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.