Activation of Surface Lattice Oxygen Over Nanosheet LaFeO3 with La Vacancy for Boosting Catalysis and Energy Conversion

Regulation of A‐site vacancy and activation of lattice oxygen (Olatt) are crucial for maximizing the chemical properties of perovskites (ABO3) catalysts for functional applications. Herein, an effective La vacancy (VLa) creation strategy is reported to activate surface Olatt species over 2D ultrathin LaFeO3 (2D‐U‐LFO) nanosheets by introducing urea, which can precisely modulate their physicochemical properties and thus remarkably enhance catalysis and energy conversion. The contained surface VLa of 2D‐U‐LFO nanosheet generates more reduced Fe─O bonding and activated Olatt species, thereby the resulted 2D‐U‐LFO exhibits remarkably improved catalytic oxidation performance than that of pristine LaFeO3 and bulk LaFeO3 with activated Olatt species. Further, 2D‐U‐LFO cathode for Li‐O2 battery also displays a higher specific capacity of 24251 mAh g−1 and longer cyclability of 1600 h than pristine LFO (10495 mAh g−1, 200 h). It is theoretically revealed that the surface VLa over LFO can promote Li2O2 adsorption. This proposed strategy will pave a novel avenue to develop vacancy‐meditated ABO3 in sheet structure for boosting functional applications.