Effect of Gd Dopant on Visible-Light-Driven Photocatalytic Properties of CeO2 Nanowires Synthesized Microwave-Assisted Hydrothermal Method

Gd-doped CeO2 nanowires were synthesized by microwave-assisted hydrothermal method at 120°C for 30 min. The X-ray diffraction patterns of CeO2 with and without Gd dopant were indexed to the pure phase of cubic CeO2 structure with no detection of a secondary phase. The transmission electron microscopic images of CeO2 and Gd-doped CeO2 show uniform nanowires with aspect ratio of 10–40. The CeO2 and Gd-doped CeO2 nanowires have the prefer orientation growth along the [111] direction. The photocatalytic activities of CeO2 nanowires with and without Gd dopant were evaluated through the degradation of rhodamine B (RhB) under visible light irradiation. The UV-visible light absorption of RhB solution was decreased to the lowest by the photocatalysis of 3% Gd-doped CeO2 nanowires with the highest photocatalytic activity of 99.51% and 1.71 times of pure CeO2 nanowires within 180 min. A possible photocatalytic mechanism of the Gd-doped CeO2 nanowires was also studied and proposed in this research.