CN109437338B

CN109437338B - Preparation method of zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterials

Info

Publication number: CN109437338B
Application number: CN201811457529.0A
Authority: CN
Inventors: 于岩; 庄赞勇; 叶嘉华
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2021-03-02
Anticipated expiration: 2038-11-30
Also published as: CN109437338A

Abstract

本发明提供了一种类锯齿型镍钴铁类普鲁士蓝烧结氧化物纳米材料的制备方法，属于于材料技术领域。本发明以六水合硝酸镍、三水合柠檬酸三钠、铁氰化钾和钴氰化钾合成立方结构的纳米镍钴铁类普鲁士蓝前驱体，然后用氨水溶液进行腐蚀后离心分离，洗样，干燥后得到类锯齿型镍钴铁类普鲁士蓝纳米材料，对其进行烧结，得到“Z”‑O_x纳米材料。“Z”‑O_x纳米材料能够有效地催化过氧单硫酸盐产生羟基自由基和硫酸根自由基，进而降解双酚A。本发明以前驱体中金属配位键分布不均匀来决定腐蚀的位置，形成各向异性腐蚀，为MOF材料的结构和性质的微调开辟新的途径，并且该方法具有操作简单、制备周期短、经济效益高、适合大规模生产的特点。The invention provides a preparation method of a zigzag-type nickel-cobalt-iron-type Prussian blue sintered oxide nanomaterial, which belongs to the technical field of materials. In the present invention, nano-nickel-cobalt-iron Prussian blue precursors with cubic structure are synthesized with nickel nitrate hexahydrate, trisodium citrate trihydrate, potassium ferricyanide and potassium cobalt cyanide, and then etched with ammonia solution, centrifuged, and washed. , after drying, a zigzag-like nickel-cobalt-iron-like Prussian blue nanomaterial is obtained, which is sintered to obtain a "Z" _-Ox nanomaterial. The "Z" _-Ox nanomaterials can effectively catalyze the generation of hydroxyl radicals and sulfate radicals from peroxymonosulfate, and then degrade bisphenol A. In the invention, the uneven distribution of metal coordination bonds in the precursor determines the position of corrosion, forms anisotropic corrosion, and opens up a new way for fine-tuning the structure and properties of MOF materials, and the method has the advantages of simple operation, short preparation period, It has the characteristics of high economic efficiency and suitable for large-scale production.

Description

Preparation method of sawtooth-like nickel-cobalt-iron Prussian blue sintered oxide nano material

Technical Field

The invention belongs to the technical field of materials, and particularly relates to a preparation method of a sawtooth-like Prussian blue sintered oxide nano material.

Background

Chemical etch-based strategies open new avenues for the preparation of Metal Organic Frameworks (MOFs) with new morphologies. The presence of an etchant (e.g., H + or OH-) that is capable of breaking the metal/organic connectors of the MOF can render the MOF precursor into crystals with tunable spherical, cubic, or tetrahedral morphology. Due to the differential reactions between the interior of the MOF precursor crystals and the facets, sometimes nano-MOFs (e.g. zeolitic imidazolate framework materials (ZIFs), prussian-like blue (PBAs)) can obtain hollow structures, further modulating the structure of the pre-synthesized MOFs can create MOFs of higher complexity.

Despite these advances, there remains a challenge to making MOFs of higher complexity. Taking PBA as an example, etching sometimes occurs preferentially on the central surfaces of the PBA cube, sometimes at their corners, resulting in different morphologies of PBAs. This may be due to uneven reactivity of the surfaces and corners. The extent and location of etching of the MOF crystals may be related to defects or to metal-ligand bonds. Unfortunately, few examples of research in this regard, particularly many still focused on the synthesis and characterization of materials, and the lack of knowledge of MOF etching behavior has limited the comprehensive exploration of MOFs with complex structures. Thus, the structures of existing nano-synthetic MOFs are still limited to mesoporous or hollow structures.

To our knowledge, this is the first report on the discovery that prussian-like blue with an unprecedented sawtooth-like pattern is obtained by etching prussian-like blue precursors. The method enriches the complex morphological structure design of the nano MOF, and brings more research opportunities for realizing the versatility of the MOF. It also provides an ideal platform for the anisotropic etching mechanism of MOFs. The nickel-cobalt-iron mixed oxide nano material (Z '-O) is successfully prepared by the heat treatment of Z' -PBA_x) It shows excellent catalytic performance for catalyzing Peroxymonosulfate (PMS) to degrade bisphenol a.

Disclosure of Invention

The invention aims to provide a preparation method of a sawtooth-like Prussian blue nano material aiming at the defects of the prior art. According to the invention, nickel-cobalt-iron Prussian blue (NiCoFe-PBA) is used as a template, and sawtooth-like Prussian blue (Z' -PBA) is obtained through ammonia corrosion, so that the complex morphological structure design of nano MOFs is enriched; the mixed oxide nano material obtained by heat treatment can well keep the structure of Z' -PBA after corrosion and can effectively catalyze and degrade bisphenol A, thereby solving the problem of pollution caused by bisphenol A.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a sawtooth-like nickel-cobalt-iron Prussian blue sintered oxide nano material comprises the following steps:

(1) preparing a cubic-structure nano nickel-cobalt-iron Prussian blue (NiCoFe-PBA) precursor: the method comprises the following steps of preparing nano nickel cobalt iron Prussian blue (NiCoFe-PBA) with a cubic structure by using potassium ferricyanide, potassium cobaltcyanide, trisodium citrate trihydrate and nickel nitrate hexahydrate as raw materials through a hydrothermal synthesis method;

(2) preparing a sawtooth-like nickel-cobalt-iron Prussian blue ('Z' -PBA) nano material: uniformly dispersing the cubic-structure nano nickel-cobalt-iron Prussian blue (NiCoFe-PBA) precursor obtained in the step (1) into 10 ml of ethanol, and stirring until the precursor is completely dispersed to obtain a mixed solution; then slowly pouring the ammonia water solution into the mixed solution, and stirring for 1 h; then carrying out centrifugal separation on the reaction liquid, and washing; putting the washed sample into an oven, and keeping the temperature for 12 h at 70 ℃ for drying to obtain a zigzag nickel-cobalt-iron Prussian blue ('Z' -PBA) nano material;

(3) sawtooth-like nickel cobalt iron Prussian blue sintered oxide ('Z' -O)_x) Preparing a nano material: putting the sawtooth-like nickel-cobalt-iron Prussian blue (' Z ' -PBA) nano material obtained in the step (2) into a muffle furnace, preserving the heat for 1.5 h at 350 ℃, and increasing the temperature at the rate of 2 ℃/min to finally obtain the sawtooth-like nickel-cobalt-iron Prussian blue sintered oxide (' Z ' -O ')_x) And (3) nano materials.

In the preparation method, in the ammonia water solution in the step (2), the volume ratio of deionized water to ammonia water is 1: 2.

in the preparation method, the step (1) of preparing the nanometer nickel-cobalt-iron Prussian blue (NiCoFe-PBA) precursor with the cubic structure comprises the following specific steps:

1) putting a certain amount of trisodium citrate trihydrate and nickel nitrate hexahydrate into a beaker, adding deionized water to obtain a mixed system, and stirring the mixed system until the raw materials are completely dissolved to obtain a mixed solution A;

2) putting a certain amount of potassium cobalt cyanide into a beaker, and adding deionized water to prepare a solution;

3) adding the potassium cobalt cyanide solution into the mixed solution 1, and magnetically stirring for 1 h to obtain a mixed solution B;

4) putting a certain amount of potassium ferricyanide into a beaker, and adding deionized water to prepare a solution;

5) adding the potassium ferricyanide solution into the mixed solution 2, and magnetically stirring for 1 h to obtain a mixed solution C;

6) pouring the mixed solution C into a reaction kettle, and reacting for 20 hours at 80 ℃; and (3) centrifugally washing the reaction product, and drying at 70 ℃ for 12 h to obtain the cubic nano nickel-cobalt-iron Prussian blue (NiCoFe-PBA).

Further, the dosage of trisodium citrate trihydrate, nickel nitrate hexahydrate and deionized water in the step 1) is 0.264 g, 0.174 g and 20 mL;

further, the dosage of the potassium cobalt cyanide in the step 2) is 0.026 g, and the dosage of the deionized water is 10 mL; further, the using amount of the potassium ferricyanide in the step 4) is 0.105 g, and the using amount of the deionized water is 10 mL;

a sawtooth-like nickel-cobalt-iron Prussian blue sintered oxide nano material is applied to catalyzing the degradation of bisphenol A.

The invention has the beneficial effects that:

1) the method adopts NiCoFe-PBA as a precursor, and then uses ammonia water for corrosion to obtain the zigzag NiCoFe Prussian blue (Z' -PBA). The complex morphological structure design of the nano MOF is enriched, and more development opportunities are brought for realizing the versatility of the MOF. It also provides a new idea for anisotropic etching of MOFs.

2) The obtained zigzag nickel-cobalt-iron Prussian blue is subjected to heat treatment to obtain zigzag nickel-cobalt-iron Prussian blue sintered oxide (' Z ' -O ')_x) Due to the sawtooth shape, the surface area is increased, more catalytic active sites are provided, the Peroxymonosulfate (PMS) is catalyzed to generate more sulfate radicals and hydroxyl radicals, and the efficiency of degrading the bisphenol A is improved.

3) The preparation method disclosed by the invention has the advantages of easiness in obtaining required equipment and materials, simplicity in process operation, concise process conditions, low cost, safety, high efficiency and easiness in popularization and application.

Drawings

FIG. 1 is the microstructure of NiCoFe-PBA in example 1.

FIG. 2 is the microstructure of "Z" -PBA from example 1.

FIG. 3 is an X-ray diffraction (XRD) pattern of NiCoFe-PBA and "Z" -PBA from example 1.

FIG. 4 is an X-ray photoelectron spectroscopy (XPS) plot of NiCoFe-PBA and "Z" -PBA in example 1.

FIG. 5 is a graph of "Z" -O obtained by sintering "Z" -PBA "in example 1 at 350 ℃_xScanning micrographs of (a).

FIG. 6 is a NiCoFe-O sintered at 350 ℃ of NiCoFe-PBA in comparative example 1_xScanning micrographs of (a).

FIG. 7 shows "Z" -O "obtained by sintering in application example 1 and application comparative example 1_xNanomaterial and NiCoFe-O_xThe point diagram of the nanometer material as the catalyst to catalyze PMS to degrade bisphenol A.

FIG. 8 shows "Z" -O "obtained by sintering in application example 1 and application comparative example 1_xNanomaterial and NiCoFe-O_xThe efficiency value K of the nanometer material used as the catalyst for catalyzing PMS to degrade bisphenol A is shown schematically.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings, which are examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features mentioned in the embodiments of the present invention described below may be combined as long as they do not conflict with each other.

Example 1

(1) preparation of NiCoFe-PBA precursor:

taking potassium ferricyanide, potassium cobaltcyanide, trisodium citrate trihydrate and nickel nitrate hexahydrate as raw materials, and preparing NiCoFe-PBA by a hydrothermal synthesis method;

(2) preparation of "Z" -PBA nanomaterial:

uniformly dispersing NiCoFe-PBA obtained in the step (1) into 10 ml of ethanol, and stirring until the NiCoFe-PBA is completely dispersed to obtain a mixed solution; then slowly pouring the ammonia water solution into the mixed solution, and stirring for 1 h; then carrying out centrifugal separation on the reaction liquid, and washing; and (3) putting the washed sample into an oven, and keeping the temperature for 12 h at 70 ℃ for drying to obtain the Z' -PBA nano material.

(3) Preparation of "Z" -Ox nanomaterial:

and (3) putting the Z '-PBA nano material sample obtained in the step (2) into a muffle furnace, and preserving the heat for 1.5 h at 350 ℃ at the heating rate of 2 ℃/min to finally obtain the Z' -Ox nano material.

in the preparation method, the step (1) of preparing the NiCoFe-PBA precursor comprises the following specific steps:

1) putting 0.264 g of trisodium citrate trihydrate and 0.174 g of nickel nitrate hexahydrate in a beaker, then adding 20 mL of deionized water to obtain a mixed system, and stirring the mixed system until the raw materials are completely dissolved to obtain a mixed solution A;

2) putting a certain amount of 0.026 g potassium cobalt cyanide into a beaker, and adding 10 mL deionized water to prepare a solution;

4) putting 0.105 g of potassium ferricyanide into a beaker, and adding 10 mL of deionized water to prepare a solution;

6) pouring the mixed solution C into a reaction kettle, and reacting for 20 hours at 80 ℃; and (3) centrifugally washing the reaction product, and drying at 70 ℃ for 12 h to obtain NiCoFe-PBA.

Comparative example 1

(1) Preparation of NiCoFe-PBA precursor:

(2) synthesis of nickel-cobalt-iron Prussian blue sintered oxide (NiCoFe-Ox) nano material

Loading the NiCoFe-PBA sample obtained in the step (1) by using a small crucible, covering, putting the sample into a muffle furnace, preserving the temperature for 1.5 h at 350 ℃, and obtaining the NiCoFe-O at the heating rate of 2 ℃/min_xAnd (3) nano materials.

The NiCoFe-O is obtained_xThe scanning microscopic image of the nanomaterial is shown in fig. 6.

Bisphenol A degradation experiment

Application example 1

"Z" -O obtained in example 1_xThe nanometer material is used for the catalytic degradation of bisphenol A, and the specific steps are as follows:

(1) preparing a 30 ppm bisphenol A solution;

(2) 50 mL of the prepared bisphenol A solution (30 ppm) was weighed, and 5mg of "Z" -O was weighed_xPutting the nano material into a bisphenol A solution, performing ultrasonic treatment for 10 min, performing magnetic stirring for 30 min to obtain a mixed solution, and establishing desorption-adsorption balance;

(3) weighing 10 mg of Peroxymonosulfate (PMS) and putting into the mixed solution obtained in the step (2), and magnetically stirring; sampling at 0 min, 10 min, 20 min, 30 min, 40 min and 50 min after the start of the degradation experiment, and quenching 1 mL of solution with 0.5 mL of methanol each time; bisphenol a was measured by liquid chromatography.

Application comparative example 1

NiCoFe-O obtained in comparative example 1_xThe nanometer material is used for the catalytic degradation of bisphenol A, and the specific steps are as follows:

(1) preparing a 30 ppm bisphenol A solution;

(2) 50 mL of the prepared bisphenol A solution (30 ppm) was weighed and 5mg of NiCoFe-O was weighed_xPutting the nano material into a bisphenol A solution, performing ultrasonic treatment for 10 min, performing magnetic stirring for 30 min to obtain a mixed solution, and establishing desorption-adsorption balance;

Analysis of results

The micro-morphology of the NiCoFe-PBA obtained in example 1 is shown in FIG. 1. The resulting "Z" -PBA has a microscopic morphology as shown in FIG. 2. The X-ray diffraction (XRD) results for NiCoFe-PBA and "Z" -PBA are shown in FIG. 3. The X-ray photoelectron spectroscopy (XPS) results for NiCoFe-PBA and "Z" -PBA are shown in FIG. 4. Analysis shows that in the process of synthesizing NiCoFe-PBA, the valence states of the cobalt and nickel elements are not changed, and the added ferric iron is subjected to oxidation-reduction reaction and is partially reduced into ferrous iron. When the 'Z' -PBA is obtained by corroding the 'Z' -PBA with ammonia water, the peak of the binding energy corresponding to the ferric iron disappears, which indicates that the ferric iron reacts with the ammonia water, but the ferrous iron does not react with the ammonia water, so that anisotropic corrosion occurs, and the sawtooth-like Prussian blue is obtained.

"Z" -O obtained by sintering "Z" -PBA "in example 1 at 350 ℃_xFig. 5; the scanning microscopic image of NiCoFe-Ox obtained by sintering NiCoFe-PBA at 350 ℃ in comparative example 1 is shown in FIG. 6;

it can be seen from FIGS. 5 and 6 that the Z '-Ox and NiCoFe-Ox obtained from the heat treatment of Z' -PBA and NiCoFe-PBA can still maintain the original morphology.

"Z" -O obtained by sintering in application example 1 and application comparative example 1_xNanomaterial and NiCoFe-O_xThe point diagram of the catalyst of the nanomaterial for catalyzing the degradation of bisphenol A by PMS is shown in figure 7. "Z" -O obtained by sintering in application example 1 and application comparative example 1_xNanomaterial and NiCoFe-O_xThe schematic diagram of the efficiency value K of the nanomaterial as the catalyst for catalyzing the degradation of the bisphenol A by PMS is shown in FIG. 8. Comparing the catalytic degradation efficiencies of application example 1 and application comparative example 1, it can be found that "Z" -PBA obtained by etching NiCoFe-PBA and "Z" -O obtained by sintering thereof_xNano materialCan complete the catalytic degradation of 30 ppm of bisphenol A within 50 minutes, the efficiency reaches 99.9 percent, and the catalytic performance is higher than that of NiCoFe-O_xThe apparent reaction rate constant k of the nano material is improved by 1.22 times. This is due to "Z" -O_xThe sawtooth shape of the nano material provides more catalytic active sites so as to catalyze PMS to generate more sulfate radicals and hydroxyl radicals, and the catalytic performance is greatly improved.

It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the invention, and is not intended to limit the invention, and that any modification, equivalent replacement or improvement made within the spirit and principle of the invention should be included within the scope of protection of the invention.

Claims

1. a kind of preparation method of zigzag type nickel cobalt iron class Prussian blue sintered oxide nanomaterial, is characterized in that, comprises the following steps:

(1) Preparation of nano-nickel-cobalt-iron Prussian blue precursor with cubic structure: using potassium ferricyanide, potassium cobalt cyanide, trisodium citrate trihydrate and nickel nitrate hexahydrate as raw materials, prepared by hydrothermal synthesis method Cubic structure of nano-nickel-cobalt-iron-like Prussian blue;

(2) Preparation of zigzag-like nickel-cobalt-iron-like Prussian blue nanomaterials: uniformly disperse the cubic-structured nickel-cobalt-iron-like Prussian blue precursor obtained in step (1) into 10 mL of ethanol, and stir until completely dispersed Then the ammonia solution was slowly poured into the mixed solution and stirred for 1 h; then the reaction solution was centrifuged and washed; the washed samples were placed in an oven at 70 °C for 12 h for drying, A zigzag-like nickel-cobalt-iron-like Prussian blue nanomaterial is obtained;

(3) Preparation of zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterials: put the zigzag-like nickel-cobalt-iron-like Prussian blue nanomaterials obtained in step (2) into a muffle furnace, and keep the temperature at 350 °C for 1.5 h, the heating rate is 2 ℃/min, and finally the zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterials are obtained.

2 . The method for preparing a zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterial according to claim 1 , wherein: step (1) preparation of a cubic-structured nano-nickel-cobalt iron-like Prussian blue precursor. 3 . , including the following specific steps:

1) Put a certain amount of trisodium citrate trihydrate and nickel nitrate hexahydrate into a beaker, then add deionized water to obtain a mixed system, and stir the mixed system until the raw materials are completely dissolved to obtain mixed solution A;

2) Put a certain amount of potassium cobalt cyanide into a beaker, add deionized water, and prepare a solution;

3) Add the potassium cobalt cyanide solution to the mixed solution A, and stir magnetically for 1 h to obtain the mixed solution B;

4) Put a certain amount of potassium ferricyanide into a beaker, add deionized water, and prepare a solution;

5) Add potassium ferricyanide solution to mixed solution B and stir magnetically for 1 h to obtain mixed solution C;

6) Pour the mixed solution C into the reaction kettle, and react at 80 °C for 20 h; the reaction product is washed by centrifugation, and dried at 70 °C for 12 h to obtain the nano-nickel-cobalt-iron-like Prussian blue with cubic structure.

3 . The method for preparing a sawtooth-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterial according to claim 1 , wherein: in the ammonia solution described in step (2), the volume of deionized water and ammonia water The ratio is 1:2.

4. The preparation method of zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterials according to claim 2, characterized in that: in step 1), the consumption of trisodium citrate trihydrate is 0.264 g, and the hexahydrate is 0.264 g. The amount of nickel nitrate was 0.174 g, and the amount of deionized water was 20 mL.

5. The method for preparing a zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterial according to claim 2, characterized in that: in step 2), the consumption of potassium cobalt cyanide is 0.026 g, and the amount of deionized water is 0.026 g. The dosage is 10 mL.

6. The preparation method of a kind of zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterial according to claim 2, characterized in that: in step 4), the consumption of potassium ferricyanide is 0.105 g, and the consumption of deionized water is 0.105 g. to 10 mL.

7. A method as claimed in claim 1 prepares a zigzag-like nickel-cobalt-iron-like Prussian blue nanomaterial.

8. A zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterial is prepared by the method according to any one of claims 1 to 6.

9 . The zigzag-like nickel-cobalt-iron-like Prussian blue sintered oxide nanomaterial according to claim 8 is applied to catalyze the degradation of bisphenol A. 10 .