Controllable hierarchical Bi₂MoO₆ spheres with ferroelectric polarization enhanced photocatalytic efficiency

AbstractThe fast recombination of photogenerated electrons and holes remains a major issue in hindering photocatalytic efficiency. Apart from traditional methods, such as rare metal deposition and element doping, the introduction of a built‐in electric field has been proven an efficient way in recent years. Ferroelectrics, which possess spontaneous polarization and associated polarization electric fields, are attracting more attention as photocatalysts. In this study, Bi2MoO6 spheres with different hierarchical upper nanostructures are synthesized through a one‐pot hydrothermal method. With this porous structure and the intrinsic ferroelectricity, BMO spheres present excellent physisorption and photodegradation ability toward dye molecules. After corona poling treatment, the ferroelectric field of the BMO samples was enhanced, and the recombination of charges was suppressed, leading to an obvious increase in photocatalytic rate. The origin BMO‐5 can reach a total degradation of RhB in 20 min, and the polarized BMO‐5 (BMO‐5P) can remove all RhB molecules instantly through the physisorption process. Apart from BMO‐5, other samples also present excellent catalytic behavior. Origin BMO‐2 can fully degrade the RhB in 40 min, and the degradation time of polarized BMO‐2P is 30 min. The hierarchical structure and internal polarized electric field endow BMO spheres with outstanding adsorption purification and photodegradation ability and provide a new comprehensive strategy for the catalyst design.