Synthesis of Ag–HNTs–MnO2 nanocomposites and their application for nonenzymatic hydrogen peroxide electrochemical sensing

Abstract

Natural halloysite nanotubes (HNTs) were attached to the flower-like MnO₂ and HNTs–MnO₂ composites were obtained, then silver nanoparticles were successfully deposited on the surface of HNTs–MnO₂ to produce Ag–HNTs–MnO₂ nanocomposites and they were used for fabricating a non-enzymatic hydrogen peroxide (H₂O₂) sensor. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy were applied to investigate the structures and morphologies of the resultant samples. The Ag–HNTs–MnO₂ composite-based modified electrode exhibited high eletrocatalytic activity to the reduction of H₂O₂ with a linear range of 2.0 μM to 4.71 mM, a detection limit of 0.7 μM (S/N = 3) and a sensitivity of 11.9 μA mM⁻¹ cm⁻². In addition, high specific surface area, low cost and good biocompatibility gives the modified electrode a bright perspective in biosensors and biocatalysis.