In situ growth of FeOOH nanoparticles on physically-exfoliated graphene nanosheets as high performance H2O2 electrochemical sensor

Abstract Compared with extensively-used chemically-exfoliated graphene, physically-exfoliated graphene-based heterogeneous structures are rarely used for electrochemical analysis. In this work, physically-exfoliated graphene nanosheets (GN) are used as the substrate material to couple high-activity FeOOH nanoparticles. Multiple characterization technology confirm that a novel hierarchical hybrid composed of physically-exfoliated graphene nanosheets and FeOOH nanoparticles (GN@FeOOH) is easily obtained by a facile solution growth strategy. Plenty of fiber-like FeOOH nanoparticles with size about 20 nm are uniformly anchored on the surface of graphene with robust adhesion. Relative to pristine GN, the electrochemical active area and electron transfer kinetics are greatly boosted for the introduction of high-activity of FeOOH nanoparticles. Benefiting from the remarkably enhanced electrochemical activity, the obtained GN@FeOOH hybrids exhibit excellent electrochemical performance toward the reduction of H2O2. As a result, a novel and rapid electrochemical sensing platform for the detection of H2O2 at low applied potential (-0.25 V vs. SCE) is fabricated with wide linear range (0.25 μM - 1.2 mM) and high sensitivity (265.7 μA mM−1 cm-2), and the limit of detection is as low as 0.08 μM, which is comparable with many other noble metal-based electrochemical sensors and exceeds many non-noble metal-based electrochemical sensors.