Europium-doped gadolinium oxide nanoparticles: A potential photoluminescencent probe for highly selective and sensitive detection of Fe3+ and Cr3+ ions

Herein, we report the facile synthesis, characterizations and photoluminescence sensing probe applications of europium (Eu3+)-doped gadolinium oxide (Gd2O3) nanoparticles. The Eu3+- doped Gd2O3 nanoparticles were synthesized by a facile and straight forward chemical synthesis followed by the calcination process. Various percent concentrations of Eu3+ ranging from 1 to 5% was used to dope into the Gd203 and calcine them for different time to optimize the photoluminescence properties of the synthesized nanoparticles. The synthesized nanoparticles were characterized by several techniques which confirmed that the 5% Eu3+- doped Gd2O3 nanoparticles exhibited best structural and optical properties. Thus, due to best structural and optical properties, the 5% Eu3+- doped Gd2O3 nanoparticles were used as photoluminescent probe for the detection of Fe3+ and Cr3+ ions. The detailed sensing results revealed that the synthesized nanoparticles are quite selective and sensitive towards Fe3+ and Cr3+ ions with 99.3% quenching efficiency for 10 ppm Fe3+ ions and 98.6% quenching efficiency for 40 ppm Cr3+ ions respectively. The detection limit for Fe3+ and Cr3+ ions were 1.48 ppm and 6.56 ppm respectively. The utilization of synthesized nanoparticles in real water samples with percentage recovery of >90% in tap water and distilled water and 87% in sewage water has unlocked numerous opening to use such nanomaterial for real water treatment applications. (C) 2016 Elsevier B.V. All rights reserved.