Bubble-driven piezo-activation of E-MoS2/PVDF piezoelectric microcapsule for antibiotic degradation with ultralow energy consumption

E-MoS2/PVDF piezoelectric microcapsules with superior piezocatalytic performance were synthesized by coupling of expanded MoS2 (E-MoS2) and polyvinylidene fluoride (PVDF). The bubble-driven piezocatalysis process was proposed for the first time, using as-prepared E-MoS2/PVDF microcapsules as piezocatalyst for the degradation of antibiotics. Results showed that the degradation efficiency of tetracycline (TC), chlortetracycline (CH), and ofloxacin (OFL) in the E-MoS2/PVDF microcapsules solution was 91.88%, 85.48% and 96.84% in 60 min, respectively. After 5 times of recycling, the degradation rate of TC still reaches more than 73%. Importantly, the energy consumption of this bubble-driven piezocatalysis process (76.00 kwh−3order−1) was only 6.43% of ultrasonic processes. In addition, the study of the degradation mechanism found that the bubble-driven stimulated the generation of more 1O2, O2− while increasing the content of dissolved oxygen in the water, which promoted the piezocatalytic degradation. The possible degradation paths were obtained, and the toxicity migration during the degradation of tetracycline was evaluated. The bubble-driven method provides a direction for reducing energy consumption and supplementing the oxygen consumption of degradation in wastewater pollutant treatment.