Co3O4 nanowires supported on 3D N-doped carbon foam as an electrochemical sensing platform for efficient H2O2 detection

Abstract

Using a simple hydrothermal procedure and a subsequent annealing treatment, one-dimensional (1D) cobalt oxide nanowires (Co₃O₄-NWs) with tunable size have been successfully in situ fabricated on a three-dimensional (3D) carbon foam (CF) network. By changing the hydrothermal treatment time (0.5, 1, or 2 h) at 180 °C, size-controlled Co₃O₄ nanowires can be formed on the CF. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) measurements showed that nanoporous Co₃O₄ nanowires grew uniformly on the 3D carbon framework. Because of the 3D porous architecture and the high conductivity of the carbon foam skeleton, the obtained composites are characterized by fast mass transport, large surface area and high electronic conductivity, which make them very promising electrochemical sensing materials. Among the studied composites, the Co₃O₄-NWs/CF hydrothermally treated for 1 h exhibited the lowest detection limit (1.4 μM) and the largest linear ranges (0.01–1.4 mM) with a sensitivity of 230 nA μM⁻¹ cm⁻² for H₂O₂ detection. The present study shows that metal oxides supported on 3D carbon materials present a class of promising sensing platform for the electrochemical detection of H₂O₂.