Coupling photothermal and piezoelectric effect in Bi4Ti3O12 for enhanced photodegradation of tetracycline hydrochloride

Semiconductor photocatalysis is an effective way to remove antibiotic pollution. However, recombination of photogenerated carriers limits the efficiency of photocatalytic degradation of antibiotic. In this work, Bi4Ti3O12 (BTO) with micro-hollow spheres (HS-BTO) was successfully self-assembled by BTO nano-sheets. The microstructure of HS-BTO can serve as a guarantee for its good adsorption capability. Assisted by photothermal effect, HS-BTO shows efficient photodegradation of tetracycline hydrochloride (TC) solution. This work reveals that heat can effectively reduce the charge transfer resistance, accelerate the charge transfer, thus promoting the charge separation and improving the photocatalytic performance. In addition, through ultrasound vibration, polarization charges and built-in polarization fields may be generated in HS-BTO. They can accelerate photogenerated charge carriers separation and greatly suppress recombination rate of electron/hole pairs, and is helpful to achieve piezoelectric catalytic degradation of TC. Consequently, a developed photocatalytic degradation of TC assisted by photothermal and piezoelectric effect is achieved. Thus, this work proposes an innovative approach to coupling optical, photothermal and mechanical energy to advance photocatalysis.