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 (O_latt) are crucial for maximizing the chemical properties of perovskites (ABO₃) catalysts for functional applications. Herein, an effective La vacancy (V_La) creation strategy is reported to activate surface O_latt 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 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 LaFeO₃ and bulk LaFeO₃ with activated O_latt 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 V_La 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.