Hydrothermal preparation of nest-like CuO nanostructures for non-enzymatic amperometric detection of hydrogen peroxide

Abstract

In this study, nest-like CuO nanostructures were hydrothermally synthesized at 160 °C for 6 h with 0.24 g Cu(NO₃)₂·2.5H₂O in 20 mL H₂O and 12 mL NH₃·H₂O without using any surfactant. The influences of the initial amount of Cu(NO₃)₂·2.5H₂O and hydrothermal reaction time on CuO morphologies were investigated. In addition to the morphology study by scanning electron microscopy (SEM) and the crystal structure study by X-ray diffraction (XRD), as-synthesized samples were also characterized systematically by electrochemical methods including cyclic voltammetry (CV), amperometric detection (i–t) and electrochemical impedance spectroscopy (EIS). It was found that the as-prepared nest-like CuO modified glassy carbon electrode exhibited good electrochemical performance towards the reduction of H₂O₂. Low detection limit (0.44 μM), fast response (<2 s), and relatively high sensitivity (14.06 μA mM⁻¹) were achieved, which was mainly due to the porous structure of the nest-like nanostructure that can provide a large specific surface area and efficient electron charge transfer and mass transport properties, thus making it a promising candidate for the efficient, stable, and precise non-enzymatic amperometric detection of H₂O₂.