High-efficiency cycling piezo-degradation of organic pollutants over three liters using MoS2/carbon fiber piezocatalytic filter

Piezocatalysis has great potential commercial application for the high-efficiency degradation of organic pollutants in a dark environment. However, the recycling of catalyst materials and the subsequent generation of secondary pollution remain challenging. In this study, MoS2 nanoflowers (NFs)/carbon fiber was synthesized to develop a piezocatalytic filter that can recycle decomposed wastewater easily without generating secondary pollutants in treated water. The MoS2/carbon fiber was constructed in pipelines to form the piezoelectric degradation system, which demonstrated a high efficiency in decomposing organic molecules in wastewater through natural water flow. The piezocatalytic filters in the circulatory system completely degraded a large amount of dye solution (1000 mL) in 40 min and can repeat three-times degradation with the total organic carbon value decreased by 90%. The theoretical calculation indicated that MoS2 grew on carbon fiber, which exhibited a bending moment effect under natural water-flow-induced pressure. This established considerable piezoelectric potential at MoS2 NFs active edge sites and MoS2–carbon fiber interfaces, triggering electron–hole pair separation under the internal electric field. The MoS2/carbon fiber piezoelectric catalyst is advantageous for its reusability and recyclability, thus preventing secondary pollution and adverse effects on water bodies during practical high-flux wastewater treatment.