Rare-Earth-Modified TiO2 photocatalysts: From Ce loaded materials to Lanthanide Phthalocyanine-Sensitized systems

Rare earth elements play a key role in the development of advanced photocatalytic materials. In this work, two classes of rare-earth-containing TiO2 based photocatalysts were investigated: (i) Ce modified TiO₂ nanomaterials synthesized through a sustainable bio-templating route using spent coffee grounds, and (ii) TiO₂ sensitized with lanthanide bis-phthalocyanines (LnPc₂, Ln = Ce, Eu, Gd). The study highlights how rare earth species can tune the oxidative and reductive properties of TiO₂-based photocatalysts under both aerobic and anaerobic conditions.