Dopants are foreign atoms introduced into the crystal lattice of a catalytic material to modify its properties. These atoms can either replace host atoms (substitutional doping) or occupy interstitial sites (interstitial doping). Dopants can significantly influence the electronic, structural, and chemical properties of the catalyst, often leading to enhanced catalytic performance. For example, doping titania with nitrogen can extend its light absorption into the visible range, making it more effective for photocatalytic applications.
