Alternating Electrical Polarity Enabled Efficient Charge Capture Triboelectric Nanogenerator for Self‐Powered Environmental Purification and Monitoring System

Abstract Air breakdown‐based tribo‐charge collection strategy addresses the interfacial discharge‐induced output bottleneck of conventional triboelectric nanogenerators (TENGs). However, random discharge beyond the designated charge collection electrodes (CCEs) results in device output falling short of theoretical expectations. Here, an alternating electrical polarity structured approach is proposed that first doubles the number of CCEs to suppress non‐targeted discharges. Then, an opposite polarity material is incorporated into the free inter‐electrode to facilitate charges more likely transfer to CCEs. This optimization leads to a 122% increase in output charge compared to conventional direct current TENGs. Furthermore, multiunit integration into a rotational configuration offers dual‐channel output charge densities of +8.18 and −8.02 mC m −2 at 60 rpm. The corresponding maximum average power densities reach 24.97 and 24.91 J m −2 , setting a new benchmark for similar direct current TENGs reported to date. In practical applications, the negative output directly activates a carbon fiber array to generate negative air ions for PM 2.5 purification, while the managed positive output drives an air quality sensor for real‐time environmental monitoring. This work not only establishes a feasible approach for boosting TENG performance but also lays a solid foundation for the self‐cleaning of environmental pollutants.