Synergy of Oxygen-Deficient LaFeO3-delta and N-Doped Reduced Graphene Oxide in Oxygen Reduction Reaction in Alkaline Solutions

The development of low-cost and efficient electrocatalysts for oxygen reduction reaction (ORR) is of prime importance to the emerging renewable energy technologies. Herein, a series of LaFeO3-delta/NrGO-x (x = 10, 20, and 25) hybrid materials have been synthesized via a facile strategy that enhanced ORR performances in alkaline solutions owing to the strong coupling effect between defect-rich LaFeO3-delta perovskite nanoparticles and N-doped reduced graphene oxide (NrGO) nanosheets. Among the oxygen-deficient perovskites/carbon hybrids, LFO/NrGO (LaFeO3-delta/NrGO-20) demonstrates relatively excellent ORR catalytic activity. The Tafel slope of LFO/NrGO is lower than that of Pt/C (20 wt %). This remarkable improvement is largely correlated to the presence of surface oxygen vacancies and the distortion of [FeO6] unit. On the other hand, the excellent durability of the LFO/NrGO hybrid mainly results from the strong interaction between LaFeO3-delta nanoparticles and NrGO nanosheets. This work highlights the importance of regulating the synergy of perovskites/carbon hybrids as an effective strategy for boosting the ORR electrocatalytic activity for applications in oxygen-related energy storage and conversion processes.