Luminescent and thermal properties of novel orange–red emitting MgNb2O6:Sm3+ phosphors for displays, photo catalytic and sensor applications

Abstract

AbstractNovel Sm3+ doped columbite-type orthorhombic structured MgNb2O6 (MNO) orange-red emitting phosphors were prepared by solution combustion method using ODH as a fuel. The powder phase purity, particle morphology, size, elemental composition, luminescence properties, photocatalytic behaviors and electrochemical studies of prepared samples were studied in detail. Photoluminescence emission spectra of MNO:Sm3+ nanophosphors show all the characteristic emissions of Sm3+ cations corresponds to the transitions 4G5/2 → 6Hj/2(j=5,7,9,11) when excited at 463 nm energy. Among these the strongest emission peak was at 608 nm which corresponds to 4G5/2 → 6H7/2 transition of Sm3+ cations in the host lattice. The luminescence quenching was confirmed by the dipole–dipole interaction among Sm3+ ions. As a result of J-O analysis the branching ratio (~ 58% > 50%) show that the phosphor was highly suitable for color display devices. Photocatalytic activity of MNO:Sm3+ (5 mol%) under UV light shows 99% degradation of AR-88 dye. Electrochemical Impedance Spectroscopy (EIS) confirms the reversibility of the redox reaction, which helps in sensing the presence of paracetamol and alcohol. Thus, MNO:Sm3+ phosphors have great potential applications in display, catalytic, photonic, chemical and thermal sensor applications.