A\nNovel Piezoelectric Nonwoven Fabric for Recoverable\nHigh-Efficiency Filters

Serious\nhaze pollution, mainly caused by fine and ultrafine particulate\nmatters (PMs) and aerosols, poses a significant threat to the public\nhealth, especially when the aerodynamic diameter is less than 2.5\nμm. Electrostatic capture techniques, such as polymer electret\nfilters and kinetic plasma processes, are widely used instead of mechanical\nfiltration with high removal efficiency and low wind resistance (pressure\ndrop). However, the inability to recharge, coupled with the generation\nof ozone byproducts, makes it challenging to meet the requirements\nfor both recoverability and highly efficient filtration. Here, we\npropose an electrostatic filter as an alternative to conventional\npolymer electrets, aiming to achieve an ultrahigh removal efficiency,\nlong-term performance stability, and reusability. Piezoelectric LiNbO<sub>3</sub> (LN) particles are integrated into the polypropylene (PP)\nmatrix through the melt-blown strategy to fabricate the LN/PP nonwoven\nfabric. Benefiting from the employment of piezoelectric LN particles,\nthe LN/PP nonwovens exhibit an ultrahigh removal efficiency of 99.9%\nfor PM<sub>0.3</sub> to PM<sub>10</sub>. The airflow facilitates the\nsustained regeneration of piezoelectric charges on the surface of\nLN/PP nonwovens, thereby maintaining a removal efficiency of approximately\n95% for continuous filtration over 11 days. Even after eight cycles\nof washing, the removal efficiency of the LN/PP nonwovens remains\nat nearly 90%, demonstrating the excellent reusability. Our proposed\nstrategy offers an ingenious combination of high-efficiency and recoverability\nfor filters, holding great promise for reducing plastic pollution.