What is the difference between nano titanium dioxide and photocatalyst?

Only anatase-type nano-titanium dioxide can be called a photocatalyst.

A photocatalyst is a nanoscale metal oxide material (titanium dioxide is more commonly used) that is coated on the surface of the substrate and dries to form a thin film.

The characteristics of photocatalyst are that the oxygen molecules and water molecules in the air are used to convert the organic matter into carbon dioxide and water, which does not change by itself, but can promote chemical reactions, and theoretically has a very long validity period and low maintenance cost.

1. Nano titanium dioxide.

Nano titanium dioxide is a white loose powder, which has a strong shielding effect on ultraviolet rays, and has good dispersion and weather resistance. It can be used in cosmetics, functional fibers, plastics, coatings, paints and other fields as an ultraviolet shielding agent to prevent ultraviolet damage. It can also be used for high-grade automotive topcoats, with an angle heterochromatic effect.

2. Photocatalyst.

Photocatalyst is a general term for photosemiconductor materials with photocatalytic function represented by nanoscale titanium dioxide, which is coated on the surface of the substrate and produces a strong catalytic degradation function under the action of ultraviolet light and visible light: it can effectively degrade toxic and harmful gases in the air; It can effectively kill a variety of bacteria, and can decompose and harmless the toxins released by bacteria or fungi; At the same time, it also has the functions of formaldehyde removal, deodorization, anti-fouling, and air purification.

Titanium dioxide is the main component of photocatalysts. Photocatalysts can decompose formaldehyde, but the photocatalysts sold on the market are all photocatalysts in the traditional sense, and the traditional photocatalysts are very inefficient due to their dependence on sunlight (ultraviolet rays), and in indoor and night environments where ultraviolet rays are insufficient. This is also one of the reasons why photocatalysts are not optimistic, in response to the dilemma of traditional photocatalysts, a new type of photocatalyst has been developed in China, adding nano photophyll (strong catalysis) on the basis of traditional photocatalysts, commonly known as photophyll catalysts, so that photocatalysts can still work effectively even in the environment of weak ultraviolet rays.

Titanium dioxide photocatalyst is an environmental treatment material based on the principle of photocatalytic reaction, and has a wide application prospect in the treatment of environmental pollutants such as organic pollutants and ozone. However, there are still some defects in titanium dioxide photocatalysts, such as narrow photoresponse, low photocatalytic efficiency, slow photocatalytic reaction speed, and easy interference by organic matter and water vapor.

In view of these defects, improvements can be made from the following aspects:

1.Crystal structure optimization: The crystal structure of titanium dioxide was optimized by means of chemical synthesis and physical preparation methods, so as to increase the separation speed of electron-hole pairs, and improve the light response range and catalytic efficiency.

For example, the crystal structure of titanium dioxide can be changed by metal doping, defect modification, etc.

2.Prevention of photogenerated electron-hole recombination: Photogenerated electron-hole recombination is one of the main factors affecting the catalytic efficiency of titanium dioxide photocatalyst. Therefore, some measures can be taken to prevent the recombination of electrons and holes, such as the addition of metal catalysts, surface modification, etc.

4.Enhanced light source: The catalytic efficiency of the photocatalyst is closely related to the energy of the light source, so increasing the energy density of the light source can effectively improve the catalytic efficiency of the photocatalyst. For example, high-energy light sources such as LEDs and solar energy can be used to provide a stronger source of excitation light.

5.Improve the service life of the catalyst: In view of the problem that the titanium dioxide photocatalyst is easily disturbed by organic matter and water vapor during use, some methods can be used to improve the service life of the catalyst, such as adding mechanical vibration or air flow to promote the decomposition of organic matter, or using filtration or inhibitors to reduce the interference of water vapor.

In general, the defects of titanium dioxide photocatalyst can be effectively solved and its application range and catalytic efficiency can be improved by optimizing the crystal structure, preventing electron-hole recombination, exposing more active sites, enhancing the light source, and improving the service life of the catalyst.

What is a Photocatalyst?

A photocatalyst is a substance that acts as a catalyst (facilitating a specific reaction in a chemical reaction) by absorbing light such as sunlight. To give an easy-to-understand example, "photosynthesis", in which plants absorb sunlight to produce starch and oxygen from carbon dioxide and water, is also one of the photocatalysts, in this case, chlorophyll is the catalyst. Nano titanium dioxide is a typical photocatalytic substance, also known as a photocatalyst.

Photocatalyst coating using nano titanium dioxide.

Nano titanium dioxide is a compound of titanium and oxygen. It is a chemically stable, safe, and environmentally friendly (*1) substance, and is often used as a cosmetic and food additive. Nano titanium dioxide uses light as energy to produce reactive oxygen species from oxygen in air and water.

It decomposes, deodorizes, and detoxifies harmful substances through chemical reactions. It also has the effect of absorbing ultraviolet rays, making it a highly functional and environmentally purifying substance. (*1) Since the refractive index of light is very high, it may actually look a little cloudy.

Features of photocatalyst coatings.

The nano-titanium dioxide contained in the photocatalyst reacts with water vapor in the air under sunlight to form reactive oxygen species. This reactive oxygen breaks down harmful substances and weakens the adhesion of dirt. By applying it to walls and ceilings, it breaks down the smell of cigarettes and pets, as well as harmful gases such as formaldehyde, which causes ward syndrome.

The nano-titanium dioxide contained in the photocatalyst has a significant effect of blocking ultraviolet rays. Prevents fading and increases the durability of facades. In addition, due to its high transparency, it does not spoil the beautiful colors of the wall material.

In addition, nano titanium dioxide, which uses ultraviolet rays contained in sunlight and light from illuminators, is an environmentally friendly substance, which is safe, environmentally friendly, non-toxic and harmless. JP-ECO photocatalyst is a new type of visible photocatalyst researched by ECO Co., Ltd. in Japan, which can effectively remove aldehyde, antibacterial and mildew, and is recognized as an air purification product.

Photocatalyst is the meaning of photocatalyst, that is to say, there is a class of substances in nature that will play a catalytic role under light, so that the chemical reaction between other substances can be carried out, and its own quantity and chemical properties remain basically unchanged before and after the reaction, among which the better one is the chlorophylin photocatalyst used to remove formaldehyde.

A photocatalyst is a photocatalyst that uses light energy to break down pollutant molecules into harmless gases. The catalyst is not consumed in the reaction and is theoretically permanently effective. One of the ways to use photocatalyst is to apply the photocatalyst solution to the surface of furniture for pollution control.

However, we know that gas molecules move extremely fast, and catalytic reactions take a certain amount of time, so the effect of this treatment method in practical application is not ideal.

Another way to use photocatalyst is to add it to materials with adsorption, such as phytophyllin, adsorption can limit the movement of polluting molecules, and this time catalyst can achieve a better decomposition effect. The effect of decomposition at the same time of adsorption is significantly better than that of a single action.

The main component of photocatalyst is titanium dioxide. The principle of photocatalyst formaldehyde removal: coated on the surface of the article to form a nano-scale colorless protective film, catalyzing the decomposition of formaldehyde, TVOC, and other gaseous organic pollutants under ultraviolet irradiation, turning them into carbon dioxide and water.

The photocatalyst itself does not react, and after spraying, it will be coated on the surface of the substrate as a film, and under the action of light, it will produce a strong catalytic degradation function: it can effectively degrade toxic and harmful gases in the air. If this layer is destroyed, harmful substances will be released, and it is possible to produce secondary pollution.

There is also a kind of photophyllin, is the upgrade material of photocatalyst, photocatalyst is the need for light, especially ultraviolet rays to participate in order to fully play a role, insufficient participation will cause secondary pollution because of residues, photophyll is extracted from the plant body, does not need light can be directly decomposed, it adds decomposition catalyst and penetrant, can better penetrate and decompose the formaldehyde pollution inside the furniture panel, the removal rate can reach 99%, is a kind of formaldehyde removal material widely used by decoration management companies.

A photocatalyst is a catalyst that only occurs when exposed to light. It does not participate in chemical reactions and is very stable in nature, but under light, it converts light energy into chemical energy, excites the surrounding water and oxygen molecules to ionize, and releases hydroxyl radical intermediates with the highest oxidation potential, thus presenting a valuable photoelectric effect. Harmful gases can be oxidized and decomposed.

There are many types of photocatalysts, including titanium oxide (TiO2), zinc oxide (ZNO), tin oxide (SNO2), zirconium dioxide (ZRO2), cadmium sulfide (CDS) and other oxide sulfide semiconductors. In the field of indoor environmental protection, nano titanium dioxide (TiO2) is the most commonly used one, which has stable properties and good photocatalytic performance. Mayan blue light catalyst uses nano titanium dioxide (TiO2).

The photocatalyst is only a kind of nano titanium dioxide, which has the functions of removing formaldehyde and preventing oxidation, especially now that a new generation of platinum photocatalyst has been developed, which can catalyze the decomposition of formaldehyde under the condition of no light, making up for the shortcomings of the domestic photocatalyst in ultraviolet rays and visible light.

1. If the adhesion of your titanium dioxide is stronger than that of DU, or the adhesion requirements of the environment are not high, it is recommended to use direct back spraying, of course.

A: Less likely;

2. If the adhesion is poor, a small amount of inorganic fixative or organic fixative can be added, but the organic fixing agent will greatly affect the catalytic ability;

3. In fact, it can be directly used as a dispersed slurry, which can also be regarded as a photocatalyst;

4. There must be a light source, generally titanium dioxide needs ultraviolet light, and some doped ones can be catalyzed under visible light.

Titanate is formed first, and it can be transformed into photosensitive titanium dioxide by fixing on the surface of glass.

In fact, nano titanium dioxide and ordinary titanium dioxide can absorb ultraviolet rays, for rutile type.

The main consideration for making cosmetics is the problem of heavy metal content.

For example, the nanoscale is transparent in the water dispersion system, and if you want to make it colorless and transparent, then of course the nanoscale is suitable. If you're making colored makeup, use cosmetic-grade titanium dioxide. Because the price is not an order of magnitude at all.

Nano-scale titanium dioxide is at least 100,000 tons, while cosmetic-grade non-nano-scale titanium dioxide is only half of it.

The absorption of ultraviolet rays is no worse than that of nanometers.

Nano titanium dioxide is titanium dioxide with an average particle size of less than 100 nanometers, and this particle size is shorter than the wavelength of visible light (300-750 nanometers), so it is transparent and colorless when observed by the naked eye, and is mainly used for cosmetics, sunscreen, special coatings, special printing inks, and is expensive.

Ordinary titanium dioxide particle size microns, uses: coatings, printing inks, plastic additives, etc.

When photocatalysts decompose organic matter, they will have different decomposition products. Carbon and hydrogen compounds, the final decomposition products are carbon dioxide and water, organic compounds containing ammonia and nitrogen, the final decomposition products are nitric acid or nitrate, and the final decomposition products of organic compounds containing sulfur and sulfhydryl groups are sulfuric acid or sulfate. When a large amount of sulfate and nitrate remain on the surface of the nano titanium dioxide crystal, the nano titanium dioxide particles will be surrounded and lose their photocatalytic properties, which is the photoetching effect of the photocatalyst.

It can be seen that the validity period of Mayan blue light catalyst to purify the air depends on the environment in which it is used, the more pollutants in the environment, the faster its photo-erosion occurs, the faster it fails, and the purer the air in the surrounding environment, the slower the photo-erosion occurs. In a typical home or office environment, photoerosion will render the photocatalyst ineffective in 1-2 years.

After adding Zixilai nano titanium dioxide, the coating will produce a unique photocatalytic effect under the action of light, which can not only decompose and eliminate toxic and harmful gases in the air, but also have a strong killing effect on bacteria, molds and viruses. For example, nano antibacterial coatings can strongly decompose and eliminate harmful gases such as formaldehyde, toluene, xylene, ammonia, and TVOC produced by indoor decoration, making indoor air fresher and avoiding the harm caused by toxic and harmful gases to the human body.

The nano antibacterial and environmentally friendly coating made by adding Zixilai nano titanium dioxide by the coating company has been tested by the authoritative test of the National Environmental Protection Product Quality Supervision and Inspection Center, and the test results show that it has a good degradation effect on indoor toxic and harmful gases (formaldehyde, benzene, ammonia, TVOC, etc.); After the authoritative test of [Guangdong Microbial Analysis and Testing Center], the test results show that it has a good killing effect on Staphylococcus aureus, Staphylococcus albicans, Escherichia coli and other bacteria. Therefore, the nano antibacterial and environmentally friendly coating made by adding nano titanium dioxide can effectively solve the air pollution problem caused by indoor decoration, and has a long-term anti-mildew and anti-algae effect. At the same time, nano antibacterial environmental protection coating has excellent self-cleaning and anti-fouling function, which can maintain long-term clean and beautiful appearance; It has excellent high weather resistance, good gloss and color retention effect; Excellent water resistance, acid resistance, alkali resistance, long-term protection is not easy to peel; Good adhesion and strong scrubbing resistance; The paint film is hard and tough, and has excellent hydrophobicity, making it easy to clean dirt.

The test results show that the nano antibacterial environmental protection coating has a washing resistance of more than 15,000 times and a strong ultraviolet resistance. The service life is more than 15 years. Strong adhesion, no peeling, no peeling, anti-aging, can be applied normally within 10 to 25 years.

The results of various performance tests of the coating are enough to prove that the market prospect of nano antibacterial and environmentally friendly coating is very good.