Synthesis of Er3+ loaded barium molybdate nanoparticles: A new approach for harvesting solar energy

Er3+ loaded BaMoO4 was synthesized by the microwave assisted hydrothermal process. Loading of Er3+ ion shifted the absorption band of BaMoO4 towards the longer wavelength and enhanced the absorption of visible light in the solar spectrum. A shift of the absorption edge to the lower energy and four absorption bands located at 390, 489, 524 and, 654 nm attributed to the 4f transitions of I-4(11/2) -> H-2(9/2), I-4(15/2) -> F-4(7/2), I-4(15/2) -> H-2(11/2), and I-4(15/2) -> F-4(9/2); respectively, were observed during DRS analysis. Moreover, Er3+ ion acts as an upconversion luminescence agent by absorbing near infrared light (NIR) thereby emitting upconversion luminescence. Enhanced absorption of the solar energy has been utilized for the degradation of methylene blue dye as a test reaction. Therefore, this work provides a new approach to harvest solar energy for the activation of scheelite crystal structures. (C) 2012 Elsevier B.V. All rights reserved.