Triple-layered Sillén–Aurivillius Perovskite Oxychloride Bi5PbTi3O14Cl as a Visible-light-responsive Photocatalyst for Water Splitting

We show that oxyhalide Bi5PbTi3O14Cl is a potential photocatalyst for visible-light-induced water splitting owing to the appropriate band levels for both water reduction and oxidation. The present oxyhalide, the first example of an active material with a triple-layered Sillén–Aurivillius perovskite structure, is found to possess a more negative valence band maximum and a smaller bandgap than those of analogous oxide Bi4Ti3O12, because of stronger hybridization between Bi/Pb-6s and O-2p orbitals. Oxyhalide Bi5PbTi3O14Cl is revealed to function as a photocatalyst for visible-light-induced water splitting and the first example of an active material with a triple-layered Sillén–Aurivillius perovskite structure. Bi5PbTi3O14Cl possesses the more negative valence band maximum and the resultant smaller bandgap due to the strong hybridization between Bi/Pb-6s and O-2p orbitals, compared to analogous oxide Bi4Ti3O12.