A new low-temperature solution route to Aurivillius-type layered oxyfluoride perovskites Bi2MO5F (MÂ =Â Nb, Ta) as photocatalysts

- A low-temperature solution synthesis was first developed for Bi2MO5F (M = Nb, Ta).
- The reaction and growth mechanisms of the products were systematically explored.
- The experimental band gap values and photocatalysis of Bi2MO5F were first reported.
- UV-light degradation of RhB and MO was driven by the photocatalytic process.
- Visible-light degradation of RhB proceeded via the photosensitization pathway.

Aurivillius oxyfluoride perovskites exhibit great potential in photocatalysis, which are generally prepared by high-temperature solid-state reactions and some impurity phases are always unavoidable. Herein, a new low-temperature solution method has been successfully developed for the synthesis of Bi2NbO5F and Bi2TaO5F pure phases. The electron microscopy results reveal that the products were composed of the hierarchical hollow spheres with porous surface. The formation and growth mechanisms of the products were proposed based on the time-dependent evolution. The experimental band gaps of Bi2NbO5F (2.86 eV) and Bi2TaO5F (2.95 eV) were also first obtained. The photodegradation tests demonstrated that the products could be effectively served as catalysts for degradation of Rhodamine B and methyl orange under UV-light irradiation via the photocatalytic reaction, and also could be used in visible-light degradation of Rhodamine B via the photosensitization process. This low-temperature solution preparation of Aurivillius oxyfluorides opens a new facile route to tackle the versatile chemistry of various oxyfluoride perovskites.

A low-temperature solution method is firstly developed to prepare Aurivillius-type perovskites Bi2MO5F hierarchical hollow spheres for UV- and visible-light photocatalysis.183