One-step synthesis and morphology evolution of luminescent Eu2+ doped strontium aluminatenanostructures

Abstract

Several shapes of Eu²⁺ doped strontium aluminate have been simply obtained by hydrolysis of Sr²⁺ and Al³⁺ in hydrothermal and solvothermal systems under mild conditions. The influence of reaction conditions on the formation of the samples has been considered. Flower-like nanoparticles are synthesized in glycol, when the solvent is substituted by H₂O, and/or adding NaOH or stirring for 30 min before injecting the prepared Eu(NO₃)₃, needle cluster-like, sheet-like and lantern-like structures are synthesized. At the same time, the doped Eu³⁺ is reduced to Eu²⁺ at much lower temperature, and the emission peaks result from the transition of 4f⁶5d–4f⁷ of Eu²⁺ around 405 nm, 435 nm and 530 nm are also observed, no typical peak of Eu³⁺ is found, which indicates the complete reduction from Eu³⁺ to Eu²⁺. The results of this article may give a guide to synthesize the similar Eu²⁺ doped luminescent materials.