Directional Anchoring of Dual Active Sites for Boosting Electrochemical Nonenzymatic H2O2 Sensing

Abstract The efficient construction of active sites is crucial for regulating the electrocatalytic activity of nanomaterials. In this work, nitrogen and ruthenium nanoparticles were anchored onto the inner and outer surfaces of graphene hollow nanospheres (N/GHSs/Ru) via the template method. Notably, the synergistic effect of the superfine Ru nanoparticles and N enhances the electrocatalytic activity of the N/GHSs/Ru nanomaterials, exhibiting excellent electrochemical performance for H 2 O 2 detection. N/GHSs/Ru nanomaterials were characterized by transmission electron microscopy (TEM), energy dispersion spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD), and X‐ray photoelectron spectrometry (XPS). The electrocatalytic reduction of H 2 O 2 showed a wide linear range from 0.02 to 5.6 mM, with a high sensitivity of 668.86 µA·mM −1 ·cm −2 and a limit of detection as low as 6.41 µM. This work offers a way to construct dual active sites, making N/GHSs/Ru as a promising material for nonenzymatic electrochemical H 2 O 2 sensors.