Shape-controlled preparation of bismuth ferrite by hydrothermal method and their visible-light degradation properties

Bismuth ferrite (BiFeO 3 ) has been prepared by hydrothermal method using Fe(NO 3 ) 3 ·9H 2 O and Bi(NO 3 ) 3 ·5H 2 O as the starting materials. The single-phase cube-like BiFeO 3 materials with defined morphologies were successfully synthesized by controlling the experimental parameters. Effects of reaction time, KOH concentration and organic dispersant on the BiFeO 3 particle morphology , size and property were systematically investigated. The prepared BiFeO 3 particles present tunable absorption characters by controlling the particle size and morphology. The prepared samples can degrade methyl orange (MO) under visible light (>420 nm). Cubic BiFeO 3 particles with a size of ca. 1.4 um could be synthesized by using PVP as the dispersant, which shows the highest activity of MO photo-degradation. The photocatalytic mechanism is proposed and active components are further convinced by EPR analysis.