The role of microstructure in piezocatalytic degradation of organic dye pollutants in wastewater

Piezoelectrically-induced catalytic effect, piezocatalysis, is considered with a great potential in addressing the environmental issues. In this work, BaTiO3 nanowires (BTO NWs) were prepared by combining the sol-gel-based electrospinning technique and post calcination process. Their microstructure characteristics, including crystal structure, crystalline size, surface area and dimension, were effectively adjusted by altering the calcination temperature, calcination time or precursor concentration. And the roles of these microstructure characteristics in the piezocatalytic activity were thoroughly investigated by degradation of methyl orange solution under ultrasonic vibration. Results indicated that the crystal structure and surface area play an important role in piezocatalytic activity of BTO NWs. Moreover, experimental results indicated that BTO NWs with smaller diameter or being composed of smaller size crystallites contributes to better piezocatalytic performance. Our present work gives a clear understanding of the role of microstructure in piezocatalysis and provides a way to develop high performance piezocatalysts.