Photoluminescence Characteristics of Pure and Dy-Doped ZnNb₂O₆ Nanoparticles Prepared by a Combustion Method

Abstract

Pure and Dy-doped ZnNb2O6 nanoparticles have been prepared by a sol−gel combustion method using citric acid as a fuel and complexing agent and nitrates as oxidants at a relatively low temperature as compared to solid-state reaction methods. X-ray diffraction patterns of the pure ZnNb2O6 samples show that the ZnNb2O6 nanoparticles exhibit an orthorhombic phase. Photoluminescence (PL) properties of all the undoped and Dy-doped samples are studied in detail. For the pure ZnNb2O6 samples, a strong blue emission band centered at 445 nm and two weak emission bands centered at 525 and 625 nm, respectively, can be observed. For Dy-doped ZnNb2O6 samples, the luminescence of Dy3+ is observed with the host blue emission remaining and the host emission intensity varying with the Dy-doping concentrations. This novel PL characteristic of the doped samples may be attributed to the energy transfer between Dy3+ and niobate groups (NbO6).

Niobium pentoxide coating replacing zinc phosphate coating

“…(001), (100) and (002), respectively. These characteristic peaks are in accordance with the literature [26,27].…”

Molten salt synthesis and optical properties of Eu3+, Dy3+or Nd3+ doped NiNb2O6 columbite-type phosphors

“…There are a few studies on the luminescent properties of rare earth doped columbite transition metal niobate compounds in the literature [2][3][4][5][6][7][8][9][10][11].…”

Hydrothermal Synthesis of a CaNb2O6 Hierarchical Micro/Nanostructure and Its Enhanced Photocatalytic Activity

“…[27] Although the photocatalytic activity of these niobates has been confirmed by theoretical calculation and experiments, the cumbersome synthesis conditions limited their practical applications. Currently, most niobates are synthesized by traditional solid-state reaction (SSR) and related methods, such as the polymerized complex (PC) method, [25,28] sol-gel method, [29,30] and the molten salt route. [31] The products obtained by the SSR method are generally bulk materials with low active surface area and wide size distribution.…”

“…The corresponding optical absorption and photocatalytic activities of CaNb 2 O 6 samples with different morphologies were also studied. We used a soluble and active Nb V precursor which is prepared by a relatively simple and convenient hydrothermal treatment of Nb 2 [30,32] Since the hexaniobate ion [Nb 6 O 19 ] 8-has been known as the dominant species in alkaline solutions [41,42] and the solution of [Nb 6 O 19 ] 8-could be obtained by hydrothermal process, [43,44] we chose the alkali salt of [Nb 6 O 19 ] 8-as the water-soluble precursor for the synthesis of CaNb 2 O 6 . Additionally, it has been mentioned above that the pH value of the solution as well as the niobium oxide concentration determines the specific niobium ionic species present in aqueous solution, [45] tions of pH = 3.65-6.5.…”

“…Usually, awkward Nb 2 O 5 treatments are needed, in order to obtain soluble and more reactive hydrated Nb 2 O 5 ·nH 2 O, which is also called "niobic acid", for example fusing Nb 2 O 5 at 400°C with KOH and dissolving Nb 2 O 5 in concentrated HF solution. [30,32] Although, there are some reports of hydrothermal synthesis under mild conditions, most of them focus on the synthesis of alkali metal niobates, [33][34][35] based on the dissolution of Nb 2 O 5 in alkaline solutions by hydrothermal treatment.…”