Basically, it is desert plants such as bow hemp that are ideal for air purification.
The ability to purify the air is due to the fact that these plants have adapted optimally to their very poor living conditions over millions of years: They feed on what the wind brings with it. The porous desert soil acts as a filter medium. The plant then forms special enzymes at its roots to interact with microorganisms to break down the filtered substances into their basic chemical components (amino acid, starch, glucose). This converts "dirt" into nutrients.
A fascinating process, which you can use with your Airy system in an optimal way.