Effect of Bi3+ incoporation on up/downconversion luminescence and photocatalytic activity of Gd2O3

Gd2O3 has been selected as host material for optical studies due to its good chemical, photothermal, and photochemical stabilities. A series of (Gd1-xBix)2O3 ( x = 0.03, 0.05, 0.1, 0.2, 0.3, 0.5) samples were ob-tained via coprecipitation method. The samples were characterized by X-ray powder diffractometry (XRD), transmission electron microscopy (TEM) combined with selected area electron diffraction (SAED), BET sur-face area method, UV-visible (UV-vis) absorption spectra and photoluminescence (PL) spectroscopy. The crystalline-to-amorphous phase transformation was found with higher concentration of Bi3 + incorpora-tion. The dependence of Bi3 + concentration on the upconversion/downconversion luminescence intensity were investigated and the photocatalytic activity of the synthesized samples was also evaluated by the degradation of Rhodamine B (RhB) dye in aqueous solution under visible light irradiations. The samples (Gd0.5Bi0.5)2O3 exhibited better photocatalytic activity for RhB degradation than Gd2O3 and Bi2O3 due to phase transformation, modified band structures and higher surface area.(c) 2022 Elsevier B.V. All rights reserved.