CN108558230A - Silver oxide tungsten bronze composite heat-insulated material with high visible photocatalysis performance and preparation method thereof - Google Patents

Abstract

The invention discloses the silver oxide tungsten bronze composite heat-insulated materials and preparation method thereof with high visible photocatalysis performance.The silver oxide tungsten bronze composite heat-insulated material by silver oxide and tungsten bronze be combined, silver oxide coat potassium tungsten bronze；It is more than 95% to the degradation rate of rhodamine B in radiation of visible light 30min to the rhodamine B solution of a concentration of 20mg/L under conditions of visible light.When preparation, tungsten bronze nano-powder is scattered in deionized water, ultrasonic disperse obtains dispersion liquid A；Silver nitrate is added in dispersion liquid A, is ultrasonically treated under dark condition, is then stirred under dark condition, tungsten bronze and silver nitrate solution are sufficiently mixed, and obtain dispersion liquid B；It is added dropwise in alkaline solution to dispersion liquid B, control ph, sustained response, washing centrifuge again after completion of dropwise addition, dry.Material of the present invention the utilization ratio for being obviously improved visible light simultaneously, also there is the good transparency, near-infrared shielding properties and heat-proof quality.

Description

Silver oxide tungsten bronze composite insulation material with high visible light photocatalytic performance and its Preparation

technical field

The invention relates to a silver oxide tungsten bronze composite heat insulating material with high visible light photocatalytic performance and a preparation method thereof.

Background technique

With the development of human society and industrial production, people's demand for energy continues to increase. Traditional energy sources such as oil and coal are gradually being exhausted, and the energy crisis is becoming more and more serious. At the same time, a large number of pollutants produced by industrial production are harmful to human health. Posing a threat, energy saving and environmental protection are getting more and more attention. Glass is widely used in construction, automobile and so on. On the one hand, ordinary glass has poor thermal insulation performance, which causes the indoor temperature to rise and wastes energy. Therefore, exploring new thermal barrier materials that can be used to prepare insulating glass has become a research hotspot for researchers; on the other hand, ordinary glass Especially after the building curtain wall glass absorbs the organic matter in the air, it will form dirt and the surface will become dirty. Its cleaning has problems such as: high-altitude operation, high risk; using a large amount of detergent, polluting the environment, etc. Therefore, it is an urgent problem to develop a material that can be used to enhance the self-cleaning ability of glass.

Tungsten bronze material is a non-stoichiometric compound containing tungsten. Its chemical formula is M _X WO ₃ , where M is alkali metal, alkaline earth metal, ammonium ion, etc., and x is between 0 and 1. In recent years, researchers have discovered that tungsten bronze nanoparticles can be used as a near-infrared shielding material to prepare transparent heat-insulating films. There have been many reports on the near-infrared shielding performance of tungsten bronze nanoparticles. A preparation method of cesium tungsten bronze nanopowder with near-infrared shielding performance and a functional transparent heat-insulating film.

Photocatalytic degradation of pollutants using sunlight is one of the means of self-cleaning, and the quality of photocatalytic performance determines the strength of self-cleaning ability. There are few studies on the photocatalytic performance of tungsten bronze nanoparticles and their composite materials, and the patent (full-spectrum response type ammonium tungsten bronze#titanium dioxide composite photocatalyst, application number 201610478351.2, announcement number CN106040280A, announcement date 2016.10.26) is published An ammonium tungsten bronze composite titanium dioxide photocatalyst was developed, which used ammonium tungsten bronze as the substrate and supported titanium dioxide. However, titanium dioxide has a large band gap and almost no absorption in the visible light band, so the composite material has a low utilization rate of visible light, which accounts for 43% of the total solar energy. The degradation rate of rhodamine B with a concentration of 20mg/L in 50ml is only 80%, and the visible light photocatalytic performance needs to be improved.

Contents of the invention

The purpose of the present invention is to provide a simple and easy-to-implement silver oxide-coated tungsten bronze composite insulation material with high visible light photocatalytic performance and its preparation method. The material can significantly improve the utilization efficiency of visible light and have high visible light photocatalytic effect , also has good transparency, near-infrared shielding performance and heat insulation performance.

In the present invention, silver oxide nanoparticles are loaded on tungsten bronze, silver nitrate is used as a silver source, and silver oxide nanoparticles are grown on tungsten bronze in a non-uniform nucleation mode by using silver nitrate and alkali solution to react in alkali solution. After centrifugation and drying, the silver oxide/tungsten bronze composite material sample can be obtained. The modified tungsten bronze has greatly improved the utilization efficiency of visible light and the photocatalytic performance of visible light. At the same time, the composite material has good transparency, near-infrared shielding performance and heat insulation performance, and can be used as a candidate material for preparing self-cleaning heat-insulating glass films. The method of the invention has simple process, is easy to implement, and has high practical application value.

The invention improves the visible light photocatalytic performance of the tungsten bronze material through the semiconductor compounding method. Compared with the tungsten bronze material, the photocatalytic performance in the visible light range is greatly improved, and the composite material has good transparency, near-infrared Shielding performance and heat insulation performance, can prepare self-cleaning heat insulation glass film.

The silver oxide and the tungsten bronze of the present invention form a synergistic effect, and while the photocatalytic performance is significantly improved, it also has infrared shielding performance and heat insulation performance. The mechanism of improvement is as follows: on the one hand, silver oxide is a semiconductor material and also a photocatalytic material with a narrow band gap and strong absorption in the visible light region, which can enhance the absorption of visible light by the composite material Strong absorption of visible light is the premise of high visible light photocatalytic performance; on the other hand, silver oxide is a p-type semiconductor, and tungsten bronze is an n-type semiconductor. The combination of the two can form a p-n heterojunction, which can effectively separate photogenerated electrons and space. The holes improve the photocatalytic performance of the composite material.

The object of the invention is achieved through the following technical solutions:

Silver oxide tungsten bronze composite insulation material with high visible light photocatalytic performance: the silver oxide tungsten bronze composite insulation material is composed of silver oxide and tungsten bronze with a mass ratio of 1:400 to 2:1, coated with silver oxide Potassium tungsten bronze; under the condition of visible light, the degradation rate of Rhodamine B exceeds 95% within 30 minutes of visible light irradiation for Rhodamine B solution with a concentration of 20mg/L.

The preparation method of the silver oxide tungsten bronze composite insulation material with high visible light photocatalytic performance is characterized in that it comprises the following steps:

1) Disperse tungsten bronze nanopowder in deionized water, and ultrasonically disperse to obtain dispersion A;

2) Silver nitrate was added to the dispersion A, ultrasonically treated in the dark, the silver nitrate was fully dissolved, and then stirred in the dark, the tungsten bronze and the silver nitrate solution were fully mixed to obtain the dispersion B;

3) Add the alkaline solution dropwise to the dispersion B obtained in step 2), control the pH value of the reaction to 4-12, continue the reaction after the dropwise addition, wash, centrifuge, and dry to obtain a silver oxide-coated tungsten bronze composite Visible light photocatalytic materials.

To further realize the purpose of the present invention, preferably, the tungsten bronze nanopowder is one or more of lithium tungsten bronze, sodium tungsten bronze, potassium tungsten bronze, ammonium tungsten bronze, rubidium tungsten bronze and cesium tungsten bronze nanopowder .

Preferably, the mass ratio of silver nitrate to tungsten bronze in the dispersion A is 1:400˜4:1.

Preferably, the ultrasonic dispersion described in step (1) takes 10-30 minutes.

Preferably, the alkaline solution is one of sodium hydroxide, potassium hydroxide, ammonia water and urea.

Preferably, the concentration of the alkaline solution is 0.001mol/L˜1mol/L.

Preferably, the pH value is 8-12; the ultrasonic power of step 1) and step 2) for ultrasonic dispersion or ultrasonic treatment is 80w; the reaction time after the dropping is 3-20min.

Preferably, the washing is sequentially washing multiple times with deionized water and absolute ethanol respectively.

Preferably, the drying is vacuum drying at 60° C. for 10-20 h; the stirring is magnetic stirring.

Compared with the prior art, the present invention has the following advantages: the present invention obtains a silver oxide/tungsten bronze composite material through composite treatment of nano-silver oxide particles and tungsten bronze photocatalyst, which can greatly improve the performance of tungsten bronze on the one hand. The absorption characteristics of light in the visible light region and the photocatalytic performance of visible light; on the other hand, the composite material has good transparency, near-infrared shielding performance and heat insulation performance, and can be used as a candidate material for the preparation of self-cleaning heat-insulating glass films. In addition, the preparation method of the silver oxide/tungsten bronze composite material of the present invention is simple, easy to implement, mild in synthesis conditions, and can be synthesized at normal temperature and pressure, which is conducive to large-scale promotion.

Description of drawings

Fig. 1 a is the XRD spectrum of the material prepared by embodiment 1 and comparative example 1 and potassium tungsten bronze

Figure 1b is the XRD slow-scan pattern of the silver oxide-coated potassium tungsten bronze composite material at 30-40° in Figure 1a.

2 is a scanning electron microscope image and an energy spectrum image of the silver oxide-coated potassium tungsten bronze composite visible light photocatalyst prepared in Example 1.

Fig. 3 is a visible light photocatalytic degradation efficiency diagram of rhodamine B of the silver oxide-coated potassium tungsten bronze composite visible light photocatalyst and potassium tungsten bronze material prepared in Example 1.

Fig. 4 is a visible-near-infrared transmittance spectrum of a thin film prepared by using the silver oxide-coated potassium tungsten bronze composite insulation material prepared in Example 3.

FIG. 5 is a heat insulation performance diagram of a thin film prepared by using the silver oxide-coated potassium tungsten bronze composite heat insulation material prepared in Example 3. FIG.

Fig. 6 is a mechanism diagram of enhanced visible light photocatalytic performance of the composite material prepared in the present invention.

Detailed ways

In order to better understand the present invention, the present invention will be further described below in conjunction with the examples and drawings, but the embodiments of the present invention are not limited thereto.

Example 1

A method for synthesizing a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of potassium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse it for 10 minutes to obtain dispersion A, weigh 0.029g of silver nitrate solid particles and place them in dispersion A, potassium tungsten bronze and oxidation The mass ratio of silver was 10 to 1; in the dark, after ultrasonic treatment for 10 min, and then magnetic stirring for 30 min in the dark, the dispersion B was obtained.

(2) Add dropwise enough to make all the silver ions in the solution into the 0.01mol/L sodium hydroxide solution of silver oxide in the dispersion B, the pH value of the control reaction is 8, while adding dropwise, magnetically stirred, After the dropwise addition, the magnetic stirring was continued for 5 min. Then, it was washed twice with absolute ethanol and deionized water, centrifuged and dried in vacuum at 60 °C for 12 h to obtain a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 2

A method for synthesizing a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of potassium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse it for 10 minutes to obtain dispersion A, weigh 0.0097g (the mass ratio of potassium tungsten bronze to silver oxide is 30 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add dropwise enough to make all the silver ions in the solution into the 0.01mol/L sodium hydroxide solution of silver oxide in the dispersion B, the pH value of the control reaction is 8, while adding dropwise, magnetically stirred, After the dropwise addition, the magnetic stirring was continued for 5 min. Then, it was washed twice with dehydrated ethanol and deionized water, and dried in vacuum at 60°C for 12 hours to obtain a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 3

A method for synthesizing a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of potassium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse it for 10 minutes to obtain dispersion A, weigh 0.000733g (the mass ratio of potassium tungsten bronze to silver oxide is 200 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add dropwise enough to make all the silver ions in the solution into the 0.01mol/L sodium hydroxide solution of silver oxide in the dispersion B, the pH value of the control reaction is 8, while adding dropwise, magnetically stirred, After the dropwise addition, the magnetic stirring was continued for 5 min. Then, it was washed twice with absolute ethanol and deionized water, and dried in vacuum at 60°C for 12 hours to obtain a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 4

A method for synthesizing a silver oxide sodium tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of sodium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse for 10 minutes to obtain dispersion A, weigh 0.029g (the mass ratio of sodium tungsten bronze to silver oxide is 10 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add dropwise enough to make all the silver ions in the solution into the sodium hydroxide solution of 0.01mol/L of silver oxide in the dispersion B, the pH value of control reaction is 6, while adding dropwise, magnetic stirring, After the dropwise addition, the magnetic stirring was continued for 5 min. Then, it was washed twice with absolute ethanol and deionized water, centrifuged and vacuum-dried at 60°C for 12 hours to obtain a silver oxide sodium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 5

A method for synthesizing a silver-rubidium-tungsten-bronze composite insulation material with high visible light photocatalytic performance, comprising the following steps:

(1) Weigh 0.2g of rubidium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse for 10 minutes to obtain dispersion A, weigh 0.029g (the mass ratio of rubidium tungsten bronze to silver oxide is 10 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add dropwise enough to make all the silver ions in the solution into the sodium hydroxide solution of 0.01mol/L of silver oxide in the dispersion B, the pH value of control reaction is 12, while adding dropwise, magnetic stirring, After the dropwise addition, the magnetic stirring was continued for 5 min. Then, it was washed twice with absolute ethanol and deionized water, centrifuged and vacuum-dried at 60°C for 12 hours to obtain a silver oxide rubidium-tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 6

A method for synthesizing a silver oxide cesium tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of cesium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse for 10 minutes to obtain dispersion A, weigh 0.029g (the mass ratio of cesium tungsten bronze to silver oxide is 10 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 30 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add dropwise enough to make all the silver ions in the solution into the 0.01mol/L sodium hydroxide solution of silver oxide in the dispersion B, the pH value of the control reaction is 8, while adding dropwise, magnetically stirred, After the dropwise addition, magnetic stirring was continued for 10 min. Then, it was washed twice with absolute ethanol and deionized water, centrifuged and vacuum-dried at 60 °C for 12 h to obtain a silver oxide cesium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 7

A method for synthesizing a silver ammonium oxide tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of ammonium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse it for 10 minutes to obtain dispersion A, weigh 0.029g (the mass ratio of ammonium tungsten bronze to silver oxide is 10 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add enough 0.01mol/L urea solution to the dispersion B to convert all the silver ions in the solution into silver oxide, and control the pH value of the reaction to be 8. While adding, magnetic stirring, dropwise adding After the end, continue magnetic stirring for 5 min. Then, it was washed twice with absolute ethanol and deionized water, centrifuged and vacuum-dried at 60°C for 12 hours to obtain a silver oxide ammonium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 8

A method for synthesizing a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.4g of potassium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse for 10min to obtain dispersion A, weigh 0.029g (the mass ratio of potassium tungsten bronze to silver oxide is 10 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add dropwise enough to make all the silver ions in the solution into the 0.01mol/L sodium hydroxide solution of silver oxide in the dispersion B, the pH value of the control reaction is 8, while adding dropwise, magnetically stirred, After the dropwise addition, the magnetic stirring was continued for 5 min. Then, it was washed twice with absolute ethanol and deionized water, centrifuged and vacuum-dried at 60 °C for 12 h to obtain a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 9

A method for synthesizing a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of potassium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse for 10 minutes to obtain dispersion A, weigh 0.029g (the mass ratio of potassium tungsten bronze to silver oxide is 10 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add enough to make all the silver ions in the solution into the sodium hydroxide solution of 0.1mol/L of silver oxide dropwise in the dispersion B, the pH value of control reaction is 8, while adding dropwise, magnetic stirring, After the dropwise addition, magnetic stirring was continued for 10 min. Then, it was washed three times with absolute ethanol and deionized water, centrifuged and vacuum-dried at 60 °C for 12 h to obtain a silver oxide potassium tungsten bronze composite insulation material with high visible light photocatalytic performance.

Example 10

A method for synthesizing a silver ammonium oxide tungsten bronze composite insulation material with high visible light photocatalytic performance, comprising the steps of:

(1) Weigh 0.2g of ammonium tungsten bronze and add it to a beaker with 50ml of deionized water, ultrasonically disperse it for 10 minutes to obtain dispersion A, weigh 0.029g (the mass ratio of ammonium tungsten bronze to silver oxide is 10 to 1) nitric acid The silver solid particles were placed in the dispersion A, and after being ultrasonicated for 10 minutes in the dark, and then magnetically stirred for 30 minutes in the dark, the dispersion B was obtained.

(2) Add enough to make all the silver ions in the solution into the sodium hydroxide solution of 0.1mol/L of silver oxide dropwise in the dispersion B, the pH value of control reaction is 8, while adding dropwise, magnetic stirring, After the dropwise addition, the magnetic stirring was continued for 5 min. Then, it was washed twice with absolute ethanol and deionized water, centrifuged and vacuum-dried at 60°C for 12 hours to obtain a silver oxide ammonium tungsten bronze composite insulation material with high visible light photocatalytic performance.

The test methods for the visible light photocatalytic performance, near infrared shielding performance and heat insulation performance of the silver oxide tungsten bronze composite insulation material with high visible light photocatalytic performance obtained in the examples are as follows:

In order to test the visible light photocatalytic performance of the silver oxide-coated tungsten bronze composite material prepared in the embodiment of the present invention, the visible light photocatalytic degradation experiment of Rhodamine B organic dye was carried out on the prepared composite material. Weigh 0.025g of the composite material prepared in each example, place it in a 250ml beaker, add 50ml of rhodamine B solution with a concentration of 20mg/L, and stir magnetically for 30min in the dark to achieve adsorption equilibrium. Subsequently, use a 300W xenon lamp as a visible light source, with a lamp distance of 15cm, turn on the lamp to irradiate the rhodamine B solution, take out 2ml of the solution from the beaker every 5min, continue to irradiate for 30min, and measure it with a Cary-60 UV-Vis spectrophotometer produced by Agilent. The concentration of rhodamine B solution with different light time was used to evaluate the visible light photocatalytic performance of the prepared composite material according to the measured concentration of rhodamine B.

The test steps for the near-infrared shielding performance of the silver oxide-coated tungsten bronze composite material prepared by the present invention are as follows: uniformly mix the sample to be tested and the film-forming aid according to a certain ratio, and evenly scrape and coat it on a 10×10cm optical glass sheet , vacuum-dried at 60°C for 1 h before use. Use a UV-visible-near-infrared spectrophotometer to test the transmittance of the sample, and then use the following integral formula

Calculate the rejection rate of the composite material to near-infrared rays.

In order to test the heat insulation performance of the silver oxide-coated tungsten bronze composite material prepared in the present invention, a self-made heat insulation device is used for detection. The incubator is made of polystyrene board bonded by polyurethane adhesive, and the specification is: 20×20×20cm cube, with an opening of 10×10cm at the top center of the box.

The steps of heat insulation performance test are: uniformly mix the sample to be tested with film-forming aid in a certain proportion, evenly scrape and coat it on a 10×10cm optical glass sheet, and dry it in vacuum at 60°C for 1 hour before use. Place the glass piece to be tested at the top center opening of the incubator, with the surface coated with the sample facing up, and place the digital display thermometer inside the incubator. A 100w infrared lamp is used as a light source, and the lower surface of the infrared lamp is 45cm from the center of the upper surface of the incubator. The room temperature was kept constant, and when the infrared lamp was turned on, a stopwatch was used to time the time, and the temperature in the incubator was recorded every 5 minutes, and the experiment time was 90 minutes.

Figure 1a is the XRD spectrum of the materials prepared in Example 1 and Comparative Example 1 and potassium tungsten bronze, the instrument used is X'Pert PRO X-ray diffractometer from PANalytical Company in the Netherlands, using Cu target K _α ray. Among the figure, e, f, g collection of illustrative plates correspond respectively to the X-ray diffraction collection of potassium tungsten bronze, comparative example 2, the material prepared in embodiment 1, can draw from the figure, the phase of matter of the material prepared in embodiment 1 is basically the same as that of potassium tungsten bronze. The phase of tungsten bronze is consistent, and there is an additional relatively short peak at 38.067°. Figure 1b is the XRD slow-scan pattern of the silver oxide-coated potassium tungsten bronze composite material in Figure 1a at 30-40°, which can be clearly observed There is a peak at 38.067°, which belongs to the peak corresponding to the crystal plane of silver oxide (200) with card number 00-041-1104.

Fig. 2 is the SEM spectrum and the energy spectrogram of the composite material prepared in Example 1, and the instrument used is a SEM430 ultra-high resolution field emission microscope produced by Nova Nano Company. It can be seen from the figure that potassium tungsten bronze is in the shape of a long rod, and there is silver element in the material composition.

3 is a graph showing the photocatalytic degradation curve of 20 mg/L rhodamine B of the silver oxide-coated potassium tungsten bronze composite material and potassium tungsten bronze prepared in Example 1 under the irradiation of visible light (wavelength range 420-780nm). It can be seen from the figure that the silver oxide-coated potassium tungsten bronze composite material prepared in Example 1 with a mass ratio of potassium tungsten bronze and silver oxide of 10:1 has a degradation rate of more than 95% for rhodamine B after 30 min of visible light irradiation . However, the degradation rate of rhodamine B on potassium tungsten bronze was only 9% after 30min of visible light irradiation. Therefore, the visible light photocatalytic performance of the composite material loaded with silver oxide nanoparticles on potassium tungsten bronze is significantly improved.

Figure 4 shows the transmittance in the wavelength range of 380-2500nm from the silver oxide-coated potassium tungsten bronze composite material and the film prepared from potassium tungsten bronze prepared in Example 3, respectively. It can be seen from the figure that the film prepared from the composite material obtained in Example 3 has a shielding rate of more than 70% for near-infrared rays.

Fig. 5 is a graph showing the heat insulation performance test results of the silver oxide-coated potassium tungsten bronze composite material and the film prepared from potassium tungsten bronze prepared in Example 3, respectively. It can be seen from the figure that the temperature of the film prepared from the composite material prepared in Example 3 is 5.7° C. lower than that of the film without adding materials.

Figure 6 is a mechanism diagram of the enhanced visible light photocatalytic performance of the composite material prepared by the present invention. It can be seen from the figure that silver oxide is a p-type semiconductor with a band gap of 1.4eV, which has strong absorption of visible light and is coated on tungsten bronze The surface energy can effectively enhance the absorption capacity of the composite material for visible light, and the strong absorption capacity for visible light is the prerequisite for high visible light photocatalytic activity; at the same time, tungsten bronze is an n-type semiconductor with a band gap close to 2.5eV, and the surface of tungsten bronze is coated with After silver oxidation, the two form a p-n heterojunction. Under the irradiation of visible light, both silver oxide and tungsten bronze can generate photogenerated electrons and holes. Photogenerated electrons will be transferred from silver oxide to tungsten bronze, and photogenerated holes will be transferred from tungsten bronze to silver oxide, which realizes the separation of photogenerated electrons and holes, thus significantly improving the photocatalytic performance of visible light.

The visible light photocatalytic performance, near-infrared shielding performance and heat insulation performance test results of the silver oxide tungsten bronze composite thermal insulation material with high visible light photocatalytic performance obtained in different embodiments of the present invention are basically the same as those of the above-mentioned embodiment 1 and embodiment 3, but Offer them one by one. All the materials obtained in the examples have a degradation rate of more than 95% to rhodamine B within 30min under the irradiation of a visible light source of 300W, and the film produced has a barrier rate of more than 70% to near-infrared light, compared with the film without adding this product The temperature dropped by more than 5.7°C.

It can be seen from the test results of the above examples and the accompanying drawings that the silver oxide-coated tungsten bronze composite material is synthesized in the present invention under normal temperature and pressure, and the synthesis process is simple and easy to implement. At the same time, the invention improves the utilization efficiency of tungsten bronze to visible light, and obtains a composite material with high visible light photocatalytic effect. The composite material also has good transparency, near-infrared shielding performance and heat insulation performance, and the material can be used to prepare The self-cleaning heat-insulating glass film has excellent application prospects.

The above embodiments do not limit the technical solution of the present invention in any form, and any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to the scope of the technical solution of the present invention.

Claims (10)

1. the silver oxide tungsten bronze composite heat-insulated material with high visible photocatalysis performance, it is characterised in that：The silver oxide tungsten Bronze composite heat-insulated material is 1 by mass ratio:400~2:1 silver oxide and tungsten bronze is combined, and it is green that silver oxide coats potassium tungsten Copper；Under conditions of visible light, to the rhodamine B solution of a concentration of 20mg/L, to rhodamine B in radiation of visible light 30min Degradation rate be more than 95%.

2. the preparation side of the silver oxide tungsten bronze composite heat-insulated material described in claim 1 with high visible photocatalysis performance Method, it is characterised in that include the following steps：

1) tungsten bronze nano-powder is scattered in deionized water, ultrasonic disperse obtains dispersion liquid A；

2) silver nitrate is added in dispersion liquid A, is ultrasonically treated under dark condition, silver nitrate fully dissolves, then in dark item It is stirred under part, tungsten bronze and silver nitrate solution are sufficiently mixed, and obtain dispersion liquid B；

3) it is 4-12 to be added dropwise and control the pH value of reaction in the dispersion liquid B obtained by alkaline solution to step 2), is held again after completion of dropwise addition Continuous reaction, is washed, and is centrifuged, dry, obtains silver oxide cladding tungsten bronze composite visible light catalysis material.

3. the system of the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation Method, it is characterised in that：The tungsten bronze nanometer powder be lithium tungsten bronze, sodium tungsten bronze, potassium tungsten bronze, ammonium tungsten bronze, It is one or more in rubidium tungsten bronze and caesium tungsten bronze nanometer powder.

4. the system of the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation Method, it is characterised in that：The mass ratio of silver nitrate and tungsten bronze is 1 in the dispersion liquid A:400~4:1.

5. the system of the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation Method, it is characterised in that：The time of ultrasonic disperse described in step (1) is 10-30min.

6. the system of the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation Method, it is characterised in that：The alkaline solution is one kind in sodium hydroxide, potassium hydroxide, ammonium hydroxide and urea.

7. the system of the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation Method, it is characterised in that：A concentration of 0.001mol/L~1mol/L of the alkaline solution.

8. the system of the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation Method, it is characterised in that：The pH value is 8-12；The ultrasonic power of step 1) and step 2) ultrasonic disperse or supersound process For 80w；The time of sustained response is 3-20min again after the completion of dropwise addition.

9. the system of the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation Method, it is characterised in that：The washing is to use deionized water and absolute ethyl alcohol to wash successively repeatedly respectively.

10. the silver oxide tungsten bronze composite heat-insulated material according to claim 2 with high visible photocatalysis performance Preparation method, it is characterised in that：The drying is to be dried in vacuo 10-20h at 60 DEG C；The stirring is magnetic agitation.