Rolling Friction Enhanced Free-Standing Triboelectric Nanogenerators and their Applications in Self-Powered Electrochemical Recovery Systems

Heavy metals contained in wastewater are one of the most serious pollutions in natural resources. A self‐powered electrochemical recovery system for collecting Cu ions in wastewater by incorporating a rolling friction enhanced freestanding triboelectric nanogenerator (RF‐TENG) is developed here. The RF‐TENG utilizes integrated cylindrical surfaces using the conjunction of rolling electrification and freestanding electrostatic induction, which shows outstanding output performance and ultrarobust stability. By using the kinetic energy of flowing water, a collection efficiency of up to 80% for Cu2+ ions in wastewater has been achieved. Self‐powered electrochemical systems are one of the most promising applications of TENGs for independent and sustainable driving of electrochemical reactions without the need for any additional power supply. This research is a substantial advancement towards the practical applications of triboelectric nanogenerators and self‐powered electrochemical systems. A self‐powered electrochemical recovery system for collecting Cu ions from wastewater by a rolling friction enhanced free‐standing triboelectric nanogenerator (RF‐TENG) is demonstrated. The rolling contact electrification and free‐standing electrostatic conduction‐based TENG used as a system to harvest the kinetic energy of running water shows an outstanding output performance and ultrarobust stability. This research forms a substantial advancement towards the practical applications of nanogenerators and self‐powered electrochemical systems.