At present, the domestic formaldehyde removal market mainly uses photocatalyst products. The photocatalyst products they use not only include transparent, milky translucent, light blue liquid, but also the product categories are confused, and their prices are also irregular. Off line, the asking price of formaldehyde removal companies is at least 1 discount per square meter, and at most 300 or 400 yuan per square meter. On line, the same 500g photocatalyst ranges from more than 10 yuan to more than 300 yuan. So can photocatalyst remove formaldehyde under living conditions?
The answer is no for the following reasons:
What is photocatalyst?
Catalyst is a complete word, in fact, it is the Japanese expression of catalyst. The normal Chinese expression of photocatalyst is photocatalyst. If it is a reliable photocatalyst, it can decompose harmful substances in the air into carbon dioxide and water under the irradiation of light containing ultraviolet wave band and near ultraviolet visible light.
Photocatalyst was invented by Japanese
In 1967, Professor Kenichi Honda and doctoral student Shigeru Fujishima of the University of Tokyo, Japan found that water electrolysis reaction can be carried out by irradiating titanium dioxide with light. This is the famous "Honda Fujishima Effect". Japan named such a chemical material that can produce photocatalytic effect under light as "photocatalyst". In 2001, the products related to photocatalysis technology officially entered the daily life of families, and in a short period of six months, they quickly swept across Europe, America and developed regions in Southeast Asia, becoming one of the important consumer products of families, and miraculously increased at an annual average rate of 4.6%. In Japan, photocatalyst is mainly used for sterilization, mildew prevention and odor elimination.
There are few really good photocatalysts in China
Referring to the color of photocatalyst, according to the communication with Japan Asaka Technology Co., Ltd., we learned that "good photocatalyst is milky white with high concentration. Transparent photocatalyst products on the market may have been diluted with few components. The photocatalyst without substance cannot remove aldehyde, and the basic function of sterilization, deodorization and mildew prevention cannot be achieved. "The average particle size of photocatalyst should be at least 10 nanometers, and the good ones are usually about 5 nanometers, because the smaller the particle size is, the larger the specific surface area is, the more intensive the reaction is. On the contrary, the opposite is true. According to Dr. Li of China Photocatalytic Standards Committee, the photocatalyst products in the market with a discount of 60 per liter or less are not photocatalysts, and they must be large manufacturers to reduce the cost to around 60.
Under normal family living conditions, photocatalyst cannot remove aldehyde
Photocatalyst is actually nanometer titanium dioxide, which reacts with organic pollutants in the air through redox reaction. Then water and carbon dioxide are produced. When photocatalyst is applied in living and working spaces, it can decompose odor molecules, bacteria, viruses and other microorganisms, so as to achieve the role of cleaning the indoor environment and creating fresh air. The prerequisite is that photocatalyst can only react within the wavelength of ultraviolet light, while the sunlight used in ordinary homes only contains 3% ultraviolet light, Most energy-saving lamps contain almost no ultraviolet light.
If a useful photocatalyst product is sprayed, what will be the result?
1. Deodorization
Photocatalyst has obvious deodorization results for odor, toilet odor, garbage odor, animal odor, etc. According to the test of European and American laboratories, the deodorization capacity of 1cm2 photocatalyst is 150 times that of high-performance fiber activated carbon, equivalent to 500 activated carbon refrigerator deodorants, and has no secondary pollution.
2. Sterilization
The good oxidation ability of photocatalyst can destroy the cell membrane of bacteria in the air, make the bacterial plasm lose to death, coagulate the protein of virus, inhibit the activity of virus, and have sterilization effect on Escherichia coli and Staphylococcus aureus floating in the air, with its ability up to 99. 5% 997%。 And dust mites, the culprit of 90% asthma and allergic diseases, can be completely removed. In addition, it can completely decompose the harmful compounds released from the bacterial corpse while sterilizing, which is impossible for all bactericides. However, TiO2 particles themselves are non-toxic to microorganisms and cells and have been certified by FDA as food additives.
3. Anti mildew and antifouling
Prevent oil stain, dust, etc. Mold, flavine, rust and discoloration of the painted surface also have the effect of preventing them.
4. UV resistance
Because photocatalyst has extremely strong ultraviolet absorption capacity and converts this light energy into chemical energy, it has the functions of anti ultraviolet, anti fading, aging, etc.
Application of photocatalyst in Japan:
In Japan, many business vehicles need to be disinfected once a month, but vehicles treated with nano titanium dioxide photocatalyst do not need to be disinfected again within two years. At present, more than 20000 cars in Japan have received photocatalyst treatment. The use of photocatalyst treatment before new cars leave the factory can remove the pungent smell and toxicity of new cars, greatly improving the driving experience and health support. In short, it has many results, and they are all true. However, it is limited to sterilization, deodorization, mildew prevention and antifouling, but formaldehyde removal is untrue. The product classification on the website of the Japanese Photocatalyst Industry Association (PIA) does not mention formaldehyde at all.
Website of Silver Light Environment: http://www.jiameng.com/vingochina/
