A method for preparing size-tunable porous Mn / Fe-based Prussian blue nanomaterials and its application

Abstract

This invention discloses a method for preparing size-tunable porous Mn / Fe-based Prussian blue nanomaterials and their applications. This invention utilizes ion doping to prepare a series of uniformly tunable Prussian blue nanoporous materials by adjusting the ratio of Mn / Fe ions. The Prussian blue nanoporous materials prepared by this invention can activate H₂O₂ and rapidly degrade a 20 ppm ciprofloxacin solution within 20 min, exhibiting good cycling performance. This invention provides a simple one-step method for preparing size-tunable porous Mn / Fe-based Prussian blue nanomaterials, characterized by high economic efficiency and a simple preparation process, resulting in significant economic and environmental benefits.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to a method for preparing size-tunable porous Mn / Fe-based Prussian blue nanomaterials and their applications. Background Technology

[0002] Controlling the size of nanocrystal particles hinges on balancing the nucleation and crystal growth kinetics of the material. The presence of surfactants can control particle size because they stabilize the growing particles through weak interactions with the particle surface. Ion doping helps tune the particle size as it mediates growth kinetics. However, inorganic systems remain a challenge for MOFs because the coordinated structure of inorganic nodes and organic junctions during MOF growth makes them susceptible to modulators or dopant ions.

[0003] MOFs, as classic porous materials, possess high porosity and large surface area, similar to other porous materials. Their most significant characteristic is their excellent designability, as MOFs connect organic and inorganic molecular building blocks through strong directional chemical bonds. This makes MOFs more likely to yield porous materials with superior catalytic applications. Even so, preparing uniformly sized, tunable porous nanomaterials remains a major challenge in the field of inorganic materials. These applications and effects have been expanded by constructing nano-MOFs, especially when porous materials are miniaturized. Pore engineering can endow catalysts with high surface area and high absorption capacity, thus forming ideal candidate materials for catalysis, energy storage, and other related applications. Therefore, exploring methods for synthesizing size-tunable porous Mn / Fe-based Prussian blue nanomaterials is of paramount importance. Summary of the Invention

[0004] The purpose of this invention is to provide an efficient and simple method for preparing size-tunable porous Mn / Fe-based Prussian blue nanomaterials, addressing the shortcomings of current technologies.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for preparing size-tunable porous Mn / Fe-based Prussian blue nanomaterials and their applications, comprising the following raw materials: potassium ferrocyanide (K4[Fe(CN)6]·3H2O), polyvinylpyrrolidone (PVP), potassium permanganate (KMnO4), 1 mmol / L dilute hydrochloric acid (HCl), and ethanol (CH5OH).

[0007] A method for preparing size-tunable porous Mn / Fe Prussian blue-like nanomaterials and their applications: Using potassium ferrocyanide as the iron source, potassium ferrocyanide, polyvinylpyrrolidone, and 50 ml of 1 mmol / L HCl solution were stirred at room temperature until the solution became clear. Then, ground KMnO4 was added and stirred until dissolved. The mixed solution was transferred to a reaction vessel and reacted under the same hydrothermal conditions. After natural cooling to room temperature, the resulting precipitate was washed three times with deionized water and ethanol, respectively, and dried at 60°C in a vacuum drying oven to obtain a series of Prussian blue-like compounds.

[0008] The aforementioned size-tunable porous Mn / Fe-based Prussian blue nanomaterial specifically includes the following steps:

[0009] (1) Add polyvinylpyrrolidone (PVP) and potassium ferrocyanide to dilute hydrochloric acid and stir at room temperature to completely dissolve the drugs;

[0010] (2) Grind potassium permanganate into powder and add it to the mixed solution obtained in step (1);

[0011] (3) Mix and dissolve the solution obtained in step (2) thoroughly at room temperature and pressure;

[0012] (4) The mixed solution after complete dissolution in step (3) is loaded into the reaction vessel for hydrothermal reaction;

[0013] (5) The precipitate was centrifuged, washed and dried to obtain a series of porous Mn / Fe Prussian blue nanomaterials of different sizes.

[0014] Further, in step (1), the amount of polyvinylpyrrolidone used is 3.8 g, and the amount of potassium ferrocyanide used is 0.12 g.

[0015] Further, in step (1), the concentration of dilute hydrochloric acid is 1 mmol / L and the amount used is 50 ml.

[0016] Furthermore, the stirring in step (1) is at 500 rpm and the stirring time is 5-10 min.

[0017] Further, the grinding in step (2) is grinding to 100 mesh, the amount of potassium permanganate is 0.02244 g - 0.08976 g, and the molar ratio of potassium permanganate to potassium ferrocyanide is 1:2-2:1.

[0018] Further, the thorough mixing and dissolution in step (3) specifically involves: magnetic stirring; stirring speed of 500-1000 rpm; stirring time of 30 min; and then sonicating in an ultrasonic machine for 10 min.

[0019] Further, the hydrothermal reaction described in step (4) is as follows: the heating rate is 5-20 ℃ / min, the holding temperature is 120 ℃, and the holding time is 12 h.

[0020] Further, the centrifugation in step (5) specifically involves centrifuging with a centrifuge at a speed of 8000 rpm - 10000 rpm for 3 - 5 min.

[0021] Further, the washing in step (5) specifically involves washing with ethanol three times and then washing with deionized water three times.

[0022] Further, the drying in step (5) specifically involves vacuum drying at 60°C for 6-12 hours.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) This invention prepares a series of size-tunable porous Mn / Fe-based Prussian blue nanoparticles by ion doping. Unlike traditional size control, this invention controls the size of nanoparticles by controlling the proportion of high-valence manganese doping during the synthesis process, preventing excessive nucleation during crystal growth, and providing a new approach to achieve precise size control of nanoparticles.

[0025] (2) The size-tunable Mn / Fe Prussian blue nanoparticles prepared by the present invention have a uniform size distribution and the size can be controlled from the sub-nanometer level to tens of nanometers, and have a porous structure.

[0026] (3) The preparation method of the present invention is a one-step method, which can achieve one-step synthesis of size-tunable nanoparticles with porous structures through a simple hydrothermal reaction. The required raw materials and equipment are simple and readily available, and the process is simple, easy to operate and safe.

[0027] (4) The preparation method of the present invention is green and environmentally friendly. Compared with other precious metal elements, Mn / Fe has less environmental pollution and is an ecologically friendly material. Attached Figure Description

[0028] Figure 1 These are X-ray diffraction (XRD) patterns of the porous Mn / Fe-based Prussian blue nanomaterials prepared in Examples 1-3 of this invention and the original Fe-based Prussian blue nanomaterials prepared in Comparative Example 1.

[0029] Figure 2 The graphs show the rate of degradation of ciprofloxacin by the porous Mn / Fe-based Prussian blue nanomaterials prepared in Examples 1-3 of this invention and the original Fe-based Prussian blue nanoparticles prepared in Comparative Example 1.

[0030] Figure 3This is a performance graph of the porous Mn / Fe-type Prussian blue nanomaterial prepared in Example 2 of the present invention under a cyclic experiment;

[0031] Figure 4 This is a SEM image of the original Fe-based Prussian blue nanomaterials prepared in Comparative Example 1 of this invention.

[0032] Figure 5 This is a transmission electron microscope (TEM) image of the original Fe-based Prussian blue nanomaterials prepared in Comparative Example 1 of this invention;

[0033] Figure 6 This is a SEM image of the porous Mn / Fe-type Prussian blue nanomaterial prepared in Example 1 of this invention;

[0034] Figure 7 This is a transmission electron microscope (TEM) image of the porous Mn / Fe-type Prussian blue nanomaterials prepared in Example 1 of this invention;

[0035] Figure 8 This is a SEM image of the porous Mn / Fe-type Prussian blue nanomaterial prepared in Example 2 of this invention.

[0036] Figure 9 This is a transmission electron microscope (TEM) image of the porous Mn / Fe-type Prussian blue nanomaterials prepared in Example 2 of this invention;

[0037] Figure 10 This is a SEM image of the porous Mn / Fe-based Prussian blue nanomaterials prepared in Example 3 of this invention;

[0038] Figure 11 This is a transmission electron microscope (TEM) image of the porous Mn / Fe-type Prussian blue nanomaterial prepared in Example 3 of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined as long as they do not conflict with each other.

[0040] Example 1

[0041] Preparation of size-tunable porous Mn / Fe-based Prussian blue nanomaterials:

[0042] (1) Weigh 3.8 g of polyvinylpyrrolidone (PVP) and 0.12 g of potassium ferrocyanide into a beaker using an electronic balance.

[0043] (2) Measure 50 ml of 0.1 mmol / L dilute hydrochloric acid into a beaker using a graduated cylinder, and stir at room temperature to completely dissolve the drug to obtain solution A.

[0044] (3) Grind potassium permanganate into powder, weigh 0.02244 g, and add it to mixed solution A to obtain mixed solution B.

[0045] (4) Stir solution B magnetically for 30 minutes at room temperature and pressure, and then sonicate it for 10 minutes in an ultrasonic machine.

[0046] (5) Transfer the fully dissolved mixed solution B from the beaker into the reactor, put the outer liner in, and carry out the hydrothermal reaction. The temperature is increased from room temperature to 120 ℃ at a rate of 5℃ / min, and kept at 120 ℃ for 12 h.

[0047] (6) The reactants were separated by centrifugation to obtain a precipitate, which was washed three times with ethanol and three times with deionized water, and then dried under vacuum at 60 °C for 12 h to obtain porous Mn / Fe Prussian blue nanomaterials.

[0048] Example 2

[0049] Preparation of size-tunable porous Mn / Fe-based Prussian blue nanomaterials:

[0050] (1) Weigh 3.8 g of polyvinylpyrrolidone (PVP) and 0.12 g of potassium ferrocyanide into a beaker using an electronic balance.

[0051] (2) Measure 50 ml of 0.1 mmol / L dilute hydrochloric acid into a beaker using a graduated cylinder, and stir at room temperature to completely dissolve the drug to obtain solution A.

[0052] (3) Grind potassium permanganate into powder, weigh 0.04488 g, and add it to mixed solution A to obtain mixed solution B.

[0053] (4) Stir solution B magnetically for 30 minutes at room temperature and pressure, and then sonicate it for 10 minutes in an ultrasonic machine.

[0054] (5) Transfer the fully dissolved mixed solution B from the beaker into the reactor, put the outer liner in, and carry out the hydrothermal reaction. The temperature is increased from room temperature to 120 ℃ at a rate of 5℃ / min, and kept at 120 ℃ for 12 h.

[0055] (6) The reactants were separated by centrifugation to obtain a precipitate, which was washed three times with ethanol and three times with deionized water, and then dried under vacuum at 60 °C for 12 h to obtain porous Mn / Fe Prussian blue nanomaterials.

[0056] Example 3

[0057] Preparation of size-tunable porous Mn / Fe-based Prussian blue nanomaterials:

[0058] (1) Weigh 3.8 g of polyvinylpyrrolidone (PVP) and 0.12 g of potassium ferrocyanide into a beaker using an electronic balance.

[0059] (2) Measure 50 ml of 0.1 mmol / L dilute hydrochloric acid into a beaker using a graduated cylinder, and stir at room temperature to completely dissolve the drug to obtain solution A.

[0060] (3) Grind potassium permanganate into powder, weigh 0.08976 g, and add it to mixed solution A to obtain mixed solution B.

[0061] (4) Stir solution B magnetically for 30 minutes at room temperature and pressure, and then sonicate it for 10 minutes in an ultrasonic machine.

[0062] (5) Transfer the fully dissolved mixed solution B from the beaker into the reactor, put the outer liner in, and carry out the hydrothermal reaction. The temperature is increased from room temperature to 120 ℃ at a rate of 5℃ / min, and kept at 120 ℃ for 12 h.

[0063] (6) The reactants were separated by centrifugation to obtain a precipitate, which was washed three times with ethanol and three times with deionized water, and then dried under vacuum at 60 °C for 12 h to obtain porous Mn / Fe Prussian blue nanomaterials.

[0064] Comparative Example 1

[0065] Preparation of original Fe-based Prussian blue nanoparticles:

[0066] (1) Weigh 3.8 g of polyvinylpyrrolidone (PVP) and 0.12 g of potassium ferrocyanide into a beaker using an electronic balance.

[0067] (2) Measure 50 ml of 0.1 mmol / L dilute hydrochloric acid into a beaker using a graduated cylinder, and stir at room temperature to completely dissolve the drug to obtain solution A.

[0068] (3) Stir solution A magnetically for 30 minutes at room temperature and pressure, and then sonicate it for 10 minutes in an ultrasonic machine.

[0069] (4) Transfer the fully dissolved mixed solution A from the beaker into the reactor, put the outer liner in, and carry out the hydrothermal reaction. The temperature is increased from room temperature to 120 ℃ at a rate of 5℃ / min, and kept at 120 ℃ for 12 h.

[0070] (5) The reactants were separated by centrifugation to obtain a precipitate, which was washed three times with ethanol and three times with deionized water, and then dried under vacuum at 60 °C for 12 h to obtain the original Fe-based Prussian blue nanoparticles.

[0071] Antibiotic degradation experiment

[0072] Application Example 1

[0073] The porous Mn / Fe-based Prussian blue nanomaterials obtained in Example 1 were used to degrade antibiotics. The specific steps are as follows:

[0074] (1) Prepare a 20 ppm ciprofloxacin solution;

[0075] (2) Take 10 mg of porous Mn / Fe Prussian blue nanomaterial and put it into the above solution, and sonicate for 2 min;

[0076] (3) Place the solution under dark reaction conditions and stir magnetically for 30 min to reach adsorption equilibrium.

[0077] (4) Take 25 μl of 30% H2O2 solution and add it to the above solution, and degrade it under visible light;

[0078] (5) After different time periods, the ultraviolet absorption value of ciprofloxacin in water was measured using an ultraviolet-visible spectrophotometer, and the removal rate of ciprofloxacin was calculated.

[0079] Application Example 2

[0080] The porous Mn / Fe-based Prussian blue nanomaterials obtained in Example 2 were used to degrade antibiotics. The specific steps are as follows:

[0081] (1) Prepare a 20 ppm ciprofloxacin solution;

[0082] (2) Take 10 mg of porous Mn / Fe Prussian blue nanomaterial and put it into the above solution, and sonicate for 2 min;

[0083] (3) Place the solution under dark reaction conditions and stir magnetically for 30 min to reach adsorption equilibrium.

[0084] (4) Take 25 μl of 30% H2O2 solution and add it to the above solution, and degrade it under visible light;

[0085] (5) After different time periods, the ultraviolet absorption value of ciprofloxacin in water was measured using an ultraviolet-visible spectrophotometer, and the removal rate of ciprofloxacin was calculated.

[0086] Application Example 3

[0087] The porous Mn / Fe-based Prussian blue nanomaterials obtained in Example 3 were used to degrade antibiotics. The specific steps are as follows:

[0088] (1) Prepare a 20 ppm ciprofloxacin solution;

[0089] (2) Take 10 mg of porous Mn / Fe Prussian blue nanomaterial and put it into the above solution, and sonicate for 2 min;

[0090] (3) Place the solution under dark reaction conditions and stir magnetically for 30 min to reach adsorption equilibrium.

[0091] (4) Take 25 μl of 30% H2O2 solution and add it to the above solution, and degrade it under visible light;

[0092] (5) After different time periods, the ultraviolet absorption value of ciprofloxacin in water was measured using an ultraviolet-visible spectrophotometer, and the removal rate of ciprofloxacin was calculated.

[0093] Application Example 4

[0094] The original Fe-based Prussian blue nanoparticles obtained in Comparative Example 1 were used to degrade antibiotics. The specific steps are as follows:

[0095] (1) Prepare a 20 ppm ciprofloxacin solution;

[0096] (2) Take 10 mg of porous Mn / Fe Prussian blue nanomaterial and put it into the above solution, and sonicate for 2 min;

[0097] (3) Place the solution under dark reaction conditions and stir magnetically for 30 minutes to reach adsorption equilibrium.

[0098] (4) Take 25 μl of 30% H2O2 solution and add it to the above solution, and degrade it under visible light;

[0099] (5) After different time periods, the ultraviolet absorption value of ciprofloxacin in water was measured using an ultraviolet-visible spectrophotometer, and the removal rate of ciprofloxacin was calculated.

[0100] Figure 2 This is a graph showing the degradation rate of ciprofloxacin by porous Mn / Fe-based Prussian blue nanomaterials prepared in Examples 1-3 of this invention and the original Fe-based Prussian blue nanomaterials prepared in Comparative Example 1; the experiment shows that the degradation performance of porous Mn / Fe-based Prussian blue nanomaterials of different sizes varies greatly. Figure 2 The porous Mn / Fe-based Prussian blue nanomaterials prepared in Example 2 exhibit the best adsorption and degradation activities, with adsorption performance and degradation activity far exceeding those of other example materials. Figure 3 This is a schematic diagram of the degradation performance of the porous Mn / Fe-type Prussian blue nanomaterial prepared in Example 2 of the present invention under a cyclic experiment. After 4 cycles, the performance of the porous Mn / Fe-type Prussian blue nanomaterial did not decrease significantly. Figure 4 , Figure 5 The images show the SEM and TEM images of the original Fe-based Prussian blue nanomaterial, Comparative Example 1. As can be seen from the images, the original Fe-based Prussian blue nanomaterial exhibits a regular cubic structure with a particle size of approximately 900 nm and a solid internal structure.

[0101] Figure 5 , Figure 6 The images show SEM and TEM images of Example 1, a porous Mn / Fe-based Prussian blue nanomaterial. The images show that the porous Mn / Fe-based Prussian blue nanomaterial is granular with a particle size of approximately 300 nm and contains internal pores. Furthermore, from... Figure 7 , Figure 8 and Figure 9 , Figure 10 It can be seen that the preparation method proposed in this invention can achieve control over the size of nanoparticles. The differences between the metal doping ratio and the size of the porous nanoparticles obtained in the specific embodiments and comparative experiments are as follows.

[0102] Table 1: Experimental conditions and size comparison for the examples and sample examples

[0103]

[0104] It is well known that reducing the size of nanomaterials increases their specific surface area, thereby improving their performance. This invention utilizes the designability of metallic framework materials to prepare porous nanomaterials with tunable size using a simple method. By controlling the size, the adsorption and degradation activities of the material can be significantly improved. However, due to the inherent porosity of the material, the performance improvement resulting from size reduction is limited. This invention allows for the acquisition of a suitable size for optimal performance by adjusting experimental conditions. Specific adsorption and degradation performance and sample size are as follows:

[0105] Table 2: Comparison of Adsorption and Degradation Performance between Examples and Samples

[0106]

[0107] C / C0 refers to the ratio of remaining antibiotics to the original antibiotics in 10 mg of catalyst after adsorbing and degrading 50 ml of 20 ppm CIP within the same time period. Example 2, as shown in the table, exhibits the best adsorption and degradation performance.

[0108] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The application of a size-tunable porous Mn / Fe-based Prussian blue nanomaterial in the efficient degradation of ciprofloxacin, characterized in that: The method for preparing the size-tunable porous Mn / Fe-based Prussian blue nanomaterial includes the following steps: (1) Mix potassium ferrocyanide and polyvinylpyrrolidone; (2) Then add dilute hydrochloric acid solution and stir thoroughly at room temperature and pressure until potassium ferrocyanide and polyvinylpyrrolidone turn into a clear yellow-green solution; (3) Add potassium permanganate to the solution obtained in step (2), mix and stir thoroughly under normal temperature and pressure and sonicate to obtain a mixed solution; (4) Pour the mixed solution into the reaction vessel to carry out the hydrothermal reaction; (5) After centrifugation, washing, and drying until the moisture is completely evaporated, porous Mn / Fe-type Prussian blue nanomaterials with adjustable size are obtained; The molar ratio of potassium permanganate to potassium ferrocyanide is 1:2-2:1; The hydrothermal reaction conditions in step (4) are as follows: heating rate: 5 - 20 ℃ / min, hydrothermal temperature: 120℃, hydrothermal time: 12 h.

2. The application according to claim 1, characterized in that: The concentration of the dilute hydrochloric acid in step (2) is 1 mmol / L.

3. The application according to claim 1, characterized in that: Step (2) involves thorough stirring: magnetic stirring at room temperature; stirring speed of 500-1000 rpm; stirring time of 5-10 min.

4. The application according to claim 1, characterized in that: Step (3) involves thorough mixing and ultrasonication: magnetic stirring in an air atmosphere; stirring speed of 500-1000 rpm; stirring time of 30 min, followed by ultrasonication in an ultrasonic machine for 10 min.

5. The application according to claim 1, characterized in that: The centrifugation in step (5) specifically refers to centrifugation at a speed of 10,000 rpm.

6. The application according to claim 1, characterized in that: the washing in step (5) specifically involves washing with ethanol 3 times and washing with deionized water 3 times.

7. The application according to claim 1, characterized in that: the drying in step (5) is: vacuum drying at 60°C for 6-12 hours.

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