阅读说明：本技术 一种制备磁性氯四氧化三铋复合光催化剂的方法 (Method for preparing magnetic chlorine-bismuth tetroxide composite photocatalyst ) 是由 王海龙 徐龙君 冯岐 刘成伦 于 2020-07-02 设计创作，主要内容包括：一种制备磁性氯四氧化三铋复合光催化剂的方法,其属于无机催化材料技术领域。本发明先用水热法制备了软磁性材料锰锌铁氧体Mn<Sub>x</Sub>Zn<Sub>1-x</Sub>Fe<Sub>2</Sub>O<Sub>4</Sub>,再通过水热-焙烧法制备出了磁性氯四氧化三铋复合光催化剂(Bi<Sub>3</Sub>O<Sub>4</Sub>Cl/Mn<Sub>x</Sub>Zn<Sub>1-</Sub><Sub>x</Sub>Fe<Sub>2</Sub>O<Sub>4</Sub>)。本发明方法制备工艺简单、使用设备少、能耗低。制备的Bi<Sub>3</Sub>O<Sub>4</Sub>Cl/Mn<Sub>x</Sub>Zn<Sub>1-x</Sub>Fe<Sub>2</Sub>O<Sub>4</Sub>磁性能稳定、光催化活性高,在模拟太阳光氙灯照射下,用0.1g磁性复合光催化剂降解100mL浓度为10mg/L的罗丹明B溶液,100min对罗丹明B的降解率达到99.5％,在外加磁场下对光催化剂的磁回收率为91.3％,重复使用3次后对罗丹明B的降解率为92.2％。本发明制备出的产品可广泛用于光催化降解有机污染物领域。(Magnetic materialA method for preparing a bismuth oxychloride composite photocatalyst belongs to the technical field of inorganic catalytic materials. The invention firstly prepares the Mn-Zn ferrite Mn of the soft magnetic material by a hydrothermal method x Zn 1‑x Fe 2 O 4 Then preparing the magnetic chlorine-bismuth oxide composite photocatalyst (Bi) by a hydrothermal-roasting method 3 O 4 Cl/Mn x Zn 1‑ x Fe 2 O 4 ). The method has the advantages of simple preparation process, less used equipment and low energy consumption. Prepared Bi 3 O 4 Cl/Mn x Zn 1‑x Fe 2 O 4 The magnetic property is stable, the photocatalytic activity is high, under the irradiation of a simulated sunlight xenon lamp, 100mL of rhodamine B solution with the concentration of 10mg/L is degraded by 0.1g of magnetic composite photocatalyst, the degradation rate of rhodamine B in 100min reaches 99.5%, the magnetic recovery rate of the photocatalyst under an external magnetic field is 91.3%, and the degradation rate of rhodamine B after repeated use for 3 times is 92.2%. The product prepared by the invention can be widely used in the field of photocatalytic degradation of organic pollutants.)

1. A method for preparing a magnetic chlorine bismuth oxide composite photocatalyst is characterized by comprising the following steps:

(1)Mn_xZn_1-xFe₂O₄preparation of

Preparation of Mn by hydrothermal method_xZn_1-xFe₂O₄1.386g of manganese sulfate, 0.9652g of zinc sulfate and 5.3884g of ferric sulfate are respectively weighed, and are dissolved by ultrasonic oscillation after 50mL of distilled water is added; dropwise adding NaOH solution with a certain concentration into the solution under the action of magnetic stirring, adjusting the pH of the solution to 13, and continuing stirring for 15 min; after stirring, transferring the solution into a 100mL reaction kettle, and reacting for 5h at 200 ℃; cooling and filtering after the reaction is finished, washing the reaction product for 5 times by using distilled water and ethanol respectively, drying the reaction product for 12 hours at the temperature of 80 ℃, and grinding the reaction product to obtain Mn_xZn_1-xFe₂O₄。

(2) Magnetic Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄Preparation of composite photocatalyst

0.97g of Bi (NO) is weighed₃)₃·5H₂Adding O into a beaker filled with 20mL of glycol, and carrying out ultrasonic treatment for 10min to obtain a suspension; weighing 0.039g of NaCl and dissolving in 50mL of distilled water to obtain a NaCl solution; weighing 10-20% of Mn by mass fraction_xZn_1-xFe₂O₄Adding the suspension into the suspension, mechanically stirring for 10min, and dropwise adding a NaCl solution into the mixed suspension; continuously mechanically stirring for 10min, transferring to a 100mL reaction kettle, and reacting for 12h at 160 ℃; cooling to room temperature, performing suction filtration to obtain a filter cake as an intermediate product, washing with distilled water and absolute ethyl alcohol for multiple times, and drying at 75 ℃ for 12 hours; grinding the dried sample, putting the ground sample into a 100mL ceramic crucible, placing the ceramic crucible into a muffle furnace at the temperature of 500 ℃ for continuous roasting for 2 hours, naturally cooling the roasted sample to room temperature, and grinding the roasted sample to obtain magnetic Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄A composite photocatalyst is provided.

2. The preparation method of the magnetic composite bismuth chlorotetraoxide photocatalyst as claimed in claim 1, wherein the preparation method is a hydrothermal-roasting method, so that effective compounding of the active component of chlorotetrabismuth oxide and the magnetic matrix of manganese zinc ferrite is realized.

Technical Field

The invention relates to a method for preparing magnetic chlorine bismuth oxide (Bi)₃O₄Cl/Mn_xZn_1-xFe₂O₄) A method for compounding a photocatalyst belongs to the technical field of inorganic catalysts.

Background

Bismuth oxychloride (Bi)₃O₄Cl) is an oxygen-rich bismuth-based oxyhalide nano-photocatalyst. Due to its excellent electrical properties, suitable band placement and high efficiency photocatalytic activity, it has received much attention in the degradation of organic contaminants. Bi₃O₄The structure of Cl is represented by [ Cl]Ionic layer and sandwich between two [ Cl]Between layers [ Bi₃O₄]The unique structure facilitates the establishment of an internal electrostatic field, thereby promoting the separation and transfer of photogenerated electrons and holes. Bi₃O₄The common preparation methods of Cl mainly include a hydrothermal method, a coprecipitation method, a baking method, and the like. Bi₃O₄Cl is dispersed in liquid when pollutants are degraded in a photocatalysis mode, and the practical application of the photocatalyst is limited due to the difficulty in separation and recovery. The composite magnetic photocatalyst realizes the recycling of the catalyst through an external magnetic field, and overcomes the defects of high energy consumption, long time consumption and complex process of the conventional recycling modes such as centrifugation or filtration and the like.

Manganese zinc ferrite (Mn)_xZn_1-xFe₂O₄) Belongs to a soft magnetic ferrite material, and refers to mMnFe with a spinel structure₂O₄·nZnFe₂O₄With a small amount of Fe₃O₄Single phase solid solutions of composition, with conventional metalsSoft magnetic material (Fe)₃O₄) In contrast, Mn_xZn_1-xFe₂O₄Has the advantages of high saturation magnetization, high magnetic conductivity, low loss, strong product stability and the like. Thus, the Mn content is_xZn_1-xFe₂O₄The composite photocatalyst prepared for the magnetic matrix has stable magnetism, and is convenient for the recovery and the recycling of the catalyst. Common Mn_xZn_1-xFe₂O₄The preparation method comprises a chemical coprecipitation method, a sol-gel method, a calcination method and the like.

At present, to Bi₃O₄The research on Cl mainly focuses on improving the photocatalytic activity of the Bi, and the research on how to prepare the magnetic Bi₃O₄The Cl composite photocatalyst is reported less. Such as "Preparation, characterization of Bi" in Journal of Water Process Engineering "volume 18 of 2017₃O₄Cl/g-C₃N₄composite and iterative activity in dye degradation "(reference 1), pure Bi was prepared by a baking method₃O₄Cl and g-C₃N₄Then preparing Bi by a roasting method₃O₄Cl/g-C₃N₄A composite photocatalyst is provided. The method has the following disadvantages: (1) bi₃O₄Cl is prepared from BiOCl and Bi₂O₃Roasting at 650 deg.C for 6h to obtain g-C₃N₄Is prepared by roasting melamine at 520 ℃ for 4h, and Bi₃O₄Cl/g-C₃N₄Is prepared from Bi₃O₄Cl and g-C₃N₄The material is prepared by roasting at the high temperature of 400 ℃ for 2h, and the preparation process is complex, the energy consumption is high, and the cost is high; (2) prepared Bi₃O₄Cl and Bi₃O₄Cl/g-C₃N₄The catalytic activity is not high, and the degradation rate of rhodamine B in 100min is lower than 90 percent; (3) the photocatalyst is difficult to recycle, the operation cost is high, and secondary pollution is easily caused.

In another example of the invention patent, "a method for preparing a manganese-zinc-ferrite-bismuth oxide magnetic photocatalyst" (publication No. CN104437536A) (reference 2), a manganese-zinc-ferrite is prepared by a baking method, and then a manganese-zinc-ferrite/bismuth oxide composite magnetic photocatalyst is prepared by a dip-baking method. The method has the following disadvantages: (1) the manganese-zinc ferrite is prepared by roasting at 1200 ℃ for 3h, and the energy consumption is high; (2) the manganese-zinc ferrite sample prepared by the roasting method has large particle size and small specific surface area, is not beneficial to the full combination of the manganese-zinc ferrite and bismuth oxide, and cannot ensure the combination stability; (3) the composite magnetic photocatalyst is prepared by adopting a roasting method, so that the specific surface area of the composite magnetic photocatalyst is small, and the full contact and reaction between the catalyst and organic pollutants in the photocatalytic degradation process are not facilitated.

Disclosure of Invention

The purpose of the invention is to provide Bi₃O₄The problem that Cl is difficult to recycle is provided with a magnetic Bi₃O₄Cl/Mn_xZn_{1- x}Fe₂O₄The preparation method of the composite photocatalyst is simple and low in cost. Prepared magnetic Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄The composite photocatalyst has higher photocatalytic efficiency under the irradiation of simulated sunlight, is convenient to separate and recover from a liquid phase system through an external magnetic field, and the recovered catalyst still has higher photocatalytic activity. The method not only realizes resource recycling simply and efficiently, but also avoids secondary pollution possibly brought by the catalyst.

Bi of the invention₃O₄Cl/Mn_xZn_1-xFe₂O₄The preparation method comprises the following steps:

(1)Mn_xZn_1-xFe₂O₄preparation of

Preparation of Mn by hydrothermal method_xZn_1-xFe₂O₄1.386g of manganese sulfate, 0.9652g of zinc sulfate and 5.3884g of ferric sulfate are respectively weighed, and are dissolved by ultrasonic oscillation after 50mL of distilled water is added; dropwise adding NaOH solution with a certain concentration into the solution under the action of magnetic stirring, adjusting the pH of the solution to 13, and continuing stirring for 15 min; after the stirring was completed, the solution was transferred to a 100mL reaction vessel at 200 deg.CReacting for 5 hours; cooling and filtering after the reaction is finished, washing the reaction product for 5 times by using distilled water and ethanol respectively, drying the reaction product for 12 hours at the temperature of 80 ℃, and grinding the reaction product to obtain Mn_xZn_1-xFe₂O₄。

(2) Magnetic Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄Preparation of composite photocatalyst

0.97g of Bi (NO) is weighed₃)₃·5H₂Adding O into a beaker filled with 20mL of glycol, and carrying out ultrasonic treatment for 10min to obtain a suspension; weighing 0.039g of NaCl and dissolving in 50mL of distilled water to obtain a NaCl solution; weighing 10-20% of Mn by mass fraction_xZn_1-xFe₂O₄Adding the suspension into the suspension, mechanically stirring for 10min, and dropwise adding NaCl solution into the mixed suspension; continuously mechanically stirring for 10min, transferring to a 100mL reaction kettle, and reacting for 12h at 160 ℃; cooling to room temperature, performing suction filtration to obtain a filter cake as an intermediate product, washing with distilled water and absolute ethyl alcohol for multiple times, and drying at 75 ℃ for 12 hours; grinding the dried sample, putting the ground sample into a 100mL ceramic crucible, roasting the ceramic crucible in a muffle furnace at the temperature of 500 ℃ for 2 hours, naturally cooling the baked sample to room temperature, and grinding the baked sample to obtain magnetic Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄A composite photocatalyst is provided.

By adopting the technical scheme, the invention mainly has the following effects:

(1) magnetic Bi prepared by the method of the invention₃O₄Cl/Mn_xZn_1-xFe₂O₄The composite photocatalyst has higher photocatalytic activity, and 0.1g of magnetic Bi is irradiated by a simulated sunlight xenon lamp₃O₄Cl/Mn_xZn_1-xFe₂O₄The composite photocatalyst is dispersed in 100mL of 10mg/L rhodamine B solution, and the degradation rate of rhodamine B after 100min of illumination reaches 99.5 percent (better than Bi prepared by the comparison document 1)₃O₄Cl/g-C₃N₄A composite photocatalyst).

(2) Magnetic Bi prepared by the method of the invention₃O₄Cl/Mn_xZn_1-xFe₂O₄The recovery rate of the composite photocatalyst under the action of an applied magnetic field is up to 91.3%, and the degradation rate after 3 times of repeated use is still up to 92.2%.

(3) Magnetic Bi prepared by the method of the invention₃O₄Cl/Mn_xZn_1-xFe₂O₄The specific surface area of the composite photocatalyst is 7.27m²The preparation method has the advantages of simple preparation operation, less required equipment and low energy consumption.

Drawings

FIG. 1 shows Bi₃O₄Cl、Mn_xZn_1-xFe₂O₄And Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄X-ray diffraction pattern of (a).

FIG. 2 shows Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄Scanning electron microscopy of (a).

FIG. 3 shows Mn_xZn_1-xFe₂O₄And Bi₃O₄Cl/Mn_xZn_1-xFe₂O₄Magnetic hysteresis loop diagram of (1).

Detailed Description

The present invention will be further described with reference to the following specific embodiments.