An obvious rolling process in the synthesis of Y2O3:Eu3+ micro-urchins built from nanoscrolls

We report a novel method to synthesize Y2O3:Eu3+ nanoscrolls by hydrothermal and post-heat treatments. In the hydrothermal process, a precursor compound with well-defined urchinlike morphology has been obtained with the aid of BO33− and L-glutamic acid. The formed micro-urchins consist of numerous nanoscrolls rolled up from nanosheets. Condition experiments and analysis reveal that BO33− anions and L-glutamic acid were vital for the rolling process of the nanoscrolls. Under ultrasound treatment, the micro-urchins can break into separated nanoscrolls. In a subsequent calcination process, the as-prepared precursors can transform into Y2O3:Eu3+ with the same morphology. The resultant Y2O3:Eu3+ micro-urchins exhibit a strong red emission corresponding to the 5D0 →7F2 transition of the Eu3+ ions under UV light excitation. Moreover, our method may provide a new way to realize the “rolling-up” process of other compounds.