Study on the Mechanism and Electrochemical Performance of Self‐Powered Cathodic Protection for Reinforced Concrete in Marine Environment

In marine environments, reinforced concrete structures are vulnerable to long‐term corrosion of steel reinforcement caused by chloride ingress. Conventional cathodic protection systems that depend on external power sources suffer from well‐known limitations, including high maintenance costs, considerable energy consumption, and limited sustainability. To address these issues, this study presents a self‐powered cathodic protection system driven by a triboelectric nanogenerator (TENG) for environmentally friendly corrosion prevention. The system employs a polytetrafluoroethylene particle‐copper electrode TENG integrated with a buoy structure to efficiently harvest wave energy. Coupled with integrated rectification and energy management circuits, the system converts irregular, low‐frequency wave motion into a stable direct current output, thereby enabling sustained cathodic protection. Under simulated marine conditions, the TENG exhibited an open‐circuit voltage ( V oc ) exceeding 2000 V, a short‐circuit current ( I sc ) of approximately 50 μA, and a maximum power density of 1428 mW·m⁻² at an excitation frequency of 2.0 Hz. Electrochemical analyses confirmed that this self‐powered system significantly suppressed steel corrosion, showing a notable negative shift in corrosion potential and a sharp drop in corrosion current density. No visible rust was observed even after long‐term immersion.