Anti-fouling piezoelectric ceramic membrane for universal water treatment: Performance, mechanisms and validation

The lead-free piezoelectric ceramic is considered a promising functional anti-fouling membrane material with no risk of lead leaching. Among the various types of lead-free piezoelectric ceramics, barium titanate (BaTiO₃) stands out for its exceptional piezoelectric property and thermal stability, making it suitable for membrane separation applications. However, the mechanism and applicable separation system of the piezoelectric ceramic membrane (PCM) remain ambiguous, lacking both theoretical and practical guidance for the development of anti-fouling membranes. Herein, porous and dense phases and the orientation of ferroelectric domains are modulated to maximum the piezoelectric and permeability by optimizing sintering temperature and poling parameters of lead-free BaTiO₃ PCM. The thus-optimal PCM equips a benign piezoelectricity (∼ 55 pC·N⁻¹) and permeability (∼ 257 L·m⁻²·h⁻¹·bar⁻¹). Further, we investigate the anti-fouling performance during the universal water treatment process (Al₂O₃, yeast, and oil) and extended the finite element simulations to illustrate the mechanisms from the perspectives of displacement (1500 nm) and acoustic pressure (2.22 × 10⁵ Pa). The establishment of the model makes a significant contribution to providing scientific guidance for the structural design and development of piezoelectric membrane materials (lead zirconate titanate (PZT), poly (vinylidene fluoride) (PVDF), etc.) in the future.