CeO2 nanofibers-CdS nanostructures n–n junction with enhanced visible-light photocatalytic activity

Abstract

In the present work, the n-cerium (IV) oxide (CeO2)/n-cadmium sulfide (CdS) composite nanofibers were successfully synthesized via a facile electrospinning and hydrothermal synthesis strategy. The physicochemical properties of the synthesized composite nanofibers were investigated by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy Dispersive X-Ray Spectroscopy (EDS), diffuse Reflectance Spectroscopy (DRS), Fourier-transform infrared (FTIR), photoluminescence (PL), Brunauer–Emmett–Teller (BET) and Raman spectroscopy analysis. The activities of the CeO2/CdS were evaluated through the photocatalytic degradation of Rose Bengal (RB) in an aqueous solution under blue LED light radiation. CeO2/CdS composites exhibit higher photocurrent density in photocurrent response experiment and smaller charge-transfer resistance in electrochemical impedance spectroscopy (EIS). Overall, the results confirmed higher charge separation efficiency in CeO2/CdS composites compared to pristine CeO2 nanofibers, and CdS, which is related to intimately contact among the CeO2, and CdS. The present work provides a new approach to construct n-n heterojunction photocatalysts based on electrospinning and a deeper insight for the photocatalytic degradation activity. In addition, possible degradation mechanism and pathways were proposed according to the identified intermediates.