A highly stable bimetallic organic framework for enhanced electrical performance of cellulose nanofiber-based triboelectric nanogenerators

Abstract

Triboelectric nanogenerators (TENGs) have garnered considerable attention as an emerging energy harvesting technology. To improve the electrical properties of the triboelectric materials in TENGs, various micro- and nanomaterials with strong charge-trapping capabilities are introduced as filler materials. However, the fillers generally perform a single function and lack long-term operational durability. Hence, further research is required to achieve stable and efficient TENGs. In this study, NH₂ metal–organic frameworks (NH₂-MOFs) were combined with a cellulose nanofiber (CNF) to prepare a composite film. NH₂-MOFs have an aminated bimetallic organic backbone with strong charge-induction and charge-trapping capabilities. Thus, their addition significantly improved the stability, positive triboelectric properties and charge-trapping performance of the composite film. The optimized composite film and a fluorinated ethylene propylene film were used as triboelectric pairs to assemble a TENG. The electrical performance of the TENG was approximately 230% greater than that of a TENG with a pure CNF film and remained very stable for at least 90 days. These results demonstrate that NH₂-MOFs are promising fillers for improving the performance of TENGs and expanding the range of materials used in TENG construction.