Visible Light Photocatalytic Activity of Bismuth Ferrites Tuned by Bi/Fe Ratio

Pure perovskite BiFeO 3 , sillenite Bi 2 Fe 4 O 9 , and BiFeO 3 / Bi 2 Fe 4 O 9 were synthesized facilely by controlling the precursor Bi / Fe ion ratio through a hydrothermal method. The phase composition, morphology, optical properties, and photocatalytic activity of as‐prepared samples were investigated in detail. Our results indicate that the morphology and properties of products strongly dependent on the precursor Bi/Fe ion ratio. Photocatalysis of Congo Red reveals that sillenite Bi 2 Fe 4 O 9 shows superior activity to perovskite BiFeO 3 , and BiFeO 3 / Bi 2 Fe 4 O 9 exhibited higher activity with 71.45% degradation rate in 90 min. It provides an easy and efficient way to tune the composition and photocatalytic activity of Bi‐based oxides.