Air pollution from fine particulate matter (PM2.5 and PM10) poses serious risks to human health, highlighting the need for efficient and sustainable filtration materials. Here, we present a renewable, a metal-free filtration platform produced by upcycling coconut husk waste into carbonized cellulose aerogels (CCAs) via alkaline delignification, sol–gel processing, and carbonization. By adjusting precursor α-cellulose content (61.2%, 72.5%, and 80.6%), we tuned the aerogels' morphology, porosity, and electronic properties. The highest-purity precursor (80.6% α-cellulose) produced a densely interconnected graphitic network that enabled tunneling–percolation charge transport and Coulombic electrostatic capture, a dual mechanism not previously reported for biomass-derived aerogels. This synergy effect enables near-complete removal of PM2.5 (98.6%) and PM10 (99.0%) at a high airflow rate (1.09 m/s) with minimal pressure drops, outperforming many reported filters. Extended cycling demonstrated that CCA-80.6% exhibited ⁓89% PM10 removal efficiency after 30 cycles under active electrostatic filtration. Furthermore, correlation analysis indicated that electrical conductivity was the primary factor governing filtration performance and stability. These results establish CCAs as a scalable, sustainable alternative, providing a new design framework for next-generation air filtration technologies. © 2026 Elsevier B.V.