Bulk-effect-enhanced tribo-piezoelectric membrane for efficient and self-sustained pollutant degradation

To overcome the limitations of conventional electrocatalytic wastewater treatment-including high external energy consumption, low solid-liquid interfacial charge density, unstable electrical output, and severe charge backflow-we developed an excited tribo-contact electrocatalytic (E-TCE) system. This system integrates a charge excitation module and a rectified energy-storage unit into a conventional TCE setup, enabling self-powered operation. By coupling a PTFE@MoS₂ composite membrane with the bulk effect, the charge transport pathway is extended from the membrane surface into the material interior, significantly enhancing interfacial charge utilization. Under optimized conditions (dual-electrode configuration, 68 nF capacitance, 0.5 g/L MoS₂ loading, 20 cm droplet height, 60° membrane inclination, and 15 mg/L crystal violet (CV)), the E-TCE system achieved a CV degradation efficiency of 94.3%, with a current output of 8.3 nA and a charge output of 9.4 nC-substantially outperforming the original TCE system. The system also demonstrated broad-spectrum efficacy, degrading methyl orange (MO), rhodamine B (RhB), and tetracycline (TC), and maintained >85% CV removal after five consecutive cycles. Radical scavenging and EPR analyses identified ·O₂^- and ·OH as the primary reactive species, while LC-MS-based degradation pathway and ecotoxicity assessments confirmed progressive detoxification. This work presents a self-powered, bulk-effect-enhanced interfacial charge regulation strategy for sustainable water remediation.