / L was added. The above four triangular flasks were placed in a gas bath oscillator, and oscillated at 25°C and 200 r / min for 7 hours. After the adsorption of the indium complex nanomaterial to the Congo red dye, the liquid in the above four triangular flasks was added to four 15 mL centrifuge tubes, and centrifuged at 4000 r / min for 5 min. The filtered liquid was taken as the detection liquid, and was analyzed by a UV-visible spectrometer with a model number of UH-5700 of Hitachi, Japan. The results are shown in Figure 17 As can be seen, under the same conditions, the adsorption effect of the indium complex nanomaterial prepared by using 5-bromoisophthalic acid as the ligand to Congo red dye in the water environment is obviously better than that of the ligands used in Comparative Example 2 and Comparative Example 3. Figure 17

[0112] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, any equivalent changes made on the basis of the structure, shape and principle of the present application should be covered within the protection scope of the present application.​

Claims

1. A method for preparing indium complex nanomaterials, characterized in that, The preparation method includes the following steps: adding indium salt and 5-bromoisophthalic acid to N,N-dimethylformamide, stirring and mixing evenly at room temperature to obtain a transparent reaction solution; The reaction solution is added to a reaction vessel, which is kept at 120°C to 140°C for a solvothermal reaction. After the solvothermal reaction is completed, the reaction vessel is cooled to room temperature, and a solid crude product is obtained by separation. The solid crude product is washed with a washing solution and dried to obtain the final product, indium complex nanomaterials. The indium salt is In(NO3)3·4H2O; The molar ratio of In(NO3)3·4H2O to 5-bromoisophthalic acid is 1.0:0.6; The reaction time for the solvothermal reaction is 24 hours.

2. The method for preparing an indium complex nanomaterial according to claim 1, characterized in that, The amount of N,N-dimethylformamide used is: 20 mL to 30 mL of N,N-dimethylformamide solvent for every 0.01 mol of In(NO3)3·4H2O.

3. The method for preparing an indium complex nanomaterial according to claim 1, characterized in that, The washing solution is N,N-dimethylformamide or ethanol.

4. An indium complex nanomaterial, characterized in that, The indium complex nanomaterial is prepared according to any one of claims 1-3 by a method for preparing indium complex nanomaterials.

5. The application of the indium complex nanomaterial according to claim 4 in the adsorption of organic dye wastewater, characterized in that, The indium complex nanomaterials are used to adsorb Congo red dye, methyl orange dye, and rhodamine B dye from the organic dye wastewater.

6. The application of the indium complex nanomaterial according to claim 5 in the adsorption of organic dye wastewater, characterized in that, When the indium complex nanomaterial is used to adsorb Congo red dye from the organic dye wastewater, the indium complex nanomaterial is added to the wastewater containing Congo red dye, and adsorption is performed by shaking at 20℃~30℃ and 100r / min~200r / min for 30min~7h; the initial concentration of Congo red dye in the wastewater is 200mg / L~340mg / L, and the dosage of the indium complex nanomaterial added per 100mL of wastewater containing Congo red dye is 10mg~30mg.

Images