In situ synthesis of flexible Bi7O9I3/carbon paper with enhanced photocatalytic activity

Although Bi7O9I3 is an oxygen-rich bismuth oxyiodide with higher photocatalytic activity than BiOI, its applicability for photocatalytic oxidation is limited by the rapid recombination of photogenerated carriers and poor reusability. Depositing Bi7O9I3 on flexible macro-sized carbonaceous materials is a promising approach for promoting photogenerated electron migration and improving reusability. In this study, a composite consisting of Bi7O9I3 supported on graphitic carbon paper (Bi7O9I3-CP) was synthesized via the in situ transformation of a BiOI-deposited carbon paper precursor (BiOI-CP). The as-prepared Bi7O9I3-CP exhibited higher visible-light-driven photocatalytic activity than both Bi7O9I3 and BiOI-CP precursor for phenol removal. The improved photocatalytic activity of Bi7O9I3-CP was attributed to its hierarchical structure and promoted carrier separation, as revealed by photoluminescence, pore structure, and reactive radical analyses. Moreover, owing to its macroscale size and flexibility, the Bi7O9I3-CP composite could be easily operated and reused, which are favorable for practical applications.