Environmentally friendly and non-toxic
The representative substance of photocatalyst is TiO2, which has high chemical stability, and has been recognized by the U.S. Food and Drug Administration (FDA) as a safe substance, which is not harmful to the human body, and is widely used in food, daily necessities, cosmetics, medicine, and aquaculture.
Disinfection and sterilization
After absorbing natural light, the photocatalyst has a strong ability to absorb electrons, that is, strong oxidation, which can effectively catalyze the decomposition of harmful organic and inorganic substances, and can also eliminate bacteria and viruses. For example, photocatalysts can degrade indoor harmful volatile organic compounds such as formaldehyde, dichlorobenzene, toluene, xylene, TVOC, etc., into non-toxic and harmless small molecule water and CO2. [1] At the same time, it can also decompose and harmless the toxins released by bacteria and fungi.
Permanence
The photocatalyst stock solution has the characteristics of quick-drying, which can quickly dry and become a non-water-soluble substance after being applied to the surface of the substrate, and can reach a hardness equivalent to 4H of a pencil within 10 days. [7] Under the condition that environmental pollution is not serious, as long as it is not worn and peeled, the photocatalyst itself will not change and be lost. Under the irradiation of light, pollutants can be continuously purified, which has the advantages of long-lasting and continuous effect. However, if the environmental pollution is more serious, some sulfate and nitrate ions will affect the life and effect of the photocatalyst, and the phenomenon of inactivation will occur, but its activity can be restored through related technical processes.
Super hydrophilic
Normally, the surface of the photocatalyst coating has a large contact angle with water, but after irradiation with ultraviolet light, the contact angle with water is reduced to less than 5°, and even reaches 0°, that is, the water droplets are completely infiltrated on the surface of the photocatalyst, showing very strong superhydrophilicity. After stopping the light, the surface can remain superhydrophilic for a few hours to about a week, and then slowly return to the hydrophobic state before irradiation. Then irradiated with ultraviolet light, it can be shown as superhydrophilic, and the surface can always be kept in a superhydrophilic state by using intermittent ultraviolet light.
Self-purity
The surface processed by photocatalyst is stimulated by ultraviolet irradiation to decompose the organic matter that comes into contact, which not only plays a sterilizing role, but also decomposes harmful substances into harmless small molecules. At the same time, due to the super hydrophilic characteristics under light conditions, when dust falls on the photocatalyst coating, it only needs to be cleaned with water to achieve the purpose of cleaning the surface.