Two-electron oxygen reduction on NiFe alloy enclosed carbonic nanolayers derived from NiFe-metal-organic frameworks

Herein, we report a generic way for in-situ fabricate of NiFe alloy enclosed carbonic nanolayers on graphite substrate (NiFe@C/G) through a facile annealing step of NiFe-metal-organic frameworks (NiFe-MOFs). The NiFe@C/G electrode shows numerous surficial active centers, more positive onset potential, and higher limiting current density for generation of hydrogen peroxide (H2O2) through two-electron reduction of dissolved oxygen than unmodified graphite electrode. Moreover, the H2O2 electrogeneration of as-prepared electrode (167.06μmol/L) was more than 7 times than unmodified graphite electrodes (22.82μmol/L) at 300mA/cm2. Modification of the surface of graphite electrode also enhanced the durability and stability of the as-prepared electrode, so that after 50cycles the NiFe@C/G electrode retains its electrocatalytic activity. [Display omitted] •Preparation of NiFe@C/G electrode and its application in ORR system.•Investigation of the oxygen reduction reaction performance of NiFe@C/G electrode.•High H2O2 electrogeneration on the NiFe@C/G electrode in compared with graphite.•Study of the effect of pH and current density on H2O2 electrogeneration.•Display the high stability and reusability of the NiFe@C/G electrode.