Activated carbon is a porous carbonaceous material with a highly developed pore structure. The porous structure of activated carbon provides a large surface area and can be in full contact with gases (impurities), thereby imparting the unique adsorption properties of activated carbon, making it very easy to absorb and collect impurities. Just like magnetic force, all molecules have mutual attraction. Because of this, a large number of molecules on the pore walls of the activated carbon can generate strong gravitational force, thereby attracting harmful impurities into the pores. However, not all activated carbon can adsorb harmful gases. Only when the pore structure of activated carbon is slightly larger than the diameter of harmful gas molecules, the harmful adsorption of gas molecules can be fully entered to achieve the best adsorption effect.

Polyurethane and polystyrene foam boards are also absorbent, but they are small and negligible.

The multi-space structure of activated carbon provides a large amount of surface area to diffuse from the outside to the inside, thereby achieving a process of reducing the concentration.