Fe3C-functionalized 3D nitrogen-doped carbon structures for electrochemical detection of hydrogen peroxide

Fe 3 C-functionalized three-dimensional (3D) porous nitrogen-doped graphite carbon composites (Fe 3 C/NG) were synthesized via a facile solution-based impregnation and pyrolysis strategy using the commercially available melamine foam and FeCl 3 as precursors. The structural characterizations confirmed that Fe 3 C nanoparticles with an average core size about 122   nm were assembled on the surface of the carbonized melamine foam (CMF) skeletons. The electrochemical measurements demonstrated the superior electrocatalytic activity of the advanced Fe 3 C/NG composite for hydrogen peroxide reduction reaction in 0.1   mol/L PBS electrolyte and the limit of detection of H 2 O 2 is estimated to be 0.035   mmol/L at a signal-to-noise ratio of 3 with a wide linear detection range from 50   μmol/L to 15   mmol/L ( R 2 = 0.999). Compared with the pure CMF, the Fe 3 C/NG exhibited higher catalytic activity , more stable response, lower detection limit, higher selectivity and a wider detection range, which could be attributed to the synergic effect between the two types of active sites from the iron carbide species and the nitrogen-doped graphite carbon. Meanwhile, the large surface area, high conductivity and the improved mass transport from the 3D porous material can also promote the electrochemical sensing performance. Moreover, the Fe 3 C/NG-based electrochemical sensor showed high anti-interference ability and stability for H 2 O 2 detection. Thus, the novel and low-cost Fe 3 C/NG composite may be a promising alternative to noble metals and offer potential applications in various types of electrochemical sensors, bioelectronic devices and catalysts.