The floating photocatalytic spheres loaded with weak light-driven TiO2-based catalysts for photodegrading tetracycline in seawater

To effectively treat organic pollutants in seawater, this study fabricated different floating photocatalytic spheres by loading TiO2-based photocatalysts to degrade tetracycline in simulated seawater. In photodegradation for tetracycline, the content of the active TiO2 component in the powder photocatalyst played a major role in degrading the performance of the material. A polyurethane porous sponge with a large specific surface area was used as a carrier in loading the powder photocatalyst to avoid the interference of salt ions in seawater for photodegradation. The adsorption ability and performance in tetracycline photodegradation of the PU sponge filled photocatalytic spheres were significantly higher than those of PMMA photocatalytic spheres under the same conditions. The Pt-deposited P25-A (Pt-P25-A) powder photocatalyst with the strongest visible light response exhibited the highest performance. The rate removal for tetracycline in the simulated seawater by the PU sponge-filled spheres loaded with Pt-P25-A exceeded 80% after 20 h.