Enhanced photoluminescence and photocatalytic properties in Dy-doped sodium zinc molybdate synthesized <i>via</i> a green microwave-assisted method

This study focuses on the structural, photoluminescence and photocatalytic properties of a Dy³⁺-doped sodium zinc molybdate phosphor. The samples were synthesized using a green microwave-assisted method owing to its efficiency in time and energy consumption. The powder X-ray diffraction (P-XRD) analysis confirmed the monoclinic structure of as-synthesized Dy³⁺-doped sodium zinc molybdate with space group <i>C</i>2/<i>m</i>. The most prominent excitation band appeared at 348 nm under 590 nm, and the emission spectra for all samples exhibited a sharp peak at around 590 nm, which is attributed to the ⁴F_9/2 → ⁶H_13/2 electric dipole transition of Dy³⁺ ions. The emission intensity increases with higher Dy³⁺ doping levels, reaching maximum intensity at a concentration of 6 mol% of Dy³⁺ in sodium zinc molybdate. Additionally, the Commission Internationale de l'Éclairage (CIE) chromaticity coordinates of the Dy³⁺ sodium zinc molybdate phosphor places it within the orangish region. Dy³⁺ is also found to play a great role in enhancing the photocatalytic activity of sodium zinc molybdate under UV light. These findings indicate that the as-synthesized phosphor holds promise for white LED and water purification applications.