Piezoelectric enhanced photocatalytic degradation of levofloxacin by La doped Bi4Ti3O12 nanosheets

The emerging piezo-photocatalysis technology is a potential method for reducing carrier recombination and accelerating carrier migration, leading to improved catalytic activity and further prospects for application in practice. In this study, Bi4-xLaxTi3O12(x 4- x La x Ti 3 O 12 ( x = 0, 0.5, 0.75, 1) nanosheets as the piezoelectric photocatalysts were successfully synthesized using a simple hydrothermal method. The effects of La doping content on the piezophotocatalytic performances of Bi4Ti3O12 4 Ti 3 O 12 are investigated by degrading levofloxacin (LVX) and rhodamine B (RhB) for the first time. The mechanism and possible pathways of the degradation process are determined by free radical trapping experiments, electron spin resonance (ESR) spectroscopy, and Liquid Chromatography-Mass Spectrometry (LC-MS). Among all samples, when x = 0.75, Bi 3.25 La 0.75 Ti 3 O 12 exhibits outstanding piezoelectric photocatalytic activity, with a 92.5 % degradation rate of LVX in 5 min and an apparent rate constant of 0.4753 min(-1) , which is approximately 4.16 times higher than that of pure Bi4Ti3O12 4 Ti 3 O 12 and superior to most reported piezoelectric photocatalyst materials. The excellent degradation ability of Bi 3.25 La 0.75 Ti 3 O 12 is mainly attributed to the appropriate amount of La doping resulting in nanosheets with higher specific surface area, increased number of active sites, superior energy band structure, and larger piezoelectric response. Additionally, the low-frequency water flow can also induce the piezoelectric polarization field of Bi 3.25 La 0.75 Ti 3 O 12 , thus increasing the sensitivity of bismuth titanate to small stresses and expanding the range of applications. This study provides a promising strategy for designing efficient piezoelectric photocatalysts in the future, confirming that a suitable number of ions can significantly enhance the catalytic performance.