阅读说明：本技术 一种多层复合光催化薄膜材料及其制备方法和应用 (Multilayer composite photocatalytic film material and preparation method and application thereof ) 是由 任会学 武道吉 张娜 于春峰 李方军 张帅 成文清 索心睿 李灵婕 于 2020-07-24 设计创作，主要内容包括：本发明涉及一种多层复合光催化薄膜材料及其制备方法和应用,由AgInS<Sub>2</Sub>薄膜和ZnO薄膜多层复合,结构通式为[AgInS<Sub>2</Sub>(<Sub>X</Sub>)/ZnO(y)]<Sub>n</Sub>,其中x和y分别表示单个踱膜循环中AgInS<Sub>2</Sub>薄膜和ZnO薄膜的厚度,且1<x<30nm,1<y<30nm,n为复合镀膜的叠加数,且1<n<5。先将玻璃基片转动到AgInS<Sub>2</Sub>靶材的正上方射频磁控溅射镀膜,再将玻璃基片的转盘转动到ZnO靶材的正上方射频磁控溅射镀膜制得。本发明利用三元的AgInS<Sub>2</Sub>量子点特性与二元的氧化锌的纳米材料的能带结构,拓宽了光催化材料的禁带宽度,实现了光催化剂应用由紫外光向可见光方向的拓展,提高了降解废水的强度和效率。(The invention relates to a multilayer composite photocatalytic film material, a preparation method and application thereof, and the material is prepared from AgInS 2 Film and ZnO filmThe film is multi-layer compounded and has a structural general formula of [ AgInS 2 ( X )/ZnO(y)] n Wherein x and y denote AgInS in a single pacing cycle 2 The thickness of the film and the ZnO film, and 1<x<30nm,1<y<30nm, n is the number of the composite coating film and is 1<n<5. Firstly, the glass substrate is rotated to AgInS 2 And (3) performing radio frequency magnetron sputtering coating right above the target material, and then rotating a turntable of the glass substrate to the position right above the ZnO target material to obtain the ZnO target material. The invention utilizes ternary AgInS 2 The quantum dot characteristic and the energy band structure of the binary zinc oxide nano material widen the forbidden band width of the photocatalytic material, realize the expansion of the application of the photocatalyst from ultraviolet light to visible light, and improve the intensity and efficiency of degrading wastewater.)

1. A multi-layer composite photocatalytic film material is prepared from AgInS₂The film and the ZnO film are compounded in a multilayer way, and the structural general formula is [ AgInS ]₂(_X)/ZnO(y)]_nWherein x and y denote AgInS in a single pacing cycle₂The thickness of the film and the ZnO film, and 1<x<30nm,1<y<30nm, n is the number of the composite coating film and is 1<n<5。

2. The multilayer composite photocatalytic film material as set forth in claim 1, wherein the total thickness of the multilayer composite photocatalytic film material is 150-200 nm.

3. The multi-layer composite photocatalytic film material as set forth in claim 1, wherein AgInS is present in each coating cycle of the composite film material₂The mass composition ratio of the film to the ZnO film is 1: 2-200.

4. The multilayer composite photocatalytic film material as set forth in claim 1, wherein the AgInS is₂The multilayer composite of the film and the ZnO film is prepared by radio frequency magnetron sputtering coating.

5. The method for preparing the multilayer composite photocatalytic film material as recited in any one of claims 1-4, characterized by comprising the steps of:

(1) cleaning and drying the glass substrate, placing the glass substrate on a mask plate, fixing and sending the glass substrate into a pretreatment chamber; vacuumizing the pretreatment chamber, opening a baffle between the pretreatment chamber and the magnetic control chamber when the magnitude of the vacuum degree of the pretreatment chamber reaches the vacuum degree of the magnetic control chamber, conveying the glass substrate into the magnetic control chamber, and closing the baffle between the magnetic control chamber and the pretreatment chamber; vacuumizing the magnetic control chamber, firstly vacuumizing by using a mechanical pump, then vacuumizing the magnetic control chamber by using a molecular pump, and introducing argon; glow discharge, when the discharge color is stable and presents a blue-white color, preparing to start coating;

(2) rotating a glass substrate to AgInS₂Directly above the target, regulating the sputtering power to 180-class 300W, regulating the rotation power of a turntable of the glass substrate to 2-5W, setting the temperature of the glass substrate to 120-class 180 ℃, introducing gas into the magnetron chamber to enable the flow ratio of oxygen and argon of a gas flowmeter to be 1:3-5, simultaneously controlling the total working pressure of the gas in the magnetron chamber to be kept at 0.5-2.0Pa, enabling the substrate to be in the range of glow discharge, starting timing film coating, and performing film coating for 1-2 hours in the atmosphere of stable glow discharge;

b. rotating a turntable of a glass substrate to be right above a ZnO target, adjusting the sputtering power to be 180-class 300W, adjusting the rotation power of the turntable of the substrate to be 2-5W, setting the temperature of the glass substrate to be 120-class 180 ℃, introducing gas into a magnetron chamber to enable the flow ratio of oxygen and argon of a gas flowmeter to be 1:3-5, simultaneously controlling the working total pressure of the gas in the magnetron chamber to be kept at 0.5-2.0Pa, enabling the substrate to be in the range of glow discharge, starting timing film coating, and performing film coating for 1-2 h in the atmosphere of stable glow discharge;

c. repeating the steps a and b until the composite multilayer [ AgInS ] is completed₂(_X)/ZnO(y)]_nSetting the total layer number;

(3) after the radio frequency magnetron sputtering is finished, the pressure intensity of the pretreatment chamber and the magnetron chamber is adjusted, and the substrate plated with the film is taken out.

6. According to the claimsThe preparation method of the multilayer composite photocatalytic film material in the step (5) is characterized in that the current vacuum degree of the magnetron chamber in the step (1) reaches 6.0 multiplied by 10^-4And (3) closing a valve of the molecular pump in the magnetic control chamber, opening a valve of the argon gas tank, adjusting the valve of the molecular pump, observing the vacuum gauge, and fixing the position of the valve of the molecular pump when the working pressure of the magnetic control chamber reaches 1.0 Pa.

7. The method for preparing a multilayer composite photocatalytic film material according to claim 5, wherein in the step (2), the sputtering power is 240W, the rotation power of a turntable of a substrate is 3W, the temperature of a glass substrate is 150 ℃, the total working pressure of gas in a magnetron chamber is kept at 1.0Pa, and the film coating is carried out for 0.5h in the atmosphere of stable glow discharge.

8. The method for preparing a multilayer composite photocatalytic film material according to claim 5, wherein in the step (2) b, the sputtering power is 240W, the rotation power of a turntable of a substrate is 3W, the temperature of a glass substrate is 150 ℃, the total working pressure of gas in a magnetron chamber is kept at 1.0Pa, and the film is coated for 1.5 hours in a stable glow discharge atmosphere.

9. Use of the multilayer composite photocatalytic film material of any one of claims 1-4 in wastewater treatment.

10. Use of the multi-layer composite photocatalytic film material of any one of claims 1-4 in treatment of dye wastewater or antibiotic wastewater.

Technical Field

The invention relates to a composite photocatalytic film material, a preparation method thereof and application thereof in wastewater treatment, belonging to the technical field of photocatalytic materials.

Background

The photocatalytic oxidation technology is an environment-friendly green water treatment technology, can thoroughly degrade organic pollutants in wastewater, has no toxicity or toxic byproducts due to the fact that a catalyst of the photocatalytic oxidation technology is nontoxic, can react at normal temperature and normal pressure, thoroughly destroys the molecular structure of organic matters, is used for degrading antibiotic wastewater, and has the characteristics of high treatment efficiency, mild reaction, wide application range and the like, so that the photocatalytic oxidation technology has a good application prospect. Mechanism process of photocatalytic oxidation reactionThe photocatalyst generates photon-generated carriers under the irradiation of a specific light source to enable surrounding water molecules and oxygen to form extremely active free radicals (such as. OH free radicals and. O)₂ ^-Free radical), can oxidize and degrade macromolecular organic matters into H₂O and CO₂And the like. The photocatalytic semiconductor material widely used at present is mainly TiO₂、ZnO、CdS、WO₃、SnO₂And the like. Some mainstream photocatalytic materials such as titanium dioxide have inefficient separation of photo-generated charges, resulting in large amounts of inefficient recombination of photo-generated electrons and holes, thereby reducing photon efficiency; due to the energy band structure (Eg ═ 3.2ev) of the anatase type titanium dioxide semiconductor material, it is determined that such photocatalyst can only absorb the ultraviolet part (only 4% of sunlight) with the wavelength less than 380nm in sunlight, and the solar energy utilization rate is low. Although the powder catalyst has high catalytic efficiency, the powder catalyst is difficult to continuously recycle, the post-treatment process is complex and the cost is high, therefore, the catalyst needs to be immobilized, but the immobilization of the catalyst can cause the reduction of the specific surface area of the catalyst, the reduction of the catalytic activity and the difficulty in maintaining the high-efficiency photocatalyst loading technology; the catalytic activity of the photocatalyst has a great relationship with the granularity, the smaller the granularity is, the larger the specific surface area is, the higher the photocatalytic activity is, but the granularity is too small, secondary agglomeration is easy to occur, and a powder photocatalytic system is a thermodynamically unstable system and is easy to generate particle agglomeration, so that the practicability is poor; some photocatalysts have poor stability and are often deactivated.

Compared with granular and powdery materials, the film material has the characteristics of being more easily changed into a regular material, being more easily recycled and being more beneficial to catalytic reaction in a catalytic modification mode. The existing photocatalytic film materials are mostly single-component or single-layer photocatalytic materials, and the materials generally have some problems, such as low quantum efficiency and pure single TiO₂Materials such as ZnO and the like have high recombination rate of photo-generated electron-hole pairs, and the photocatalytic performance cannot be well exerted; the available spectrum range is very small, is limited to the ultraviolet range with the wavelength less than 400nm, and other spectra occupying a large part of sunlight cannot be used; is provided withFor high-concentration industrial wastewater, such as dye wastewater and pharmaceutical wastewater, the photocatalytic reaction is difficult to occur due to the large amount of impurities, high turbidity and poor light transmittance.

Multilayer composite thin film materials have also been investigated and are limited in many ways by the choice of preparation methods and materials. The preparation method of the single-layer film material is divided into a chemical deposition method (CVD) and a physical deposition method (PVD), wherein the chemical deposition method is a technology for generating a solid film by utilizing a gaseous precursor reactant through an atomic and intermolecular chemical reaction path, the technology can conveniently control the components of the deposit, but the method uses expensive equipment and has higher preparation cost of the film; the Physical Vapor Deposition (PVD) technique is a technique of vaporizing a material source, i.e., a solid or a liquid surface, into gaseous atoms, molecules or partially ionized ions by a Physical method under a vacuum condition, and depositing a thin film having a specific function on a substrate surface by a low-pressure gas (or plasma) process. The main methods of physical vapor deposition include vacuum evaporation, sputter coating, arc plasma coating, ion coating, and molecular beam epitaxy. The sputtering coating refers to a process of bombarding the surface of a target material by particles with kinetic energy under a vacuum condition to enable atoms on the surface of the target material to obtain enough energy to escape, namely sputtering; the sputtered target material is deposited on the surface of the substrate, and the sputtering coating is called; at present, the method is mainly applied to coating films for large-scale architectural decoration and functional coating films of industrial materials, and plating Ni and Ag on the surfaces of foamed plastics and fiber fabrics of coiled materials by TGN-JR type multi-arc or magnetron sputtering. Physical vapor deposition techniques have been developed to date to deposit not only metal films, alloy films, but also compound, ceramic, semiconductor, polymer films, and the like. The preparation of multilayer composite film materials requires a combination of material composition and properties. Chinese patent CN104529184A discloses a zinc oxide-tantalum pentoxide composite nano-film, which uses conductive glass as a substrate and tantalum oxide film as a protective layer to be uniformly coated on the surface of a one-dimensional zinc oxide nano-rod array, and comprises preparing a precursor solution of a ZnO seed crystal layer, preparing a coating of conductive glass with the ZnO seed crystal layer, preparing a solvothermal precursor solution of zinc nitrate and hexamethylenetetramine, and carrying out liquid-phase reactionSynthesizing to obtain ZnO nanorod array film, and depositing Ta by atomic layer₂O₅The film is uniformly coated on the surface of the ZnO nanorod array to form ZnO/Ta₂O₅And (3) a nano film. The tantalum oxide film plays a role in protecting a zinc oxide material and passivating the surface state of zinc oxide, and the activity and stability of hydrogen production by photolysis of water are obviously improved. The preparation of the multilayer film material with better catalytic activity by developing and designing the material composition with better semiconductor structure is an important direction for the functionalization of the photocatalytic film.

Disclosure of Invention

The invention aims to solve the problems of the existing photocatalytic materials and provides a multilayer composite photocatalytic film material, a preparation method thereof and application thereof in wastewater treatment.

The invention is realized by the following technical scheme:

a multi-layer composite photocatalytic film material is prepared from AgInS₂The film and the ZnO film are compounded in a multilayer way, and the structural general formula is [ AgInS ]₂(x)/ZnO(y)]_nWherein x and y denote AgInS in a single pacing cycle₂The thickness of the film and the ZnO film, and 1<x<30nm,1<y<30nm, n is the number of the composite coating film and is 1<n<5。

The total thickness of the multilayer composite photocatalytic film material is 150-200 nm. AgInS in each coating cycle in the whole composite film material₂The mass composition ratio of the film to the ZnO film is preferably 1: 2-200.

The AgInS₂The multilayer composite of the film and the ZnO film is prepared by radio frequency magnetron sputtering coating.

The preparation method of the multilayer composite photocatalytic film material comprises the following steps:

(1) cleaning and drying the glass substrate, placing the glass substrate on a mask plate, fixing and sending the glass substrate into a pretreatment chamber; vacuumizing the pretreatment chamber, opening a baffle between the pretreatment chamber and the magnetic control chamber when the magnitude of the vacuum degree of the pretreatment chamber reaches the vacuum degree of the magnetic control chamber, conveying the glass substrate into the magnetic control chamber, and closing the baffle between the magnetic control chamber and the pretreatment chamber; vacuumizing the magnetic control chamber, firstly vacuumizing by using a mechanical pump, then vacuumizing the magnetic control chamber by using a molecular pump, and introducing argon (Ar); glow discharge, when the discharge color is stable and presents a blue-white color, preparing to start coating;

(2) rotating a glass substrate to AgInS₂Directly above the target material, the sputtering power is adjusted to 180-300W, the rotation power of the turntable of the glass substrate is adjusted to 2-5W, the temperature of the glass substrate is set to 120-₂) Controlling the flow ratio of argon (Ar) to be 1:3-5, simultaneously controlling the working total pressure of gas in a magnetron chamber to be kept at 0.5-2.0Pa, enabling the substrate to be in the range of glow discharge, starting timing film coating, carrying out the film pacing for 0.2-1 h in the atmosphere of stable glow discharge, and sputtering for corresponding time according to the set thickness until the sputtering requirement is met;

b. rotating the turntable of the glass substrate to the position right above the ZnO target, adjusting the sputtering power to 180-300W, adjusting the rotation power of the turntable of the substrate to 2-5W, setting the temperature of the glass substrate to 120-₂) Controlling the flow ratio of argon (Ar) to be 1:3-5, simultaneously controlling the working total pressure of gas in a magnetron chamber to be kept at 0.5-2.0Pa, enabling the substrate to be in the range of glow discharge, starting timing film coating, carrying out film coating for 0.5-2.5 h in the atmosphere of stable glow discharge, and sputtering for corresponding time according to the set thickness until the sputtering requirement is met;

c. repeating the steps a and b until the composite multilayer [ AgInS ] is completed₂(x)/ZnO(y)]_nSetting the total layer number;

(3) after the radio frequency magnetron sputtering is finished, the pressure intensity of the pretreatment chamber and the magnetron chamber is adjusted, and the substrate plated with the film is taken out.

In the preparation method of the multilayer composite photocatalytic film material, the vacuum degree of the magnetic control chamber in the step (1) reaches 6.0 multiplied by 10^-4Closing a molecular pump valve of the magnetic control chamber while Pa, opening an argon (Ar) gas tank valve, adjusting the molecular pump valve, observing a vacuum gauge, and when the working pressure of the magnetic control chamber reaches 1.0Pa, controlling the molecular pump valveAnd (5) fixing the position.

Step (2) a, preferably, the sputtering power is 240W, the rotating power of a rotating disc of the substrate is 3W, the temperature of the glass substrate is 150 ℃, and the working total pressure of gas in the magnetron chamber is kept at 1.0 Pa. The plating is preferably carried out in an atmosphere of stable glow discharge for 0.5 h.

And (2) b, preferably, the sputtering power is 240W, the rotating power of a rotating disc of the substrate is 3W, the temperature of the glass substrate is 150 ℃, and the total working pressure of gas in the magnetron chamber is kept at 1.0 Pa. The plating is preferably carried out in an atmosphere of stable glow discharge for 1.5 h.

Composite multilayer AgInS prepared by using method₂And ZnO thin film, the photocatalytic performance of which can be improved by including AgInS₂And structural parameters including the component content of ZnO, the thickness ratio of the film layers, the number of the film layers and the like are regulated and controlled.

The prepared multilayer composite photocatalytic film material is applied to wastewater treatment, in particular to the treatment of refractory wastewater (such as refractory dye wastewater and refractory antibiotic wastewater).

The invention utilizes ternary AgInS₂The quantum dot characteristic and the energy band structure of the binary zinc oxide nano material implement the multi-layer composition of the two materials in the nano scale, and construct the nano composite multi-layer photocatalysis functional film. Compared with the traditional single-component photocatalytic material, the composite multilayer nano photocatalytic film has higher photocatalytic efficiency and longer service life.

The invention has the advantages that:

(1) the composite semiconductor material with multilayer composite film is combined and designed, and ternary AgInS is selected₂And the binary ZnO composite film layer fully utilizes the reduction of the energy band structure of the two layers after the two layers are compounded, promotes the separation of photoproduction electrons and holes, and inhibits the compounding of the photoproduction electrons and the holes, thereby improving the quantum efficiency, enlarging the wavelength range of exciting light and improving the stability of the photocatalyst by fully utilizing solar energy;

(2) by utilizing a magnetron sputtering technology, the designed semiconductor material is used for preparing a multilayer composite photocatalytic film by utilizing an efficient double-target and steering target method, so that the load problem and the catalytic efficiency problem of photocatalysis are thoroughly solved, and the application of the photocatalysis technology is greatly promoted;

(3) the bottleneck problems of low efficiency and poor catalytic activity of a photocatalytic system caused by easy dispersion and difficult loading technology of the powder catalyst are solved, and the large-scale application of the difficultly degraded wastewater is facilitated; meanwhile, the composition and the structure of the photocatalyst are improved, the forbidden bandwidth of the photocatalytic material is widened, the application of the photocatalyst is expanded from ultraviolet light to visible light, the intensity and the efficiency of degrading waste water are improved, and a foundation is laid for realizing the high-efficiency treatment of the difficultly-degraded waste water.

Drawings

FIG. 1 is a Scanning Electron Micrograph (SEM) of the composition of a photocatalytic film; (a) scanning electron microscope images of single zinc oxide films; (b) scanning electron microscope images of the indium disulfide silver composite zinc oxide film;

FIG. 2 is a transmission electron micrograph (TEM image) of a thin film composed of indium silver sulfide and zinc oxide at different ratios; (a) the mass ratio of the indium sulfide silver to the zinc oxide is (1: 10); (b) the mass ratio of the indium sulfide silver to the zinc oxide is (5: 10);

FIG. 3 is a photoluminescence spectrum (PL diagram) of a thin film composed of indium silver sulfide and zinc oxide at different ratios, in which AgInS₂Abbreviated as AIS;

FIG. 4 shows titanium dioxide and [ AgInS ]₂(x)/ZnO(y)]_nA degradation contrast curve of the composite film on amoxicillin;

FIG. 5 shows a zinc oxide film, an indium-silver disulfide film and [ AgInS ]₂(x)/ZnO(y)]_nA degradation contrast curve of the composite film on amoxicillin;

FIG. 6 shows titanium dioxide and [ AgInS ]₂(x)/ZnO(y)]_nCOD degradation curve of composite film dye to wastewater.

Detailed Description

The present invention is further illustrated by the following specific examples.