Hygia inspired by Mother Nature, and uses light to activate a catalyst. A catalyst is a substance that modifies the rate of a chemical reaction without being involved itself. Chlorophyll in plants is a natural photo-catalyst. The difference between natural chlorophyll and the Hygia photo-catalyst is that while chlorophyll captures sunlight to turn water and carbon dioxide into oxygen and glucose, Hygia’s photo-catalyst creates a strong oxidation agent to break down organic matter into carbon dioxide and water.