A new luminescent host material K3GdB6O12: synthesis, crystal structure and luminescent properties activated by Sm3+

2018 ◽  
Vol 233 (6) ◽  
pp. 411-419 ◽  
Author(s):  
Dan Zhao ◽  
Cong-Kui Nie ◽  
Ye Tian ◽  
Bao-Zhong Liu ◽  
Yun-Chang Fan ◽  
...  

Abstract A new borate compound K3GdB6O12 has been prepared using a high temperature flux method and structurally characterized by single crystal X-ray diffraction analysis. The structure can be described as a three-dimensional framework that is composed of [B5O10]5− groups, K+ ions and Gd3+ ions. In this structure, one crystallographic distinct site is mixed occupied by K and Gd atoms at the molar ratio of 1:1. Furthermore, Sm3+ ion was used as the activator to test primary of K3GdB6O12 to be used as a luminescent host matrix. A series of phosphors K3Gd1−xB6O12:xSm3+ were synthesized by conventional solid-state reaction. The photoluminescence properties and concentration quenching of the prepared phosphors were investigated. The results show that K3Gd1−xB6O12:xSm3+ can be efficiently excited by near-UV light. K3Gd1−xB6O12:xSm3+ might be a promising candidate for visual display and solid-state lighting as an orange emission phosphor.

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1624 ◽  
Author(s):  
Xiaoya Yuan ◽  
Xin Cheng ◽  
Qiuye Jing ◽  
Jiawei Niu ◽  
Dong Peng ◽  
...  

Three dimensional (3D) ZnO/ZnAl2O4 nanocomposites (ZnnAl-MMO) were synthesized by a simple urea-assisted hydrothermal process and subsequent high-temperature calcination. The as-prepared samples and their precursors were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), and Photoluminescence spectra (PL). It was observed that the morphology of ZnnAl-MMO nanocomposites could be tuned from cubic aggregates, hierarchically flower-like spheres to porous microspheres by simply changing the molar ratio of metal cations of the starting reaction mixtures. The photocatalytic performance of ZnO/ZnAl2O4 nanocomposites in the photoreduction of aqueous Cr(VI) indicated that the as-prepared 3D hierarchical sphere-like ZnnAl-MMO nanocomposite showed excellent photocatalytic activity of Cr(VI) reduction under UV light irradiation. The results indicated that the maximum removal percentage of aqueous Cr(VI) was 98% within four hours at 10 mg/L initial concentration of Cr(VI), owing to the effective charge separation and diversion of photogenerated carriers across the heterojunction interface of the composite. Our study put forward a facile method to fabricate hierarchical ZnO/ZnAl2O4 composites with potential applications for wastewater treatment.


2011 ◽  
Vol 287-290 ◽  
pp. 1460-1463 ◽  
Author(s):  
Lin Yan Jia ◽  
Zhong Bao Shao ◽  
Yan Wen Tian

The pure phase red phosphor yttrium borate doped with Eu3+was prepared by a new solid state reaction named high temperature ball milling method. The phosphor was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectra. The results show that the single phase YBO3:Eu3+phosphor was obtained at 600°C, which is obviously decreased in contrast to conventional solid state reaction method. The particles are approximately nanometer size with narrow distribution range and spherical morphology. In emission spectra, the strongest peak at 597nm is due to the transition5D0→7F1 of Eu3+ions under 394nm monitoring wavelength. The luminescent properties of YBO3:Eu3+phosphor with 25 mol% doping concentration of Eu3+is optimal.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.


2013 ◽  
Vol 423-426 ◽  
pp. 426-429
Author(s):  
Xin Ze Wang ◽  
Zhong Xin Liu ◽  
Hong Jian Gao ◽  
Yani Jing ◽  
Chang Lin Li ◽  
...  

LiTaO3: Tm3+, Yb3+powders were synthesized by a high-energy ball-milling (HEB) method compared with the conventional solid-state reaction (SSR) method. Under the excitation of 980 nm laser, the strong blue emission (477 nm) band is observed and attributed to1G4-3H6of Tm3+. Because of it causing high local temperature and narrow particles size, increasing the contact area between the particles and improved crystallinity of the host, synthesis by high-energy ball milling show higher photoluminescence (PL) intensity compared to the solid state reaction method. In the process of mechanical milling, Tm3+, Yb3+co-doped LiTaO3phosphors with high photoluminescence property could be achieved at a relatively low reaction temperature.


Crystals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 372
Author(s):  
Mei-An Zhu ◽  
Shuai-Shuai Han ◽  
Feng Deng ◽  
Jia-Le Li ◽  
Shui-Sheng Chen

The coordination polymer, namely, [Cd(H2L)(nobda)]n (1) was prepared by the reaction of Cd(NO3)2·4H2O with 4-amino-1,2-benzenedicarboxylic acid (H2nobda) and 1,4-di(1H-imidazol-4-yl)benzene (H2L), and characterized by single-crystal X-ray diffraction, elemental analysis, infrared (IR) spectroscopy, thermogravimetric analysis, and powder X-ray diffraction (PXRD). The carboxylic acid of H2nobda ligands was completely deprotonated to be nobda2− anions, which act as tridentate ligand to connect the Cd2+ to form two-dimensional (2D) network, while the neutral H2L ligands serve as a linear didentate bridge to connect two adjacent Cd2+ ions upper and down the 2D layer. The adjacent 2D layers were further linked into the three-dimensional (3D) supramolecular polymer by the weak interactions such as hydrogen bonds and π−π stacking interactions. The ultraviolet-visible (UV-vis) absorption spectra and luminescent properties in the solid state at room temperature have been investigated.


RSC Advances ◽  
2018 ◽  
Vol 8 (28) ◽  
pp. 15613-15620 ◽  
Author(s):  
Xiaochun He ◽  
Ruiqing Chu ◽  
Zhijun Xu ◽  
Zhongran Yao ◽  
Jigong Hao

Lead-free ceramics, SrBi2Nb2O9–xBi2O3 (SBN–xBi), with different Bi contents of which the molar ratio, n(Sr) : n(Bi) : n(Nb), is 1 : 2(1 + x/2) : 2 (x = −0.05, 0.0, 0.05, 0.10), were prepared by conventional solid-state reaction method.


2016 ◽  
Vol 16 (4) ◽  
pp. 4029-4034 ◽  
Author(s):  
Chunxia Liu ◽  
Lixia Yang ◽  
Dan Yue ◽  
Mengnan Wang ◽  
Lin Jin ◽  
...  

Rare earth ions (Tb3+, Eu3+) doped CaWO4 microstructures were synthesized by a facile hydrothermal route without using any templates and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results indicate that the asprepared samples are well crystallized with scheelite structure of CaWO4, and the average diameter of the microstructures is 2∼4 μm. The morphology of CaWO4:Eu3+ microstructures can be controllably changed from microspheres to microflowers through altering the doping concentration of Eu3+ from 3% to 35%, and the microflowers are constructed by a number of CaWO4:Eu3+ nanoflakes. Under the excitation of UV light, the emission spectrum of CaWO4:Eu3+ is composed of the characteristics emission of Eu3+ 5D0-7FJ (J = 1, 2, 3, 4) transitions, and that of CaWO4:Tb3+ is composed of Tb3+ 5D4-7FJ (J = 6, 5, 4, 3) transitions. Both of the optimal doping concentrations of Tb3+ and Eu3+ in CaWO4 microstructures are about 5%.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 442 ◽  
Author(s):  
Antigoni Katsiki ◽  
Tobias Hertel ◽  
Tine Tysmans ◽  
Yiannis Pontikes ◽  
Hubert Rahier

This work aims to study an aluminosilicate phosphate cementitious matrix. The cementitious matrix was studied on paste samples. The synthesis of metakaolinite phosphate cement (MKPC) was investigated using calorimetric techniques. A systematic study was performed by emphasizing a broad range of Al/P molar ratios, covering the different behavior of the material to the extremes, as well as the optimum composition. X-ray diffraction and scanning electron microscopy revealed that the final structure was mainly an amorphous network, albeit with some non-reacted phases. The compressive strength was studied on mortars using a cement/sand ratio of 1:3. MKPC specimens with Al/P ratios close to 1/1 showed optimal behavior. MKPCs with Al/P ratios above 1/1 were characterized by high porosity and low strength, whereas MKPCs with Al/P < 1 contained an excess of phosphates. The influence of the Al/P molar ratio on compressive strength was also studied, reaching a maximum of 68 MPa for the optimum composition. Based on the results, MKPC may be a promising candidate for construction purposes.


2020 ◽  
Vol 76 (11) ◽  
pp. 1024-1033
Author(s):  
Fang-Hua Zhao ◽  
Shi-Yao Li ◽  
Wen-Yu Guo ◽  
Zi-Hao Zhao ◽  
Xiao-Wen Guo ◽  
...  

Two new CdII MOFs, namely, two-dimensional (2D) poly[[[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ2-heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C7H10O4)(C18H18N4)]·4H2O} n or {[Cd(Pim)(bbimb)]·4H2O} n (1), and 2D poly[diaqua[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ4-decanedioato)(μ2-decanedioato)dicadmium(II)], [Cd2(C10H16O4)2(C18H18N4)(H2O)2] n or [Cd(Seb)(bbimb)0.5(H2O)] n (2), have been synthesized hydrothermally based on the 1,4-bis(1H-benzimidazol-1-yl)butane (bbimb) and pimelate (Pim2−, heptanedioate) or sebacate (Seb2−, decanedioate) ligands. Both MOFs were structurally characterized by single-crystal X-ray diffraction. In 1, the CdII centres are connected by bbimb and Pim2− ligands to generate a 2D sql layer structure with an octameric (H2O)8 water cluster. The 2D layers are further connected by O—H...O hydrogen bonds, resulting in a three-dimensional (3D) supramolecular structure. In 2, the CdII centres are coordinated by Seb2− ligands to form binuclear Cd2 units which are linked by bbimb and Seb2− ligands into a 2D hxl layer. The 2D layers are further connected by O—H...O hydrogen bonds, leading to an 8-connected 3D hex supramolecular network. IR and UV–Vis spectroscopy, thermogravimetric analysis and solid-state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe3+ in aqueous solution.


2019 ◽  
Vol 75 (7) ◽  
pp. 883-890 ◽  
Author(s):  
Ya-Li Xue ◽  
Ai-Yun Zhang ◽  
Xiao-Yang Han ◽  
Xiao-Qi Cui ◽  
Ling Deng ◽  
...  

An anhydrous orthophosphate, K3Eu5(PO4)6 (tripotassium pentaeuropium hexaphosphate), has been prepared by a high-temperature solid-state reaction combined with hydrothermal synthesis, and its crystal structure was determined by single-crystal X-ray diffraction analysis (SC-XRD). The results show that the compound crystallizes in the monoclinic space group C2/c and the structure features a three-dimensional framework of [Eu5(PO4)6]∞, with the tunnel filled by K+ ions. The IR spectrum, UV–Vis spectrum and luminescence properties of polycrystalline samples of K3Eu5(PO4)6, annealed at temperatures of 650, 700, 750, 800 and 850 °C, were investigated. Although with a full Eu3+ concentration (9.96 × 1021 ions cm−3), the self-activated phosphor K3Eu5(PO4)6 shows s strong luminescence emission intensity with a quantum yield of 37%. Under near-UV light excitation (393 nm), the series of samples shows the characteristic emissions of Eu3+ ions in the visible region from 575 to 715 nm. The sample sintered at 800 °C gives the strongest emission and its lifetime sintered at 800 °C (1.88 ms) is also the longest of all.


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