阅读说明：本技术 一种Z型异质结MoS2/Bi2WO6复合光催化剂及其制备方法和应用 (Z-shaped heterojunction MoS2/Bi2WO6Composite photocatalyst and preparation method and application thereof ) 是由 鞠鹏 张雨 郝雷 蒋凤华 李景喜 曹为 孙承君 于 2020-07-29 设计创作，主要内容包括：本发明属于光催化领域,具体涉及一种Z型MoS<Sub>2</Sub>/Bi<Sub>2</Sub>WO<Sub>6</Sub>异质结复合光催化剂及其制备方法和应用。MoS<Sub>2</Sub>/Bi<Sub>2</Sub>WO<Sub>6</Sub>异质结复合光催化剂由MoS<Sub>2</Sub>和Bi<Sub>2</Sub>WO<Sub>6</Sub>组成,其中,MoS<Sub>2</Sub>与Bi<Sub>2</Sub>WO<Sub>6</Sub>的质量比为0.08:1～0.12:1。MoS<Sub>2</Sub>/Bi<Sub>2</Sub>WO<Sub>6</Sub>异质结复合光催化剂采用两步操作获得,首先通过水热合成法制备花状MoS<Sub>2</Sub>,然后在超声条件下分散剥离,并加入Bi(NO<Sub>3</Sub>)<Sub>3</Sub>·5H<Sub>2</Sub>O和Na<Sub>2</Sub>WO<Sub>4</Sub>·2H<Sub>2</Sub>O,最终在水热条件下得到MoS<Sub>2</Sub>/Bi<Sub>2</Sub>WO<Sub>6</Sub>异质结复合光催化剂。本发明的制备方法工艺简单、成本低廉、易于实现,构建了具有可见光响应的Z型MoS<Sub>2</Sub>/Bi<Sub>2</Sub>WO<Sub>6</Sub>异质结结构,加速了光生载流子的分离,在可见光下具有高效的光催化活性和稳定性,对水体中的有害微生物和染料污染物具有高效的杀灭和降解效果,在水体净化和海洋防污等领域具有很好的实用价值和潜在的应用前景。(The invention belongs to the field of photocatalysis, and particularly relates to Z-shaped MoS 2 /Bi 2 WO 6 A heterojunction composite photocatalyst and a preparation method and application thereof. MoS 2 /Bi 2 WO 6 Heterojunction composite photocatalyst composed of MoS 2 And Bi 2 WO 6 The components of the composition are as follows,wherein, MoS 2 And Bi 2 WO 6 The mass ratio of (A) to (B) is 0.08: 1-0.12: 1. MoS 2 /Bi 2 WO 6 The heterojunction composite photocatalyst is obtained by two-step operation, and flower-shaped MoS is prepared by hydrothermal synthesis method 2 Then dispersed and stripped under ultrasonic condition, and Bi (NO) is added 3 ) 3 ·5H 2 O and Na 2 WO 4 ·2H 2 O, finally obtaining MoS under hydrothermal conditions 2 /Bi 2 WO 6 A heterojunction composite photocatalyst. The preparation method has simple process, low cost and easy realization, and constructs the Z-shaped MoS with visible light response 2 /Bi 2 WO 6 The heterojunction structure accelerates the separation of photon-generated carriers, has high-efficiency photocatalytic activity and stability under visible light, has high-efficiency killing and degrading effects on harmful microorganisms and dye pollutants in water, and has good practical value and potential application prospect in the fields of water purification, marine antifouling and the like.)

1. Z-shaped MoS₂/Bi₂WO₆The heterojunction composite photocatalyst is characterized in that the Z-shaped MoS₂/Bi₂WO₆The heterojunction composite photocatalyst consists of molybdenum disulfide MoS₂And bismuth tungstate Bi₂WO₆Composition of, wherein MoS₂And Bi₂WO₆The molar ratio of (A) to (B) is 0.08-0.12: 1.

2. The Z-MoS of claim 1₂/Bi₂WO₆The heterojunction composite photocatalyst is characterized in that the Z-shaped MoS₂/Bi₂WO₆The preparation method of the heterojunction composite photocatalyst comprises the following steps:

1)MoS₂the preparation of (1): adding ammonium molybdate (NH) into ultrapure water₄)₆Mo₇O₂₄·5H₂O and thioacetamide CH₄N₂S, transferring the dissolved solution into a high-pressure reaction kettle with a polytetrafluoroethylene lining, and putting the high-pressure reaction kettle into an electric heating constant-temperature air blast drying oven for heat treatment at 200-240 ℃ for 12-20 h; then cooling the reaction kettle to room temperature, and obtaining the flower-shaped structure after suction filtration, washing and dryingMoS of (1)₂；

2)MoS₂/Bi₂WO₆Preparing a heterojunction composite photocatalyst: the MoS obtained in the step 1) is treated₂Adding the mixture into ethanol, and performing ultrasonic dispersion to obtain a dispersion liquid A; adding bismuth nitrate Bi (NO)₃)₃·5H₂O and sodium tungstate Na₂WO₄·2H₂Adding O into ethylene glycol and ultrapure water respectively, magnetically stirring until completely dissolving, and adding Na₂WO₄The dissolution solution was added dropwise to Bi (NO)₃)₃Continuing magnetically stirring the solution for 30-90 min to obtain a suspension B; dropwise adding the dispersion liquid A into the suspension liquid B under magnetic stirring, continuously carrying out magnetic stirring for 30-90 min, transferring the mixed liquid into a high-pressure reaction kettle with a polytetrafluoroethylene lining, and putting the high-pressure reaction kettle into an electric heating constant-temperature air-blast drying oven for heat treatment at 140-200 ℃ for 6-12 h; after the reaction is finished, cooling the reaction kettle to room temperature, and obtaining MoS after suction filtration, washing and drying₂/Bi₂WO₆A heterojunction composite photocatalyst.

3. The Z-MoS of claim 2₂/Bi₂WO₆A heterojunction composite photocatalyst, characterized in that (NH) in the step 1)₄)₆Mo₇O₂₄·5H₂O and CH₄N₂The molar ratio of S is 1: 20 to 30.

4. The Z-MoS of claim 2₂/Bi₂WO₆The heterojunction composite photocatalyst is characterized in that Bi (NO) in the step 2)₃)₃·5H₂O and Na₂WO₄·2H₂The molar ratio of O is 2-4: 1.

5. The Z-MoS of claim 2₂/Bi₂WO₆The heterojunction composite photocatalyst is characterized in that the ultrasonic dispersion time in the step 2) is 4-8 h.

6. The method of any one of claims 1 to 5The Z-shaped MoS₂/Bi₂WO₆Application of the heterojunction composite photocatalyst in degradation of dye.

7. MoS type Z according to any of claims 1 to 5₂/Bi₂WO₆The application of the heterojunction composite photocatalyst in sterilization.

Technical Field

The invention belongs to the technical field of photocatalyst preparation, and particularly relates to a Z-shaped MoS₂/Bi₂WO₆A heterojunction composite photocatalyst and a preparation method and application thereof.

Background

Since Fujishima and Honda first reported TiO in 1972₂Since water can be decomposed into hydrogen and oxygen under ultraviolet irradiation, semiconductor photocatalysis has received much attention due to its excellent properties^[1]. Through the intensive research on the photocatalytic technology, researchers promote the continuous development of the application of the photocatalytic technology in the aspects of photolysis of water, degradation of organic pollutants, antifouling sterilization, energy conversion and the like^[2-4]. To improve TiO₂Researchers improve the utilization rate and the photocatalytic efficiency of sunlight by methods such as element doping, noble metal loading, material compounding and the like, and develop various novel visible light response photocatalystsIncluding BiVO₄BiOI and Ag₃PO₄And the like.

Among them, Bi having an orthogonal structure is the simplest member of Aurvillius family₂WO₆Due to the alternating (Bi)₂O₂)_n(WO₄)_nAnd a unique layered structure and a narrow forbidden band width (about 2.7eV), has strong absorption capacity for visible light, and has attracted extensive attention in the field of photocatalysis in recent years^[5]. However, Bi₂WO₆The monomer material has the problem of rapid recombination of photon-generated carriers, and the photocatalytic activity of the monomer material is greatly influenced. Therefore, it is necessary to provide a method for greatly increasing Bi₂WO₆The visible light photocatalytic activity of (1).

[1]K.Nakata,A.Fujishima.TiO₂photocatalysis:Design andapplications.Journal of Photochemistry and Photobiology C:PhotochemistryReviews,2012,13,169-189.

[2]Z.Yi,J.Ye,N.Kikugawa,T.Kako,S.Ouyang,H.Stuart-Williams,H.Yang,J.Cao,W.Luo,Z.Li,Y.Liu,R.L.Withers.An orthophosphate semiconductor withphotooxidation properties under visible-light irradiation.Nature Materials,2010,9,559-564.

[3]P.Ju,P.Wang,B.Li,H.Fan,S.Ai,D.Zhang,Y.Wang.A novel calcined Bi₂WO₆/BiVO₄heterojunction photocatalyst with highly enhanced photocatalyticactivity.Chemical Engineering Journal,2014,236,430-437.

[4]S.Malato,P.Fernández-Ibanez,M.I.Maldonado,J.Blanco,W.Gernjak.Decontamination and disinfection of water by solar photocatalysis:Recent overview and trends.Catalysis Today,2009,147,1-59.

[5]H.Fu,C.Pan,W.Yao,Y.Zhu.Visible-light-induced degradation ofrhodamine B by nanosized Bi₂WO₆.Journal of Physical Chemistry B,2005,109,22432-22439。

Disclosure of Invention

The invention aims to provide a Z-shaped MoS aiming at the problems in the prior art₂/Bi₂WO₆A heterojunction composite photocatalyst and a preparation method and application thereof.

The Z-shaped MoS provided by the invention₂/Bi₂WO₆A heterojunction composite photocatalyst is prepared from molybdenum disulfide (MoS)₂) And bismuth tungstate (Bi)₂WO₆) Composition of, wherein MoS₂And Bi₂WO₆The molar ratio of (A) to (B) is 0.08-0.12: 1.

The MoS provided by the invention₂/Bi₂WO₆The preparation method of the heterojunction composite photocatalyst comprises the following steps:

1)MoS₂the preparation of (1): adding ammonium molybdate ((NH) into ultrapure water₄)₆Mo₇O₂₄·5H₂O) and thioacetamide (CH)₄N₂S), completely dissolving, transferring the dissolved solution into a high-pressure reaction kettle with a polytetrafluoroethylene lining, and putting the reaction kettle into an electric heating constant-temperature air-blast drying oven for heat treatment at 200-240 ℃ for 12-20 h; then cooling the reaction kettle to room temperature, and obtaining the MoS with the flower-like structure after suction filtration, washing and drying for 6h at 60 DEG C₂；

2)MoS₂/Bi₂WO₆Preparing a heterojunction composite photocatalyst: the MoS obtained in the step 1) is treated₂Adding the mixture into ethanol, and performing ultrasonic dispersion to obtain a dispersion liquid A; adding bismuth nitrate (Bi (NO)₃)₃·5H₂O) and sodium tungstate (Na)₂WO₄·2H₂O) are respectively added into glycol and ultrapure water, the mixture is magnetically stirred until the mixture is completely dissolved, and then Na is added₂WO₄The dissolution solution was added dropwise to Bi (NO)₃)₃Continuing magnetically stirring the solution for 30-90 min to obtain a suspension B; and then, dropwise adding the dispersion liquid A into the suspension liquid B under magnetic stirring, continuously carrying out magnetic stirring for 30-90 min, transferring the mixed liquid into a high-pressure reaction kettle with a polytetrafluoroethylene lining, and putting the high-pressure reaction kettle into an electric heating constant-temperature air-blast drying oven for heat treatment at 140-200 ℃ for 6-12 h. After the reaction is finished, cooling the reaction kettle to room temperature, and obtaining MoS after suction filtration, washing and drying at 60 ℃ for 6h₂/Bi₂WO₆A heterojunction composite photocatalyst.

(NH) in the step (1)₄)₆Mo₇O₂₄·5H₂O and CH₄N₂The molar ratio of S is 1: 20 to 30.

Bi (NO) in the step (2)₃)₃·5H₂O and Na₂WO₄·2H₂The molar ratio of O is 2-4: 1;

and (3) the ultrasonic dispersion time in the step (2) is 4-8 h.

In another aspect, the invention also provides MoS₂/Bi₂WO₆The heterojunction composite photocatalyst is applied to dye degradation or sterilization.

The invention has the beneficial effects that:

(1) z-type MoS prepared by the invention₂/Bi₂WO₆The heterojunction composite photocatalyst has good visible light absorption performance and photocatalysis performance, and the photocatalysis activity is compared with that of Bi₂WO₆And MoS₂Are all obviously improved;

(2) MoS prepared by the invention₂/Bi₂WO₆The heterojunction composite photocatalyst has good stability and reusability;

(3) MoS prepared by the invention₂/Bi₂WO₆The heterojunction composite photocatalyst has a Z-shaped heterostructure, accelerates the separation of photon-generated carriers, improves the visible light catalytic activity, and has good practical value and potential application prospect in the fields of water purification, marine antifouling and the like.

Drawings

FIG. 1 is an XRD pattern of a sample prepared according to the present invention, wherein the abscissa is 2 θ (angle) and the unit is degree; intensity on the ordinate, in a.u. (absolute units);

FIG. 2 is a Field Emission Scanning Electron Microscope (FESEM) photograph of a sample prepared according to the present invention, in which (A) MoS₂，(B)Bi₂WO₆，(C,D)MoS₂/Bi₂WO₆；

FIG. 3 is a graph of the ultraviolet-visible diffuse reflectance spectrum (UV-DRS) of a sample prepared according to the present invention, wherein the abscissa is the Wavelength (Wavelength) in nm (nanometers) and the ordinate is the Absorbance (Absorbance) in a.u (absolute units);

FIG. 4 shows the variation of RhB concentration with Time (A) and the variation of bacterial survival with Time (B) in the photocatalytic degradation reaction of Pseudomonas aeruginosa in the sample prepared by the present invention, wherein the abscissa of the graph A is Time in min and the ordinate is C_t/C₀，C₀Initial concentration of RhB before reaction initiation, C_tThe RhB concentration at reaction time t; on the graph B, the ordinate represents the survivability ratio in%.

Detailed Description

The invention is prepared by mixing Bi₂WO₆And MoS₂Compounding, constructing a composite material with a Z-shaped heterostructure, accelerating the separation of photon-generated carriers on the surface of the composite material, further improving the photocatalytic performance, and carrying out the photocatalytic reaction on Bi₂WO₆And MoS₂The practical application of the two materials in the field of photocatalysis is of great significance.

The present invention is further illustrated by the following specific examples, which are intended to provide a more complete understanding of the invention by one of ordinary skill in the art, and are not intended to be limiting in any way.