Sonophotocatalytic treatment of rhodamine B using visible-light-driven CeO2/Ag2CrO4 composite in a batch mode based on ribbon-like CeO2 nanofibers via electrospinning

摘要

CeO2/Ag2CrO4 composite photocatalyst was successfully fabricated using electrospinning and calcination and chemical precipitation method based on CeO2 ribbon-like fibers and characterized by field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS) and Fourier-transform infrared spectroscopy (FT-IR). The as-obtained CeO2/Ag2CrO4 composite used photocatalytic performance in the sonophotodegradation of rhodamine B in aqueous solution under visible-light (LED) irradiation. DRS analysis illustrates that CeO2/Ag2CrO4 composite exhibited enhanced absorption in the visible region-attributed CeO2 nanofibers(.) The effect of four effective parameters including initial concentration of rhodamine B (RhB), photocatalyst dosage, pH, and irradiation time was studied and optimized using central composite design. The kinetic studies confirmed ability of pseudo first-order reaction based on the Langmuir-Hinshelwood model for fitting empirical data, while its rate constant (k(obs)), L-H rate constants (k(r)), and L-H adsorption constants (K-A) were 0.0449min(-1), 11.66mgL(-1)min(-1) and 1.09E-3mgL(-1), respectively. The enhanced photocatalytic activity could be ascribed to the ultrasound field and formation of a heterojunction system among CeO2 and Ag2CrO4, which lead to a better mass transfer and higher efficiency of charge electron-hole separation, respectively.