Hierarchical BiF₃–Bi₂NbO₅F Core–Shell Structure and Its Application in the Photosensitized Degradation of Rhodamine B under Visible Light Irradiation

Catalytic photodegradation has been found to be a versatile, low-cost, and green technology for environmental decontamination. Bismuth-based compounds have attracted a lot of attention for their efficient photocatalytic properties. It is always of great importance to develop new catalysts in the photodegradation field. In this research, hierarchical porous BiF₃–Bi₂NbO₅F core–shell structures have been successfully prepared via a simple solvothermal route. A possible growth mechanism for the core–shell structure was proposed based on time-dependent-evolution experiments. X-ray powder diffraction was used to determine the phase composition. Scanning electron microscopy and transmission electron microscopy were employed to characterize the morphologies of the as-prepared samples. Experiments demonstrated that the volume ratio of ethylene glycol to water played a determinative role in the final morphology of the products. The band gap of the as-prepared BiF₃–Bi₂NbO₅F composite was estimated to about 3.47 eV. The novel hierarchical BiF₃–Bi₂NbO₅F core–shell structures could serve as a catalyst for photosensitized degradation of Rhodamine B under visible light irradiation. Moreover, the photodegradation efficiency of the samples was greatly associated with their surface morphology