阅读说明：本技术 一种Ag-AgBr/TiO2纳米棒复合阵列薄膜的制备方法 (Ag-AgBr/TiO2Method for preparing nano-rod composite array film ) 是由 王艳芬 程详 刘银 李孟婷 高娟 徐初阳 于 2020-06-21 设计创作，主要内容包括：本发明属于光催化材料领域,具体涉及一种Ag-AgBr/TiO<Sub>2</Sub>纳米棒复合阵列薄膜的制备方法。该复合薄膜活性组分是Ag-AgBr和TiO<Sub>2</Sub>纳米棒阵列,其结构是由Ag-AgBr异质结纳米颗粒修饰的一维TiO<Sub>2</Sub>纳米棒阵列生长在FTO导电玻璃表面。本发明提供的制备方法操作易于控制,不涉及昂贵设备,适合大规模生产。本发明制备的Ag-AgBr/TiO<Sub>2</Sub>纳米棒复合阵列,将表面等离子体共振效应和异质结构相结合,显示拓展的太阳光光谱响应范围、高效的光生载流子分离效率、良好的光电化学性能和可见光驱动光催化活性,在可见光下对罗丹明B和甲基橙的降解率可分别达到58％和80％。(The invention belongs to the field of photocatalytic materials, and particularly relates to Ag-AgBr/TiO 2 A method for preparing a nano-rod composite array film. The active components of the composite film are Ag-AgBr and TiO 2 The structure of the nanorod array is one-dimensional TiO modified by Ag-AgBr heterojunction nano particles 2 The nanorod array is grown on the surface of the FTO conductive glass. The preparation method provided by the invention is easy to operate and control, does not relate to expensive equipment, and is suitable for large-scale production. Ag-AgBr/TiO prepared by the invention 2 Nano-rod composite array for eliminating surface plasma resonance effectThe combination of the texture and the structure shows expanded sunlight spectral response range, high photo-generated carrier separation efficiency, good photoelectrochemical performance and visible light driven photocatalytic activity, and the degradation rate of rhodamine B and methyl orange under visible light can reach 58 percent and 80 percent respectively.)

1. Ag-AgBr/TiO₂The preparation method of the nanorod composite array film is characterized by comprising the following steps of:

(1) cutting FTO conductive glass into a proper size by a glass cutter, ultrasonically cleaning the FTO conductive glass for 20-40min by using acetone, deionized water and absolute ethyl alcohol sequentially to remove dust and pollutants on the surface of the glass, then measuring 15mL of concentrated hydrochloric acid (37%) and 0.5mL of tetrabutyl titanate, adding the obtained mixture into 15mL of deionized water, stirring the obtained mixture at normal temperature for more than 30min at a stirring speed of more than 180r/min, pouring the obtained mixture into a 50-75mL high-pressure reaction kettle inner container with the cleaned FTO glass (with the conductive surface facing downwards) at the bottom, reacting the obtained product for 10-12h under the hydrothermal condition of 160 ℃ and 150-₂A nanorod array film;

(2) dissolving 0.08-0.15mmol of alkaline mineralizer in 35mL of deionized water, sequentially adding 0.1g of hexadecyl trimethyl ammonium bromide and 1mmol of silver nitrate into the solution under the condition of magnetic stirring, and continuously stirring for 30-40min at normal temperature for later use;

(3) transferring the mixed solution in the step (2) into a stainless steel high-pressure reaction kettle with a 50-75mL polytetrafluoroethylene lining, wherein the product TiO in the step (1) is₂The nanorod array film is placed at the bottom of the reaction kettle and undergoes hydrothermal reaction for 3-15h at the temperature of 150-;

(4) taking out the sample after the reaction in the step (3), washing with deionized water, and vacuum drying to finally obtain visible light driven Ag-AgBr/TiO₂A nano-rod composite array film.

2. Ag-AgBr/TiO according to claim 1₂The preparation method of the nanorod composite array film is characterized by comprising the following steps of: in the step (2), the alkaline mineralizer is NaOH or C₆H₁₂N₄One of (1); in the step (3), the product TiO placed at the bottom of the reaction kettle₂The front surface of the nanorod array is downward and obliquely arranged; in step (4), the vacuum drying conditions are: the vacuum degree is 1-300Pa, the drying temperature is 60-80 ℃, and the drying time is 8-12 h.

3. Ag-AgBr/TiO prepared according to claim 1₂The nanorod composite array film is used as a photocatalyst for photodegradation of rhodamine B and methyl orange under visible light.

Technical Field

The invention belongs to the field of preparation of photocatalytic materials, and particularly relates to Ag-AgBr/TiO₂A method for preparing a nano-rod composite array film. Ag-AgBr/TiO prepared by the invention₂The nanorod composite array film is used as a photocatalyst and has a good photocatalytic effect when being used for degrading rhodamine B and methyl orange by visible light.

Background

In recent years, TiO₂Because of good biocompatibility, higher photocatalytic activity, stable chemical performance, low cost and no toxicity, the photocatalyst is taken as an ideal material for solving the environmental problem and the energy crisis. In particular one-dimensional TiO₂The nano-array material has wide application prospect in the fields of solar cells, photocatalytic water splitting or photocatalytic degradation of toxic organic small molecules, electrochemical energy storage, sensors and the like due to large length-diameter ratio, high specific surface area and fast electron transfer efficiency (X.D. Wang, et al, One-dimensional titanium dioxide nanomaterials: nanowines, nanoros, and ndnanobelts, chem.Rev.114(2014) 9346-. However, single phase TiO₂The solar energy collector has a large forbidden band width (3.0-3.2eV), can only be excited by ultraviolet light to respond, and the utilization rate of sunlight is low; meanwhile, the high photon-generated electron-hole recombination efficiency leads to lower photon quantum efficiency, which leads to low photoelectrochemical performance and sunlight catalytic activity, and limits the practical application of the material.

Compared with the single-component material, the binary or multi-component semiconductor-based composite nano material not only can overcome the limitation of single-phase material performance, but also has the comprehensive performance of various materials, and shows great application prospect. In recent years, silver/silver halide (Ag/AgX) based composite semiconductor materials have attracted extensive research interest. Under the condition of illumination, the silver ions in the AgX nano material are easily reduced to Ag⁰Atoms, forming an Ag/AgX heterostructure. The coexistence of Ag and AgX can not only generate Surface Plasma Resonance (SPR) effect and self-sensitization, but also obviously enhance the absorption of visible light and improve the utilization rate of sunlight; at the same time, goldThe presence of Ag also improves the photostability of AgX (Q.Y.Li, et al, Synthesis of cubic Ag @ AgCl and Ag @ AgBr colloidal catalysis and composition of the colloidal catalysis for the degradation of methyl orange and 2, 4-dichlorphenol, Res.chem.Intermed.44(2018)4651- "4661).

In the preparation process of the material, the preparation method and the process conditions of the nano material can obviously influence the composition, the morphology, the grain size, the heterogeneous interface, the energy band matching and other microstructures of the composite material, thereby changing the photocatalysis and photoelectrochemical properties of the material. Therefore, the selection of proper preparation method and process parameters plays a crucial role in the construction of the composite nano-material.

Disclosure of Invention

The invention provides Ag-AgBr/TiO aiming at the characteristics that an Ag-AgBr heterojunction can effectively expand the photoresponse range of a wide-band-gap semiconductor material, improve the carrier separation efficiency and effectively enhance the photocatalytic activity₂Preparation method of nanorod composite array film and novel Ag-AgBr/TiO obtained by preparation method₂The nanorod composite array film has the advantages of enhanced sunlight absorption capacity, high charge transfer efficiency, excellent photoelectrochemical property and visible light photocatalytic activity, low cost, simple preparation process and easy realization of industrial production and application.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the invention provides Ag-AgBr/TiO₂The active components of the nano-rod composite array film are Ag-AgBr and TiO₂The structure of the nanorod array is one-dimensional TiO modified by Ag-AgBr heterojunction nano particles₂The nanorod array is grown on the surface of the FTO conductive glass.

Ag-AgBr/TiO₂The preparation method of the nanorod composite array film is characterized by comprising the following steps of:

(1) cutting FTO conductive glass into a proper size by a glass cutter, ultrasonically cleaning the FTO conductive glass for 20-40min by using acetone, deionized water and absolute ethyl alcohol in sequence to remove dust and pollutants on the surface of the glass, and then measuring 15mL of concentrated hydrochloric acid (37%) and 15mL of absolute ethyl alcoholAdding 0.5mL tetrabutyl titanate into 15mL deionized water, stirring at normal temperature for more than 30min, with the stirring speed being more than 180r/min, pouring the tetrabutyl titanate into a 50-75mL high-pressure reaction kettle liner with cleaned FTO glass (conductive surface downward) at the bottom, reacting for 10-12h under the hydrothermal condition of 150-160 ℃, taking out the sample, cleaning for 3-5 times by using absolute ethyl alcohol and deionized water, and drying for 10-15h at 60-80 ℃ to obtain a product TiO₂A nanorod array film;

(2) dissolving 0.05-0.15mmol of alkaline mineralizer in 35mL of deionized water, sequentially adding 0.1g of hexadecyl trimethyl ammonium bromide and 1mmol of silver nitrate into the solution under the condition of magnetic stirring, and continuously stirring for 30-40min at normal temperature for later use;

(3) transferring the mixed solution in the step (2) into a stainless steel high-pressure reaction kettle with a 50-75mL polytetrafluoroethylene lining, wherein the product TiO in the step (1) is₂The nanorod array film is placed at the bottom of the reaction kettle and undergoes hydrothermal reaction for 3-15h at the temperature of 150-;

(4) taking out the sample after the reaction in the step (3), washing with deionized water, and drying in vacuum to finally obtain Ag-AgBr/TiO₂A nano-rod composite array film.

Preferably, the further technical scheme of the invention is as follows:

in the step (2), the alkaline mineralizer is NaOH or C₆H₁₂N₄One kind of (1).

In the step (3), the product TiO placed at the bottom of the reaction kettle₂The nano-rod array is obliquely arranged with the front face facing downwards.

In the step (4), the vacuum drying condition is as follows: the vacuum degree is 1-300Pa, the drying temperature is 60-80 ℃, and the drying time is 8-12 h.

Ag-AgBr/TiO prepared by the invention₂The nanorod composite array film as a photocatalyst shows a good visible light driving photocatalytic effect in the degradation of rhodamine B and methyl orange. Ag-AgBr/TiO prepared by the invention₂The reaction conditions of the nanorod composite array film for degrading rhodamine B and methyl orange are as follows: 300W xenon lamp with concentration of 15mg/L and volume of 10mL and 420nm filter is used as a lampThe degradation rate can reach 58% and 80% at most when the light source is used for irradiating for 150 min. In addition, the composite film can also be used as a photo-anode in transient photo-current test, and the photo-current density reaches 130 muA/cm²And shows a low interfacial charge transport resistance.

Compared with the prior art, the method for preparing Ag-AgBr/TiO₂The nano-rod composite array film has the following advantages:

1. uniformly growing one-dimensional TiO on the surface of the FTO conductive glass₂The nanorod array is loaded with Ag-AgBr heterojunction nanoparticles, so that the agglomeration phenomenon of a powder material in a photocatalytic reaction can be effectively avoided, the separation of a photocatalyst and a solution is realized without using post-treatment technologies such as centrifugation or suction filtration, and the process is simple.

2. The process of the present invention is carried out on TiO₂The Ag-AgBr heterojunction nano-particles are grown on the surface of the nanorod array by adopting a one-step hydrothermal method, the particles are uniformly distributed, the size is controllable, the preparation route is simple and easy, expensive equipment is not involved, the problem that the subsequent calcination or reduction process is adopted, and the generated Ag-AgBr heterojunction interfaces are tightly connected, so that the interface charge transfer is facilitated.

3. Ag-AgBr/TiO prepared by the method of the invention₂The nanorod composite array film has a highly ordered one-dimensional nanostructure matrix, a rough surface structure and a high specific surface area, is beneficial to adsorption and diffusion of organic micromolecules and transmission of hydroxyl radicals in a photocatalytic reaction, and further improves the photo-generated quantum efficiency and the photocatalytic efficiency.

4. Ag-AgBr/TiO prepared by the method of the invention₂The nanorod composite array combines the SPR effect of a noble metal material with a heterostructure, shows expanded sunlight spectral response range, high-efficiency photo-generated carrier separation efficiency and excellent photoelectrochemical performance, shows obviously enhanced photocatalytic efficiency in degradation of organic dyes rhodamine B and methyl orange under the irradiation of visible light, and has potential application prospects in the fields of solar cell photo-anode materials and photocatalysis.

Drawings

FIG. 1 shows (a) TiO prepared in example 1 of the present invention₂A substrate and (b) Ag-AgBr/TiO₂XRD spectrum of the nano-rod composite array film;

FIG. 2 shows (a) TiO prepared in example 1 of the present invention₂A substrate and (b) Ag-AgBr/TiO₂SEM picture of the nano-rod composite array film, (c) EDS map of the composite array;

FIG. 3 shows Ag-AgBr/TiO prepared in example 2 of the present invention₂An XRD (a) spectrum and an SEM (b) picture of the nanorod composite array film;

FIG. 4 shows Ag-AgBr/TiO prepared in example 3 of the present invention₂SEM picture of the nano-rod composite array film;

FIG. 5 shows TiO prepared according to the present invention₂Substrates and Ag-AgBr/TiO prepared in examples 1, 2 and 3₂The ultraviolet-visible absorption spectrogram (a) and the correspondingly calculated forbidden bandwidth (b) of the nanorod composite array film;

FIG. 6 shows TiO prepared according to the present invention₂Substrates and Ag-AgBr/TiO prepared in examples 1 and 2₂A photocurrent density-time curve and an EIS Nyquist plot of the nanorod composite array film (a);

FIG. 7 shows two Ag-AgBr/TiO materials prepared in (a) example 1 and (b) example 2 of the present invention₂The nano-rod composite array film is used as a photocatalyst to degrade the ultraviolet-visible absorption spectrum of rhodamine B solution under visible light, (c) TiO₂Substrate and Ag-AgBr/TiO₂Comparing the photo-degradation effect of the nanorod composite array;

FIG. 8 shows TiO prepared according to the present invention₂Substrate, Ag-AgBr/TiO prepared in example 1 and example 2₂And the comparative graph of the photodegradation effect of the nanorod composite array film as a photocatalyst for degrading methyl orange solution under visible light is shown.

Specific implementation procedure

The present invention will be described in further detail below with reference to examples. It should be noted, however, that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of the invention. Various modifications and improvements of the technical solution of the present invention may be made by those skilled in the art without departing from the spirit of the present invention, and the technical solution is intended to fall within the scope of the present invention defined by the claims.

Example 1:

(1) cutting FTO conductive glass into a proper size of 2.5cm × 5cm by a glass cutter, ultrasonically cleaning the FTO conductive glass for 20min by using acetone, deionized water and absolute ethyl alcohol sequentially to remove dust and pollutants on the surface of the glass, then measuring 15mL of concentrated hydrochloric acid (37%) and 0.5mL of tetrabutyl titanate, adding the concentrated hydrochloric acid and the tetrabutyl titanate into 15mL of deionized water, stirring the mixture for 30min at normal temperature at a stirring speed of 200r/min, pouring the mixture into a 50mL high-pressure reaction kettle inner container with cleaned FTO glass (conductive surface downward) at the bottom, reacting for 12h under the hydrothermal condition of 150 ℃, taking out a sample, cleaning the sample by using the absolute ethyl alcohol and the deionized water for 3 times, and drying the sample at 60 ℃ for 10h to obtain a TiO product₂A nanorod array film;

(2) dissolving 0.1mmol of sodium hydroxide in 35mL of deionized water, sequentially adding 0.1g of hexadecyl trimethyl ammonium bromide and 1mmol of silver nitrate into the solution under the condition of magnetic stirring, and continuously stirring for 30min at normal temperature for later use;

(3) transferring the mixed solution in the step (2) into a 50mL stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, wherein the product TiO in the step (1) is₂The nanorod array is placed at the bottom of the reaction kettle in a way of facing downwards, and hydrothermal reaction is carried out for 12 hours at the temperature of 150 ℃;

(4) taking out the sample after the reaction in the step (3), washing the sample for 3 times by deionized water, and drying the sample for 12 hours in vacuum at 80 ℃ to finally obtain Ag-AgBr/TiO₂A nano-rod composite array film.