Synergistic effects of coordinated metals and fluoridation in metal-covalent organic framework for efficient triboelectric nanogenerator

Improving the performance of triboelectric nanogenerators (TENG) depends on the development of new and effective friction electrode materials. Metal-covalent organic frameworks (MCOFs) are promising functional materials with applications in various fields owing to their structural diversity and tunability; howerver, however, the use of MCOFs in the preparation of TENG devices has not yet been investigated. In this study, a MCOF (Cu-COF) were designed and constrcuted via the post metalation method by introducing transition metal ions through the delicate chelating structure of a CF3 substituted covalent organic framework (CF3-COF) for the first time. The constructed Cu-COF exhibited higher triboelectric nanogenerator output performance, with a peak value of short circuit current of 104.0 µA and an output voltage of 1107 V, which are 1.47 and 1.39 times those of CF3-COF, respectively. This can be attributed to the excellent charge density, improved conductivity and narrow band gap of Cu-COF. In addition, the Cu-COF-based TENG exhibits excellent stability and power density, and is capable of lighting 1440 commercial green LEDs. This study also suggests that the strategy for engineering metalation coordination environments on the skeletons of COFs could provide a novel method to fabricate TENG devices with MCOFs.