TWI577560B - Nano composite film and method of fabricating the same - Google Patents

Description

Nano composite film and manufacturing method thereof

The present invention relates to a nanocomposite film and a method for producing the same, and more particularly to a nanocomposite film having visible light catalytic ability and a method for producing the same.

"Photocatalyst" (or photocatalyst) is a special catalyst that must be catalyzed by the energy of absorbing light to chemically react with the reactants to promote the degradation, synthesis, and inhibition of organic compounds. This process is called " Photocatalytic reaction". Most of today's photocatalysts react under the action of ultraviolet light.

However, in the solar light source distribution, the ultraviolet light portion accounts for only about 5 percent of the total solar energy, so the photocatalyst utilizes solar energy efficiency very low, and the ultraviolet light content is lower in the indirect region. In addition, in the indoor light source, the ultraviolet light content is also very low, and the ultraviolet light is harmful to the human body, which may cause skin lesions.

At present, the industry is working on a visible light catalytic material that has high photocatalytic properties under visible light. However, most of the above visible light catalyzed materials are studied by powder process technology. However, photocatalytic powders with high surface area should be It must be used on the substrate, and once it is fixed on the substrate, its surface area will be reduced, which will limit its photocatalytic ability. Therefore, how to develop a photocatalytic film with visible light catalysis, visible light penetration, ultraviolet shielding, weak photocatalytic bacteriostasis and low cost will become an important issue in the future.

The invention provides a nano composite film and a method for producing the same, which have high visible light transmittance and visible light catalytic ability.

The invention provides a nano composite film and a method for producing the same, which have excellent weak photocatalytic bacteriostatic ability.

The present invention provides a nanocomposite film which can be disposed on a substrate. The above nanocomposite film comprises a plurality of titanium dioxide particles and a plurality of silver nanoparticles. The above silver nanoparticles are uniformly distributed between the above titanium dioxide particles. The above silver nanoparticles have a particle diameter of less than 10 nm. The content of the above silver nanoparticles is from 1 vol% to 5 vol%.

In an embodiment of the invention, the silver nanoparticles have a particle diameter of 5 nm to 10 nm.

In an embodiment of the invention, the nano composite film has a thickness of 50 nm to 300 nm.

In an embodiment of the invention, the nanocomposite film can absorb ultraviolet light and pass visible light, and has visible light catalyzing ability.

The invention provides a method for manufacturing the above nano composite film, the steps thereof as follows. A titanium dioxide solution is provided. The silver ion solution was uniformly mixed with the above titanium oxide solution to form a mixed solution. A reducing agent is added to the mixed solution to cause silver ions in the mixed solution to undergo a reaction of reducing precipitation of nano silver. The above mixed solution is dried to form a nano composite powder. The above nano composite powder is subjected to a hot pressing process to form a target. The substrate is subjected to a sputtering process using the target to form a nanocomposite film on the substrate.

In an embodiment of the invention, the reducing agent comprises sodium borohydride (NaBH ₄ ), hydrazine or a combination thereof.

In an embodiment of the invention, the step of adding a reducing agent to the mixed solution further includes performing a cooling treatment. The temperature of the above cooling treatment is from 0 ° C to 25 ° C.

In an embodiment of the invention, in the step of performing a sputtering process on the substrate, wherein the temperature of the substrate is lower than 100 ° C.

In an embodiment of the present invention, after the step of performing the sputtering process on the substrate, the annealing treatment is not performed, so that the silver nanoparticles in the nano composite film are not precipitated and exposed, thereby causing nano The danger of particle shedding.

In an embodiment of the invention, the sputtering process includes RF magnetron sputtering.

Based on the above, the present invention utilizes a target prepared from a nanocomposite powder of silver nanoparticles and titanium dioxide particles to form a nanocomposite film on a substrate through a sputtering process. The silver nanoparticles of the nanocomposite film can be uniformly distributed between the titanium dioxide particles. Moreover, the above-mentioned silver nanoparticle has a particle diameter of less than 10 nm, so that the present hair The bright nano composite film has the effects of visible light catalysis, visible light penetration and ultraviolet absorption. Further, since the above-mentioned silver nanoparticles have a small particle diameter, they are not easily peeled off or scraped off, so that the problem of dust poisoning of the silver nanoparticles is not caused, or the effect of the substrate is not affected when applied.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧Substrate

101‧‧‧Nano composite film

102‧‧‧ Titanium dioxide particles

104‧‧‧Silver Nanoparticles

1 is a schematic cross-sectional view of a nanocomposite film according to an embodiment of the invention.

2 is a transmission electron microscope (TEM) photograph of the nanocomposite film of Experimental Example 2.

3 is an X-ray diffraction (XRD) analysis chart of the nanocomposite film of Experimental Example 2.

4 is a field emission scanning electron microscope (FE-SEM) photograph of a nanocomposite film of Experimental Example 2.

Fig. 5 is a graph showing the dye cracking rate versus time for the nanocomposite films of Comparative Examples 1 and 2 and Experimental Examples 1 to 3 under irradiation with visible light and ultraviolet light.

Fig. 6 is an ultraviolet-visible light transmission spectrum of a nanocomposite film of Comparative Example 2 and Experimental Examples 1 to 3.

7 is an ultraviolet light-visible film of Comparative Example 2 and Experimental Examples 1 to 3 nanocomposite film. Light absorption spectrum.

Fig. 8 is a bar graph showing the survival rate of Escherichia coli of the composite films of Comparative Examples 2 to 5 and Experimental Examples 1 to 3 in a dark environment.

Fig. 9 is a bar graph showing the survival rate of Escherichia coli of the composite films of Comparative Examples 2 to 5 and Experimental Examples 1 to 3 in a visible light environment.

1 is a schematic cross-sectional view of a nanocomposite film according to an embodiment of the invention.

Referring to FIG. 1, the nano composite film 101 of the present embodiment can be disposed on a substrate 100. In the present embodiment, the substrate 100 may be, for example, soda-lime glass. Although the present embodiment is based on sodium silicate, the present invention is not limited thereto. In other embodiments, the substrate 100 may also be a substrate such as glass, tile, metal component, plastic product, fabric, non-woven fabric, or the like. .

The nanocomposite film 101 includes a plurality of titanium dioxide particles 102 and a plurality of silver nanoparticles 104. The silver nanoparticles 104 are uniformly distributed between the titanium oxide particles 102 and are not aggregated on the surface of the substrate 100 or the nanocomposite film 101. In the present embodiment, the silver nanoparticle 104 has a particle diameter of less than 10 nm. The silver nanoparticle 104 has a particle diameter of between 5 nm and 10 nm, and the silver nanoparticle 104 has a content of from 1 vol% to 5 vol%. The particle size of the titanium dioxide particles 102 is between 10 nm and 30 nm. The thickness of the nanocomposite film 101 is between 50 nm and 300 nm. In this embodiment, the titanium dioxide particles 102 can absorb ultraviolet light; and the silver nano particles 104 can be increased. See light absorption and enhance the visible light catalysis ability of the nanocomposite film 101. In addition, since the thickness of the nanocomposite film 101 is thin enough and the silver nanoparticles 104 are uniformly distributed between the titanium dioxide particles 102, the nanocomposite film 101 of the present embodiment can absorb not only ultraviolet light but also visible light. It also has visible light catalysis.

The present invention provides a method of producing a nanocomposite film 101, the steps of which are as follows. A titanium dioxide solution is provided. In detail, the titanium oxide powder may be added to a solvent and stirred using a magnet mixer to uniformly disperse the titanium oxide powder in a solvent to avoid an aggregation phenomenon. In an embodiment, the solvent can be, for example, DI water, an alcohol, or a combination thereof.

Then, the silver ion solution was uniformly mixed with the above titanium oxide solution to form a mixed solution. In detail, the silver ions are first dissolved in a solvent and oscillated by an ultrasonic oscillator, so that the above silver ions are completely dissolved in the solvent. In this embodiment, the silver ion solution may be, for example, a silver nitrate solution, silver acetate, or a combination thereof; and the solvent may be, for example, DI water, an alcohol, or a combination thereof. Next, the above completely dissolved silver ion solution was added to the above titanium oxide solution, and stirring was continued using a magnet mixer.

Thereafter, the mixed solution is subjected to a cooling treatment, and a reducing agent is added to the mixed solution to cause a silver ion in the mixed solution to undergo a reduction reaction. In the present embodiment, the cooling treatment may be, for example, placing the above mixed solution in an ice bath. The temperature of the cooling treatment may be between 0 ° C and 25 ° C. The purpose of the cooling treatment is because the nucleation rate of the silver nanoparticles in the above reduction reaction can be lowered in the cooling treatment environment to avoid the aggregation of the silver nanoparticles. In an embodiment, the reducing agent can be, for example, sodium borohydride (NaBH ₄ ), hydrazine, or a combination thereof. In the present embodiment, an ultrasonic sonicator may be used to uniformly disperse the silver nanoparticles in the above mixed solution while performing the above reduction reaction.

Next, the mixed solution is subjected to a drying treatment to form a nano composite powder. In the present embodiment, the drying treatment can be carried out using a vacuum concentrator to completely remove the above solvent.

Thereafter, the above nano composite powder is poured into a mold to perform a hot pressing process to form a target. In the present embodiment, the target may be, for example, a circular ingot shaped target having a diameter of 2 Å and a thickness of about 4 mm. The above target is composed of silver nanoparticles and titanium dioxide particles.

Next, the substrate is subjected to a sputtering process using the target to form the nanocomposite film 101 on the substrate. In this embodiment, the sputtering process can be, for example, a radio frequency magnetron sputtering process. It should be noted that in the step of performing the sputtering process on the substrate, the temperature of the substrate may be, for example, less than 100 °C. Since the temperature of the substrate is too high, the silver nanoparticles in the formed nanocomposite film 101 are aggregated and precipitated on the surface of the nanocomposite film 101. Further, after the step of the above-described sputtering process, the annealing treatment is not performed, so that the silver nanoparticles 104 in the above-mentioned nanocomposite film 101 are not aggregated and precipitated.

In order to demonstrate the achievability of the present invention, the nanocomposite film 101 of the present invention will be further illustrated by enumerating a plurality of experimental examples and a plurality of comparative examples. Although the following experiments are described, the materials used, the amounts and ratios thereof, the processing details, the processing flow, and the like can be appropriately changed without departing from the scope of the invention. Therefore, the invention should not be construed restrictively based on the experiments described below.

First, a production method and an experimental method of Experimental Example 1 (a nanocomposite film having a plurality of titanium oxide particles and a plurality of silver nanoparticles, hereinafter abbreviated as Ag/TiO ₂ film) will be described.

Experimental Example 1: Ag/TiO with a silver content of 1 vol% (volume percent) ₂ film Ag/TiO ₂ Powder preparation

First, 24.42 g of 40 nm particle size TiO ₂ powder was added to 400 ml of deionized water and stirred using a magnet mixer for more than two hours. The purpose of the agitation is to uniformly disperse the TiO ₂ powder in deionized water to avoid agglomeration. Next, 0.58 g of AgNO ₃ powder was dissolved in 20 ml of deionized water and shaken for 10 minutes using an ultrasonic oscillating machine to completely dissolve it. The above completely dissolved AgNO ₃ solution was added to the above TiO ₂ solution to form a mixed solution. Thereafter, the above mixed solution was continuously stirred for three hours or more using a magnet mixer.

Then, 0.13 g of NaBH ₄ powder having a molar ratio of AgNO ₃ :NaBH ₄ =1:1 was taken, and the NaBH ₄ powder was completely dissolved in 10 ml of deionized water using an ultrasonic oscillator. Next, the above mixed solution was placed in an ice bath. The above NaBH ₄ solution is further added to the mixed solution by means of a dropper, so that the silver nitrate in the mixed solution is reduced to silver nanoparticles, and at this time, the mixed solution is converted from white to brown, which indicates that the reduction reaction is completed. At the same time as the above reduction reaction, an ultrasonic shatter can also be used to uniformly disperse the reduced silver nanoparticles.

Next, the deionized water was completely removed using a vacuum concentrator to leave a dry brown Ag/TiO ₂ powder. The above Ag/TiO ₂ powder was further ground using an agate mortar.

Ag/TiO ₂ Taojin target preparation

24 g of the above-prepared Ag/TiO ₂ powder was poured into a graphite mold, and the hot pressing temperature was set at 970 ° C due to different melting point considerations, and hot pressing was performed under Ar gas. The above hot pressing process was performed by applying a pressure of 150 psi from above the graphite mold and holding the temperature for 30 minutes. Finally, a pottery gold target composed of a circular ingot Ag/TiO _{2 having} a diameter of 2 Å and a thickness of about 4 mm was prepared.

Ag/TiO ₂ Film preparation

After the prepared Ag/TiO ₂ pottery gold target was surface-polished and ground, a silver content of 1 vol% Ag was sputtered on a 20 mm×20 mm×1 mm soda glass substrate by a radio frequency (RF) magnetron sputtering machine. The /TiO ₂ film, hereinafter referred to simply as the Ag/TiO ₂ film of Experimental Example 1. The sputtering time is 1 hour, the power is 80W, the sputtering gas is argon gas, and the working pressure is 3×10 ^-3 torr. It should be noted that the temperature of the sputtered substrate is an unheated room temperature, and the heating temperature of the substrate under the action of plasma may be, for example, less than 100 °C.

Photocatalytic experiment

The Ag/TiO ₂ film of Experimental Example 1 is used as a photocatalyst, the Acid Black is used as the dye, and the mercury lamp is used as the light source. Since the source of the mercury xenon lamp covers infrared light, visible light, and ultraviolet light, the filter is added in the experiment. The film only passes visible light and ultraviolet light.

First, the Ag/TiO ₂ film of Experimental Example 1 plated on soda glass (20 mm × 20 mm) was placed in a 50 ml dye solution having a concentration of 10 ppm. Next, the above dye solution and the Ag/TiO ₂ film of Experimental Example 1 were placed on a magnet mixer to be stirred and irradiated with a light source. In order to observe the change in the concentration of the dye solution, 5 ml of the dye solution was taken every 20 minutes. The total observation time was 80 minutes, during which the dye solution was taken out 5 times. Finally, the extracted dye solution was separated by a centrifuge, and subjected to UV-vis absorption spectrum analysis at a wavelength of 615 nm. This is to confirm the case where the visible light and the dye under the ultraviolet light are decomposed.

Next, preparation and experiments of the Ag/TiO ₂ thin films of Comparative Examples 1 to 2 and Experimental Examples 2 to 3 were carried out in a manner similar to the above.

2 is a transmission electron microscope (TEM) photograph of the nanocomposite film of Experimental Example 2. 3 is an X-ray diffraction (XRD) analysis chart of the nanocomposite film of Experimental Example 2. 4 is a field emission scanning electron microscope (FE-SEM) photograph of a nanocomposite film of Experimental Example 2.

Experimental Example 2: Ag/TiO having a silver content of 3 vol% ₂ film

Experimental Example 2 was to prepare a Ag/TiO ₂ film having a silver content of 3 vol% by using 23.32 g of 40 nm particle diameter TiO ₂ powder, 1.68 g of AgNO ₃ powder, and 0.37 g of NaBH ₄ powder, and in the same manner as in Experimental Example 1. Hereinafter, it is simply referred to as the Ag/TiO ₂ film of Experimental Example 2. As shown in FIG. 2, the nanocomposite film 101 of Experimental Example 2 (i.e., the Ag/TiO ₂ film) includes a plurality of titanium oxide particles 102 and a plurality of silver nanoparticles 104. Silver nanoparticles 104 having a particle size of less than 10 nm (a plurality of black particles in Fig. 2, i.e., portions indicated by white dashed line boxes) are uniformly distributed between the titanium dioxide particles 102. As shown in FIG. 3, the Ag/TiO ₂ film of Experimental Example 2 had anatase crystal phase titanium oxide and pure silver. The surface of the Ag/TiO ₂ film of Experimental Example 2 was observed by a field emission scanning electron microscope (FE-SEM). As can be seen from Fig. 4, the particles on the surface of the Ag/TiO ₂ film formed in Experimental Example 2 were uniformly distributed, and the whole appeared to be very flat, and the surface morphology thereof was not affected by the silver nanoparticles.

Experimental Example 3: Ag/TiO having a silver content of 5 vol% ₂ film

Experimental Example 3 was to prepare a Ag/TiO ₂ film having a silver content of 5 vol% by using 22.275 g of 40 nm particle size TiO ₂ powder, 2.725 g of AgNO ₃ powder, and 0.61 g of NaBH ₄ powder, and in the same manner as in Experimental Example 1. Hereinafter, it is simply referred to as the Ag/TiO ₂ film of Experimental Example 3.

Comparative example 1

In Comparative Example 1, the photocatalytic experiment was carried out in the same manner as described above using the Ag/TiO ₂ film of Experimental Example 2 (the silver content of which is 3 vol%) without being irradiated with visible light and ultraviolet light, hereinafter referred to as Comparative Example 1. Ag/TiO ₂ film.

Comparative Example 2: Ag/TiO with a silver content of 0 vol% ₂ film

Comparative Example 2 was to prepare a Ag/TiO ₂ film having a silver content of 0 vol% by using 25 g of a 40 nm particle diameter TiO ₂ powder, 0 g of AgNO ₃ powder, and 0 g of NaBH ₄ powder, in the same manner as in Experimental Example 1. Hereinafter, it is simply referred to as the Ag/TiO ₂ film of Comparative Example 2.

Thereafter, the experimental results of Comparative Examples 1 and 2 and Experimental Examples 1 to 3 were plotted to obtain a dye cracking rate as a function of time, wherein the horizontal axis is time (minutes) and the vertical axis is dye decomposition rate (residual concentration/original concentration). , expressed as C/C ₀ ).

Fig. 5 is a graph showing the dye cracking rate versus time for the nanocomposite films of Comparative Examples 1 and 2 and Experimental Examples 1 to 3 under irradiation with visible light and ultraviolet light.

Silver content 5 Comparative Example of Ag ₂ / TiO 2 film, and the experimental examples 1, 2, Ag / TiO ₂ films were 0vol%, 1vol%, 3vol% , 5vol%, the irradiation with visible light and After 80 minutes of ultraviolet light, the Ag/TiO ₂ film of Experimental Example 2 (having a silver content of 3 vol%) reached a dye cracking rate of approximately 18.8%. On the other hand, in Comparative Example 1, the Ag/TiO ₂ film of Comparative Example 1 (having a silver content of 3 vol%) did not cleave the dye at all without being irradiated with visible light and ultraviolet light.

The above results demonstrate that the Ag/TiO ₂ film of Experimental Example 2 (having a silver content of 3 vol%) has a photocatalytic effect of visible light and ultraviolet light. In contrast, the Ag/TiO ₂ film of Comparative Example 2 (having a silver content of 0 vol%), the Ag/TiO ₂ film having silver nanoparticles can enhance visible light absorption to promote visible light catalysis.

Fig. 6 is an ultraviolet-visible light transmission spectrum of a nanocomposite film of Comparative Example 2 and Experimental Examples 1 to 3. Fig. 7 is an ultraviolet-visible absorption spectrum of a nanocomposite film of Comparative Example 2 and Experimental Examples 1 to 3.

6, Comparative Example silver content of Ag ₂ / TiO 2 film, and the experimental examples 1, 2, Ag / TiO ₂ films were 0vol%, 1vol%, 3vol% , 5vol%. The transmittance of Experimental Example 3 is smaller than that of Experimental Example 2 at a wavelength of 350 nm to 800 nm; the transmittance of Experimental Example 2 is smaller than that of Experimental Example 1; the penetration rate of Experimental Example 1 is smaller than that of Comparative Example 2 penetration rate. This is because the silver nanoparticle can absorb light of a wavelength of 350 nm to 800 nm (as shown in FIG. 7), and therefore, the transmittance of the Ag/TiO ₂ film is lowered as the content of the silver nanoparticle is increased. However, the Ag/TiO ₂ film of Experimental Example 2 still retained 70% transmittance in the visible light wavelength range. The above results prove that the Ag/TiO ₂ film of Experimental Example 2 is still light-transmitting, and therefore, covering the substrate does not affect the appearance and penetration of the original substrate.

Photocatalytic bacteriostatic experiment

First, an appropriate amount of E. coli solution prepared on the previous day was taken out from the shaker. The above E. coli bacterial solution was added to a liquid culture solution (Luria-Bertani broth, LB broth) at a ratio of 1:100 to enlarge, and the purpose was to dilute and activate the above E. coli bacterial solution. Then, 1 ml of each of the liquid culture solution (without E. coli) and the diluted E. coli bacteria solution was separately dropped into different quartz tubes, and the concentration of the bacteria solution was measured by a biochemical analysis spectrometer. Using the above liquid culture solution (without E. coli) as the background value, the optical density value (Optical Density, OD, where 1 OD = 6 × 10 ⁷ CFU, CFU is Colony-) of the diluted E. coli bacteria solution was measured using a wavelength of 595 nm. Forming Units). After the measurement, the 1OD bacterial solution was formulated to a concentration of 2 × 10 ⁵ CFU using LB broth. Next, a good concentration of the bacterial solution was prepared, and 50 μl was dropped on the sample. The samples in which the bacterial liquid was dropped were placed in a 20 W fluorescent lamp (i.e., in the environment of illuminating visible light, and the experimental results are shown in Fig. 9) and in a dark environment (the experimental results are shown in Fig. 8) for 30 minutes and 60 minutes. After the above standing time (30, 60 minutes) was over, 10 μl of the bacterial liquid was taken from the test piece and diluted to 1000 times. 50 μl of the bacterial solution diluted 1000-fold was dropped onto a solid medium (LB agar plates) and uniformly coated until dry. Thereafter, the coating was completed, and the solid medium was placed in an oven at 37 ° C for 12 hours. Finally, the solid medium was taken out of the oven and the colonies on the solid medium were counted.

Next, the photocatalytic bacteriostatic experiments of Experimental Examples 1 to 3 and Comparative Examples 2 to 5 were carried out in a manner similar to the above.

Comparative example 3

Comparative Example 3 The above photocatalytic bacteriostatic test was carried out using only glass (uncovered Ag/TiO ₂ film).

Comparative example 4

Comparative Example 4 was an Ag/TiO ₂ film of Experimental Example 2, and then annealed at 500 ° C for one hour in air to form an Ag/TiO ₂ film of Comparative Example 4 having a silver content of 3 vol%, hereinafter referred to as comparison. The Ag/TiO ₂ film of Example 4. Next, the above photocatalytic bacteriostatic test was carried out using the Ag/TiO ₂ film of Comparative Example 4.

Comparative Example 5

Comparative Example 5 using Comparative Example 4 of Ag / TiO ₂ film, and then, using of NaBH ₄ solution to the silver oxide of Comparative Example 4 of Ag / TiO ₂ film in the reduction treatment, to form a silver content of Comparative Example 5 of 3vol% The Ag/TiO ₂ film is hereinafter referred to as the Ag/TiO ₂ film of Comparative Example 5. Next, the above photocatalytic bacteriostatic test was carried out using the Ag/TiO ₂ film of Comparative Example 5.

Fig. 8 is a bar graph showing the survival rate of Escherichia coli of the composite films of Comparative Examples 2 to 5 and Experimental Examples 1 to 3 in a dark environment. Fig. 9 is a bar graph showing the survival rate of Escherichia coli of the composite films of Comparative Examples 2 to 5 and Experimental Examples 1 to 3 in a visible light environment.

As shown in Fig. 8 and Fig. 9, the survival rate of the bacteria in Comparative Example 3 was not reduced in the visible light environment or in the dark (unilluminated) environment, but a slight increase was observed. The survival rate of the bacteria in Comparative Example 2 increased in the dark environment with an increase in time; while in the visible light environment, it had a slight effect of inhibiting the growth of bacteria, and the bacterial survival amount was only slightly lowered. In Experimental Example 1, the photocatalytic bacteriostatic ability of Experimental Example 1 began to increase significantly under the visible light environment, after 60 minutes of illumination, Bacterial survival has dropped to 60%. Further, in Experimental Example 1, the bacterial survival rate in the dark environment was slightly lower than that of Comparative Example 2 by about 10%.

In Experimental Example 2, the photocatalytic ability was remarkably improved. Under the irradiation of 20W fluorescent lamp, not only the titanium dioxide particles can absorb ultraviolet light, but the silver nano particles can also increase the visible light absorption to enhance the visible light catalysis ability of the Ag/TiO ₂ film of Experimental Example 2. Since the Ag/TiO ₂ film of Experimental Example 2 has not only ultraviolet light catalysis ability but also visible light catalysis ability, Experimental Example 2 has no bacteria to survive after standing for 60 minutes (as shown in FIG. 9). Obviously, Experimental Example 2 has a high photocatalytic bacteriostatic ability. In addition, in the dark environment, since only the silver nanoparticles are bacteriostatic, the bacterial survival rate is about 70% after standing for 60 minutes.

Since the silver content of the Ag/TiO ₂ film of Experimental Example 3 is larger than the silver content of the Ag/TiO ₂ film of Experimental Example 2, in Experimental Example 3, the photocatalytic speed inhibition ratio in the visible light environment is compared with the experimental example. 2) In the dark environment, the bacterial survival rate of Experimental Example 3 was also lower than that of Experimental Example 2 (only 60% of the bacterial survival rate remained after 60 minutes of standing).

In Comparative Example 4, the bacterial survival of Comparative Example 4 was about 90% in a dark environment and after standing for 60 minutes (as shown in Fig. 8); while in the visible light environment, the bacteria of Comparative Example 4 survived. The amount is about 70% (as shown in Figure 9). This may be because most of the silver nanoparticles in Comparative Example 4 are oxidized, which causes the photocatalytic ability of the silver nanoparticles to be lowered, which in turn leads to a significant decrease in photocatalytic bacteriostatic ability. The photocatalytic bacteriostatic ability of Comparative Example 5 showed an upward trend in comparison with Comparative Example 4 in both the dark environment and the visible light environment. However, compared with the experimental example 2, since the silver nanoparticles in the Ag/TiO ₂ film of Comparative Example 5 are subjected to a reduction treatment, voids are generated, which causes the interface between the silver nanoparticles and the titanium dioxide particles to be not dense. Thereby, the visible light catalytic ability of both the silver nanoparticle and the titanium dioxide particles is lowered. Therefore, the photocatalytic bacteriostatic ability of Comparative Example 5 was much lower than that of Experimental Example 2.

Experimental Example 2 The above results demonstrate the Ag / TiO ₂ film of Experimental Example 3 Ag / TiO ₂ thin film having high photocatalytic antibacterial activity. FIGS. 6 to 9 in conjunction with experimental results, the experiment of Example 2 Ag / TiO ₂ film of Experimental Example 3 Ag / TiO ₂ film may be applied in a home, hospitals, public places, outdoor use of glass, tile, Metal components, plastic products, fabrics, non-woven fabrics, etc., indoors (only visible or weak light) or outdoor environment, so that the objects in contact with the surrounding can achieve the effect of inhibiting bacteria or vector, and can continue to absorb and Decompose harmful organic matter in the air to achieve the effect of air purification.

In summary, the present invention utilizes a target prepared from a nanocomposite powder of silver nanoparticles and titanium dioxide particles to form a nanocomposite film on a substrate through a sputtering process. The silver nanoparticles of the nanocomposite film can be uniformly distributed between the titanium dioxide particles. Further, the above-mentioned silver nanoparticle has a particle diameter of less than 10 nm, and therefore, the nanocomposite film of the present invention has visible light catalysis, visible light penetration, ultraviolet absorption, and weak photocatalytic bacteriostatic action. In addition, since the above-mentioned silver nanoparticle has a small particle size, is uniformly dispersed, and has no agglomeration and precipitation, it is not easily peeled off or scraped off, so that the silver nanoparticle particle dust poisoning problem or the coating is not affected. Problems such as the aesthetics of the substrate.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Substrate

101‧‧‧Nano composite film

102‧‧‧ Titanium dioxide particles

104‧‧‧Silver Nanoparticles

Claims (10)

A nano composite film formed on a substrate by a sputtering process, the nano composite film comprising: a plurality of titanium dioxide particles; and a plurality of silver nanoparticles, uniformly distributed between the titanium dioxide particles, wherein The silver nanoparticles have a particle size of less than 10 nm, and the silver nanoparticles have a content of from 1 vol% to 5 vol%. The nanocomposite film according to claim 1, wherein the silver nanoparticles have a particle diameter of 5 nm to 10 nm. The nanocomposite film of claim 1, wherein the nanocomposite film has a thickness of 50 nm to 300 nm. The nanocomposite film according to claim 1, wherein the nanocomposite film absorbs ultraviolet light and passes visible light, and has visible light catalyzing ability. A method of producing a nanocomposite film according to any one of claims 1 to 4, comprising: providing a titanium dioxide solution; uniformly mixing a silver ion solution with the titanium dioxide solution to form a mixture a solution; adding a reducing agent to the mixed solution, causing silver ions in the mixed solution to undergo a reaction of reducing and depositing nano silver; and drying the mixed solution to form a nano composite powder; The nano composite powder is subjected to a hot pressing process to form a target; A sputtering process is performed on the substrate by using the target to form a nano composite film on the substrate. The method for producing a nanocomposite film according to claim 5, wherein the reducing agent comprises sodium borohydride (NaBH ₄ ), hydrazine or a combination thereof. The method for producing a nanocomposite film according to claim 5, wherein the step of adding the reducing agent to the mixed solution further comprises performing a cooling treatment at a temperature of 0 ° C to 25 ° C. The method for producing a nanocomposite film according to claim 5, wherein in the step of performing the sputtering process on the substrate, wherein the temperature of the substrate is lower than 100 °C. The method for manufacturing a nanocomposite film according to claim 5, after the step of performing a sputtering process on the substrate, an annealing treatment is not performed to make the silver nanoparticles in the nano composite film. Will not aggregate and precipitate. The method for fabricating a nanocomposite film according to claim 5, wherein the sputtering process comprises a radio frequency magnetron sputtering process.