Piezocatalytic performance of Na0.5Bi0.5TiO3 nanoparticles for degradation of organic pollutants

Piezocatalysis has been considered as a promising technology in water pollution treatment. In this work, a series of piezoelectric Na0.5Bi0.5TiO3 (NBT) nanoparticles were prepared by hydrothermal method using different titanium sources as titanium precursors. The piezocatalytic performances of the NBT nanoparticles were investigated by the degradation of Rhodamine B (RhB) with the concentration of 10 mg/L under ultrasonic vibration. It is found that the NBT nanoparticles prepared by using anatase titanium oxide as titanium precursor show optimum piezocatalytic activity and the rate constant of 0.022 min−1 is achieved for RhB. The initial RhB concentration, ultrasonic power, particles size and specific surface area of NBT materials play an important role in optimizing the piezocatalytic performance. Moreover, the NBT nanoparticles show a satisfactory stability and reusability for the piezocatalytic degradation. The piezocatalytic mechanism of NBT nanoparticles was elucidated by the identification of free radicals and intermediates in the degradation process. The work provides a guidance to design and develop new high-performance piezocatalysts.