What is a photocatalyst?
Photocatalyst is a nano-scale metal oxide material (titanium dioxide is more commonly used), it is coated on the surface of the substrate, after drying to form a thin film, under the action of light, produce a strong catalytic degradation function: it can effectively degrade the toxic and harmful gases in the air; it can effectively kill many kinds of bacteria, the antibacterial rate is as high as 99.99%, and it can decompose the toxins released by the bacteria or fungi and harmless treatment; at the same time it has the function of Deodorant, anti-dirt and other functions.
Photocatalyst [Photocatalyst] is a synthetic word for light [Photo=Light] + catalyst (catalyst) [catalyst]. Photocatalyst is a kind of photo-semiconductor material with photocatalytic function represented by nano-sized titanium dioxide, which is the most ideal material for the treatment of indoor environmental pollution in the current international arena.
Photocatalysts, under the irradiation of light, will produce a photocatalytic reaction similar to photosynthesis, and produce free hydroxyl and active oxygen with strong oxidation capacity, with strong photo-oxidation reduction function, can oxidize and decompose all kinds of organic compounds and part of inorganic substances, can destroy the cell membrane of bacteria and solidify the protein of viruses, can kill bacteria and decompose organic pollutants, and decompose organic pollutants into non-polluting water (H2O) And carbon dioxide (CO2), so it has a strong bactericidal, deodorant, mildew, anti-fouling self-cleaning, air purification function.
Introduction to the working principle of photocatalyst
Photocatalyst photocatalyst photocatalyst in a specific wavelength (388nm) light irradiation, will produce a series of energy conversion processes similar to chlorophyll photosynthesis in plants, the light energy into chemical energy and endowed with the surface of the photocatalyst is very strong oxidation, oxidation decomposition of a variety of organic compounds and mineralisation of some of the inorganic substances, and has the role of antibacterial.
Under light irradiation, the photocatalyst can absorb light energy equivalent to the band gap energy below, so that the surface of the incentive produces electrons (e-) and holes (h+). These electrons and holes have strong reducing and oxidising abilities and can react with water or capacitated oxygen to produce hydroxide radicals (-OH) and superanions (-O). As shown in Table 1, the oxidation energy of these cavities and hydroxide radicals is greater than 120kcal/mol, and they have a strong oxidising capacity, which can cut and decompose almost all the chemical bonds constituting organic molecules. Therefore, it can decompose or harmlessly treat all kinds of harmful chemicals and malodorous substances to purify the air, anti-pollution and deodorisation.
What are the functions of photocatalysts?
Air purification function: purify formaldehyde, benzene, ammonia, sulphur dioxide, carbon monoxide, nitrogen oxides and other harmful organic substances that affect the health of people.
Bactericidal function: E. coli, yellow staphylococcus and another bactericidal effect. At the same time, it can decompose the harmful compounds released from the dead body of bacteria.
Deodorant function: it has a deodorant effect on cigarette, toilet, rubbish and animal odour.
Anti-fouling function: Prevents the production of oil and dust. It is also effective in preventing the generation of mould, water rust, yellow alkali, rust and discolouration of coated surfaces in the bathroom.
Purification function: It has the function of purifying water pollution and organic harmful substances in the water, and the surface is super hydrophilic, with the effect of anti-fog, easy to wash and easy to dry.