Functionalization　and　lightweighting　of　high-performance　air　filters　can　markedly　improve　quality　of　life.　However,　achieving　this　goal　with　green　processes　and　fully　bio-based　materials　remains　challenging,　placing　significant　strain　on　the　environment　and　energy　resources.　The　key　lies　in　mastering　the　appropriate　material　matching　strategy　and　its　mechanism　for　the　forming　of　membrane　structure.　Here,　ethyl　cellulose　(EC)/tea　polyphenol　(TP)/betaine　(BT)　bimodal　nanofibrous　membranes　were　fabricated　by　blended　electrospinning　using　green　solvents.　The　synergistic　interaction　between　TP　and　BT　termed　the　＇small　molecule　mutual　support　mechanism＇,　is　particularly　compelling.　TP　could　prevent　polymer　chains　from　being　difficult　to　deform　because　of　BT,　making　it　good　spinnable　even　under　high　BT　loading.　In　this　case,　the　cations　of　BT　were　sufficient　to　cause　jet　splitting,　forming　a　bimodal　structure.　Consequently,　high-performance　antibacterial　air　filtration　had　been　achieved　under　ultra-light　and　ultra-thin　conditions　(15%　and　8%　of　N95　masks,　respectively).　The　filtration　efficiency　for　0.3　μm　NaCl　particles,　pressure　drop,　and　quality　factor　were　99.79%,　58.7　Pa,　and　0.1050　Pa-1,　respectively.　The　antibacterial　rates　for　Escherichia　coli　and　Staphylococcus　aureus　were　all　99.99%.　This　study　offers　insights　into　the　green　and　sustainable　design　of　advanced　protective　equipment.　©　2024　Elsevier　Ltd