Highly uniform Gd(OH)3 and Gd2O3:Eu3+ hexagram-like microcrystals: glucose-assisted hydrothermal synthesis, growth mechanism and luminescence property

Monodispersed and uniform Gd(OH)3 microcrystals with novel hexagram-like morphology have been successfully prepared through a simple and green hydrothermal process with the assistance of glucose. The results of control experiments revealed that the glucose concentration in the reaction system was an important factor, which affected the morphology of the Gd(OH)3 microcrystals significantly. On the basis of time-dependent experiments, the growth mechanism of the Gd(OH)3 hexagrams was discussed. Furthermore, the Gd2O3 and Eu3+-doped Gd2O3 hexagram-like microcrystals, inheriting the Gd(OH)3 precursors' morphology, were obtained during a direct annealing process in air. The corresponding Gd2O3:Eu3+ hexagram-like microcrystals exhibit strong red emission pertaining to the 5D0→7F2 transition of the Eu3+ ions under UV light, which have potential applications in novel optoelectronic devices.