SYNTHESIS AND PROPERTIES OF LUMINESCENT MATERIALS OF CaS : Mn; Pb COMPOSITION FROM PHOSPHOGYPSUM

For citation: Yakhonova D.V., Zemchenko G.N., Baranova V.A., Medennikov O.A., Egorova M.A., Shabelskaya N.P. Synthesis and properties of luminescent materials of CaS : Mn; Pb composition from phosphogypsum. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2026. V. 69. N 9. P. 98-105. DOI: 10.6060/ivkkt.20266909.6978. The possibility of obtaining luminescent materials in the process of thermal reduction of phosphogypsum has been studied. Materials have been synthesized, the main phase of which is calcium sulfide. Materials doped with manganese (II) and lead (II) cations with luminosity under the influence of ultraviolet radiation have been obtained. The synthesized materials are characterized by X-ray diffraction and electron microscopy methods. The dependence of the luminosity intensity on the amount of the introduced alloying additive has been studied, and the optimal ratio of alloying cations has been established for obtaining samples with the highest luminescence intensity. The possibility of obtaining ultraviolet pigments of orange and red glow from phosphogypsum has been shown for the first time. It is shown that during the heat treatment of phosphogypsum in the presence of a reducing agent, a calcium sulfide matrix is formed while preserving the shape of the precursor crystals. The luminescence spectrum of doped sulfide phosphors is represented by three bands of varying intensity: 502-505 nm; 580-611 nm; 672-696 nm; with an increase in the Mn2+ content, the emission peaks shift to the red region. The sample containing 0.1 mmol Mn2+ per 0.1 mol CaS has the highest luminosity. In the CaS : Pb samples, the emission spectra are also represented by three peaks: 505-509 nm; 571-581 nm; 666-672 nm; As the Pb2+ content increases, the intensity of the peak in the red region increases. The sample containing 0.12 mmol Pb2+ per 0.1 mol CaS has the highest luminosity. For phosphors of the CaS : Mn composition, an abrupt increase in the intensity of luminescence in the red region was found when irradiated with ultraviolet short-wave radiation. The results obtained open up wide possibilities for using high–tonnage waste from the chemical industry, phosphogypsum, to produce innovative products.