Defect‐Engineered SrTiO _3‐x for Flexoelectric‐Dominated Catalysis

ABSTRACT Flexocatalysis provides an alternative route for converting mechanical energy into electrical energy through flexoelectricity, thereby avoiding the crystal‐symmetry constraints that limit conventional piezocatalysis to non‐centrosymmetric materials. In this study, strong flexocatalytic effects were established in reduced strontium titanate (R‐STO) nanoparticles prepared by a facile solid‐state reduction route. Regulated generation of oxygen vacancies generates near‐surface lattice distortion and a gradient in lattice strain, which together give rise to substantial flexoelectric polarization, and thus R‐STO demonstrates an excellent capability for Rhodamine B (RhB) decomposition, achieving > 78% degradation within 45 min. The kinetic rate constant of R‐STO (0.0307 min −1 ) is nearly double that of pristine STO (0.0163 min −1 ), primarily due to enhanced charge separation and prolonged electron–hole pair lifetimes induced by the flexoelectric polarization. R‐STO also exhibits an impressive co‐catalyst‐free hydrogen production rate of 380.8 μmol/g/h, representing a fourfold increase over pristine STO (94.5 μmol/g/h). This enhancement is attributed to synergistic effects of improved charge separation and transfer, a favorable band structure, and optimized adsorption configurations during catalysis. These results underscore the promise of flexocatalysis for applications in environmental remediation and renewable energy production.