Triboelectric-induced self-powered electrostatic and antibacterial filtration system for improving indoor air quality

We present an electrospun triboelectric membrane pair comprising both tribonegative PVDF/BaTiO3 and tribopositive PCL/kraft lignin/tannic acid membranes. The incorporated BaTiO3 induces a conformational transition of PVDF from non-polar (TGTG′) to polar β-phase (TTTT), aligning –CF2 groups and strengthening negative surface potential. The PCL-based ternary composite possesses abundant electron-donating hydroxyl groups that elevate tribopositive properties and improve mechanical robustness via hydrogen-bond networks within the polymeric interconnections. In addition, tannic acid with multivalent galloyl- and phenolic groups successfully retained its inherent antibacterial effect against both Gram-positive (S. aureus) and -negative (E. coli) bacterial species, even embedded within the ternary polymer complex. As a result, under a 10 Hz contact-to-separation condition, the developed pair generates 146 V, which is 12.4-fold higher than the non-additive PCL–PVDF pair. Consistently, it demonstrated triboelectric-enhanced filtration performance across various sizes of particulate matter (PM), achieving a PM2.5 removal efficiency of 99.83 % with the corresponding quality factor of 0.11. This performance remained sustainable even after rinsing the adsorbed pollutants from the tribonegative membrane, resulting in only a slight decrease and maintaining a sufficient removal efficiency of 97.69 % for fine 0.3 μm PM, compared to 98.99 % for the pristine membrane. By integrating such mechanical robustness, antibacterial action, strong triboelectric properties, and reusability, this membrane platform offers a practical pathway for effective indoor air quality management.