Why can t nano modified photocatalysts be used on solid wood?

It's not that it can't be used on solid wood. In fact, the use of nano photocatalysts is very restrictive, the first is that there must be natural light to be effective; The second is that titanium dioxide is easy to turn white when sprayed on the surface of black objects, causing color difference; The third is the phenomenon of slight yellowing of white paint due to the formation of highly oxidizing groups around it due to catalysis. Therefore, photocatalyst construction must be carried out by professionals, and it is generally not necessary to use solid wood, and solid wood, especially high-grade solid wood, has very little formaldehyde and VOC content, so in order to prevent color difference, solid wood does not use photocatalyst.

It's not that it can no longer be used on solid wood, but the content of formaldehyde and other harmful gases in solid wood is safe, and there is generally no need to remove formaldehyde.

The photocatalyst will be sprayed on the surface of the substrate to form a protective layer, seal the formaldehyde and catalyze the decomposition of formaldehyde, but it will oxidize, wear and tear for a long time, and formaldehyde will leak, which will produce secondary pollution, so it must be treated many times. Moreover, the photocatalyst must be irradiated by light or ultraviolet rays to have an effect. Now this drawback has also been solved, adding photophyll to the photocatalyst can excite the potential difference between the crystals, which means that the photocatalyst can also catalyze the decomposition of formaldehyde when there is no light at night.

Therefore, a better way to remove formaldehyde is to use upgraded photophyll catalysts.

Photocatalyst is essentially a catalyst for photoreaction, it should be used on any surface, the so-called solid wood can not be used, it means that it cannot be used on solid wood without lacquer, it will penetrate into the wood, because there is no light, it will volatilize very slowly, the photocatalyst itself is not a good thing, it will cause secondary pollution more serious than formaldehyde, in fact, it is not recommended at all, the manufacturer's gimmick is just a gimmick, the symptom is not a cure, only the surface can be removed, and the harmful substances that can be volatilized by opening the window for ventilation in 3 months, Because this thing is coated on the surface, it may still be slowly volatilized after five or six years, or the catalyst itself is not done well, causing the secondary pollution mentioned above

Under the irradiation of light, the photocatalyst will produce a photocatalytic reaction similar to photosynthesis, which will decompose organic pollutants into non-polluting substances, so it has a strong function of removing formaldehyde and purifying the air. Under light irradiation, the photocatalyst can absorb light energy equivalent to the energy of the band gap, and the surface of the photocatalyst is excited to produce electrons and holes. These electrons and holes have strong reducing and oxidizing abilities and can react with water or confined oxygen to produce hydroxide radicals and super anion ions.

It is through the chemical effect of these ions that formaldehyde is removed from the air.

Here I want to remind that the photocatalyst will only work under ultraviolet irradiation, and the ordinary indoor light is weak, and its strength and energy level are not enough to catalyze the photocatalyst, and the amount of decomposition is very limited, so the effect of directly using the photocatalyst for indoor formaldehyde removal is not ideal.

It can be used as a photocatalyst on solid wood, artwork, glass, and lustrous metal, and a fully transparent photocatalyst is used, and it is recommended to use wood-powered nano zinc oxide photocatalyst.