Surface-Capping and Endohedral-Encapsulation of Bismuth in Two Polyoxophosphovanadates

Two novel bismuth-doped polyoxovanadates with distinct bismuth doping sites were successfully synthesized under solvothermal conditions and characterized. Structural analysis revealed that the bismuth ions in compound 1 exist as external decorating positions on the surface of the polyoxovanadate skeleton; however, in compound 2, the bismuth ions are deeply integrated into the cluster, becoming an integral component of the cluster. Both compounds 1 and 2 exhibited good catalytic activity and stability in the oxidation of sulfides. This study demonstrates the feasibility of embedding bismuth ions as critical structural nodes within polyoxometalate clusters, providing important structural foundations and novel strategies for the development of new multifunctional bismuth-doped polyoxometalate materials through atomic-level structural design.