Fabrication of Bi4Ti3O12/MoS2 heterojunctions for efficient piezocatalytic degradation of ciprofloxacin in water

Traditional water treatment methods still face limitations in addressing environmental and health concerns posed by antibiotic pollutants. Piezoelectric catalysis, as an emerging environmental remediation technology, demonstrates potential in this regard due to its highly efficient catalytic activity. Based on this, this study constructed a binary n-n Type-II heterojunction piezoelectric catalytic material, Bi 4 Ti 3 O 12 /MoS 2 (BTO/MS), for the efficient removal of ciprofloxacin (CIP). A series of BTO/MS composites were synthesized via a simple hydrothermal method, with the 5%BTO/MS composite exhibiting optimal piezocatalytic performance toward CIP: Under conditions of 100 W ultrasonication for 60 min, the removal rate of 10 mg/L CIP reached 94.46%, with an apparent reaction rate constant of 0.0539 min −1 . This represents a 3.46-fold and 17.39-fold increase over pure MoS 2 and pure Bi 4 Ti 3 O 12 , respectively. The composite structure effectively mitigated MoS 2 nanosheet agglomeration and suppressed electron-hole pair recombination via an n-n Type-II heterojunction, significantly enhancing the piezoelectric catalytic activity of 5%BTO/MS. Electron paramagnetic resonance (EPR) results indicate that singlet oxygen ( 1 O 2 ) and superoxide radical (·O 2 − ) are the dominant reactive oxygen species governing the piezoelectric catalytic degradation process. Simulations using T.E.S.T. software revealed that most intermediates exhibited reduced ecotoxicity compared to the parent compound CIP. Additionally, 5%BTO/MS demonstrated excellent catalytic performance in removing CIP from tap water and lake water matrices, as well as in degrading other organic pollutants, indicating the material's promising application potential in the field of piezoelectric catalytic water purification.