Surfactant-induced photocatalytic performance enhancement of europium oxide nanoparticles

Recently, rare earth (RE) elements and their oxides have been attracting more and more attention in the field of photocatalytic degradation . Due to the unique 4  f electronic structure and optical properties , the RE element, europium (Eu), together with its oxides, are often used for surface modification of other photocatalysts . Nevertheless, the photocatalytic degradation property of europium oxide has been rarely reported. In this study, we synthesized Eu 2 O 3 nanoparticles via chemical precipitation and calcination processes, and performed surface modification by using surfactants as polyvinyl pyrrolidone (PVP) and hexadecyl trimethyl ammonium bromide (CTAB). Compared with pure Eu 2 O 3 nanoparticles and those synthesized with PVP, photocatalytic degradation efficiencies of Eu 2 O 3 nanoparticles synthesized with surfactant CTAB for degrading rhodamine B dye demonstrated to be improved by 16% and 12%, respectively. The ultraviolet-visible diffuse reflectance spectra measurements indicate that CTAB can increase the bandgap of Eu 2 O 3 due to the reduction of oxygen defects. Photoluminescence spectra demonstrate that the surfactant would affect the luminescence of Eu 3+ and carrier redistribution of energy levels.