Spatial Band Separation in a Surface Doped Heterolayered Structure for Realizing Efficient Singlet Oxygen Generation

Abstract Singlet oxygen (¹O₂) with electrical neutrality and long lifetime holds great promise in producing high‐added‐value chemicals via a selective oxidation reaction. However, photocatalytic ¹O₂ generation via the charge‐transfer mechanism still suffers from low efficiency due to the mismatched redox capacities and low concentration of photogenerated carriers in confined systems. Herein, by taking bismuth oxysilicate (Bi₂O₂SiO₃) with alternating heterogeneous layered structure as a model, it is shown that iodine doping can facilitate the spatial redistributions of bands on alternated [Bi₂O₂] and [SiO₃] layers, which can promote the separation and transfer of photogenerated charge carriers. Meanwhile, the band positions of Bi₂O₂SiO₃ are optimized to match the redox potential of ¹O₂ generation. Benefiting from these features, iodine‐doped Bi₂O₂SiO₃ exhibits efficient ¹O₂ generation with respect to its pristine counterpart, leading to promoted performance in the selective sulfide oxidation reaction. A new strategy is offered here for optimizing charge‐transfer‐mediated ¹O₂ generation.