The Types segment classifies photocatalytic materials by their physicochemical composition, each contributing uniquely to market dynamics. Titanium‑dioxide (TiO₂)‑based catalysts remain the largest sub‑type, prized for stability, UV activation, and scalable manufacturing, supporting both air and water solutions. Metal‑sulfide catalysts (e.g., CdS, ZnS) offer visible‑light responsiveness, expanding applicability in low‑light indoor environments but raise concerns over toxicity and lifecycle costs. Carbon‑based photocatalysts, including graphene‑oxide and doped carbon nitride, provide high surface area and tunable band gaps, fostering niche markets such as portable air purifiers. Composite systems—heterojunctions that couple TiO₂ with metal‑sulfides or carbon matrices—enhance charge separation, delivering superior degradation rates and justifying premium pricing. Doped variants (e.g., nitrogen‑doped TiO₂) further extend absorption into the visible spectrum, enabling energy‑efficient designs. Collectively, these types diversify the market taxonomy, driving differentiated pricing, regulatory pathways, and adoption rates across application segments.