NiFe2O4 octahedrons have been successfully synthesized by a one-step hydrothermal method.
Hydrogenation modifies the surface structure of NiFe2O4 and generates some oxygen vacancies and metallic Ni.
Hydrogenation largely improves the cycling capacity (60% higher at 50th cycle) and rate capability (3 times higher at 1 A/g).
The simple hydrogenation modification method might also be applied to other transition metal oxides electrodes.