Firelight catalyst and its application in househol

Photocatalyst and its application in household paper

Abstract: This paper introduces what is photocatalyst, its action mechanism, sterilization and application, as well as the application of nano photocatalyst paper in household paper

key words: photocatalyst; Sterilization; Household paper

has entered the 21st century. With the development of industry, the living environment on which people rely for survival is deteriorating, and harmful chemicals and bacteria may pollute the atmosphere at any time. Therefore, it is more and more important to protect the environment, reduce pollution and develop good health habits. In particular, the severe test of SARS in 2003 and the emergence of avian influenza in some areas some time ago have attracted more attention to environmental health. As a result, "Photocatalyst", which has the functions of sterilization, antibacterial and deodorization, has quickly become a new favorite of environmental protection academia and industry. An article pointed out that it (photocatalyst) accounted for two of China's top ten business opportunities in the post SARS period

1 what is photocatalyst

this substance is activated when exposed to light (UV) and promotes the surrounding chemical reactions. Anatase TiO2 "Photocatalyst" has this function. It is a substance that does not change itself under light (UV) conditions, but can promote chemical reactions, just like chlorophyll in plant photosynthesis

the research on Photocatalyst in foreign countries is earlier than that in Japan, such as the four-wheel positioning and detection system. A Japanese occasionally found that the titanium dioxide semiconductor single crystal was cut into an electrode with a diamond, and the opposite pole was made into a circuit with a platinum electrode, and the titanium dioxide semiconductor single crystal was irradiated with a xenon lamp. It was found that oxygen appeared on the side of TiO2 and hydrogen appeared on the side of platinum. The results showed that under light conditions, titanium dioxide was activated to decompose water in the air into oxygen and hydrogen, while TiO2 itself was not dissolved. Both sunlight and indoor light contain ultraviolet rays below 400nm, that is, a very small amount of ultraviolet rays. It only needs less than 1MW/cm2, that is, indoor lighting, and no additional light source is required. It can stimulate the activity of TiO2

2 photocatalyst action principle

when photocatalyst is irradiated by sunlight or fluorescent lamp, the electrons on titanium atom are excited by ultraviolet light to form electron hole pairs, that is, light generated carriers, which then quickly migrate to its surface and activate oxygen and water in the air adsorbed on the surface to produce free radicals (· oh-) and (· o2-). When pollutants and bacteria adsorb its surface, chain degradation reaction will occur

3 bactericidal effect of photocatalyst

foreign experimental data show that TiO2 photocatalyst can kill all Staphylococcus aureus and coliform bacteria within 24 hours, and can completely decompose formaldehyde, ammonia, hydrogen sulfide, etc. in a short time. However, TiO2 itself does not react, can act repeatedly, and has no side effects on the surrounding environment. TiO2 certified by FDA is very safe to use and can be used as food and drug additives. Its oxidative decomposition, deodorization and sterilization ability is stronger than carbon fiber and ozone, and the effect is lasting. Its super oxidizability can destroy the bacterial membrane, make the bacterial substance lose and die, solidify the protein of the virus, inhibit the activity of the virus, kill the Staphylococcus aureus and Escherichia coli of the technology and equipment of carbon fiber composites adsorbed on its surface in the lightweight process of automotive parts (Xue Jian, chief representative of KANGLONG Far East Beijing Representative Office), and also can remove formaldehyde, benzene Ammonia and other harmful substances are decomposed into CO2 and water, and no intermediate products are generated. The purification effect is safe and lasting. It can also be used to purify the exhaust gas discharged by cars

according to the tests conducted by the China Indoor Environmental Monitoring Center and the China Center for Disease Control and prevention and other national authoritative departments, the bactericidal effect of photocatalyst can reach 99.9%, and the elimination rate of harmful gases such as formaldehyde, benzene and ammonia can reach more than 90%. The air purification capacity of photocatalyst is 150 times that of high fiber activated carbon. It also has a strong anti mildew and hydrophilic effect. The cloth packaged food treated with photocatalyst can significantly inhibit mildew, It will remain fresh after 10 days. According to the experiment, the effect of spraying 1000m2 photocatalyst is equivalent to the air purification ability of 70 birch trees. Photocatalyst can bring people a fresh, natural and healthy environment

4 photocatalyst application in China

a few years ago, Japan, South Korea and the United States have transformed photocatalyst technology into products. After SARS, photocatalyst finally entered China. Since the end of last year, five photocatalyst products have entered Guangzhou, and the products can be divided into three categories. Most of them are photocatalyst coating liquid, which is sprayed on the surface of indoor furniture and walls; The other is photocatalyst paint additive, which is added to ordinary decoration paint. The amount of photocatalyst paint additive is generally 2%~5%, which can make ordinary decoration paint have the purification function of photocatalyst; Another kind, which is relatively rare, is photocatalyst paint, which has high technical content and relatively expensive price. Photocatalyst has been applied as an environmental protection product. According to information, Tsinghua University uses photocatalyst in air conditioners to kill bacteria. Bluebird automobile uses photocatalyst in the inner wall of cars, and some building materials companies use it in building ceramics and air conditioning, but it has not been reported in China that it is used in paper

5 Application of photocatalyst in household paper

Japan has done a lot of work in the research and application of photocatalyst paper, and ein photocatalyst paper manufacturing technology has been patented in the United States (No.). First, a small amount of nano anatase titanium oxide is directly added to the pulp without using paint or adhesive to make photocatalyst pulp (as shown in Figure 2), and then 15% - 20% photocatalyst pulp is mixed with ordinary pulp to produce various household paper with sterilization, antibacterial and deodorization functions by using ordinary papermaking technology, as shown in Table 1

photocatalyst household paper is more and more widely used. Especially after SARS, the photocatalyst mask with powerful sterilization function has attracted much attention. Its structure is shown in Figure 3. Photocatalyst household paper produced by adding in pulp has less surface loss and can be used for a long time because nano titanium oxide photocatalyst is mixed in pulp; In addition, the loose interweaving of fibers in the paper ensures a large contact surface between air and photocatalyst, which can give full play to the sterilization and deodorization of photocatalyst. It is believed that photocatalyst household paper will bring us a healthier life

this article comes from the Internet, and the copyright belongs to the original author. We specially interviewed secretary general Zheng Long of China synthetic resin supply and Marketing Association for everyone to share and learn. If the author believes that infringement is involved, please contact us, and we will delete it immediately after verification