Photocatalytic degradation of persistent brilliant green dye in water using CeO2/ZnO nanospheres

In the present work, ceria/zinc oxide (CeO2/ZnO) nanocomposite has been synthesized by controlled annealing of cerium and zinc precursors. The obtained CeO2/ZnO nanocomposite was characterized using common analytical methods such as Fourier transform infrared spectroscopy (FT-IR), UV-Visible diffuse reflectance spectroscopy (UV-DRS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy dispersive spectrum (SEM with EDS) and elemental mapping measurements. The band gap energy of CeO2/ZnO nanocomposite was about similar to 2.9 eV calculated from the Tauc plot. The XRD pattern of CeO2/ZnO nanocomposite consisted mixed phases of CeO2 and ZnO with crystalline nature. The XPS spectrum of CeO2/ZnO revealed the presence of C, Zn, N, O and Ce elements, where Zn and Ce existed in 2+ and 4+ oxidation states, respectively. The particle size and shape of synthesized CeO2/ZnO nanocomposite was approximately 0.32 mu m with a distorted spherical shape identified from the SEM images. The synthesized CeO2/ZnO nanocomposite effectively degraded BG in water and the calculated kinetic rate constant was 0.0471 min-1. The results suggested that CeO2/ZnO nanocomposite behave as a good photocatalyst towards the degradation of BG, identified from the quick degradation as compared with pure ZnO and CeO2. The enhanced catalytic performance of CeO2/ZnO nanocomposite was attributed to the synergistic effect of both CeO2 and ZnO semiconductors, which decrease the bandgap energy and increase the degradation kinetics. (c) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, CeO2/ZnO nanocomposite was successfully synthesized and characterized using various analytical methods. The material showed a small band gap energy and good photocatalytic performance, demonstrating high efficiency in degrading dyes.