Characterization of europium doped yttrium nano-oxide prepared by plasma electrolysis in nitrate solution under air atmosphere at room temperature

Abstract

Europium-doped yttrium oxide is widely used because its unique optical properties, excellent thermal stability, and chemical stability. This paper reports a process for preparing a Y2O3:Eu3+ red fluorescent material through plasma discharge electrolysis at room temperature in a normal atmosphere and a 0.38 M Y(NO3)3 - 0.02 M Eu(NO3)3 mixed rare earth nitrate solution. Several techniques, including emission spectroscopy, X-ray diffraction, TG-DSC thermal analysis, Fourier transform infrared spectroscopy and photoelectron spectroscopy, were performed to characterize the electrolysis process and the obtained products. The results show that the electrolytic products were mainly composed of Y(OH)3, the electrolytic hydroxide products were not obviously granular, and Eu was uniformly distributed in the products. After heat treatment at 400–900 °C, cubic phase yttrium oxide was formed, and the products were irregular spherical, with particle sizes between 30 and 200 nm. After annealing at 800 °C, the products showed strong red emission at 612 nm, corresponding to 5D0→7F2 excitation. In addition, charge transfer band (CTB) absorption was observed in the excitation spectrum, and the emission spectra of fluorescent materials also showed some sharp emission bands generated by the 5D0→7FJ (J = 0,1,3,4) transition. The colour coordinate of the Y2O3:Eu3+ powder produced by plasma electrolysis is close to the standard red coordinate, showing excellent colour properties.