Performance-Enhanced and Washable Triboelectric Air Filter Based on Polyvinylidene Fluoride/UiO-66 Composite Nanofiber Membrane

Applying triboelectric nanogenerators (TENGs) in air filtration systems to generate electric charges through friction is a major advancement in air cleaning technology. The performance of triboelectric air filter strongly depends on the properties of triboelectric materials. In this work, a better triboelectric material, polyvinylidene fluoride (PVDF)/UiO-66 composite nanofiber membrane (P6-NFM), is designed and fabricated through electrospinning technology by doping UiO-66 into PVDF matrix. As the weight ratio of UiO-66 increases to 1%, PVDF/UiO-66 composite nanofiber-based TENG (P6-TENG) achieves the maximum current, voltage, and triboelectric charge of 4.29 mu A, 52.8 V, and 22.02 nC, which are 6.5 times, 5.1 times, and 8.0 times as large as those of pure PVDF-based TENG (P-TENG). Therefore, the triboelectric air filter based on P6-NFM can be easily charged by slapping the fiber membrane and spun-bond fabric. After charging, the removal efficiency of P6-NFM is 92% for PM0.5 and 98% for PM2.5, which are 2.8 and 1.2 times those of the uncharged one. More importantly, the filtration efficiency of this air filter keeps stable after the membrane is washed four times. This method of loading UiO-66 on the triboelectric fiber material shows tremendous potential in self-charging and reusable air purification applications.