Synthesis of Ce/Mo-V4O9 nanoparticles with superior visible light photocatalytic activity for Rhodamine-B degradation

Abstract

The role of Ce/Mo-V4O9 nanoparticles and the possible active species in the Rhodamine-B degradation over the visible-light-driven Ce/Mo-V4O9 catalyst have firstly been investigated in this work. The samples were characterized by UV–visible-diffuse reflectance spectroscopy (UV–vis-DRS), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The results indicated that the doping element did not affect the final crystalline structure of V4O9, but it had great influences on the photocatalytic activity of Ce/Mo-V4O9 towards rhodamine-B (Rh-B) degradation. Factors such as pH, initial Rh-B concentration and catalyst dosage that may affect the photodegradation of Rhodamine-B were studied. More importantly, the codoped V4O9 significantly improved the separation efficiency of the photogenerated electron-hole pairs. These factors contribute to the enhancement of photocatalytic activity. A possible mechanism was also proposed to understand the origin of enhanced performance in the codoped system. On the basis of radical scavenger experiments, superoxide radicals and holes are suggested to play a critical role in Rh-B degradation over Ce/Mo-V4O9. Overall, this work could provide new insights in to the synthesis of Ce/Mo-V4O9 nanoparticles as high performance photocatalyst and promise as a visible light photocatalyst for dye waste water treatment.