Novel bismuth ferrite nanopowder prepared by polyethylene glycol-assisted two-step solid-state reaction: Synthesis and magneto-optical properties

In this study, a bismuth ferrite (BiFeO₃) nanopowder was synthesized by combining Bi(NO₃)₃·5H₂O, Fe(NO₃)₃·9H₂O, and NaOH raw materials in the presence of polyethylene glycol (PEG) with varying polymerization degrees (i.e. PEG200, PEG400, PEG600, and PEG10000). The synthesis process was carried out by room-temperature solid-state reaction followed by subsequent secondary solid-state reaction at 550 °C. The results suggested a significant influence of PEG polymerization degree on the morphology and size of the as-synthesized products. The grain size decreased after the introduction of PEG but increased with the polymerization degree. The vibrating-sample magnetometry data revealed PEG400 and PEG600 with obvious room-temperature ferromagnetism properties. In UV–Vis spectroscopy, the absorption edge exhibited a blue shift as the polymerization degree of PEG rose. In sum, BiFeO₃ nanopowder possessed room-temperature ferromagnetism, thereby suitable photocatalyst for wastewater treatment and environmental purification with convenient recycling and substantial economic value.