M-Nx (M = Fe, Co, Ni, Cu) doped graphitic nanocages with High specific surface Area for non-enzymatic electrochemical detection of H2O2

N-doped porous-walled graphitic nanocages (NGCs) with high specific surface area have been successfully doped by metallic ions (M2+ = Fe2+, Co2+, Ni2+ or Cu2+) for efficiently detecting H2O2. To increase surface area, NGCs were prepared by partially removing N-doped template inserted in their graphitic layers to sharply create nanopores in graphitic shells of nanocages, which were approached from removing ferrous cores of core-shell precursor (Fe3[email protected]) synthesized from short-time floating catalytic pyrolysis. With high specific surface area (920 m2 g−1), mesopore volume (1.6 cm3 g−1) and good graphitization, the synergistic effects of metallic ions and N-doped structure, which improves their dispersion and increases active sites, plays a very important role in detection of H2O2. Fe-N coordination much easier forms in the condition of our experiment than Co-N, Ni-N and Cu-N, which might lead to better electrochemical performance of Fe-Nx doped graphitic nanocages (Fe-NGCs), including wider linear range (0.001−5 mM), lower LOD (0.53 μM), higher sensitivity (184.4 μA mM−1 cm-2), selectivity and stability. Such results demonstrate Fe-NGCs nanocomposite is a promising candidate for the detection of H2O2 in practical application.