阅读说明：本技术 一种ZnFe2O4/Bi7O9I3磁性复合光催化材料及其制备方法 (ZnFe2O4/Bi7O9I3Magnetic composite photocatalytic material and preparation method thereof ) 是由 赵梅 李成栋 刘孟辰 谢美霞 何俊贤 李逸博 杜成功 于 2020-07-02 设计创作，主要内容包括：本发明属于磁性复合光催化材料领域,具体涉及一种ZnFe<Sub>2</Sub>O<Sub>4</Sub>/Bi<Sub>7</Sub>O<Sub>9</Sub>I<Sub>3</Sub>磁性复合光催化材料及其制备方法,首次将ZnFe<Sub>2</Sub>O<Sub>4</Sub>磁性纳米颗粒穿插于由Bi<Sub>7</Sub>O<Sub>9</Sub>I<Sub>3</Sub>纳米片构成的微米级花状结构中,形成颗粒插入微米花的复合结构；所述ZnFe<Sub>2</Sub>O<Sub>4</Sub>纳米颗粒尺寸为20-80nm；所述构成Bi<Sub>7</Sub>O<Sub>9</Sub>I<Sub>3</Sub>微米花的Bi<Sub>7</Sub>O<Sub>9</Sub>I<Sub>3</Sub>纳米片厚度为5-10nm；所述ZnFe<Sub>2</Sub>O<Sub>4</Sub>与Bi<Sub>7</Sub>O<Sub>9</Sub>I<Sub>3</Sub>以1:(2-6)的质量比例进行复合,形成的磁性复合光催化材料表现出超顺磁性,饱和磁化强度高,光催化活性强的同时磁性可分离性强,对目标污染物双酚A具有良好的可见光降解能力,通过外加磁场迅速回收该光催化材料以达到多次回收利用的目的；而且该磁性复合光催化材料采用的制备方法原理可靠、简单易控,绿色安全,无需高温煅烧,设备常规,成本低廉,具有大规模生产的工业前景。(The invention belongs to the field of magnetic composite photocatalytic materials, and particularly relates to ZnFe 2 O 4 /Bi 7 O 9 I 3 The magnetic composite photocatalytic material is prepared by firstly preparing ZnFe 2 O 4 Magnetic nanoparticles are interpenetrated with Bi 7 O 9 I 3 In the micron-sized flower-shaped structure formed by the nano sheets, a composite structure with particles inserted into micro popcorn is formed; the ZnFe 2 O 4 The size of the nano particles is 20-80 nm; said composition Bi 7 O 9 I 3 Bi of micro-flower 7 O 9 I 3 The thickness of the nano-sheet is 5-10 nm; the ZnFe 2 O 4 And Bi 7 O 9 I 3 The composite material is compounded according to the mass ratio of (2) to (6), the formed magnetic composite photocatalytic material has superparamagnetism, high saturation magnetization, strong photocatalytic activity and strong magnetic separability, has good visible light degradation capability on target pollutant bisphenol A, and can be rapidly recycled through an external magnetic field so as to achieve the purpose of recycling for multiple times; and the preparation method adopted by the magnetic composite photocatalytic material has the advantages of reliable principle, simplicity, easy control, environmental protection, safety, no need of high-temperature calcination, conventional equipment, low cost and industrial prospect of large-scale production.)

1. ZnFe₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material is characterized by consisting of ZnFe₂O₄And Bi₇O₉I₃According to the mass ratio of 1 (2-6)Line recombination of said ZnFe₂O₄Is nano-particle with size of 20-80nm, and the Bi is₇O₉I₃Is in a micron-sized flower shape formed by inserting nano sheets to form Bi₇O₉I₃Bi of flower-like structure₇O₉I₃The thickness of the nano-sheet is 5-10 nm; the ZnFe₂O₄Nanoparticles are interpenetrated with Bi₇O₉I₃The micron-sized flower-shaped structure formed by the nano sheets forms a composite structure with particles inserted into micro popcorn.

2. ZnFe according to claim 1₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material is characterized in that ZnFe₂O₄And Bi₇O₉I₃Compounding according to the mass ratio of 1:4, wherein the ZnFe is₂O₄Is spherical nanoparticle with size of 20-40 nm; the Bi₇O₉I₃The thickness of the nano-sheet is 5-8 nm.

3. ZnFe according to claim 1₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material is characterized in that ZnFe₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material shows superparamagnetism, and the saturation magnetization is 23.1 emu/g; has good visible light degradation capability on the target pollutant bisphenol A, and the degradation rate reaches 96 percent within 40 minutes.

4. The ZnFe of any of claims 1 to 3₂O₄/Bi₇O₉I₃The preparation method of the magnetic composite photocatalytic material is characterized in that the magnetic composite photocatalytic material is prepared by the following steps:

(1) ZnFe is mixed with water₂O₄Dissolving in 50-100ml deionized water, stirring at room temperature for 10-30min to obtain product solution I;

(2) adding Bi₇O₉I₃Dissolving in 50-100mlStirring in deionized water at room temperature for 10-30min to obtain a product solution J;

(3) mixing the product solutions I and J according to the mass ratio of 1 (2-6), stirring at 40 ℃ for 2-5h, centrifuging the product solution for 5-9min to obtain precipitate K, controlling the rotating speed at 7000-9000r/min, washing the precipitate K, and drying, wherein the precipitate K is ZnFe₂O₄/Bi₇O₉I₃A magnetic composite photocatalytic material.

5. The method for preparing the magnetic composite photocatalytic material according to claim 4, wherein the ZnFe is used as a material₂O₄The preparation method comprises the following steps:

(1) reacting ZnCl₂And FeCl₃·6H₂Dissolving O in deionized water according to the molar ratio of 1: 2-7, and stirring until the O is completely dissolved to obtain a solution A;

(2) adding a certain amount of NaAc into the solution A, stirring at room temperature until the NaAc is completely dissolved to obtain a solution B, NaAc and ZnCl₂The molar ratio is 1: 6-16;

(3) transferring the solution B into a three-neck flask, and preserving the heat for a certain time at a certain temperature to obtain a product solution C;

(4) after the solution C is kept stand for a certain time, the product solution C is centrifugally treated for 5-9min by controlling the rotating speed at 7000 once 9000r/min to separate the product solution C and obtain a precipitate D, and the precipitate D is washed and dried, wherein the precipitate D is ZnFe₂O₄。

6. The method for preparing the magnetic composite photocatalytic material according to claim 5, wherein the ZnCl is used as a material for preparing the magnetic composite photocatalytic material₂With FeCl₃·6H₂The molar ratio of O is 1:4, and the NaAc and the ZnCl are adopted₂The molar ratio of (A) to (B) is 1:8, the reaction temperature is 80 ℃, the heat preservation time is 8 hours, and the standing time is 2 hours.

7. The method for preparing the magnetic composite photocatalytic material as recited in claim 4, wherein the Bi is₇O₉I₃By the following stepsThe preparation method comprises the following steps:

(1) adding 1-20mmol of Bi (NO)₃)₃·5H₂Dissolving O in 50-100ml of ethylene glycol, and stirring at room temperature for 10-50min to obtain a solution E;

(2) adding 1-10mmol KI into the solution E, and stirring for 2-6h in water bath at 50-100 ℃ to obtain a solution F;

(3) carrying out oil bath on the solution F at the temperature of 150 ℃ and 250 ℃ for 2-6h to obtain a product solution G;

(4) taking out the solution G after the solution G is naturally cooled to room temperature, then carrying out centrifugal treatment on the product solution G for 5-9min by a centrifugal mode and controlling the rotating speed at 7000 once per minute (9000 r/min) to separate the product solution G and obtain a precipitate H, washing the precipitate H, and drying the precipitate H, wherein the precipitate H is Bi₇O₉I₃。

8. The ZnFe of any of claims 1 to 3₂O₄/Bi₇O₉I₃Magnetic composite photocatalytic material or ZnFe prepared by adopting method of any one of claims 4 to 7₂O₄/Bi₇O₉I₃The application of the magnetic composite photocatalytic material in degrading target pollutant bisphenol A.

Technical Field

The invention belongs to the field of magnetic composite photocatalytic materials, and particularly relates to a magnetic composite photocatalytic material and a preparation method thereof₂O₄/Bi₇O₉I₃Has the characteristics of strong photocatalytic activity, high magnetism and recoverability.

Background

It is known that, for a semiconductor photocatalyst material, under visible light, electrons in a full valence band thereof cross a forbidden band and enter a vacant conduction band under the irradiation of visible light with energy greater than or equal to a band gap energy thereof, and a photogenerated hole hydrogen ion with positive charge is generated at a position of a corresponding transition electron. The photo-generated electron hole pairs can form a strong oxidation-reduction system in a water solution, and impurities such as organic substances and the like adsorbed on the surface of the catalyst are oxidized and reduced, so that the water body is purified. However, conventional TiO₂The photocatalyst can only absorb ultraviolet rays, so that the photocatalytic efficiency under visible light is greatly limited. Therefore, research and development of a photocatalyst having a more excellent response effect to visible light has been a focus of attention of researchers.

Hitherto, the use ofSo far, bismuth-based photocatalysts have been the focus of research because of their advantages such as high photocatalytic performance and low energy consumption, and among bismuth halide (BiOX, X ═ Cl, Br and I) families, Bi is₇O₉I₃Due to the wide band gap, the photocatalyst can show good photocatalytic activity under the irradiation of visible light. For example "a Bi" disclosed in Chinese patent CN103861621B₇O₉I₃Bi pointed out in the specification of the/graphene composite visible-light-driven photocatalyst and preparation method thereof₇O₉I₃Compared with the traditional photocatalyst, the bismuth oxyiodide photocatalyst has better activity, is beneficial to reducing the recombination probability of electron-hole pairs due to the specific internal electric field, open lamellar structure and indirect transition mode, and simultaneously has a series of defects of difficult decomposition, low quantum efficiency, low utilization rate of sunlight and the like of a single bismuth oxyiodide catalyst. While such problems have been advanced in recent years as a focus of research in the field of photocatalysis, for example, "a Bi" disclosed in Chinese patent CN106881120A₇O₉I₃/Zn₂SnO₄The preparation method and application of the heterojunction visible light catalyst provide a method for compounding a wide bandgap semiconductor with high hole-electron pair separation efficiency and a narrow bandgap semiconductor with wide spectral absorption, and the method can solve the problems of narrow photoresponse range, low hole-electron pair separation efficiency and the like of the catalyst in the prior art. However, after the photocatalyst provided by the invention finishes degradation of toxic and harmful substances such as organic dyes, the photocatalyst remains in water and cannot be recycled through simple operation, and secondary pollution is easy to generate.

Composite metal oxides such as ZnFe₂O₄The special spinel structure is widely applied to the fields of metallurgy, chemical industry and the like, has the characteristics of strong magnetism, easiness in recovery and the like, but is still limited in the field of environmental management due to the defects of high density, low adsorption efficiency and the like. The Chinese patent CN109876814A discloses a method for preparing an oxygen defect TiO @ ZnFeO heterojunction photocatalytic material, which refers to the preparation of nano TiO₂With substances having very good magnetic properties, e.g. ZnFe₂O₄To complex and thereby enlarge the TiO₂Light response range ofA method for improving photocatalytic activity and realizing recyclability. However, the preparation process of the photocatalyst needs inevitable high-temperature calcination, and the price of the titanium salt is higher than that of the zinc salt, so that the energy consumption and the cost are increased in industrial production application. Also, for example, Chinese patent CN109012752A discloses a method for preparing a magnetic ZnFeO/PANI/Au composite photocatalyst, and the catalyst prepared by the method is applied to ZnFe₂O₄The migration rate of photon-generated carriers is improved under the synergistic action of the PANI and the Au, and the photocatalyst has higher photocatalytic activity under visible light.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide ZnFe₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material and the preparation method thereof have the characteristics of strong photocatalytic activity, high magnetism and easiness in recovery, do not need high-temperature calcination in the preparation process, are simple and easy to operate, and are green and safe.

ZnFe₂O₄/Bi₇O₉I₃A magnetic composite photocatalytic material made of ZnFe₂O₄And Bi₇O₉I₃Compounding according to the mass ratio of 1 (2-6), wherein the ZnFe is₂O₄Is nano-particle with size of 20-80nm, and the Bi is₇O₉I₃Is in a micron-sized flower shape formed by inserting nano sheets to form Bi₇O₉I₃Bi of flower-like structure₇O₉I₃The thickness of the nano-sheet is 5-10 nm; the ZnFe₂O₄Nanoparticles are interpenetrated with Bi₇O₉I₃The micron-sized flower-shaped structure formed by the nano sheets forms a composite structure with particles inserted into micro popcorn.

Preferably, the ZnFe₂O₄And Bi₇O₉I₃Compounding according to the mass ratio of 1: 4; the ZnFe₂O₄Spherical nanoparticles, preferably 20-40nm in size; the Bi₇O₉I₃The thickness of the nano-sheet is 5-8 nm.

In the present invention, the above ZnFe₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material shows superparamagnetism, and the saturation magnetization is 23.1 emu/g; has good visible light degradation capability on the target pollutant bisphenol A, and the degradation rate reaches 96 percent within 40 minutes.

The invention also provides the ZnFe₂O₄/Bi₇O₉I₃The preparation method of the magnetic composite photocatalytic material specifically comprises the following steps:

(1) ZnFe is mixed with water₂O₄Dissolving in 50-100ml deionized water, stirring at room temperature for 10-30min to obtain product solution I;

(2) adding Bi₇O₉I₃Dissolving in 50-100ml deionized water, stirring at room temperature for 10-30min to obtain product solution J;

(3) mixing the product solutions I and J according to the mass ratio of 1 (2-6), stirring at 40 ℃ for 2-5h, centrifuging the product solution for 5-9min to obtain precipitate K, controlling the rotating speed at 7000-9000r/min, washing the precipitate K, and drying, wherein the precipitate K is ZnFe₂O₄/Bi₇O₉I₃A magnetic composite photocatalytic material.

In the present invention, the ZnFe₂O₄The preparation method comprises the following steps:

(1) reacting ZnCl₂And FeCl₃·6H₂Dissolving O in deionized water according to the molar ratio of 1: 2-7, and stirring until the O is completely dissolved to obtain a solution A;

(2) adding a certain amount of NaAc (with ZnCl)₂The molar ratio is 1:6-16) is added into the solution A, and the solution A is stirred at room temperature until the solution A is completely dissolved to obtain a solution B;

(3) transferring the solution B into a three-neck flask, and preserving the heat for a certain time at a certain temperature to obtain a product solution C;

(4) after the solution C is kept stand for a certain time, the product solution C is centrifugally treated for 5-9min by controlling the rotating speed at 7000 once 9000r/min to separate the product solution C and obtain a precipitate D, and the precipitate D is washed and dried, wherein the precipitate D is ZnFe₂O₄。

Preferably, the ZnCl is₂And FeCl₃·6H₂The molar ratio of O is 1:4, and the NaAc and the ZnCl are adopted₂The molar ratio is 1: and 8, the reaction temperature is 80 ℃, the heat preservation time is 8 hours, and the standing time is 2 hours.

In the present invention, the above-mentioned Bi₇O₉I₃The preparation method comprises the following steps:

(1) adding 1-20mmol of Bi (NO)₃)₃·5H₂Dissolving O in 50-100ml of ethylene glycol, and stirring at room temperature for 10-50min to obtain a solution E;

(2) adding 1-10mmol KI into the solution E, and stirring for 2-6h in water bath at 50-100 ℃ to obtain a solution F;

(3) carrying out oil bath on the solution F at the temperature of 150 ℃ and 250 ℃ for 2-6h to obtain a product solution G;

(4) taking out the solution G after the solution G is naturally cooled to room temperature, then carrying out centrifugal treatment on the product solution G for 5-9min by a centrifugal mode and controlling the rotating speed at 7000 once per minute (9000 r/min) to separate the product solution G and obtain a precipitate H, washing the precipitate H, and drying the precipitate H, wherein the precipitate H is Bi₇O₉I₃。

The invention also provides the ZnFe₂O₄/Bi₇O₉I₃Magnetic composite photocatalytic material or ZnFe prepared by adopting method₂O₄/Bi₇O₉I₃The application of the magnetic composite photocatalytic material in degrading target pollutant bisphenol A.

In the invention, ZnFe is firstly synthesized by adopting a green synthesis method without high-temperature calcination₂O₄And Bi₇O₉I₃Are compounded to form a magnetic photocatalytic material, and ZnFe₂O₄Nanoparticles are interpenetrated with Bi₇O₉I₃The micron-sized flower-shaped structure formed by the nano sheets forms a composite structure with particles inserted into micro-flowers, and ZnFe with a specific structure₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material enlarges the specific surface area and contact sites of the photocatalytic material, greatly improves the photocatalytic activity, has good magnetism, and has good effect on target pollutants bisphenolThe A has good visible light degradation capability and can be recycled for multiple times.

Compared with the prior art, the invention has the following advantages and remarkable progress: ZnFe₂O₄/Bi₇O₉I₃The magnetic composite photocatalytic material has superparamagnetism, high saturation magnetization, strong photocatalytic activity and strong magnetic separability, has good visible light degradation capability on the target pollutant bisphenol A, and can be rapidly recycled through an external magnetic field so as to achieve the aim of recycling for many times; and the preparation method adopted by the magnetic composite photocatalytic material has the advantages of reliable principle, simplicity, easy control, environmental protection, safety, no need of high-temperature calcination, simple operation, conventional equipment and low cost, and has industrial prospect of large-scale production.

Drawings

FIG. 1 ZnFe₂O₄/Bi₇O₉I₃X-ray powder diffraction pattern of the magnetic composite photocatalytic material;

FIG. 2 ZnFe₂O₄/Bi₇O₉I₃SEM picture of magnetic composite photocatalytic material;

FIG. 3 ZnFe₂O₄/Bi₇O₉I₃A magnetic hysteresis loop diagram of the magnetic composite photocatalytic material;

FIG. 4 ZnFe₂O₄/Bi₇O₉I₃The photodegradation rate of the magnetic composite photocatalytic material to bisphenol A is shown.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings.