Facile hydrothermal synthesis of polyhedral Fe3O4 nanocrystals, influencing factors and application in the electrochemical detection of H2O2

Polyhedral Fe3O4 nanocrystals have been successfully synthesized by a facile hydrothermal technique, employing FeSO4·7H2O, N2H4 and NH3·H2O as the reactants without the assistance of any surfactant. The phase of the as-obtained Fe3O4 was characterized by X-ray powder diffraction (XRD) and further proved by Rietveld refinement of XRD data. Energy dispersive spectrometry (EDS) and scanning electron microscopy (SEM) were used for the composition and morphology analyses of the final product. Some factors influencing the formation of polyhedral Fe3O4 nanocrystals were systematically investigated, including the reaction temperature and time, and the original volume ratio of NH3·H2O/N2H4·H2O. It was found that the as-prepared Fe3O4 polyhedra exhibited a good electrochemical property in 0.1 M phosphate buffer solution (PBS) with pH 7.0 and could be prepared into an electrochemical sensor for the detection of H2O2. The linear response range of the sensor was 10.0 × 10−6 to 140.0 × 10−6 M and a sensitivity was 11.05 μA/mM. Furthermore, the room-temperature magnetic property of the product was also investigated.

► Fe3O4 polyhedra had been successfully synthesized by a facile hydrothermal technology. ► The as-obtained product exhibited the room-temperature ferrimagnetic property. ► The final product could be prepared into an electrochemical sensor for the detection of H2O2.