Non-enzymatic amperometric detection of hydrogen peroxide using grass-like copper oxide nanostructures calcined in nitrogen atmosphere

Abstract

In this research, grass-like CuO nanostructure was synthesized via a simple hydrothermal reaction at 100°C for 6h without using any surfactant. The as-prepared sample was further calcined at 500°C for 1h in nitrogen atmosphere for comparison. The surface morphology, crystal structure and chemical composition of the products were investigated by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and room temperature photoluminescence spectroscopy (PL). The 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 sample prepared after calcination in a nitrogen atmosphere exhibited better electrochemical catalytic performance for the determination of H2O2. In addition, high sensitivity (119.35μA/mM) and fast amperometric response (< 3s) were achieved; mainly due to the large specific surface area of the grass-like morphology, efficient electron charge transfer property resulting from the increased crystallinity after calcination, as well as more available and active absorption sites induced by surface defects and the CuO/Cu2O heterostructure, thus making it one of the promising candidates for the efficient and sensitive non-enzymatic amperometric detection of H2O2.