Photocatalysts can occur under the light photocatalytic reaction, can be combined with water and oxygen in the air, and degrade formaldehyde and other organic pollutants, with the increase in relative humidity, formaldehyde degradation first increases and then decrease, so the moisture should be controlled.
Is photocatalyst formaldehyde effective?
1. Photocatalyst in the ultraviolet light, the photocatalytic effect occurs, the release of electrons (e-) hole (h +), and with the water in the air and oxygen combination, and degradation of formaldehyde and other organic pollutants, and ultimately generate carbon dioxide and water. In this process, titanium dioxide will not be lost, just like the photosynthesis of plants, as long as there is light, it can continue deleting formaldehyde.
2. In the experimental environment, photocatalysts do have the effect of degrading formaldehyde (purification effect of up to 90% or more). Still, these air purification products in indoor conditions can also be effective, and what factors will affect the effect of formaldehyde purification?
In light conditions, pure titanium dioxide needs to be in the wavelength of about 387nm ultraviolet light (UVA) irradiation to stimulate catalytic activity. The ultraviolet wavelengths in daylight account for less than 5% of the solar spectrum, daytime indoor light UV is minimal (after many reflections), and at night, energy-saving lamps UV outside of 1 meter is almost 0, so the ordinary photocatalyst products in the normal indoor light is almost ineffective.
With the increase of relative humidity, formaldehyde degradation is the first to increase and then decrease, the best humidity around 50% formaldehyde degradation effect is the best, humidity is too high (higher than 70%) or too low (less than 30%) photocatalytic degradation effect will be significantly weakened.
Represented by titanium dioxide photocatalytic products to remove indoor formaldehyde and other harmful gases is real and effective, but the current domestic market is very confusing! In the face of the business blind false propaganda, we should be sensible, under the premise of understanding the role of photocatalysts, choosing a truly effective photocatalyst product, and scientific use of photocatalyst products to remove indoor formaldehyde.