Hydrothermal synthesis and luminescence properties of 3D walnut-like CaMoO4:Eu3+ red phosphors

• CaMoO4:Eu3+ red phosphors were synthesized by (EG)-mediated hydrothermal method.
• The prepared CaMoO4:Eu3+ phosphors have walnut-like microsphere structure.
• The effects of the ratio of H2O to EG and reaction time were studied.
• The effects of Eu3+ concentration on the PL intensity were studied.

Tetragonal CaMoO4:Eu3+ red phosphors with walnut-like 3D microsphere ere synthesized via an ethylene glycol (EG)-mediated hydrothermal method in the presence of urea. The as-synthesized products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL). It was found that the volume ratio of H2O to EG, reaction time and urea concentration played critical roles in the morphology of Eu3+-doped calcium molybdate microstructures. The results showed that the Eu3+-doped CaMoO4 microwalnuts were well-crystallized and assembled by many nanosheets. The walnut-like CaMoO4:Eu3+ microspheres can display a red emission under ultraviolet (394 nm) and Eu3+ concentration has great effect on the luminescence intensity in 5D0 → 7F2 transition.