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Chen H.,CAS Fujian Institute of Research on the Structure of Matter | Chen H.,Fujian Normal University | Lin H.,CAS Fujian Institute of Research on the Structure of Matter | Lin H.,Fujian Provincial Key Laboratory of Nanomaterials | And 7 more authors.
Journal of Materials Chemistry C | Year: 2015

The commercially dominant phosphor-converted illumination white light-emitting-diodes (w-LEDs) generally suffer from red deficiency and the poor thermal stability of the organic encapsulants, resulting in cool white light, luminous degradation and chromatic aberration for the embedded YAG:Ce3+ phosphors after long-term working. Aiming to solve these problems, herein, a chromaticity-tunable robust phosphor-in-glass (PiG) inorganic color converter was successfully fabricated by co-sintering YAG:Ce3+,Mn2+,Si4+ phosphor particles and the innovatively-designed TeO2-B2O3-ZnO-Na2O-Al2O3 low-melting precursor glass. At first, the spectrally-modified YAG:Ce3+,Mn2+,Si4+ phosphor was prepared by doping Mn2+ as the red emitter and doping Si4+ as the charge compensator through a solid-state reaction route. Then, the YAG:Ce3+,Mn2+,Si4+ powder was incorporated into a specifically prepared precursor glass to form the PiG composite at 550 °C. Owing to the density and the refractive index matches for the phosphor particles and the glass matrix, the particle dispersion in PiG is quite homogeneous and the adverse light-scattering is depressed. The high-power warm w-LED was constructed by coupling a PiG plate with an InGaN blue chip. Remarkably, the chromaticity coordinate of such a w-LED can be well tuned to follow along the Planckian locus with the correlated color temperature evolving from cool white (5541 K) to warm white (3050 K) and a color rendering index around 70, under a driving current of 350 mA. Moreover, the PiG-based warm w-LED presents much superior thermal stability to the traditional phosphor-in-silicone (PiS)-based one. This work highlights the practical applications of the PiG luminescent material in the long-lifetime high-power warm w-LEDs. © 2015 The Royal Society of Chemistry.


Zhao M.,CAS Fujian Institute of Research on the Structure of Matter | Zhao M.,Fujian Normal University | Huang F.,CAS Fujian Institute of Research on the Structure of Matter | Huang F.,Fujian Provincial Key Laboratory of Nanomaterials | And 9 more authors.
Nanoscale | Year: 2016

In this work, novel CuGaS2-ZnS p-n type semiconductor nanoheterostructures were synthesized by a solution route, and demonstrated experimentally to be a very promising visible light active photo-catalyst for water-splitting hydrogen production. The construction of CuGaS2-ZnS heterostructures follows a multi-step strategy, employing Cu1.94S nanocrystals first as catalytic assistants for the hetero-growth of ZnS on their surfaces, and then as sacrificial seeds for the formation of CuGaS2. Excitingly, attributed to the efficient charge separation introduced by the p-n heterojunctions, the hydrogen production ability of the CuGaS2-ZnS nanoheterostructures under visible light irradiation is 15 times higher than that of the CuGaS2 component, and comparable to that of the CdS nanophase which is currently regarded as one of the most active visible photo-catalysts for hydrogen generation. © 2016 The Royal Society of Chemistry.


Lin H.,CAS Fujian Institute of Research on the Structure of Matter | Lin H.,Fujian Provincial Key Laboratory of Nanomaterials | Xu J.,CAS Fujian Institute of Research on the Structure of Matter | Xu J.,Fujian Provincial Key Laboratory of Nanomaterials | And 6 more authors.
ACS Applied Materials and Interfaces | Year: 2015

The state-of-the-art alternating-current light-emitting diode (AC-LED) technique suffers from adverse lighting flicker during each AC cycle. Aiming to compensate the dimming time of AC-LED, herein, we report a novel Mg3Y2(Ge1-xSix)3O12:Ce3+ inverse-garnet persistent phosphor whose afterglow is efficiently activated by blue light with persistent luminescence in millisecond range. It is experimentally demonstrated that Si doping tailors the host bandgap, so that both the electron charging and detrapping in the persistent luminescence process are optimized. To explore the origin of the millisecond afterglow, we performed a series of thermoluminescence analyses, revealing three types of continuously distributed traps in the host. Finally, an AC-LED prototype device was fabricated, which exhibits the warm white emission with a reduced percent flicker of 71.7%. These results demonstrate that the newly developed persistent phosphor might be a promising candidate applicable in low flickering AC-LED which has advantages of cheaper price, longer lifetime, and higher energy utilization efficiency. © 2015 American Chemical Society.


Xia C.-K.,CAS Fujian Institute of Research on the Structure of Matter | Xia C.-K.,Fujian Provincial Key Laboratory of Nanomaterials | Wu X.-Y.,CAS Fujian Institute of Research on the Structure of Matter | Wu X.-Y.,Fujian Provincial Key Laboratory of Nanomaterials | And 4 more authors.
Jiegou Huaxue | Year: 2011

The reactions of SbCl3 and HgCl2 with 2-(3-pyridyl)benzimidazole (PyBIm) in solution acidified with HCl have been investigated. The PyBIm ligands are protonated into 2-(3-pyridinio) benzimidazolium (H2PyBIm) cations and the corresponding metal ions are bonded with chloride atoms into coordination anions, forming two new coordination compounds, namely, (H2PyBIm)(SbCl5) 1 and (H2PyBIm)2(Hg2Cl8) 2. Both compounds were characterized by X-ray crystallography. Crystal data for 1: triclinic, space group P1 with a = 5.7030(7), b = 9.0625(11), c = 16.5929(18) Å, a = 91.808(7), β = 93.234(6), γ = 99.216(7)̊, C12H 11N3SbCl5, Mr = 496.24, V = 844.44(17) Å3, Z = 2, Dc = 1.952 g/cm3, μ(MoKa) = 2.419 mm-1, F(000) = 480, the final R = 0.0496 and wR = 0.1382 for 3433 observed reflections (I > 2σ(I)). Crystal data for 2: monoclinic, space group P21/c with a = 7.8061(5), b = 15.8127(9), c = 12.2435(9) Å, β = 91.955(4)̊, C24H22N6Hg2Cl8, Mr = 1079.26, V = 1510.40(17) Å3, Z = 2, Dc = 2.373 g/cm3, μ(MoKa) = 10.889 mm-1, F(000) = 1008, the final R = 0.0293 and wR = 0.0562 for 2854 observed reflections (I > 2σ(I)). X-ray diffraction analysis reveals that the antimony(III) is five-coordinated, exhibiting a slightly distorted square-pyramidal coordination geometry; while in 2, a dimeric [Hg2Cl8]4- anion consists of two trigonal bipyramids sharing two common edges. The organic cations and coordination anions are connected into a one-dimensional belt and a two-dimensional sheet through N-H⋯Cl hydrogen bonding interactions in compounds 1 and 2, respectively; both are further aggregated into 3D frameworks by strong π-π contacts. Copyright © 2008 Chinese Journal of Structural Chemistry.


Zhou J.,CAS Fujian Institute of Research on the Structure of Matter | Zhou J.,Longyan University | Huang F.,CAS Fujian Institute of Research on the Structure of Matter | Huang F.,Fujian Provincial Key Laboratory of Nanomaterials | And 7 more authors.
Journal of Materials Chemistry C | Year: 2016

In this work, inorganic perovskite CsPbBr3-xIx (x = 0-3) quantum dots (QDs) were synthesized, and their luminescence properties were studied. The optimized CsPbBrI2 QDs were chosen as red-emitting components to modify Ce3+:YAG-based white LEDs (WLEDs), which exhibit promising performance with a luminous efficacy (LE) of 58 lm W-1, a correlated color temperature (CCT) of 5907 K, and a color rendering index (CRI) of 90, at an operation current of 20 mA. More importantly, optical performance of the CsPbBrI2 QD-modified WLEDs do not exhibit serious degeneration when the operational current increases to as high as 350 mA, being obviously superior to most of the chalcogenide QD-assisted phosphor-converted WLEDs reported previously. These results indicate that the CsPbBr3-xIx QDs are promising red phosphors for high-power WLEDs. © 2016 The Royal Society of Chemistry.


Zhou J.,CAS Fujian Institute of Research on the Structure of Matter | Huang F.,CAS Fujian Institute of Research on the Structure of Matter | Huang F.,Fujian Provincial Key Laboratory of Nanomaterials | Xu J.,CAS Fujian Institute of Research on the Structure of Matter | And 4 more authors.
Journal of Materials Chemistry C | Year: 2015

A novel Sr3La(VO4)3 phosphor is explored which exhibits the bright self-activated luminescence and the ability to sensitize emission of rare earth activators, under the excitation of near UV light. The self-activated emission of the Sr3La(VO4)3 host is peaked at 520 nm with a broad emission band ranging from 400 nm to 700 nm, ascribing to the charge transfer in (VO4)3- groups; while the Sr3La(VO4)3:Eu3+ phosphors show both the broad band luminescence of (VO4)3- groups and the sharp peak emissions of Eu3+ ions. Through doping concentration optimization, intense warm white light is achieved under near UV excitation, with a quantum yield of 31.2%. This phosphor is therefore potentially applicable in near UV chip excited white LEDs. © The Royal Society of Chemistry 2015.


Wang B.,CAS Fujian Institute of Research on the Structure of Matter | Lin H.,CAS Fujian Institute of Research on the Structure of Matter | Lin H.,Fujian Provincial Key Laboratory of Nanomaterials | Huang F.,CAS Fujian Institute of Research on the Structure of Matter | And 8 more authors.
Chemistry of Materials | Year: 2016

Owing to its low cost and admirable luminescent characteristics for use in warm white-light-emitting diode (w-LED) applications, the non-rare-earth Mn4+-activated red phosphor has emerged as a potent competitor of commercial Eu2+-doped nitrides in recent years. In this work, the novel red-emitting phosphor BaMgAl10-2xO17:xMn4+,xMg2+ is successfully synthesized, which exhibits bright and narrow-band luminescence peaking at 660 nm with a full width at half-maximum of merely ∼30 nm upon blue light excitation. The unique structural feature of BMA, i.e., alternating arrangements of Mn4+-doped MgAl10O16/undoped BaO layers in the z direction and Mn4+-doped [AlO6]/undoped [AlO4] groups in the x-y plane, favors efficient Mn4+ luminescence by reducing nonradiative energy loss channels. Unlike previously reported hosts, BMA accommodates Mg2+ in the lattice without destabilizing the crystal structure. Remarkably, partitioning Mg2+ in the host not only greatly enhances Mn4+ luminescence by 1.84-fold but also retards the concentration quenching effect induced by Mn4+ dipole-dipole interactions owing to the reduced number of Mn4+-Mn4+-O2- pairs. Spectroscopy demonstrates that the luminescence of optimized BMA:0.02Mn4+,0.02Mg2+ exhibits a high color purity of 98.3%, good color stability against heat, and excellent resistance to thermal impact. When incorporating BMA:0.02Mn4+,0.02Mg2+ and YAG:Ce3+ phosphors into an oxide glass matrix at various ratios and then coupling the phosphor-in-glass color converters using a blue chip, the chromaticity parameters of the fabricated w-LED are well-tuned, with the correlated color temperature decreasing from 6608 to 3622 K and the color rendering index increasing from 68.4 to 86.0, meeting the requirements for in-door lighting use. © 2016 American Chemical Society.


Xu J.,CAS Fujian Institute of Research on the Structure of Matter | Xu J.,Fujian Provincial Key Laboratory of Nanomaterials | Yu Q.,CAS Fujian Institute of Research on the Structure of Matter | Yu Q.,Fujian Provincial Key Laboratory of Nanomaterials | And 4 more authors.
Journal of Materials Chemistry A | Year: 2015

Due to the high cost of Pt-based materials used in the electrocatalysis of the oxygen reduction reaction (ORR), an alternative composed of non-precious metals is highly desirable. Herein a hybrid with cobalt monoxide nanocrystals spatially confined in holey N-doped carbon nanowires (CoO/NCWs) was synthesized via metal oxide assisted surface pitting of chemical vapor deposited carbon nitrogen nanowires and colloidal assembly. The catalyst consists of a Co2+ enriched surface and delivers a remarkably higher ORR electrocatalytic activity and stability than its surface smooth N-doped carbon nanotube supported counterpart, with a kinetically limited current density (30.3 mA cm-2 at 0.7 V) nearly three times that of the latter. It also outperformed the commercial Pt/C catalyst. As characterized by cyclic voltammetry and XPS, the enlarged interfacial area by spatially confined hybridization is believed to be responsible for the improved ORR performance, which might create more active catalytic sites for the ORR. We propose that in-depth consideration of interfacial construction is essential when designing carbon supported metal oxide catalysts for the ORR in alkaline media. © The Royal Society of Chemistry 2015.


Lin Z.,CAS Fujian Institute of Research on the Structure of Matter | Lin H.,CAS Fujian Institute of Research on the Structure of Matter | Lin H.,Fujian Provincial Key Laboratory of Nanomaterials | Xu J.,CAS Fujian Institute of Research on the Structure of Matter | And 7 more authors.
Journal of Alloys and Compounds | Year: 2015

We realize a facile chromaticity tuning for the Y3Al5O12:Ce3+ phosphor-in-glass (PiG) based w-LED, with the aid of a CaAlSiN3:Eu2+ red phosphor layer in a remote-type stacking configuration. It was experimentally demonstrated that both the stacking order and the relative amount of red phosphor influence the electroluminescent performance of the constructed w-LED significantly, and the optimized warm w-LED exhibits admirable performance with a luminous efficacy of 93.9 lm/W, a correlated color temperature of 3346 K, a color rendering index of 77.3, and a color shift deviating from Planckian locus in Duv of 0.0034. Significantly, the red phosphor layer stacked PiG based warm w-LED presents an excellent heat resistance, endowing the device with long life-time, which may serve as a promising robust high-power indoor lighting source. © 2015 Elsevier B.V. All rights reserved.


Xu J.,CAS Fujian Institute of Research on the Structure of Matter | Xu J.,Fujian Provincial Key Laboratory of Nanomaterials | Yu Q.,CAS Fujian Institute of Research on the Structure of Matter | Yu Q.,Fujian Provincial Key Laboratory of Nanomaterials | And 2 more authors.
Journal of Materials Chemistry A | Year: 2015

Hierarchically nanoporous N-doped carbon nanowires (N-CWs) were prepared by a novel space-confinement-induced assembly strategy, for which nitrogen-enriched pyrimidine and anodic aluminium oxide (AAO) template bearing metal oxides are employed as precursor and nanoscale channels, respectively, and the Fe/Co metal oxide not only blocks the AAO surface from the original surface-templating carbonization, but also introduces nanoporosity with acid etching. Thus-obtained carbon nanowires composed of N-doped graphene-like carbon nanosheets not only contain a high N content (up to ∼12%), but also possess a hierarchically meso/microporous structure (∼1.3 cm3 g-1) with high specific surface area (∼455 m2 g-1). This protocol allows for the simultaneous optimization of graphitization, porous structure and surface functionalization. As a result, the prepared N-CWs demonstrate an attractive electrocatalytic capability towards oxygen reduction reaction (ORR). Specifically, in addition to the improved kinetic current density and overpotential, the N-CWs prepared at 700 °C show the optimized ORR performance with an electron-transfer number of ∼4.0, which very close to that of a commercial Pt/C catalyst. This journal is © The Royal Society of Chemistry.

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