Degradation and detection of tetracycline by a bifunctional Bi4Ti3O12/Ag heterojunction under light and piezoelectric effect†

Photocatalytic degradation and low-concentration detection of tetracycline (TC) are often limited by the high recombination ratio of carriers and low sensitivity. Herein, we synthesized Bi₄Ti₃O₁₂ nanosheets (BiTO NSs) by a molten salt method and decorated them with silver nanoparticles (Ag NPs) to obtain BiTO/Ag heterojunctions for degradation via piezo-photocatalysis and detection by surface enhanced Raman spectroscopy (SERS). The synergetic effect originating from piezoelectricity and surface plasmon resonance (SPR) can improve the photon utilization, resulting in an enhancement in the catalytic performance and detection sensitivity. The reduction of TC by BiTO/Ag was as high as 92.1% within 120 min in a solution of 10 ppm, and the limit of detection (LOD) can reach 0.01 ppm. This work offers a new strategy to achieve the effective degradation and high-sensitivity detection of TC by a BiTO/Ag bifunctional heterojunction material.