Controllable synthesis of Sc2Mo3O12 microcrystals with exposed {001} facets and their remarkable tunable luminescence properties by doping lanthanides

Novel chocolate-like scandium molybdate precursors with exposed {001} facets were hydrothermally synthesized in the presence of PVP, which were transformed into morphology-preserved Sc2Mo3O12 crystals by calcination at 800 °C for 2 h. The as-synthesized samples were characterized by XRD, FT-IR SEM, TEM, HRTEM, and PL analysis. Four different types of precursors including prismatic structures, octahedra, truncated octahedra and compressed decahedra could be obtained by varying the amount of MoO42−. Moreover, in the presence of H+, the percentage of high-energy {001} facets could be enhanced. The Mo sources, PVP consumption, reaction time and hydrothermal temperature had significant influences on the morphology of the precursors. As good matrix materials, the tunable down/upconversion (DC/UC) luminescence properties of Sc2Mo3O12:Ln3+ (Ln = Tb, Eu, Tb/Eu, Yb/Er, Yb/Ho, Yb/Tm) were comprehensively investigated. It is found that the materials showed strong morphology-dependent luminescence properties. Particularly, the energy transfer (ET) of MoO42− → Tb3+ → Eu3+ resulted in multicolor emissions from green to red in Sc2Mo3O12:5%Tb3+,x%Eu3+. The Sc2Mo3O12:Ln3+ (Ln = Tb, Eu, Tb/Eu, Yb/Er, Yb/Ho, Yb/Tm) microcrystals show great potential applications in the areas of fluorescent lamps and color displays.