A truncated octahedron NaCe(MoO4)2 nanostructure: a potential material for blue emission and acetone sensing

Abstract

Scheelite-type NaCe(MoO₄)₂, a promising nanostructure for optoelectronic applications, has been synthesized using a typical hydrothermal technique, and its structural and microstructural properties have been characterized using several microscopic and spectroscopic techniques. We observed intense blue emission from the 5d–4f transitions of Ce³⁺ within CeO₈, while the presence of mono-(CeO₇) and divacancies (CeO₆) of oxygen cause relatively weak emissions at 488 nm, 462 nm and 531 nm. Our study reveals that the use of trisodium citrate during synthesis plays a significant role to tune the formation of CeO₇ and CeO₆, which in consequence also modify the band edges of the system. The Commission Internationale de l'Eclairage (CIE) coordinates are found to be within the blue region with a correlated color temperature (CCT) of ∼7854 K, indicating the potential of NaCe(MoO₄)₂ nanostructures for cold solid-state lighting applications. Moreover, the oxygen deficiencies are found to act as active sites for the selective adsorption of acetone, leading to acetone sensing. Hence, NaCe(MoO₄)₂ nanostructures may be potential smart materials for blue-lighting and acetone sensors. Ab initio calculations have been carried out to obtain theoretical insights into the electronic structure of the bare and oxygen-deficient NaCe(MoO₄)₂ and to understand the guiding parameters for acetone sensing. Our calculations also demonstrate that acetone adsorption occurs mostly through the (112) plane.