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

Abstract Regulation of A‐site vacancy and activation of lattice oxygen (O latt ) are crucial for maximizing the chemical properties of perovskites (ABO 3 ) catalysts for functional applications. Herein, an effective La vacancy (V La ) creation strategy is reported to activate surface O latt species over 2D ultrathin LaFeO 3 (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 V La of 2D‐U‐LFO nanosheet generates more reduced Fe─O bonding and activated O latt species, thereby the resulted 2D‐U‐LFO exhibits remarkably improved catalytic oxidation performance than that of pristine LaFeO 3 and bulk LaFeO 3 with activated O latt species. Further, 2D‐U‐LFO cathode for Li‐O 2 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 V La over LFO can promote Li 2 O 2 adsorption. This proposed strategy will pave a novel avenue to develop vacancy‐meditated ABO 3 in sheet structure for boosting functional applications.