Controlled synthesis of Bi25FeO40 with different morphologies: growth mechanism and enhanced photo-Fenton catalytic properties.

Bi25FeO40 microtetrahedra, microcubes and microspheres were successfully synthesized by a simple hydrothermal process and by adding different additive agents. The formation mechanism of Bi25FeO40 microcrystals was proposed; the additive agents had important influences on the morphology and facet exposure of the products. The catalytic activity of these materials was evaluated by the degradation of RhB in a heterogeneous photo-Fenton process. The Bi25FeO40 microcubes showed enhanced photo-Fenton catalytic activity, which can be attributed to an exposed {001} facet with the active O atoms. The hydroxyl radicals are the main active group in the heterogeneous photo-Fenton catalytic degradation. This study may provide a new method to design and synthesize novel nanoscale and microscope functional materials.