Hierarchical Porous, Self‐Supporting La‐ and F‐Codoped TiO ₂ with High Durability for Continuous‐Flow Visible Light Photocatalysis

Hierarchical porous, self‐supporting La‐ and F‐codoped TiO 2 with high durability was prepared using a simple polymer template gel. The TiO 2 foams were in the anatase phase, with a specific surface area of up to 88 m 2 /g, and showed a network‐like structure containing meso‐/macropores. The macropores had a diameter of ca. 300 nm and a wall thickness of 100–300 nm, while the mesopores were narrowly distributed with a mean diameter of around 5.4 nm. The UV‐vis diffuse reflection spectra of the sample showed that the presence of intraband gap states was likely responsible for its absorption of visible light. X‐ray photoelectron spectroscopy revealed that La 2 O 3 and O–Ti–F bonds were formed. The sample showed an excellent visible light photocatalytic activity and a high durability of photocatalytic activity for the degradation of methylene blue solution.