Synthesis, characterization, and photoluminescence of Er₂O₃-Er₂SO₂ nanoparticles on reduced graphene oxide

Thermal reduction of erbium nitrate and S-doped reduced graphene oxide (rGO) mixture resulted in the formation of small (∼3-18 nm sized) Er₂O₃-Er₂SO₂ nanoparticles with a high degree of surface coverage on the reduced GO support. The morphology, structure, and the chemical composition of the synthesized nanoparticles have been studied by scanning and transmission electron microscopy, x-ray photoelectron spectroscopy, x-ray diffraction, and by optical spectroscopies. The rGO-supported Er₂O₃-Er₂SO₂ nanoparticles (Er₂O₃-Er₂SO₂/rGO) demonstrate sufficiently strong light emission (luminescence and upconversion) in the visible and near-infrared range via intra-4f Er³⁺ optical transitions. The reported synthetic approach demonstrates a novel method for synthesizing Er-containing nanoparticles for sensor applications.