CN108905976A - Manganese ion doping metal-organic framework materials and its preparation method and application - Google Patents

Abstract

The invention discloses a manganese ion-doped metal organic framework material and its preparation method and application. The material includes UiO‑66 (Zr) and is doped with manganese ions. The preparation method comprises: mixing zirconium chloride, terephthalic acid, manganese chloride tetrahydrate and N,N dimethylformamide for solvothermal reaction to obtain the manganese ion-doped metal organic framework material. The manganese ion-doped metal-organic framework material of the present invention has the advantages of large adsorption capacity, good adsorption performance, and good stability, and is simple to synthesize, can be widely used, and can efficiently adsorb and remove pollutants in water bodies. It is a new type of adsorbent. The preparation method has the advantages of simple operation, convenient preparation, less types of raw materials, high output, low cost and the like. The material of the invention can be widely used to treat antibiotic wastewater and/or heavy metal wastewater, and has the advantages of convenient operation, simple equipment, low treatment cost, high treatment efficiency and good removal effect, and has good application value and application prospect.

Description

Manganese ion doped metal organic framework material and its preparation method and application

technical field

The invention belongs to the field of composite materials, and relates to a manganese ion-doped metal organic framework material and a preparation method and application thereof.

Background technique

Antibiotics are widely used in human and veterinary therapy, animal husbandry and aquaculture. For example, tetracycline is a broad-spectrum antibiotic with an annual output of thousands of tons. However, tetracyclines are rarely biodegraded and metabolized, and most (approximately 30%-90%) tetracyclines are excreted into the environment through feces or raw urine. Tetracycline residues can be detected in soil, sediment, surface water, groundwater and even drinking water. In addition to antibiotic pollution, heavy metal pollution also harms the environment. For example, chromium in the positive hexavalent form in the aquatic environment is considered to be a toxic and carcinogenic substance in most cases. Therefore, it is extremely urgent to effectively remove antibiotics and heavy metals from the water environment.

At present, various technologies are used to remove antibiotics and heavy metals in aquatic environments, such as biodegradation, membrane separation, photocatalytic degradation, electrochemical, but the above methods have certain shortcomings and cannot be widely used in tetracycline and positive hexavalent Chromium removal. The adsorption method has been considered as a very competitive method because of its low cost, simple operation and no secondary pollution. Therefore, it is particularly important to develop and prepare efficient adsorbents. Recently, metal-organic frameworks (MOFs), as a porous functional material, are mainly composed of central metal ions and organic ligands through chemical bonds. Due to their ultra-high porosity, large specific surface area, and adjustable pore size and shape as well as easy functionalization, has become a research hotspot. However, MOFs lack functional groups and adsorption sites, resulting in poor adsorption performance for pollutants in water. Therefore, how to comprehensively improve the performance of existing metal organic framework materials, obtain a metal organic framework material with good stability and good adsorption performance, and obtain a metal organic framework material with simple operation, few types of raw materials, and low cost. Preparation method , which is of great significance for efficient and low-cost adsorption of antibiotics and heavy metals in water.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, provide a manganese ion-doped metal-organic framework material with good stability and good adsorption performance, and also provide a simple processing technology, few types of raw materials, and low cost. A method for preparing low-manganese ion-doped metal-organic framework materials and the application of the manganese-ion-doped metal-organic framework materials in removing antibiotics and/or heavy metals in water bodies. In this application method, the manganese-ion-doped metal-organic framework materials can efficiently , Low-cost adsorption to remove antibiotics and heavy metals in water.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A metal organic framework material doped with manganese ions, including UiO-66 (Zr); the UiO-66 (Zr) is doped with manganese ions.

The above manganese ion doped metal organic framework material is further improved, the molar ratio of the manganese ion to UiO-66(Zr) is 1:1.

The above-mentioned manganese ion-doped metal-organic framework material is further improved, and the manganese-ion-doped metal-organic framework material is composed of zirconium chloride, terephthalic acid, manganese chloride tetrahydrate and N,N dimethylformamide The starting materials were prepared by solvothermal reaction.

As a general technical idea, the present invention also provides a method for preparing a manganese ion-doped metal organic framework material, comprising the following steps: combining zirconium chloride, terephthalic acid, manganese chloride tetrahydrate and N, N di Methylformamide is mixed for solvothermal reaction to obtain manganese ion-doped metal-organic framework materials.

The above preparation method is further improved, the molar ratio of manganese chloride tetrahydrate, zirconium chloride, terephthalic acid and N,N dimethylformamide is 1:1:1:162.

The above preparation method is further improved, the mixing is carried out under stirring conditions; the stirring speed is 300 r/min to 500 r/min; the stirring time is 1h to 3h; the solvothermal reaction is The temperature is 120°C-150°C; the time for the solvothermal reaction is 24h-36h.

The above preparation method, further improved, also includes the following steps: centrifuging, washing and drying the reaction product obtained after the solvothermal reaction is completed; the rotation speed of the centrifugation is 5000 r/min～6000 r/min; the washing N,N dimethylformamide and ethanol are used, and each wash is 3 to 5 times; the drying treatment is to dry under vacuum conditions; the drying temperature is 60°C to 80°C; the drying The time is 8 h ~ 12 h.

As a general technical concept, the present invention also provides the above-mentioned manganese ion-doped metal organic framework material or the manganese ion-doped metal organic framework material prepared by the above preparation method in the removal of antibiotics and/or heavy metals in water Applications.

The above-mentioned application, further improved, includes the following steps: mixing manganese ion-doped metal organic framework material, antibiotic wastewater and/or heavy metal wastewater for oscillation adsorption, and completing the treatment of antibiotics and/or heavy metals in water; the manganese ion The ratio of the doped metal-organic framework material to the antibiotic wastewater and/or heavy metal wastewater is 0.3g-0.5g:1L.

The above application is further improved, the antibiotic in the antibiotic wastewater is tetracycline hydrochloride; the concentration of the antibiotic in the antibiotic wastewater is 5 mg/L-70 mg/L; the pH of the antibiotic wastewater is 2-12; The heavy metal in the heavy metal wastewater is Cr(VI); the concentration of the heavy metal in the heavy metal wastewater is 1 mg/L-30 mg/L; the pH of the heavy metal wastewater is 2-12.

The above application is further improved, the vibration adsorption is carried out at a rotation speed of 150r/min-300r/min; the vibration adsorption time is 12h-24h.

Compared with the prior art, the present invention has the advantages of:

(1) The present invention provides a metal-organic framework material doped with manganese ions, including UiO-66 (Zr) and UiO-66 (Zr) doped with manganese ions. In the present invention, the doping of manganese ions will affect the crystal structure of UiO-66 (Zr), causing changes in its specific surface area and pore structure, wherein the specific surface area and pore diameter of manganese ion-doped UiO-66 (Zr) crystals are respectively is 797.18 m ² g ^-1 and 1.68 nm, showing a large specific surface area and pore size, which is beneficial to improve the adsorption capacity of UiO-66(Zr) crystals, while the specific surface area and pore size of UiO-66(Zr) crystals are respectively is 582.34 m ² g ^-1 and 1.35 nm. At the same time, manganese ions doped into the lattice of UiO-66(Zr) crystals will contribute valence band electrons and generate more adsorption sites. Compared with other metal-organic framework materials, the manganese ion-doped metal-organic framework material of the present invention has the advantages of large adsorption capacity, good adsorption performance, good stability, etc., and is simple to synthesize, can be widely used, and can efficiently adsorb and remove pollutants in water bodies , is a new type of adsorbent.

(2) The present invention provides a method for preparing manganese ion-doped metal-organic framework materials, using zirconium chloride, terephthalic acid, manganese chloride tetrahydrate and N,N dimethylformamide as raw materials through a solvent The manganese ion-doped metal-organic framework material with good stability and good adsorption performance was synthesized for the first time by thermal reaction. It has the advantages of simple operation, convenient preparation, fewer types of raw materials, high output, and low cost. It is suitable for large-scale preparation and is conducive to industrial utilization. .

(3) The present invention provides an application of a manganese ion-doped metal organic framework material in the removal of antibiotics and/or heavy metals in water, by oscillating the manganese ion doped metal organic framework material with antibiotic wastewater and/or heavy metal wastewater Adsorption completes the removal of antibiotics and heavy metals in wastewater. The present invention uses manganese ion-doped metal-organic framework materials to remove antibiotics and/or heavy metals in water bodies, and has the advantages of convenient operation, simple equipment, low processing cost, high processing efficiency, and good removal effect, and can be widely used in the treatment of antibiotic wastewater And/or heavy metal wastewater, has very good application value and application prospect.

Description of drawings

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

Figure 1 is the scan of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1 of the present invention and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1 Electron micrographs, where (a) is UiO-66(Zr), and (b) is MnUiO-66(Zr).

Figure 2 shows the manganese ion-doped metal organic framework material (MnUiO-66 (Zr)) prepared in Example 1 of the present invention, and the manganese ion doped metal organic framework material with adsorbed tetracycline hydrochloride prepared in Example 2 ( MnUiO-66 (Zr) + TC) and manganese ion-doped metal-organic frameworks with Cr(Ⅵ) adsorbed (MnUiO-66 (Zr) + Cr(Ⅵ)), metal-organic frameworks prepared in Comparative Example 1 (UiO-66(Zr)) XRD pattern.

Figure 3 is the Fu of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1 of the present invention and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1. Infrared spectrum diagram.

Fig. 4 shows the thermal conductivity of the manganese ion-doped metal organic framework (MnUiO-66(Zr)) prepared in Example 1 of the present invention and the metal organic framework (UiO-66(Zr)) prepared in Comparative Example 1. Reanalyze the spectrum.

Figure 5 is a diagram of the adsorption effect of manganese ion-doped metal organic framework material (MnUiO-66(Zr)) on tetracycline hydrochloride and Cr(VI) in Example 2 of the present invention, where (a) is TC, (b) is Cr (VI).

Figure 6 shows the adsorption effect of tetracycline hydrochloride and Cr(VI) on manganese ion-doped metal organic framework material (MnUiO-66(Zr)) under different coexisting ion conditions in Example 3 of the present invention, where (a) is TC , (b) is Cr(Ⅵ).

Fig. 7 is the adsorption effect diagram and corresponding zeta potential diagram of manganese ion-doped metal organic framework material (MnUiO-66 (Zr)) on different pH tetracycline hydrochloride wastewater and Cr(VI)-containing wastewater in Example 4 of the present invention, wherein (a) is TC, (b) is Cr(VI).

Figure 8 is the adsorption effect diagram of manganese ion-doped metal organic framework material (MnUiO-66(Zr)) on different concentrations of tetracycline hydrochloride wastewater and Cr(VI)-containing wastewater in Example 5 of the present invention, where (a) is TC, ( b) is Cr(VI).

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

The raw materials and instruments used in the following examples are all commercially available. In the following examples, unless otherwise specified, the obtained data are the average values of more than three repeated experiments.

Example 1

A metal-organic framework material doped with manganese ions, including UiO-66(Zr), wherein UiO-66(Zr) is doped with manganese ions.

In this embodiment, the molar ratio of manganese ions to UiO-66 (Zr) is 1:1.

A method for preparing the manganese ion-doped metal-organic framework material in the above embodiment, comprising the following steps:

(1) Weigh zirconium chloride, terephthalic acid, and manganese chloride tetrahydrate and disperse them in N, N dimethylformamide (DMF), and stir for 1 hour at a rotation speed of 150r/min to obtain a mixed solution; among them, The molar ratio of zirconium chloride, manganese chloride tetrahydrate, terephthalic acid and N,N dimethylformamide is 1:1:1:162.

(2) The mixed solution prepared in step (1) was placed in a reaction kettle lined with polytetrafluoroethylene, and a solvothermal reaction was carried out at a temperature of 120° C., and the reaction time was 24 hours.

(3) The reaction product obtained after the reaction in step (2) is cooled naturally, centrifuged at a speed of 5000 r/min, and the solid obtained by centrifugation is washed 3 times with N, N dimethylformamide and ethanol, and the After vacuum drying at 60°C for 12 hours, the obtained manganese ion-doped metal-organic framework was named MnUiO-66(Zr).

Comparative example 1

A preparation method of a metal-organic framework material (UiO-66(Zr)), which is basically the same as the preparation method in Example 1, except that manganese chloride tetrahydrate is not added in step (1).

Example 2

An application of a manganese ion-doped metal-organic framework material in removing antibiotics or heavy metals in water, specifically using manganese ion-doped metal-organic framework material to adsorb and remove tetracycline hydrochloride and Cr(VI) in water, comprising the following steps:

Weigh the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1 and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1, each 30 mg, respectively Add it to 100mL tetracycline hydrochloride wastewater with a concentration of 20 mg/L and a pH of 5.74, and perform vibration adsorption at a rotation speed of 150 r/min to complete the removal of tetracycline hydrochloride in the water. During the shaking adsorption process, 4mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant obtained by centrifugation was taken to measure the absorbance by an ultraviolet-visible spectrophotometer to determine the concentration of tetracycline hydrochloride after adsorption, thereby obtaining the adsorption effect of the manganese ion-doped metal organic framework material on tetracycline hydrochloride. After the adsorption of tetracycline hydrochloride is completed, solid-liquid separation is carried out, and the obtained solid material is a manganese ion-doped metal-organic framework material adsorbed with tetracycline hydrochloride, which is named MnUiO-66(Zr)+TC.

Weigh the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1 and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1, each 30 mg, respectively Add it to 100mL of Cr(VI)-containing wastewater with a concentration of 20 mg/L and a pH of 7.0, and perform vibration adsorption at a rotation speed of 150 r/min to complete the removal of Cr(VI) in the water. During the shaking adsorption process, 3mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant obtained by centrifugation was taken, and the concentration of Cr(VI) after adsorption was determined by diphenylcarbazide spectrophotometry, so as to obtain the adsorption effect of the manganese ion-doped MOF on Cr(VI). After the adsorption of Cr(VI) is completed, solid-liquid separation is carried out, and the obtained solid material is a manganese ion-doped metal-organic framework material adsorbed with Cr(VI), which is named MnUiO-66(Zr)+Cr(VI).

Figure 1 is the scan of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1 of the present invention and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1 Electron micrographs, where (a) is UiO-66(Zr), and (b) is MnUiO-66(Zr). It can be seen from Figure 1 that the metal organic framework material (UiO-66 (Zr)) presents an agglomerated form with poor dispersion, while the manganese ion doped metal organic framework material (MnUiO-66 (Zr)) of the present invention Cubic morphology appeared, more scattered.

The manganese ion-doped metal-organic framework material (MnUiO-66(Zr)) prepared in Example 1 and the manganese ion-doped metal-organic framework material (MnUiO-66(Zr) prepared in Example 2 with tetracycline hydrochloride adsorbed Zr) + TC) and manganese ion-doped metal-organic frameworks with Cr(Ⅵ) adsorbed (MnUiO-66(Zr)+Cr(Ⅵ)), the metal-organic frameworks prepared in Comparative Example 1 (UiO-66 (Zr)) XRD analysis, the results are shown in Figure 2. Figure 2 shows the manganese ion-doped metal organic framework material (MnUiO-66 (Zr)) prepared in Example 1 of the present invention, and the manganese ion doped metal organic framework material with adsorbed tetracycline hydrochloride prepared in Example 2 ( MnUiO-66 (Zr) + TC) and manganese ion-doped metal-organic frameworks with Cr(Ⅵ) adsorbed (MnUiO-66 (Zr) + Cr(Ⅵ)), metal-organic frameworks prepared in Comparative Example 1 (UiO-66(Zr)) XRD pattern. It can be seen from Figure 2 that the crystallinity of all samples is good, and the XRD diffraction pattern of MnUiO-66(Zr) doped with manganese ions is similar to that of pure UiO-66(Zr), and no other impurity peaks appear, indicating that the doped manganese ions The heterogeneity did not cause the topology change of UiO-66(Zr). At the same time, there is no characteristic peak of manganese or manganese oxide in the XRD diffraction pattern, indicating that manganese is doped into the UiO-66 (Zr) lattice in the form of manganese ions. According to ICP-AES analysis, the manganese ion content in the manganese ion doped metal organic framework material (MnUiO-66(Zr)) is only 1.06%. Because metal ions are difficult to dope into the crystal lattice, the content of manganese ions doped into UiO-66(Zr) crystals is low and highly dispersed, so no characteristic peaks of manganese appear in the XRD pattern. In the XRD pattern, there are three main peaks at 7.3°, 8.5° and 25.8°, corresponding to the (111), (200) and (442) crystal planes of UiO-66 (Zr), respectively. In addition, the peak shape of MnUiO-66 (Zr) did not change after adsorption of tetracycline hydrochloride and Cr(Ⅵ), which indicated that the adsorption reaction would not destroy the peak shape.

The manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1 and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1 were subjected to Fourier transform infrared analysis , the result is shown in Figure 3. Figure 3 is the Fourier of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in the example of the present invention and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1 Leaf infrared spectrum. It can be seen from Figure 3 that the peak shape of the metal-organic framework material (UiO-66(Zr)) has almost no change, and after doping with manganese ions, the manganese ion-doped metal-organic framework material (MnUiO-66(Zr) ) at 3450 cm ^-1 , the peak shape becomes wider and the peak intensity becomes stronger, indicating that the content of guest water molecules in crystal channels increases after manganese ion doping. At the same time, the doping of manganese ions may cause the pore size to become larger, making more guest water molecules condense in the pores.

The manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1 and the metal-organic framework (UiO-66(Zr)) prepared in Comparative Example 1 were subjected to thermogravimetric analysis, The result is shown in Figure 4. Fig. 4 shows the thermal conductivity of the manganese ion-doped metal organic framework (MnUiO-66(Zr)) prepared in Example 1 of the present invention and the metal organic framework (UiO-66(Zr)) prepared in Comparative Example 1. Reanalyze the spectrum. It can be seen from Figure 4 that the thermogravimetric loss is divided into two stages. The first stage is the loss of water molecules of the guest at 25°C to 400°C. In this stage, the thermogravimetric The losses were 29.69% and 41.42%, respectively, which indicated that the doping of manganese ions increased the content of guest water molecules in the pores of UiO-66(Zr) crystals. The second stage is from 400°C to 800°C, which is the collapse of the skeleton structure and finally produces metal oxides (ZrO ₂ or a mixture of ZrO ₂ and MnO). In this stage, UiO-66 (Zr) and MnUiO-66 (Zr) The thermogravimetric losses of TG were 35.83% and 26.82%, respectively, and MnUiO-66(Zr) had less residual amount, indicating that manganese ions were successfully doped into UiO-66(Zr) crystals. In addition, it can be seen from Figure 4 that the manganese ion-doped UiO-66 (Zr) crystal has good thermal stability and can maintain a stable structure within a temperature range of 400 °C.

Figure 5 is a diagram of the adsorption effect of manganese ion-doped metal organic framework material (MnUiO-66(Zr)) on tetracycline hydrochloride and Cr(VI) in Example 2 of the present invention, where (a) is TC, (b) is Cr (VI). It can be seen from Figure 5 that the first 10 minutes of oscillation adsorption is rapid adsorption, and then the adsorption is slow until equilibrium. At 60 min, UiO-66(Zr) and MnUiO-66(Zr) reached adsorption equilibrium. At 1440 min, the adsorption capacities of UiO-66(Zr) for TC and Cr(VI) were 12.2 mg/g and 8.1 mg/g, respectively, while the adsorption capacity of MnUiO-6(Zr) for TC and Cr(VI) They are 72.5 mg/g and 25.1 mg/g, respectively, which indicates that the doping of manganese ions greatly improves the adsorption capacity of UiO-66(Zr).

Example 3

An application of a manganese ion-doped metal-organic framework material in removing antibiotics or heavy metals in water, specifically using manganese ion-doped metal-organic framework material to adsorb and remove tetracycline hydrochloride and Cr(VI) in water, comprising the following steps:

Weigh 9 parts of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1, 30 mg each, and add to 9 parts of 100 mL hydrochloric acid with a concentration of 20 mg/L and a pH of 5.74 In the tetracycline wastewater, add NaCl, Na ₂ SO ₄ , Na ₃ PO ₄ to the 9 parts of tetracycline hydrochloride wastewater at the same time, and control the concentration of NaCl, Na ₂ SO ₄ , Na ₃ PO ₄ in the solution to 5mmol/L , 10 mmol/L, 15 mmol/L, vibration adsorption at 150 r/min for 24 hours to complete the removal of tetracycline hydrochloride in water. During the shaking adsorption process, 4mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant obtained by centrifugation was taken to measure the absorbance by an ultraviolet-visible spectrophotometer to determine the concentration of tetracycline hydrochloride after adsorption, thereby obtaining the adsorption effect of the manganese ion-doped metal organic framework material on tetracycline hydrochloride.

Weigh 9 parts of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1, 30 mg each, and add to 9 parts of 100 mL containing Cr(Ⅵ) wastewater, and NaCl, Na ₂ SO ₄ , Na ₃ PO ₄ were added to the 9 parts of Cr(Ⅵ) containing wastewater at the same time, and the concentration of NaCl, Na ₂ SO ₄ , Na ₃ PO ₄ in the solution was controlled. The concentrations were 5 mmol/L, 10 mmol/L, and 15 mmol/L, respectively, and the vibration adsorption was carried out at a rotation speed of 150 r/min for 24 hours to complete the removal of Cr(Ⅵ) in water. During the shaking adsorption process, 3mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant liquid obtained by centrifugation was taken, and the concentration of Cr(VI) after adsorption was determined by diphenylcarbazide spectrophotometry, so as to obtain the adsorption effect of manganese ion-doped MOF on Cr(VI).

Figure 6 shows the adsorption effect of tetracycline hydrochloride and Cr(VI) on manganese ion-doped metal organic framework material (MnUiO-66(Zr)) under different coexisting ion conditions in Example 3 of the present invention, where (a) is TC , (b) is Cr(Ⅵ). It can be seen from Figure 6 that the effects of different coexisting ions on the adsorption effect of MnUiO-66(Zr) are different. For example, adding NaCl has little effect on the adsorption effect of _{MnUiO -} 66(Zr), while adding Na Na ₃ PO ₄ will significantly reduce the adsorption effect of MnUiO-66(Zr). In addition, as the concentration of coexisting ions increases, the adsorption effect of MnUiO-66(Zr) further decreases, because too many coexisting anions will compete with pollutant molecules for the adsorption active sites, and thus the removal rate decreases. At the same time, the higher the valence state of the anion, the lower the removal rate of pollutants by MnUiO-66(Zr).

Example 4

An application of a manganese ion-doped metal-organic framework material in removing antibiotics or heavy metals in water, specifically using manganese ion-doped metal-organic framework material to adsorb and remove tetracycline hydrochloride and Cr(VI) in water, comprising the following steps:

Weigh 6 parts of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1, 30 mg each, and add them to tetracycline hydrochloride at pH 2, 4, 6, 8, 10, 12 In the wastewater (the volume of these wastewaters is 100mL and the concentration is 20mg/L), the vibration adsorption is carried out at a speed of 150 r/min for 24 hours to complete the removal of tetracycline hydrochloride in the water. During the shaking adsorption process, 4mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant obtained by centrifugation was taken to measure the absorbance by an ultraviolet-visible spectrophotometer to determine the concentration of tetracycline hydrochloride after adsorption, so as to obtain the adsorption effect of manganese ion-doped metal-organic framework materials on tetracycline hydrochloride wastewater with different pH.

Weigh 6 parts of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1, 30 mg each, and add them to Cr-containing (Ⅵ) In wastewater (the volume of these wastewaters is 100mL and the concentration is 10mg/L), the vibration adsorption is carried out at a speed of 150 r/min for 24 hours to complete the removal of Cr(Ⅵ) in the water. During the shaking adsorption process, 3mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant obtained by centrifugation was taken, and the concentration of Cr(Ⅵ) after adsorption was determined by diphenylcarbazide spectrophotometry, so as to obtain the adsorption effect of manganese ion-doped metal organic framework materials on wastewater containing Cr(Ⅵ) at different pHs.

Fig. 7 is the adsorption effect diagram and corresponding zeta potential diagram of manganese ion-doped metal organic framework material (MnUiO-66 (Zr)) on different pH tetracycline hydrochloride wastewater and Cr(VI)-containing wastewater in Example 4 of the present invention, wherein (a) is TC, (b) is Cr(VI). It can be seen from Fig. 7(a) that the adsorption capacity of MnUiO-66(Zr) for tetracycline hydrochloride increased from 16.5 mg/g to 73.5 mg/g as the pH value increased from 2 to 8. It is worth noting that the adsorption capacity of MnUiO-66(Zr) for tetracycline hydrochloride is almost unchanged in the pH range of 4 to 12, indicating that the adsorption capacity of MnUiO-66(Zr) for tetracycline hydrochloride is less affected by the pH value of the solution , the adsorption is mainly affected by the π-π bond between tetracycline hydrochloride and organic ligands in MnUiO-66(Zr). The isoelectric point of zeta potential of MnUiO-66 (Zr) in water is 9.85, while the isoelectric point of zeta potential of MnUiO-66 (Zr) in tetracycline hydrochloride solution is 11.15, the increase of zeta potential isoelectric point may be due to tetracycline hydrochloride The benzene rings of the MnUiO-66(Zr) form hydrogen bonds with the organic ligands. It can be seen from 7(b) that the adsorption of MnUiO-66(Zr) to Cr(Ⅵ) is greatly affected by the pH value, indicating that the adsorption of MnUiO-66(Zr) on Cr(Ⅵ) is mainly affected by electrostatic interaction. At pH 6, the maximum adsorption capacity of Cr(Ⅵ) on MnUiO-66(Zr) was 25.4 mg/g. The zeta potential isoelectric point of MnUiO-66 (Zr) in Cr(Ⅵ) solution is 7.11, which is lower than the zeta potential isoelectric point of MnUiO-66 (Zr) in water (9.85). This is due to the aggregation of anions in the Cr(VI) solution.

Example 5

An application of a manganese ion-doped metal-organic framework material in removing antibiotics or heavy metals in water, specifically using manganese ion-doped metal-organic framework material to adsorb and remove tetracycline hydrochloride and Cr(VI) in water, comprising the following steps:

Weigh 5 parts of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1, 30 mg each, and add to the concentration of 5 mg/L, 10 mg/L, 30 mg/L , 50 mg/L, and 70 mg/L tetracycline hydrochloride wastewater (the volume of wastewater is 100mL, pH 5.74), and the vibration adsorption was carried out at a speed of 150 r/min for 24 hours to complete the removal of tetracycline hydrochloride in the water. During the shaking adsorption process, 4mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant obtained by centrifugation was taken to measure the absorbance by an ultraviolet-visible spectrophotometer to determine the concentration of antibiotics after adsorption, so as to obtain the adsorption effect of manganese ion-doped metal-organic framework materials on tetracycline hydrochloride wastewater with different concentrations.

Weigh 5 parts of the manganese ion-doped metal-organic framework (MnUiO-66(Zr)) prepared in Example 1, 30 mg each, and add to the concentration of 1 mg/L, 5 mg/L, 10 mg/L , 20 mg/L, 30 mg/L of Cr(Ⅵ)-containing wastewater (the volume of the wastewater is 100mL, and the pH is 7.0), the vibration adsorption is carried out at the speed of 150 r/min for 24 hours, and the Cr(Ⅵ) in the water body is completed. VI) removal. During the shaking adsorption process, 3mL samples were taken at regular intervals, and the samples were centrifuged. The supernatant obtained by centrifugation was taken, and the concentration of Cr(VI) after adsorption was determined by diphenylcarbazide spectrophotometry, so as to obtain the adsorption effect of the manganese ion-doped MOF on Cr(VI).

Figure 8 is the adsorption effect diagram of manganese ion-doped metal organic framework material (MnUiO-66(Zr)) on different concentrations of tetracycline hydrochloride wastewater and Cr(VI)-containing wastewater in Example 5 of the present invention, where (a) is TC, ( b) is Cr(VI). It can be seen from Figure 8(a) that the concentration of tetracycline hydrochloride wastewater increased from 5 mg/L to 70 mg/L, and the adsorption capacity of tetracycline hydrochloride by manganese ion-doped metal-organic framework materials (MnUiO-66(Zr)) increased from 19.39 mg/L g increased to 184.49 mg/g, this is because the increase in the concentration of tetracycline hydrochloride will increase the driving force of the concentration gradient, thereby increasing the adsorption capacity. At the same time, as the concentration of tetracycline hydrochloride increased, the available adsorption sites on MnUiO-66(Zr) were relatively less, and the removal rate decreased. It can be seen from Figure 8(b) that the concentration of Cr(Ⅵ)-containing wastewater increases from 1 mg/L to 30 mg/L, and the effect of manganese ion-doped metal-organic framework (MnUiO-66(Zr)) on Cr(Ⅵ) The adsorption capacity increased from 3.32 mg/g to 32.77 mg/g, because the increase of Cr(Ⅵ) concentration would increase the driving force of the concentration gradient, thus increasing the adsorption capacity. At the same time, with the increase of Cr(Ⅵ) concentration, the available adsorption sites on MnUiO-66(Zr) were relatively less and the removal rate decreased.

Therefore, the manganese ion-doped metal organic framework material (MnUiO-66(Zr)) of the present invention has a good adsorption effect on tetracycline hydrochloride and Cr(VI). In particular, the manganese ion-doped metal-organic framework material (MnUiO-66(Zr)) of the present invention has a better adsorption effect on low-concentration tetracycline hydrochloride antibiotic wastewater and Cr(VI)-containing wastewater. In actual wastewater, the content of tetracycline hydrochloride and Cr(Ⅵ) is often very low, manganese ion doped metal organic framework material (MnUiO-66(Zr)) improves the removal of tetracycline hydrochloride and Cr(Ⅵ) in low concentration wastewater The rate shows that the manganese ion-doped metal-organic framework material (MnUiO-66(Zr)) doped metal-organic framework material (MnUiO-66(Zr)) of the present invention has high commercial value and application prospect.

The above examples are only preferred implementations of the present invention, and the scope of protection of the present invention is not limited to the above examples. All technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims (10)

1. a kind of manganese ion doping metal-organic framework materials, which is characterized in that including UiO-66（Zr）；The UiO-66（Zr） In doped with manganese ion；The manganese ion and UiO-66（Zr）Molar ratio be 1: 1.

2. manganese ion doping metal-organic framework materials according to claim 1, which is characterized in that the manganese ion doping Metal-organic framework materials pass through molten using zirconium chloride, terephthalic acid (TPA), four chloride hydrate manganese and n,N dimethylformamide as raw material Agent thermal response is prepared.

3. a kind of preparation method of manganese ion doping metal-organic framework materials, which is characterized in that include the following steps：By chlorination Zirconium, terephthalic acid (TPA), four chloride hydrate manganese and n,N dimethylformamide mixing carry out solvent thermal reaction, obtain manganese ion doping Metal-organic framework materials.

4. preparation method according to claim 3, which is characterized in that the four chloride hydrates manganese, zirconium chloride, terephthaldehyde The molar ratio of acid and n,N dimethylformamide is 1: 1: 1: 162.

5. preparation method according to claim 3 or 4, which is characterized in that the mixing carries out under agitation；It is described The revolving speed of stirring is the r/min of 300 r/min~500；The time of the stirring is 1h~3h；The solvent thermal reaction is in temperature It is to be carried out at 120 DEG C~150 DEG C；The time of the solvent thermal reaction is h for 24 hours~36.

6. preparation method according to claim 3 or 4, which is characterized in that further comprising the steps of：It is complete to solvent thermal reaction The reaction product obtained after is centrifuged, is washed and is dried；The revolving speed of the centrifugation is the r/min of 5000 r/min~6000； The washing is 3 times~5 times using n,N dimethylformamide and ethyl alcohol, each washing；It is described to be dried as in vacuum item It is dried under part；The temperature of the drying is 60 DEG C~80 DEG C；The time of the drying is the h of 8 h~12.

7. any in a kind of manganese ion doping metal-organic framework materials as claimed in claim 1 or 2 or claim 3~6 Manganese ion doping metal-organic framework materials made from preparation method described in antibiotic and/or heavy metal in removal water body In application.

8. application according to claim 7, which is characterized in that include the following steps：By the organic bone of manganese ion doping metal Frame material, antibiotic waste water and/or heavy metal wastewater thereby mixing carry out oscillation absorption, complete to antibiotic in water body and/or a huge sum of money The processing of category；The ratio of the manganese ion doping metal-organic framework materials and the antibiotic waste water and/or heavy metal wastewater thereby It is 0.3g~0.5g: 1L.

9. application according to claim 8, which is characterized in that antibiotic is quadracycline in the antibiotic waste water； The concentration of antibiotic is the mg/L of 5 mg/L~70 in the antibiotic waste water；The pH of the antibiotic waste water is 2~12；It is described Heavy metal is Cr (VI) in heavy metal wastewater thereby；The concentration of heavy metal is the mg/L of 1 mg/L~30 in the heavy metal wastewater thereby；It is described The pH of heavy metal wastewater thereby is 2~12.

10. application according to claim 8 or claim 9, which is characterized in that it is described oscillation be adsorbed on revolving speed be 150r/min~ It is carried out under 300r/min；The time of the oscillation absorption is 12h~for 24 hours.