Synthesis of BiFeO3 nanoparticles by a low-heating temperature solid-state precursor method

BiFeO3 nanoparticles were synthesized through low-heating temperature solid-state precursor method. Solid-state Bi(NO3)3·5H2O, Fe(NO3)3·9H2O and NaOH experience a chemistry reaction at room temperature, forming a nanometer-sized precursor, which is conducive to lowering the crystallization temperature of BiFeO3. Perovskite-type BiFeO3 forms at a much lower crystallization temperature at 425 °C without addition of organic agent. This method can greatly reduce the energy consumption and prevent Bi volatilization. The product was characterized by a variety of techniques such as TGA–DSC, XRD, SEM, FT-IR, VSM and UV–vis spectroscopy. The particle morphology changes from an average length of 80–100 to 400–500 nm as the annealing temperature increases from 450 to 600 °C. BiFeO3 prepared by this method can be an appropriate visible-light photovoltaic and photocatalytic material due to its strong absorption band in the visible region and smaller band gap (∼2.06 eV, BiFeO3 prepared at 600 °C).