Metal Ions as Electron Traps: Boosting the Output Performance of Covalent Organic Framework‐Based Triboelectric Nanogenerators

The development of green and sustainable energy harvesting technologies is critical to addressing the global energy crisis and environmental pollution. Triboelectric nanogenerators (TENGs) have emerged as promising platforms for converting mechanical energy into electrical energy. However, their output performance is often constrained by the charge‐trapping capacity of triboelectric layer materials. Herein, two covalent organic framework (COF) materials were designed and synthesized, and Cu 2+ and Co 2+ ions were precisely incorporated into their skeletons via coordination engineering without altering the inherent topological structure. The metal‐coordinated COFs (DAAQ‐Cu‐COF and DAP‐Co‐COF) served as positive triboelectric layers in vertical contact‐separation mode TENGs, delivering maximum instantaneous output currents of 130.7 and 61.5 μA, and peak output voltages of 850.1 and 409.5 V, respectively, significantly outperforming their pristine COF counterparts. Experimental and characterization results reveal that the metal ions act as efficient electron traps, enhancing the electron affinity, surface charge density, and charge transport efficiency of the COF materials. Furthermore, a self‐powered cathodic protection system based on the optimized COF‐TENG was constructed, which effectively inhibited the corrosion of Q235 carbon steel in simulated seawater. This work provides a facile and effective strategy to boost the output performance of COF‐based TENGs and demonstrates their great potential in self‐powered anti‐corrosion applications.