Piezocatalysis in ferroelectric Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃/polyvinylidene difluoride (PVDF) composite film

The ferroelectric Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ (BCZTO) ceramic particles were immobilized in a polymer matrix of polyvinylidene difluoride (PVDF) in order to fabricate flexible and stable composite films for the treatment of water using the piezocatalysis process. The content of BCZTO in BCZTO/PVDF composite films was 0, 5, and 10 wt. % of PVDF. The presence of the BCZTO phase in PVDF composites was confirmed using x-ray diffraction, Raman spectroscopy, and a scanning electron microscope. Piezocatalytic activity of BCZTO/PVDF composite films was investigated by monitoring the degradation of various organic dyes, pharmaceuticals, and bacteria present in the water. The highest values of dye degradation were achieved in 10 wt. % BCZTO/PVDF composite films, where the model dyes named methylene blue, Rhodamine B, and methyl orange dyes were degraded by ∼91%, ∼86%, and 90% after the sonication for 180 min, respectively. The dye degradation performance using piezocatalysis was found to be repeatable and consistent for up to five cycles. Hydroxyl radical (^⋅OH) was identified to be the main reactive species behind piezocatalytic dye degradation. An increment in dye degradation performance was observed with an increment in the power of the ultrasonicator during piezocatalysis. In addition, 10 wt. % BCZTO/PVDF composite films displayed 59% and 50% degradation of pharmaceutical antibiotics named tetracycline and ciprofloxacin, respectively, within 180 min of sonication, respectively. Also, more than 99.99% E. coli bacteria were inactivated using 10 wt. % BCZTO/PVDF composite films under 180 min of sonication treatment and showed a bacterial log reduction of 3.4. These promising results indicate the 10 wt. % BCZTO/PVDF composite film as a potential candidate for the treatment of water using piezocatalysis technology.