A new facile strategy for addressing the localized corrosion issue at damaged coating via a wind-driven triboelectric nanogenerator

Metal substrate at the damaged coating, exposed directly to the corrosive medium, is susceptible to the localized corrosion, due to the formation of occluded corrosion cells. Herein, a new facile strategy for addressing the localized corrosion issue at damaged coating using a triboelectric nanogenerator (TENG) was proposed. The wind-driven TENG with a simple double-layer structure was designed. The output performance of the TENG can be controlled by adjusting structural parameters and the wind speeds, with the maximum short circuit current, output voltage and corresponding power reaching approximately 102.5 μA, 814 V and 7.6 mW, respectively, at a wind speed of 7.5 m/s. The electrons generated by the TENG can be transferred to the metal substrate at the damaged coating, inducing the cathodic polarization of the metal and providing effective cathodic protection. The reduction reaction, with the consumption of O2 and the formation of OH-, occurs at the metal substrate at the damaged coating. A protective local environment is created by the combination of increased pH and removal of Cl- under the electric field of the TENG. To evaluate the corrosion behavior, immersion experiments and electrochemical measurements were conducted in 3.5 wt% NaCl when the Q235 steels covered the damaged coating were coupled with and without the wind-driven TENG at different wind speeds. Meanwhile, the influence of TENG's output performance on the cathodic protection effect for the metal substrate at the damaged coating is discussed. This study expands the application of the TENG in the field of corrosion resistance.