Piezoelectricity catalyzed ROS generation of MoS2 only by aeration for wastewater purification

In general, the generation of active species for the degradation of pollutants from molybdenum disulfide (MoS2) requires light illumination or ultrasonic treatment, rendering it a high-cost and not conducive to practical application. However, aeration is a common method in sewage treatment. This study describes the formation of hydroxyl radicals from water in the presence of MoS2, which occurs in the absence of light and is induced by vibration generated by simple aeration only. Wondrously, we found that the solution obtained after the extraction of the catalyst is still active in the decompose of rhodamine-B (RhB). It is even better than that of ultrasonic. As far as we know, there has been no study about this. The piezoelectric potential generated by MoS2 nanoflowers that induces the hole–electron separation is observed by atomic force microscopy, and the formation of hydroxyl radicals post aeration is detected via electron spin resonance. A screening of conditions reveals the volume of water and aeration time as key factors for the solution activity. The degradation mechanism of RhB was proposed by studying the intermediates of RhB.