A hierarchically porous hollow structure of layered Bi₂TiO₄F₂for efficient photocatalysis

KGaA, Weinheim. Research into bismuth compounds has been greatly stimulated by their extensive applications in photocatalysis, which is a promising technique for environmental decontamination. In this research, Bi2TiO4F2hierarchically porous hollow spheres are successfully prepared by a simple solvothermal method. The X-ray powder diffraction pattern shows that the sample has an Aurivillius-type layered perovskite structure. The electron microscopy analyses reveal that the obtained hierarchical hollow spheres have a porous surface composed of interlaced nanoplates. A mechanism for the formation and growth of the hollow spheres is proposed on the basis of time-dependent evolution experiments. The band gap of the prepared Bi2TiO4F2sample is measured to be ca. 2.85 eV, and its photocatalytic activity and mechanisms are explored systematically. The results demonstrate that the product can serve as an effective catalyst for the degradation of rhodamine B and methyl orange through photocatalytic reactions under irradiation with UV light and can also be used in the visible-light degradation of rhodamine B through the photosensitization process.