In Situ Grown Metal–Organic Frameworks with Diverse Ligands on Nanofibrous Sheet for Modulating Triboelectric Performance

In this study, we developed a triboelectric material by growing metal-organic frameworks (MOFs) in situ on electrospun polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) nanofiber sheets. By varying the ligand chemistry, using electron-donating (-NH₂) or electron-withdrawing (-COOH, -NO₂) groups, we modulated the triboelectric properties without altering the nanofiber morphology or β-phase crystallinity. Structural and surface characterizations confirmed in situ grown MOF integration and ligand-dependent modulation of surface properties. When applied to triboelectric nanogenerators (TENGs), the materials exhibited output responses modulated by ligand type, with the NO₂-functionalized MOF achieving the highest increase, producing a maximum peak-to-peak voltage of approximately 130 V that remained stable over 30,000 contact-separation cycles. These findings demonstrate a reliable, ligand-tunable strategy for controlling interfacial properties, emphasizing the dominant role of surface electronic characteristics in determining triboelectric performance.