Luminescent and thermal properties of novel orange–red emitting MgNb2O6:Sm3+ phosphors for displays, photo catalytic and sensor applications
N. Basavaraju, S.C. Prashantha, H. Nagabhushana, A. Naveen Kumar, M. Chandrasekhar, T.R. Shashi Shekhar, C.R. Ravikumar, M.R. Anil Kumar, B.S. Surendra, H.P. Nagaswarupa
Abstract
Abstract Novel Sm 3+ doped columbite-type orthorhombic structured MgNb 2 O 6 (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:Sm 3+ nanophosphors show all the characteristic emissions of Sm 3+ cations corresponds to the transitions 4 G 5/2 → 6 H j/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 4 G 5/2 → 6 H 7/2 transition of Sm 3+ cations in the host lattice. The luminescence quenching was confirmed by the dipole–dipole interaction among Sm 3+ 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:Sm 3+ (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:Sm 3+ phosphors have great potential applications in display, catalytic, photonic, chemical and thermal sensor applications.