Europium single-atoms on titania shift the paradigm of photocatalytic pharmaceutical removal

The contamination of wastewater by pharmaceuticals and personal care products (PPCPs) poses a significant threat to environmental and human health, necessitating innovative and efficient purification strategies. Photocatalysis is a promising approach for PPCPs degradation, however, optimizing solid-liquid interfacial adsorption and charge transfer remains a major challenge. Here, we introduce a novel europium (Eu) single-atom anchored TiO 2 photocatalyst, which simultaneously enhances adsorption capacity, light absorption range, and charge transfer efficiency, leading to unprecedented photocatalytic performance. Experimental and theoretical investigations reveal that Eu decoration lowers the adsorption potential of TiO 2 , significantly improving its ability to adsorb O 2 , H 2 O, and pharmaceuticals, the typical PPCPs. The introduction of 5d electrons from Eu creates a donor level below the conduction band, extending TiO 2 ’s absorption from the ultraviolet to the visible spectrum while improving adsorption and accelerating charge transfer at the solid-liquid interface. The yield of superoxide radicals rises significantly, while the reaction probability for pharmaceutical molecules is raised through the strong surface attraction. Consequently, the pharmaceutical-degradation efficiency increases by up to 27-fold under visible light and 3.9-fold under UV irradiation. This work presents a paradigm shift in photocatalytic water purification, offering a scalable and efficient strategy for tackling PPCPs contamination in wastewater. By unveiling a new mechanism for single-atom-enhanced photocatalysis, this study provides critical insights into the design of next-generation catalysts for sustainable water treatment.