Rietveld refinement, luminescence and catalytic study of as-synthesized and Dy³⁺-doped cubic Y₂O₃ nanopowder prepared by citrate mediated sol–gel technique

This paper reports on synthesis of undoped and Dy³⁺-doped cubic Y₂O₃ nanopowder via a neoteric and conducive citrate sol–gel technique. The size and morphology of prepared nanocrystallites are explored using XRD, TG-DSC, FTIR, FESEM, and HRTEM. Rietveld refinement is employed to affirm the preparation of as-synthesized Y₂O₃ nanocrystallites with cubic phase. The optical behavior of as-synthesized Y₂O₃, Dy³⁺-doped Y₂O₃ samples are studied in terms of absorbance, PL, and CIE coordinates. It is revealed that position of absorption peak is shifted towards higher wavelength side when Dy³⁺ ions are introduced in Y₂O₃ and further on annealing. In PL spectra, prominent emission is achieved in blue region at 485 and 369 nm under direct and indirect excitation wavelengths. Catalytic performance of the samples is also examined to de-colorize cotton blue dye. Annealing for a long time generated defect states which are helpful to accelerate the photocatalytic efficiency of the prepared nanopowder.