Nearly monodisperse hollow Fe₂O₃ nanoovals: Synthesis, magnetic property and applications in photocatalysis and gas sensors

Nearly monodisperse hollow Fe₂O₃ nanoovals (NMHFNs) composed of nanoparticles have been successfully synthesized through a solution process followed by a calcination treatment under ambient pressure. The influences of experimental parameters (e.g., time, temperature, amount of PVP) on the morphology have been investigated. The products were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. This facile reaction route presents an efficient method for mass production of monodisperse hollow magnetic nanomaterials. The NMHFNs show a typical soft ferromagnetic behavior at room temperature. They exhibit superior photocatalytic property on photocatalytic decomposition of salicylic acid and excellent response of about 8.15 even to the low ethanol concentration of 0.5 ppm and response of 32 to the concentration of 5 ppm.