阅读说明：本技术 一种非晶态TiO2/Ag复合纳米颗粒及其制备方法和应用 (Amorphous TiO2Ag/composite nano-particle and preparation method and application thereof ) 是由 袁斌霞 罗紫格 朱瑞 王道累 韩清鹏 于 2021-09-10 设计创作，主要内容包括：本发明涉及一种非晶态TiO-(2)/Ag复合纳米颗粒及其制备方法和应用,该方法包括以下步骤：(1)制备二氧化钛溶液：将分散剂溶解至溶剂中,再将钛源和去离子水逐滴加入,搅拌后,得到溶液A；(2)制备银纳米溶液：果糖和银源加入溶剂中,搅拌至全部溶解,得到溶液B；(3)制备非晶态TiO-(2)/Ag复合纳米颗粒：将A溶液和B溶液混合,光照后得到产物溶液,离心洗涤、干燥后,得到非晶态TiO-(2)/Ag复合纳米颗粒,该复合纳米颗粒应用于光电催化。与现有技术相比,本发明具有简单、快捷、产量高等优点。(The invention relates to amorphous TiO 2 The preparation method of the/Ag composite nano-particles comprises the following steps: (1) preparing a titanium dioxide solution: dissolving a dispersing agent into a solvent, dropwise adding a titanium source and deionized water, and stirring to obtain a solution A; (2) preparing a silver nano solution: adding fructose and a silver source into a solvent, and stirring until the fructose and the silver source are completely dissolved to obtain a solution B; (3) preparation of amorphous TiO 2 Ag composite nanoparticles: mixing the solution A and the solution B, illuminating to obtain a product solution, centrifugally washing and drying to obtain amorphous TiO 2 The Ag/Ag composite nano-particle is applied to photoelectrocatalysis. Compared with the prior art, the method has the advantages of simplicity, quickness, high yield and the like.)

1. Amorphous TiO₂The preparation method of the/Ag composite nano particles is characterized by comprising the following steps:

(1) preparing a titanium dioxide solution: dissolving a dispersing agent into a solvent, dropwise adding a titanium source and deionized water, and stirring to obtain a solution A;

(2) preparing a silver nano solution: adding fructose and a silver source into a solvent, and stirring until the fructose and the silver source are completely dissolved to obtain a solution B;

(3) preparation of amorphous TiO₂Ag composite nanoparticles: mixing the solution A and the solution B, illuminating to obtain a product solution, centrifugally washing and drying to obtain amorphous TiO₂Ag composite nano-particles.

2. The amorphous TiO of claim 1₂The preparation method of the/Ag composite nano-particles is characterized in that in the solution A, the volume ratio of a titanium source to deionized water is 1 (1.5-2.5).

3. The amorphous TiO of claim 1₂The preparation method of the/Ag composite nano particles is characterized in that fructose and Ag are contained in the solution B⁺The molar ratio of (1.5-2.5) to (1).

4. The amorphous TiO of claim 1₂The preparation method of the/Ag composite nano-particles is characterized in that the titanium source comprises tetrabutyl titanate, and the silver source comprises silver acetate.

5. The amorphous TiO of claim 4₂Ag composite nano-particleThe preparation method is characterized in that the volume mass ratio of the tetrabutyl titanate to the silver acetate is (0.4-0.6) ml and (0.01-0.02) g.

6. The amorphous TiO of claim 1₂The preparation method of the/Ag composite nano-particles is characterized in that the dispersing agent comprises PVP.

7. The amorphous TiO of claim 1₂The preparation method of the/Ag composite nano particles is characterized in that ultraviolet light is adopted for illumination, and the illumination time is 0-15 h.

8. The amorphous TiO of claim 7₂The preparation method of the/Ag composite nano-particles is characterized in that ultraviolet light with the wavelength of 375nm is adopted for illumination, and the illumination time is 5-15 h.

9. Amorphous TiO prepared by the method of any one of claims 1 to 8₂Ag composite nano-particles.

10. The amorphous TiO of claim 9₂The application of the/Ag composite nano particles is characterized in that the composite nano particles are applied to photoelectrocatalysis.

Technical Field

The invention relates to the technical field of functional nano materials, in particular to amorphous TiO₂The preparation method and the application of the/Ag composite nano-particles.

Background

Titanium dioxide is one of the most studied compounds in material science. It is a semiconductor material with low cost, strong chemical inertness and good light stability. Because of good physicochemical properties, the material becomes one of the most promising materials in the aspects of 'energy source' and 'environment', and is widely applied to the aspects of photoelectrocatalysis hydrogen production, photocatalytic reduction of carbon dioxide, bacterial inactivation, dye degradation and the like, wherein the semiconductor photocatalysis technology is the most extensive. Solar energy is used as an excitation source, titanium dioxide generates a light electron hole pair, photo-generated electrons have high reducibility, and the hole pair has strong oxidizing property. Likewise, titanium dioxide as a photocatalytic material has significant drawbacks. The light response range of the titanium dioxide material is narrow, and the light utilization rate is low; the band gap is too wide, and the excitation difficulty is high; the problems that the photo-generated electron hole pair is easy to recombine, the catalytic activity is reduced and the like are the current research problems.

To solve the problem, titanium dioxide and noble metal are deposited to form a Schottky barrier. The photo-generated electrons can be transferred to the surface of the noble metal in time, the recombination of the photo-generated electrons and holes is inhibited, the forbidden bandwidth of titanium dioxide is reduced, the light absorption range is expanded, and the photocatalytic activity is improved. Patents CN 110813283a and CN 109331819a respectively invent methods of depositing gold on a titanium dioxide composite material and loading Pt-Pd bimetal on the titanium dioxide composite material, and the performance of the methods in photocatalytic decomposition of water and photocatalytic benzyl alcohol is improved, but most preparation methods are highly affected by temperature, and calcination at high temperature is required to generate byproducts.

In addition, titanium dioxide research has focused on the anatase, rutile, and brookite phases, but recent research has begun to bias towards the structure and properties of amorphous titanium dioxide, which is expected to find desirable properties in this less processed, cheaper material form. The research shows that the oxidation capacity is greatly related to the crystal phase. Under the same condition, the oxidation capability of the amorphous titanium dioxide is strongest. The amorphous titanium dioxide prepared by CN 109529872A has high specific surface area, but the problem of forbidden bandwidth is still not overcome, and the utilization rate of solar energy can be improved by the band gap coupling and complementary action between different nano particles.

The preparation methods and ideas fully consider the improvement of the noble metal deposition and the amorphous titanium dioxide on the photocatalytic performance, but most experimental methods have low yield, high equipment requirement and complex process, and are not suitable for large-scale production.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned drawbacks of the prior art and providing a simple, fast, high-yield amorphous TiO₂The preparation method and the application of the/Ag composite nano-particles.

The purpose of the invention can be realized by the following technical scheme:

the normal temperature preparation method provided by the invention can improve TiO content under the condition of reducing production conditions₂Production efficiency of/Ag. The product prepared by the invention takes the amorphous titanium dioxide with a large number of pore structures as a substrate, silver nano particles are uniformly distributed in the substrate, the diameter of the silver nano particles is about nanometer, the silver nano particles are octagonally crystalline, and the crystallization degree is good. Amorphous TiO 2₂The Ag nano structure can exert more effective performance by improving the specific surface area and the precious metal deposition mode,

briefly, the present invention provides a method for preparing amorphous TiO by ultraviolet light₂The preparation method of the Ag nano particles comprises the steps of taking ethylene glycol as a solvent, adding a titanium precursor and deionized water, and stirring by magnetic force to obtain a solution A; similarly, glycol is taken as a solvent, fructose is added as a reducing agent, silver acetate is taken as a precursor of the silver nanoparticles, and a solution B is obtained by magnetic stirring; mixing the solution A and the solution B, standing at room temperature, transferring to a 375nm ultraviolet illumination device, and illuminating to obtain amorphous TiO₂Ag nanoparticles. The method provided by the invention can obtain a product with higher output efficiency under the condition of reducing synthesis. The product prepared by the invention takes amorphous titanium dioxide with a large number of pore structures as a substrate, silver nanoparticles are uniformly distributed in the substrate, the diameter of the silver nanoparticles is about 20-30 nanometers, the silver nanoparticles are octagonal crystals, the crystallization degree is good, and the specific scheme is as follows:

amorphous stateTiO₂The preparation method of the/Ag composite nano-particles comprises the following steps:

(1) preparing a titanium dioxide solution: dissolving a dispersing agent into a solvent, dropwise adding a titanium source and deionized water, and stirring to obtain a solution A;

(2) preparing a silver nano solution: adding fructose and a silver source into a solvent, and stirring until the fructose and the silver source are completely dissolved to obtain a solution B;

(3) preparation of amorphous TiO₂Ag composite nanoparticles: mixing the solution A and the solution B, illuminating to obtain a product solution, centrifugally washing and drying to obtain amorphous TiO₂Ag composite nano-particles.

Further, in the solution A, the volume ratio of the titanium source to the deionized water is 1 (1.5-2.5), preferably 1: 2.

Furthermore, in the solution B, fructose and Ag⁺The molar ratio of (1.5-2.5) to 1, preferably 2: 1.

Further, the titanium source comprises tetrabutyl titanate and the silver source comprises silver acetate.

Furthermore, the volume mass ratio of the tetrabutyl titanate to the silver acetate is (0.4-0.6) ml and (0.01-0.02) g.

Further, the dispersant comprises PVP.

Further, ultraviolet light is adopted for illumination, and the illumination time is 0-15 h.

Furthermore, ultraviolet light with the wavelength of 375nm is adopted for illumination, and the illumination time is 5-15 h.

Amorphous TiO prepared by the method₂Ag composite nano-particles.

Prepared amorphous TiO₂The structure of the/Ag nano particles is a pore structure with a large specific surface area, the silver nano particles are used as a load, and the crystallization condition and the load content of the silver nano particles can be adjusted by changing the ultraviolet illumination time.

An amorphous TiO compound as described above₂The application of/Ag composite nano particles in photoelectrocatalysis.

Compared with the prior art, the invention has the following advantages:

(1) the invention adopts one-step synthesis by ultraviolet illumination, compared with the traditional sintering method after sol-gel preparation, the method has low equipment requirement, and is simple and efficient;

(2) the titanium dioxide in the composite nano material prepared by the invention is in an amorphous state, has a large number of irregular pore structures compared with the crystalline state, increases the specific surface area of the material, can deposit a large number of noble metals, and can better improve the performance in the aspect of photoelectrocatalysis through the synergistic effect of the titanium dioxide and the noble metals.

Drawings

FIG. 1 shows amorphous TiO obtained in example 1₂XRD representation of the/Ag composite nano particle dispersion liquid;

FIG. 2 shows amorphous TiO obtained in example 1₂SEM representation of the/Ag composite nano-particle dispersion liquid;

FIG. 3 shows amorphous TiO obtained in example 1₂TEM representation of the/Ag composite nanoparticle dispersion;

FIG. 4 shows amorphous TiO obtained in examples 1 to 3₂The forbidden band width diagram of ultraviolet-visible absorption spectrum conversion of the/Ag composite nano particle dispersion liquid.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

Amorphous TiO₂The preparation method of the/Ag composite nano-particles comprises the following steps:

(1) preparing a titanium dioxide solution: dissolving a dispersing agent into a solvent, dropwise adding a titanium source and deionized water, and stirring to obtain a solution A; in the solution A, the volume ratio of the titanium source to the deionized water is 1 (1.5-2.5), and preferably 1: 2. The dispersant comprises PVP.

(2) Preparing a silver nano solution: adding fructose and a silver source into a solvent, and stirring until the fructose and the silver source are completely dissolved to obtain a solution B; in solution B, fructose and Ag⁺Has a molar ratio of (1.5)2.5) 1, preferably 2: 1. The titanium source comprises tetrabutyl titanate and the silver source comprises silver acetate. The volume mass ratio of tetrabutyl titanate to silver acetate is (0.4-0.6) ml and (0.01-0.02) g.

(3) Preparation of amorphous TiO₂Ag composite nanoparticles: mixing the solution A and the solution B, illuminating to obtain a product solution, centrifugally washing and drying to obtain amorphous TiO₂the/Ag composite nano-particles are prepared by irradiating with ultraviolet light, such as ultraviolet light with wavelength of 375nm, for 0-15h, preferably 5-15 h.

Prepared amorphous TiO₂The structure of the/Ag nano particle is a pore structure with a large specific surface area, the silver nano particle is used as a load, the crystallization condition and the load content of the silver nano particle can be adjusted by changing the ultraviolet illumination time, and the composite nano particle is applied to photoelectrocatalysis.

Example 1

Preparation of titanium dioxide solution

Weighing 0.1g of polyvinylpyrrolidone PVP to 20ml of ethylene glycol, fully dissolving, standing for 10min, transferring into a three-neck flask, magnetically stirring at the rotating speed of 1000r/min, and sequentially dripping 0.5ml of tetrabutyl titanate and 1ml of deionized water during stirring. Magnetically stirring for 1h to promote the hydrolysis of tetrabutyl titanate, and changing the transparent color of the solution into white to obtain a titanium dioxide suspension.

Preparation of silver Nano solution

Adding 0.09g of fructose and 0.016g of silver acetate into 20ml of ethylene glycol, magnetically stirring at 1000r/min, slowly dissolving the silver acetate in the ethylene glycol, and carrying out auxiliary reduction on the silver acetate by the fructose at normal temperature. After stirring for 1h, the solution turned from clear to light tan and stirring was stopped.

Preparation of amorphous TiO₂Ag composite nano solution

Mixing the above two solutions, stirring for 30min to obtain a mixed solution, irradiating under 375nm ultraviolet light for 10 hr to change the solution from white to red brown, centrifuging and washing the solution until the pH of the supernatant is about 6-6.5, and drying the solution in a forced air drying oven at 60 deg.C for 12 hr. After the solution was completely dried, 100mg of a precipitate was obtained, which was ground in a mortar. Amorphous TiO is obtained₂Ag composite nano-particles.

5mg of the product is added into 4ml of absolute ethyl alcohol, and the mixture is evenly mixed and subjected to ultrasonic treatment for 10 min. The uv-vis absorption test was performed.

The amorphous TiO prepared by the method₂The XRD characterization and analysis results of Ag nanoparticles are shown in figure 1, and TiO prepared by the method is shown in the figure₂The results of SEM and TEM analysis of Ag nanoparticles are shown in FIGS. 2-3. The diagram of the forbidden band width of the sample after the ultraviolet-visible absorption test is shown in figure 4. SEM and XRD analysis showed amorphous TiO₂The titanium dioxide is in an amorphous state, has a gentle peak at about 22 degrees, and has a large number of irregular pore structures on the surface. The silver nano-crystals have good states and diameters of nm and are uniformly deposited in pores of the titanium dioxide.

Example 2

Weighing 0.1g of polyvinylpyrrolidone PVP to 20ml of ethylene glycol, fully dissolving, standing for 10min, transferring into a three-neck flask, magnetically stirring at the rotating speed of 1000r/min, and sequentially dripping 0.5ml of tetrabutyl titanate and 1ml of deionized water during stirring. Magnetically stirring for 1h to promote the hydrolysis of tetrabutyl titanate, and changing the transparent color of the solution into white to obtain a titanium dioxide suspension.

Preparation of silver Nano solution

Adding 0.09g of fructose and 0.016g of silver acetate into 20ml of ethylene glycol, magnetically stirring at 1000r/min, slowly dissolving the silver acetate in the ethylene glycol, and carrying out auxiliary reduction on the silver acetate by the fructose at normal temperature. After stirring for 1h, the solution turned from clear to light tan and stirring was stopped.

Preparation of amorphous TiO₂Ag composite nano solution

Mixing the above two solutions, stirring for 30min to obtain a mixed solution, irradiating under 375nm ultraviolet light for 5 hr to change the solution from white to red brown, centrifuging and washing the solution until the pH of the supernatant is about 6-6.5, and drying the solution in a forced air drying oven at 60 deg.C for 12 hr. After the solution was completely dried, 100mg of a precipitate was obtained, which was ground in a mortar. Amorphous TiO is obtained₂Ag composite nano-particles.

5mg of the product is added into 4ml of absolute ethyl alcohol, and the mixture is evenly mixed and subjected to ultrasonic treatment for 10 min. The uv-vis absorption test was performed.

The main difference between this example and example 1 is that the irradiation time of the ultraviolet light is changed, which results in the reduction of the crystalline state of the silver nano-particles, and the forbidden bandwidth is significantly widened after the ultraviolet-visible absorption test, as shown in fig. 4.

Example 3

Weighing 0.1g of polyvinylpyrrolidone PVP to 20ml of ethylene glycol, fully dissolving, standing for 10min, transferring into a three-neck flask, magnetically stirring at the rotating speed of 1000r/min, and sequentially dripping 0.5ml of tetrabutyl titanate and 1ml of deionized water during stirring. Magnetically stirring for 1h to promote the hydrolysis of tetrabutyl titanate, and changing the transparent color of the solution into white to obtain a titanium dioxide suspension.

Preparation of silver Nano solution

Adding 0.09g of fructose and 0.016g of silver acetate into 20ml of ethylene glycol, magnetically stirring at 1000r/min, slowly dissolving the silver acetate in the ethylene glycol, and carrying out auxiliary reduction on the silver acetate by the fructose at normal temperature. After stirring for 1h, the solution turned from clear to light tan and stirring was stopped.

Preparation of amorphous TiO₂Ag composite nano solution

Mixing the above two solutions, stirring for 30min to obtain a mixed solution, irradiating under 375nm ultraviolet light for 15 hr to change the solution from white to red brown, centrifuging and washing the solution until the pH of the supernatant is about 6-6.5, and drying the solution in a forced air drying oven at 60 deg.C for 12 hr. After the solution was completely dried, 100mg of a precipitate was obtained, which was ground in a mortar. Amorphous TiO is obtained₂Ag composite nano-particles.

5mg of the product is added into 4ml of absolute ethyl alcohol, and the mixture is evenly mixed and subjected to ultrasonic treatment for 10 min. The uv-vis absorption test was performed.

The main difference between this example and example 1 is that the irradiation time of the ultraviolet light is changed, which results in the reduction of the crystalline state of the silver nano-particles, and the forbidden bandwidth is significantly widened after the ultraviolet-visible absorption test, as shown in fig. 4. It follows that the light exposure time cannot be too short nor too long.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.