Highly Efficient Piezocatalytic Activity of Poly(tetrafluoroethylene) for Large-Scale Organic Wastewater Purification

Abstract

Piezocatalysis is an emerging and promising catalytic technique for degrading organic pollutants by harvesting mechanical energy. However, the catalytic efficiency and environment compatibility of present piezocatalysts are still unsatisfactory. Here, the superior piezocatalytic performance of eco-friendly poly(tetrafluoroethylene) (PTFE) micron powders was demonstrated by degrading several typical dyes. Methylene blue can be degraded by 99% within 20 min (k = 0.246 min–1) using fresh PTFE under ultrasonic vibration, and PTFE exhibits excellent stability and reusability. In addition, rhodamine B, acid orange 7, and methyl orange can also be degraded by 100, 98, and 99% within 60 min, respectively, demonstrating the wide adaptability of PTFE. Catalytic mechanism investigations demonstrate that •OH and •O2– play major roles in dye degradation. Furthermore, the influence of various water sources and different containers on the catalytic performances of PTFE was explored, indicating that PTFE has nice environmental suitability and that the glass container facilitates catalytic degradation. Therefore, a designed glass spiral tube was applied for large-volume wastewater purification, which can be further extended for potential applications. This work thus demonstrates that PTFE can be regarded as a promising catalyst for wastewater treatment by harvesting mechanical energy, and the proposed Z-shaped wastewater degradation device has potential applications in wastewater treatment.