Dislocation‐enhanced piezoelectric catalysis of KNbO ₃ crystal for water splitting

Dislocations in oxides with ionic/covalent bonding hold potential for harnessing versatile functionalities. Here, high‐density dislocations in a large plastic zone in potassium niobate (KNbO 3 ) crystals are mechanically introduced by room‐temperature cyclic scratching to enhance piezocatalytic hydrogen production. Unlike conventional energy‐intensive, time‐consuming deformation at high temperature, this approach merits efficient dislocation engineering. These dislocations induce local strain and modify the electronic environment, thereby improving surface reactivity and charge separation, which are critical for piezocatalysis. This proof‐of‐concept offers a practical and sustainable alternative for functionalizing piezoelectric ceramics. Our findings demonstrate that surface‐engineered dislocations can effectively improve the piezocatalysis, paving the way for efficient and scalable piezocatalytic applications.