Synthesis and luminescent properties of multifunctional Ag@Fe3O4@Gd2O3Eu3+ composite

In this work, the synthesis of Ag@Fe3O4@Gd2O3:Eu3+ composites based on the addition of Gd2O3 with different concentrations of Eu3+ to Ag@Fe3O4 core-shell composites was performed with the aim of attaining multifunctional composites endowed with a combination of properties such as magnetic (Fe3O4) and luminescent (Gd2O3:Eu3+) together with the addition of the antimicrobial effect of AgNPs. The morphology and chemical composition of the synthesized composites were investigated by techniques such as SEM, FT-IR, Raman, XRD and luminescence, the results showed that the composites present a change from the Ag@Fe3O4 spherical shape to rice-like morphology with the cover of Gd2O3:Eu3+. We have also found that the deposition of AgNPs on the composites produces an increment in the Raman signal. However, we observed a decrement in the luminescent intensity due to a quenching effect which could be attributed to an energy transfer from Eu3+ ions to AgNPs. Finally, a comparison of the average lifetime of the nanostructures with different amounts of Eu3+ has been performed, thus finding an increment of the average lifetime after decreasing the Eu3+ composition. [Display omitted] •A new Ag@Fe3O4@Gd2O3:Eu3+ multifunctional composite were synthetized.•Composite has higher Raman intensity than Fe3O4@Gd2O3:Eu3+.•Fluorescent composite has an acceptable lifetime decay.