BaTiO3 nanocrystals with tunable exposed {001} polar facets: A high-performance piezocatalyst and piezoelectric regenerative medicine

Piezocatalysis triggered by ultrasonic vibration has emerged as an effective strategy to address the widespread environmental challenges and human health concerns. Nevertheless, the pursuit of high-performance piezoelectrics that can simultaneously realize catalysis and biotherapy still poses a significant challenge. Herein, we report a notable enhancement in piezocatalytic performance of BaTiO 3 nanoplates featuring highly exposed {001} facets. By controlling the exposure of polar facets, BaTiO 3 with highly {001} facets (I {001} /I {110} = 4.17) exhibits an impressive 1500 % improvement in degradation efficiency compared to BaTiO 3 with less-exposed {001} facets (I {001} /I {110} = 0.76). Through in vitro ultrasonic stimulation, BaTiO 3 also demonstrates a remarkable ability to regenerate neurons, facilitating the rapid differentiation of neural progenitor cells into mature neurons. The mechanism of how polar facets enhance the piezocatalytic activity is systematically investigated by finite element method (FEM) simulation and density functional theory (DFT) calculations, revealing that the enhancement stems from the abundant active sites and strong charge transfer ability. This study thus offers a comprehensive understanding of the relationship between polar facets and piezocatalytic performance, also providing inspiration for the development of high-performance piezoelectric medicine for nerve repair.