Hydrothermal synthesis of urchin-like Co₃O₄ nanostructures and their electrochemical sensing performance of H₂O₂

Nanostructured tricobalt tetraoxide, Co₃O₄, was hydrothermally synthesized starting from cobalt dichloride hexahydrate (CoCl₂·6H₂O) and urea (H₂NCONH₂) as precursor and polyethylene glycol-400 (PEG-400) as a structure-directing agent. Uniform urchin-like nanostructures were hydrothermally obtained at 150 °C for 16 h, and the Co₃O₄ morphology did not collapse after a subsequent calcination at 300 °C for 2 h. XRD measurements indicated that the average sizes of Co₃O₄ particles prior and after heating at 300 °C are 64 and 44 nm, respectively. This material has been successfully used for the nanostructuration of screen-printed carbon electrodes (SPCEs) which were used for the sensitive electrochemical detection of hydrogen peroxide (H₂O₂). The sensor is endowed with a large dynamic range (0.1 to 50 µM) and a limit of detection of 0.145 µM. The as obtained results show that the Co₃O₄ nanomaterial could be a candidate to be used as sensors for the detection of analytes. - Graphical abstract: The nanowires appear to have a common center and grow to the outside along the radial direction. - Highlights: • Nanostructured was hydrothermally prepared using PEG-400. • Uniform urchin-like Co₃O₄ nanostructures were hydrothermally obtained. • X-ray diffraction showed a cubic structure after calcinations process. • Nanostructured Co₃O₄ was used for the sensitive electrochemical detection of H₂O_2. • The sensor is endowed with a large dynamic range 0.1 to 50 µM