Hydrothermal synthesis of cobalt oxide porous nanoribbons anchored with reduced graphene oxide for hydrogen peroxide detection

A new Co3O4-reduced graphene oxide (Co3O4–rGO) nanostructure was successfully prepared by hydrothermal-synthesized Co3O4 porous nanoribbons with an approximate length of 6–17 μm, a width of 21–737 nm, and a thickness of 33–80 nm hybridizing with reduced graphene oxide. The electrochemical properties of the Co3O4–rGO-modified electrode were investigated by the cyclic voltammograms and amperometric current–time method. The modified electrode shows high electrochemical activity for the catalytic reduction and detection of H2O2 in alkaline medium. The nonenzymatic hydrogen peroxide sensor exhibits wide linear range of 1–18.5 mM (R = 0.99439), high adsorption amount about 3.24 × 10−6 mol/cm2, and a low detection limit of 5.35 × 10−7 M (S/N = 3). In addition, the sensor has a fast response (<5 s), good long-term stability, excellent repeatability (3.22 % relative standard deviation), and high selectivity. These outstanding properties of the sensor derive from their particular hybrid structure and synergistic effects between rGO and Co3O4.