Fe3O4 with novel nanoplate-stacked structure: Surfactant-free hydrothermal synthesis and application in detection of heavy metal ions

• Fe3O4 with novel nanoplate-stacked structure was successfully synthesized.
• Individual and simultaneous detection of five heavy metal ions was achieved.
• Excellent stability of nanoplate-stacked Fe3O4 modified electrode was obtained.
• The relationship between electrochemical behavior and adsorption capacity was revealed.

For the first time, magnetite (Fe3O4) with novel nanoplate-stacked structure was successfully synthesized via a facile surfactant-free hydrothermal method in this study. The as-prepared product was characterized with scanning electron microscopy (SEM) and X-ray diffractometer (XRD), suggesting that the Fe3O4 was composed of abundant nanoplate-stacked slices. The electrochemical behaviors of the as-obtained nanoplate-stacked Fe3O4 toward heavy metal ions, including Pb(II), Cd(II), Cu(II), Hg(II) and Zn(II), were investigated with square wave anodic stripping voltammetry (SWASV) and the results indicated that the modified electrode could be applied to individual and simultaneous detection of five heavy metal ions. In addition, reasonable explanation for the electrochemical responses based on adsorption measurements was proposed. Furthermore, this study provides a potential material for electrochemical detection of heavy metal ions individually and simultaneously.