Dipole Moment and Polarization Field Induced by Oxygen Vacancies Boosting Piezocatalytic Hydrogen Peroxide Production of Centrosymmetric Material.

Piezocatalysis is a sustainable and promising strategy for H2O2 synthesis; however, its efficiency is limited by sluggish interfacial charge-transfer kinetics and insufficient active sites. Herein, an oxygen vacancy-rich SnO (SnO-OVs) piezocatalyst was designed with abundant active sites, enhanced dipole moments, and intensified polarization fields, which collectively boost the piezocatalytic H2O2 production efficiency. The SnO-OVs achieve an exceptional production rate of 512.29 μmol g-1 h-1 in pure water without any sacrificial agents. Mechanistic studies reveal that under compressive strain, SnO-OVs exhibit superior water adsorption capacity and a reduced energy barrier for *OH intermediate formation, synergistically promoting the two-electron water oxidation pathway (2e- WOR) for H2O2 synthesis. Additionally, H2O2 preferentially dissociates into *OH rather than forming *O and *H2O under compressive strain, resulting in effective piezocatalytic BPA degradation via radical-dominated •OH oxidation pathways. This work introduces a novel strategy for efficient H2O2 synthesis and facilitates the advancement of sustainable water purification technologies.