High Roughness Induced Pearl Necklace-Like ZIF-67@PAN Fiber-Based Triboelectric Nanogenerators for Mechanical Energy Harvesting

Technological developments and innovations in the wearable device field have created huge consumer demand. Hence, designing energy harvesting devices are of utmost importance. Of the various types of energy harvesting devices, triboelectric nanogenerators (TENGs) have come to the fore, as it can efficiently harvest electrical energy from mechanical motions. To date, polymers and metals have dominated the triboelectric series, but there is a need to develop novel composite materials and 2D materials to enhance the performance of TENGs. In this study, electrospun polyacrylonitrile nanofibers are prepared and decorated with zeolitic imidazole framework-67 (ZIF-67@PAN) to form pearl-necklace-like fibers. ZIF-67@PAN nanofibers are prepared by immersing PAN nanofibers for different hours (1, 5, 10, and 24 h) in ZIF-67 solution, they provide more roughness, and efficient surface contact area. The immersion of PAN fibers in ZIF solution for longer times increases overall energy harvesting efficiency. Different amounts of MXene are deposited on PVDF; the inclusion of MXene improves the charge transfer properties of TENGs. PAN@ZIF-67 is used as a positive tribolayer and PVDF@MXene as a negative tribolayer. The optimized TENG device has 305 V, 10.6 µA, and 10.9 W/m² power and demonstrated promising energy harvesting characteristics and self-powered sensing efficiency.