Facile synthesis of lanthanide doped yttria nanophosphors by a simple microplasma-assisted process

Abstract

Increasing awareness of the potentially harmful impacts of nanomaterials on human health has led to a high demand for low-toxicity lanthanide (Ln)-doped nanophosphors in life science fields. The present study introduces a conceptually new approach based on a microplasma technique to produce high quality crystalline lanthanide doped nanophosphors. By selecting Eu³⁺ doped yttria as a model for study, systematic experiments are carried out to synthesize Y₂O₃:Eu³⁺ nanophosphors of controllable size and various Eu³⁺ doping concentrations. The plasma–liquid interaction and the obtained products are examined by complementary analytical methods. Results demonstrate that ultra-high purity crystalline Y₂O₃:Eu³⁺ nanophosphors can be successfully prepared from merely an aqueous solution of Y(NO₃)₃·6H₂O and Eu(NO₃)₃·6H₂O at an extremely low plasma power consumption (3–5.5 W), without involving any hazardous chemicals. Moreover, the Eu³⁺ ions prove to be efficiently and homogeneously doped into the yttria matrix, and their luminescence performance can be tuned to a large extent by adjusting the processing conditions. Due to the high degree of flexibility, this approach can be readily expanded to the green synthesis and engineering of various lanthanide doped/co-doped nanophosphors.