Triazine skeletal covalent organic frameworks: A versatile highly positive surface potential triboelectric layer for energy harvesting and self-powered applications

Covalent organic frameworks (COFs) with triazine skeleton have been developed via reticular chemistry. In this present work, a triazine-based nitrogen-rich organic moiety has been used for the COF synthesis and then tested for the output performance of a triboelectric nanogenerator (TENG) using the same. The synthesized COF has been characterized by several physical characterization techniques. For the first time, the surface potential of the prepared COF material was tested experimentally using Kelvin probe force microscopy, which indicates a very high positive triboelectric potential of 2.03 V. The single unit of COF-based TENG delivered 70 V, 0.6 μA, and 38 nC as an electrical output. In the case of multiunit TENG, the current and voltage values are boosted as the parallel connection of four units of TENG gave the peak-to-peak current output rises by 6.3 μA. In comparison, the series connection of four units of TENG gave a high peak-to-peak voltage of 175 V. This work describes the synthesis of N-rich COF material, fabrication of the TENG, and the excellent energy harvesting performance with the realization of low-cost self-powered hand strengthening device. This result paves the way to achieve fruitful exercise monitoring units towards improving lifestyle.