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

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.