Single-Atom Modulation of Local Energy States in sp2-COF for TENG-based Corrosion Protection

In recent years, with the introduction of covalent organic frameworks (COFs) to the field of triboelectric nanogenerators (TENGs), effective charge separation, higher charge density, and faster charge transport rates have become the key challenges for improving the output performance of triboelectric power generation. Therefore, a series of fully conjugated covalent organic framework platforms connected through vinyl bonds were designed and synthesized in this study. The charge density and local energy levels were manipulated in a programmable way by changing a single atom in a local region of one of the monomers, and the correlation among the charge density, local energy states, and the performance of triboelectric power generation was discussed in detail. The results indicated that COF-2N@TENG demonstrated the best triboelectric power production capability, with a maximum current of 61.7 μA and a peak instantaneous power density of 2385.72 mW m-2. In the applications of self-powered corrosion protection, COF-2N@TENG showed remarkable cathodic protection capabilities. In addition, a series of theoretical calculations and experimental studies have shown the methods by which individual nitrogen atom locations control the orbital energy, surface potential, and local electron distribution. This study elevates the optimization of TENG performance from the traditional trial-and-error approach to the level of atomically precise molecular design. By chemically modifying COF materials through the localized modification of individual atoms while maintaining physical parameters such as morphology and pore size, it revealed the independent effects of enhanced electron affinity within the COF framework and surface charge density on TENG output performance. This provides a highly insightful atomic-level gene bank design paradigm for the development of customized, high-performance COF-based TENG materials.