Photocatalytic degradation of acid orange 7 using Cr-doped CeO2 nanorods

Cr-doped CeO2 nanorods were prepared by a co-precipitation method using cerium and chromium nitrates with ammonia solution as the precipitator. The morphology and structure of the synthesized products were characterized by field emission scanning electron microscope, X-ray diffraction, and transmission electron microscopy. The specific surface area of the Cr-doped CeO2 nanorods (455 m(2) g(-1)) is higher than those of CeO2 nanoparticles (52 m(2) g(-1)). X-ray photoemission spectroscopy spectrum confirms the presence of Cr in CeO2 nanorods. UV-Vis spectra analyzes showed that the Cr-doped CeO2 nanorods exhibit the absorption band in the visible region. The synthesized products exhibited good photocatalytic activity for the degradation of acid orange 7 under UV-visible light illumination and the pseudo-first order reaction rate constant (k) of 0.250 h(-1) for Cr-doped CeO2 nanorods is higher than 0.142 h(-1) of CeO2 nanoparticles.