Lead-Free (K, Na)NbO₃ Piezocatalyst with Superior Piezocatalysis and Large-Scale Production

Although piezocatalysis has achieved preliminary achievements in environmental remediation and biomedical applications, large-scale fabrication of piezocatalysts with high degradation efficiency and low cost remains challenging. In this work, a new and easy strategy to solve this challenge is innovatively proposed, that is, ceramic-powder-driven boosted polarization intensity, and validated the strategy is by examining potassium sodium niobate ((K, Na)NbO3, KNN) ferroelectric. KNN-3 piezocatalyst, obtained by grinding as-sintered ceramics into powder, shows a degradation rate (k) as high as 148 x 10(-3) min(-1) for rhodamine B (RhB) dye and for 31 x 10(-3) min(-1) for methyl orange (MO) dye, approximate to 18 times and 66 times than those of previously reported KNN piezocatalysts. The superior piezocatalytic activity is attributed to enhanced polarization intensity, increased oxygen vacancies, and higher charge carrier concentrations. Besides, the KNN-3 piezocatalyst shows excellent inhibitory effects on Staphylococcus aureus and Escherichia coli strains. Therefore, the proven ceramic preparation technology enables the new strategy to mass produce high-performance KNN piezocatalysts that hold promise for applications in dye degradation and biomedicine.