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 (H ₂ O ₂ ) through two-electron reduction of dissolved oxygen than unmodified graphite electrode. Moreover, the H ₂ O ₂ electrogeneration of as-prepared electrode (167.06 μmol/L) was more than 7 times than unmodified graphite electrodes (22.82 μmol/L) at 300 mA/cm ² . Modification of the surface of graphite electrode also enhanced the durability and stability of the as-prepared electrode, so that after 50 cycles the NiFe@C/G electrode retains its electrocatalytic activity.