Flow-driven piezoelectric membranes for autonomous antifouling and energy-efficient water purification

Membrane separation technology has emerged as a cornerstone for water purification due to its high separation efficiency, energy efficiency, and minimal environmental footprint. However, membrane fouling remains a critical challenge to its sustainable application, increasing energy consumption and operational costs. This study introduces a self-triggered polytetrafluoroethylenezeolite/imidazole framework-8 (PTFE@ZIF-8) composite membrane, capable of autonomous antifouling and enhanced separation by harnessing inherent flow energy to generate piezoelectric voltage oscillations and demonstrate piezo-catalytic activity. The enhanced piezoelectricity of the PTFE@ZIF-8 membrane resulted in superior antifouling capacity and significantly enhanced rejection performance compared to the pristine PTFE membrane. Detailed characterization and simulation studies revealed that the self-triggered piezoelectric voltage oscillations induced dielectrophoresis, which played a pivotal role in fouling control and separation enhancement. Additionally, the in situ generation of reactive oxygen species (ROS) during filtration further contributed to the antifouling performance. Increasing feed flow rates further boosted ROS production and piezoelectric outputs, improving separation efficiency without external energy input. This study advances energy-efficient water purification by leveraging flow energy to power antifouling and separation processes, aligning with sustainable resource management goals.