Synergistic effects of Fe-Se dual single-atom sites for boosting electrochemical nonenzymatic H2O2 sensing

Fe-Se dual single-atom sites as novel electrocatalyst were synthesized and anchored on nitrogen-doped carbon (NC) for boosting electrochemical nonenzymatic H2O2, which is the first example of metal-nonmetal dual-atomic-sites for constructing electrochemical sensor. [Display omitted] •Fe-Se dual single-atom on N-doped ultrathin carbon were synthesized for boosting electrochemical nonenzymatic H2O2 sensing.•The synergistic effect of Fe-Se could accelerate electron transfer rate and increase electrochemical active area.•A novel strategy was proposed to enhance electrochemical sensing based on the metal-nonmetal dual-atom sites. The study of single atoms in the field of electrochemical sensing is at the early stage. How to boost the catalytic performance of single atoms is still a big challenge. Herein, we prepare Fe-Se dual single-atom sites on N-doped ultrathin carbon carrier (Fe1Se1/NC) for realizing highly sensitive nonenzymatic detection of H2O2. Fe1Se1/NC was synthesized through the pyrolysis strategy, and then was characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) mapping, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), and electrochemical techniques, respectively. The results displayed that Fe and Se both existed in an atomically dispersed status. Compared to the single-atom Se or Fe catalyst (Se1/NC or Fe1/NC), the Fe1Se1/NC significantly boosted the electrocatalytic activity for H2O2 reduction. The Fe1Se1/NC modified electrode could be used to detect H2O2 in a wide linear range of 0.02 mM to 13 mM with a high sensitivity of 1508.6 µA·mM−1·cm−2 and a low detection limit of 11.5 µM. Moreover, the sensor was successfully employed for detecting H2O2 in disinfectant and urine samples. This work provides a novel design of dual-atom catalysts for excellent electrochemical sensing applications.