Controlled synthesis various shapes Fe₃O₄ decorated reduced graphene oxide applied in the electrochemical detection

Abstract The various shapes Fe₃O₄ decorated reduced graphene oxide (Fe₃O₄/rGO) were prepared by one-step solution co-precipitation method, in which the shapes (sphere, rod and band) of Fe₃O₄ in the nanocomposites could be carefully controlled by adjusting the mole ratio of Fe²⁺/Fe³⁺ in the presence of rGO modified PVP. The structure of Fe₃O₄/rGO was characterized by SEM, EDS, TEM and Raman. Furthermore, the band Fe₃O₄/rGO modified glassy carbon electrode (GCE) was characterized by cyclic voltammetry (CV) and electrochemical impedance spectra (EIS). And the effect of shapes of Fe₃O₄ decorated reduced graphene oxide on the electrochemical detection of Pb(II) was investigated in detail. It was found that the shape of Fe₃O₄ had great effects on sensitivity. The band Fe₃O₄/rGO modified electrode toward Pb(II) showed high sensitivity (13.6 μA/μM), which was higher than that of spherical and rod Fe₃O₄/rGO modified electrode, respectively. The band Fe₃O₄/rGO was further demonstrated to be useful for the individual electrochemical detection of Cd(II) and Cu(II) in water for the first time. This report provides an opportunity to study relationship between the shapes and properties of Fe₃O₄ decorated reduced graphene oxide with high performance.