Defect engineering-driven enhancement of piezocatalysis in (K, Na)NbO3 lead-free piezocatalysts†

Abstract

Currently, environmental pollution, particularly water contamination, poses a significant threat to human health, necessitating the urgent development of efficient catalytic degradation methods. Piezocatalysis is attracting attention as an innovative and environmentally friendly technology. However, the performance of piezocatalysis remains hindered by challenges such as low carrier separation efficiency and limited active sites for surface reactions. To address these issues, we conducted defect engineering on (K, Na)NbO₃ (KNN) lead-free piezocatalysts to modulate the concentration of oxygen vacancies. The results demonstrate that KNN-250, enriched with oxygen vacancies, exhibits significantly enhanced degradation efficiency for Rhodamine B and Methyl Orange dyes, with reaction rate constants 1.3 and 4.4 times higher, respectively, compared to pristine KNN. In addition, in vitro bacterial inhibition experiments demonstrate the antibacterial activity of KNN-250. This work demonstrates that defect engineering serves as an effective strategy for enhancing the catalytic performance of piezoelectric materials.