Alternating Interlayered Piezoelectric Self‐Heterojunction Boosts Sono‐Piezocatalytic Pyroptosis Oncotherapy

Abstract Recombination of sono‐generated charge carriers is a major barrier hindering the effectiveness of piezocatalytic oncotherapy. Herein, ultrathin oxygen vacancy‐engineered self‐heterojunction bismuth oxysilicate (O _v ‐BOS) nanosheets with alternating hetero‐layered nanostructure are constructed for enhanced sono‐piezocatalytic tumor therapy. Benefiting from its out‐of‐plane asymmetry, O _v ‐BOS features an exceptional electromechanical strain coefficient (d ^* ₃₃ = 203 pm/V), highlighting its outstanding capability as a piezoelectric heterojunction for energy conversion. Particularly, the oxygen vacancy engineering facilitates the spatial redistribution of bands across the alternating [Bi ₂ O ₂ ] and [SiO ₃ ] layers in O _v ‐BOS, promoting effective charge separation and stratified charge storage, thereby further suppressing recombination of sono‐generated charge carriers in a manner analogous to heterojunctions. Leveraging this strategy, O _v ‐BOS demonstrates efficient reactive oxygen species production and exhibits superior peroxidase and catalase‐like activities compared to the conventional piezoelectric nanocatalysts. Consequently, the enhanced radical generation induced the specific cancer‐cell pyroptosis via caspase‐3 mediated gasdermin E‐dependent pathway. Therefore, the engineered interlayer self‐heterojunction provides an efficient strategy for the design and engineering of high‐performance piezoelectric nanocatalysts.