Hierarchical architecture of nanographene-coated rice-like manganese dioxide nanorods/graphene for enhanced electrocatalytic activity toward hydrogen peroxide reduction

Rice-like MnOx nanorods covered by nanographene (MxNRS@NG) are prepared via a simple one-step hydrothermal route. After combination with graphene (GS) and calcination, MxNRS are converted into MnO2 nanorods (MNRS) and the hierarchical architecture of MNRS@NG/graphene (MNRS@NG/GS) is obtained. In this ternary architecture, GS is an excellent supporting substrate for the electrocatalysis of MNRS, and NG can provide abundant active carbon atoms of edge phase and accelerate the electron transfer between MnO2 and GS. Electrochemical results demonstrate that the electroreduction of MNRS toward H2O2 is significantly enhanced by the assembly of GS and NG. The MNRS@NG/GS modified electrode exhibits excellent performance in H2O2 detection over the concentration range of 0.002-4.44 mM, with a high sensitivity (707.9 μA mM−1 cm−2) and a low detection limit (0.2 μM).