Search

Electride [Y2Ti2O6]2+(2e−) was prepared by solid reducing processes, which was characterized by XRD, TG and EPR. The electride has high conductivity (1.09 S cm−1 at 300 K).

Traditional fluorescent materials used in anti-counterfeiting field usually exhibit monochromatic luminescence at a single-wavelength excitation, which is easily be forged by sophisticated counterfeiters. In this work, Zn2GeO4:Mn, x%Li (x=0 and 20), Zn2GeO4­NaLiGe4O9:Mn, x%Li (x=50 and 70) and NaLiGe4O9:Mn micro-phosphors with the multi-chromatic and multi-mode luminescence have been successfully synthesized via a hydrothermal approach followed by an annealing treatment. As expected that these Li+ doped Zn2GeO4:Mn and NaLiGe4O9:Mn phosphors exhibit a double peak emission including a long green afterglow (~540 nm) and a red photoluminescence (∼668 nm). By tuning Li+ doping concentrations, a gradual colour output and a tuneable afterglow duration are achieved. Particularly, the Zn2GeO4:Mn,Li and NaLiGe4O9:Mn phosphors exhibit excellent performance as security inks for printing luminescent numbers and anti-counterfeiting patterns, which shows an afterglow time-dependent or excitation wavelength-dependent luminescence colour evolution. This work proves the feasibility of Li+ doping strategy in emission tuning, which can stimulate further studies on multi-mode luminescent materials in anti-counterfeiting applications.

A new nitridolithosilicate La4Ba3Li3Si9N19 was synthesized by the flux method. The La4Ba3Li3Si9N19:Pr3+ phosphor shows a narrow-band red emission peaking at 640 nm with an fwhm of 50 nm when excited under near-UV light.

A high-performance ultra-narrow-band green-emitting phosphor LaMgAl11O19:0.28Mn2+ (λem = 517 nm, FWHM ∼24 nm) is prepared by a solid-state reaction in air, which can be applied in a pc-wLED with wide color-gamut value of 131% NTSC and 97.8% Rec. 2020.

Oxygen-depleted samples [Y

This work presents three series of Eu/Tb metal-organic frameworks (MOFs) containing benzophenone-4,4'-dicarboxylic acid (H

Near-infrared luminescent materials have attracted considerable interest because of their excellent performance in the field of optical imaging. Here, a series of Cr3+/Ni2+ co-doped near-infrared phosphors Zn1+ySnyGa2−2yO4 (ZSGO) were synthesized via a solid-state reaction. The phosphors show broad emissions in the range of 1100–1700 nm in the second NIR window. The emission intensity of Ni2+ could be greatly enhanced owing to the energy transfer from Cr3+ to Ni2+. The energy transfer mechanism was inferred from the excitation and emission spectra and the decay lifetime curve, which confirm that the primary process is the electric dipole–dipole interaction. In order to evaluate the potential optical imaging application, NIR-LED light source packages were fabricated with Cr3+/Ni2+ co-doped Zn1+ySnyGa2−2yO4 (ZSGO) phosphors and blue LED chips, which revealed high stability and a strong transilluminated biological tissue effect. These results indicate a great prospect in advanced optical imaging for NIR pc-LED applications.

Two cobalt metal–organic frameworks (Co-MOFs), [Ch]2[Co3(BDC)3Cl2] (1) and [Ch]2[Co3(BDC)4]·2DMU (2) (Ch+ = choline cation; H2BDC = terephthalic acid; DMU = 1,3-dimethylurea), were prepared through ionothermal reactions with deep eutectic solvents (DESs) of ChCl and DMU as the reaction media. The 1/GCE electrode with better current response was selected as the electrocatalyst. The detection performance of the 1/GCE electrode towards glucose is excellent with a wide linear range of 10–1200 μmol L−1, a detection limit of 3.2 μmol L−1 (S/N = 3), and a rapid response less than 3 s in 0.01 mol L−1 NaOH. 1 also exhibits high anti-interference with the existence of D-Man, D-Fru, DL-AA, and BA, long-term stability of 15 days and reproducibility for glucose detection. 1 was utilized to detect glucose in human serum and orange juice. The found glucose concentrations are very close to the added glucose concentrations in the selected situations with low RSD and high recoveries. This demonstrates that as a non-enzymatic glucose sensor, 1/GCE can detect glucose with high accuracy and reliability in different environments.

The new oxonitridosilicates Ln4−xSr2+xSi5N12−xOx (Ln = La, Ce) were synthesized by high temperature solid-state reactions. The crystal structures were solved and refined from both single-crystal and powder X-ray diffraction data. These oxonitridosilicate compounds crystallize in the monoclinic space group P21/n (no. 14) and exhibit a double-layer structure made up of corner-sharing Si(O/N)4 tetrahedra. When excited with near-UV and blue light, the Pr3+ doped La2.31Sr3.69Si5N10.31O1.69 phosphor shows a narrow-band red emission peaking at 625 nm with a full width at half-maximum of 40 nm.

Flux synthesis is an effective method to discover large crystals of new compounds. In this paper, a solid-state reaction in Li flux produced a new nitridolithosilicate La

Fabricating highly efficient electrocatalysts for electrochemical hydrogen generation is a top priority to relief the global energy crisis and environmental contamination. Herein, a rational synthetic strategy is developed for constructing well-defined FeP-CoMoP hierarchical nanostructures (HNSs). In general terms, the self-supported Co nanorods (NRs) are grown on conductive carbon cloth and directly serve as a self-sacrificing template. After solvothermal treatment, Co NRs are converted into well-ordered Co-Mo nanotubes (NTs). Subsequently, the small-sized Fe oxyhydroxide nanorods arrays are hydrothermally grown on the surface of Co-Mo NTs to form Fe-Co-Mo HNSs, which are then converted into FeP-CoMoP HNSs through a facile phosphorization treatment. FeP-CoMoP HNSs display high activity for hydrogen evolution reaction (HER) with an ultralow cathodic overpotential of 33 mV at 10 mA cm-2 and a Tafel slope of 51 mV dec-1 . Moreover, FeP-CoMoP HNSs also possess an excellent electrochemical durability in alkaline media. First-principles density functional theory (DFT) calculations demonstrate that the remarkable HER activitiy of FeP-CoMoP HNSs originates from the synergistic effect between FeP and CoMoP.

Nitridomagnesosilicate phosphors are promising candidates for white light emitting diodes. Here, we report a yellow nitride phosphor Ca8Mg7Si9N22:Ce3+, which exhibits a broad band emission in the spectral range of 475–675 nm under the excitation of 445 nm. The photoluminescence intensity of Ca8–xMg7Si9N22:xCe3+ (0.01 ≤ x ≤ 0.11) reaches a maximum when x = 0.05. CIE coordinates and the color purity of Ca7.95Mg7Si9N22:0.05Ce3+ are (0.449, 0.531) and 84.0%, respectively. The Ca7.95Mg7Si9N22:0.05Ce3+ phosphor exhibits a good color drifting resistance with a maximum chromaticity shift of 0.0085 at 475 K. By combining the as-synthesized yellow nitride phosphor Ca7.95Mg7Si9N22:0.05Ce3+ and red nitride phosphor SrLiAl3N4:Eu2+ with a commercial blue InGaN chip, an all-nitride white light emitting diode device is fabricated, and a warm white light is generated with chromatic coordinates (0.471, 0.364) and color temperature of 2194 K.

A novel red fluoride phosphor BaNbF7:Mn4+ was synthesized via the conventional co-precipitation method. The structure and luminescence properties of BaNbF7:Mn4+ were investigated and discussed under various conditions. The BaNbF7:Mn4+ phosphor shows strong ZPL emission intensity at about 630 nm under ultraviolet (UV) and blue light excitation. It originated from the highly distorted Mn4+ octahedral coordination environment in the C3v group symmetry surrounding. A WLED fabricated with a blend of YAG:Ce3+ and the BaNbF7:Mn4+ phosphor exhibits a low color temperature (CCT = 3715 K) and a high color rendering index (Ra = 81.2), indicating its potential for application as a red phosphor for WLEDs.

Traditional fluorescent materials used in the anti-counterfeiting field usually exhibit monochromatic luminescence at a single-wavelength excitation, which is easily forged by sophisticated counterfeiters. In this work, Zn

A chemical oxidation process of aniline and a following deposition prepared polyaniline-nickel foam (PANI-NF) substrate. M(OAc)2∙4H2O (M = Co2+ and Ni2+, OAc− = acetate) reacted with 2,6-naphthalene dicarboxylic acid dipotassium (K2NDC) and in-situ deposited on the surface of PANI-NF to produce CoNi-NDC/PANI-NF composite. The reaction conditions of CoNi-NDC/PANI-NF were optimized as Co2+ and Ni2+ reacting at the starting ratio of 3:2 at 60 °C for 20 h with the presence of PANI-NF. SEM images revealed that CoNi-NDC/PANI-NF sheets distributed uniformly on the surface of PANI-NF substrate. Compared to CoNi-NDC/NF, with PANI adhered, CoNi-NDC/PANI-NF sheets grew much smaller and distributed more uniformly. Also, CoNi-NDC/PANI-NF exhibited better electrocatalytic activities toward oxygen evolution reaction (OER) (with an overpotential of 323 mV at 10 mA/cm2), and a remarkable reaction kinetics (with a Tafel slope of 73.3 mV/dec). CoNi-NDC/PANI-NF shows horizon I-t curves for 20 h at 10 and 100 mA/cm2, indicating a high durability without degradation of the OER performance. Compared to most recently reported MOF-based composites, lower or comparable overpotential and Tafel slope of CoNi-NDC/PANI-NF indicate it is a potential noble-metal-free electrocatalyst for OER.

A detailed nondestructive analytical method for quantitative food analysis was established by using a self-fabricated NIR-LED light source combined with Mg3Ga2GeO8 (MGGO) phosphor and a blue LED ch...

In general, we usually adopt the thermal coupling levels (TCLs) for measuring temperature, but the sensitivity of the temperature sensor is limited to the energy gap, which is a challenge for further improving the sensitivity. In this work, we synthesize the Ba2In2O5:Yb3+/Er3+ and Ba2In2O5:Yb3+/Ho3+ phosphors by a high temperature solid-state method. The high sensitivity of the temperature sensor is obtained, which bases on the non-thermal coupling levels (NTCLs) temperature measurement. The NTCLs exhibit temperature dependent luminescence from 303 to 573 K. The maximum sensitivities of the Ba2In2O5:Yb3+/Er3+ and Ba2In2O5:Yb3+/Ho3+ phosphors are 0.48 K−1 (303 K) and 0.034 K−1 (303 K), respectively. The results show that the Ba2In2O5:Er3+/Yb3+and Ba2In2O5:Ho3+/Yb3+ phosphors may be ideal candidates for optical temperature sensors.

The fabrication of an efficient bifunctional electrocatalyst towards alkaline overall water splitting is challenging, but in high demand. Herein, we report the construction of Mo-doped Ni2P hollow nanostructures through a solvothermal method and in situ phosphorization strategy. The Mo-doped Ni2P hollow nanostructures demonstrate excellent hydrogen evolution reaction (HER) activity in 1.0 M KOH solution with a low cathodic overpotential of 81 mV (10 mA cm−2, glassy carbon) and a small Tafel slope of 53.4 mV dec−1. First-principles density functional theory calculations reveal the mechanism of the alkaline HER. For pristine Ni2P, the P site serves as the active center. After Mo doping, the active center transforms to a bridging Mo–Ni site and the corresponding Gibbs free energy of H* absorption (ΔGH*) decreases from 0.33 eV (P site) to 0.21 eV (bridging Mo–Ni site). The optimal active site with a smaller ΔGH* can accelerate the charge transfer process for H* intermedium and H2 production. For the oxygen evolution reaction (OER), the Mo-doped Ni2P hollow nanostructures require 270 mV to attain 20 mA cm−2 (glassy carbon), with a small Tafel slope of 68.5 mV dec−1. Impressively, both the HER and OER catalysis exhibit durable performance in alkaline electrolyte. When the Mo-doped Ni2P hollow nanostructures are applied as bifunctional electrocatalysts for alkaline overall water splitting, the demanded cell voltage is only 1.54 V (10 mA cm−2, nickel foam).

For alkaline fuel cell cathode reactions, it is crucial to develop new catalysts with excellent catalytic performance. Two-dimensional molybdenum disulfide nanosheets have proven to be effective electrocatalysts, especially in hydrogen evolution reactions. However, MoS2 has been less researched as a potential electrocatalyst for oxygen reduction reaction (ORR). The introduction of vanadium atoms by chemical doping significantly increases the ORR activity of the MoS2 nanosheets, which is greatly improved compared to the bulk MoS2. The vanadium heteroatoms can not only change the electrical properties and band structure of the pristine materials, but also provide a rich active site for the catalysis.

The ionothermal reaction of EuCl3 with 4,4′-biphenyldicarboxylic acid (H2BPDC) produced a 3D fluorescence coordination polymer (CP), [PMI]2[Eu2(BPDC)3Cl2] (1). 1 was dispersed onto the bandage, and further infiltrated by polyvinylidene fluoride (PVDF) to give a mixed matrix 1@PVDF/bandage composite film (1-film). The fluorescence and the morphology indicate 1-film can emit red fluorescence and the CP particles are on the surfaces of bandage fabrics with the adhesion of PVDF. The fluorescence of 1-film can be quenched by different amines in the order of aliphatic amine > aromatic amine > alcohol amine > amide, which concerns with the amine sizes. 1-film shows a fast response and selective sensing to aniline vapor, suggesting it may be a fluorescence turn-off sensor to aniline vapor.

A narrow-band blue emitting phosphor Ca8Mg7Si9N22:Eu2+ was synthesized by a high temperature solid state reaction. Ca8Mg7Si9N22 crystallizes in a tetragonal space group P42/nmc (No. 137) with a unit cell of a = 7.3469(6) A and c = 10.3298(8) A. The structure framework is composed of [SiN4] tetrahedra and a distorted square-pyramid [MgN5] polyhedron. Under UV light excitation, Ca8−xMg7Si9N22:xEu2+ phosphors exhibit a narrow band emission peaking at 400 nm with a full width at half maximum ∼34 nm. The CIE coordinates of Ca7.95Mg7Si9N22:0.05Eu2+ are (0.1850, 0.0430) with a color purity of 89.22%. More importantly, the Ca8Mg7Si9N22:Eu2+ phosphor shows a remarkably high thermal quenching resistance, maintaining 92% photoluminescence emission intensity at 420 K and 75% at 700 K. Thus Eu2+ doped Ca8Mg7Si9N22 would be a promising blue phosphor even working under considerably high temperature (>700 K) conditions.

In this work, an airtight solid-state strategy was developed for the synthesis of K2TiF6:Mn4+ phosphor without the usage of high concentration HF solution. By heating K2TiF6, K2MnF6 and KHF2 in a sealed container at 474 K for hours and then washing the as-synthesized samples several times, K2TiF6:Mn4+ phosphor was obtained. The microstructure, luminescent properties of the phosphor were investigated systemically. The reaction mechanism were investigated and discussed in detail. KHF2 is the key role to obtain the red phosphor, which provides additional pressure and HF gas atmosphere, works as reaction intermediate and contributes to Mn4+ doping into K2TiF6 host. By using as-prepared K2TiF6:Mn4+ phosphor as a red componet for warm W-LEDs, the high color rendering index (Ra = 84) and low color temperature (CCT = 3621 K) device performance proved that this environmental friendly synthesis method would be an efficient way to produce red fluoride phosphor for W-LEDs.

The new oxonitridosilicates Ln

This study aims to examine the changes of glucose metabolism, glucose variability (GV), and ghrelin secretion within 1 week following SG in Chinese patients with obesity. Forty-nine patients with obesity (15 with type 2 diabetes) were enrolled to undergo SG. Within 1 week before and after surgery, liquid meal tests were performed in all subjects, and continuous glucose monitoring (CGM) was performed in diabetic patients. Blood samples were collected at 0, 15, 30, 45, 60, 120, and 180 min for glucose, C-peptide, insulin, and ghrelin analysis in liquid meal test. Mean amplitude of glucose excursions (MAGE), standard deviations (SD), and percent time-in-range (%TIR) determined by CGM were analyzed. Both in diabetic and non-diabetic groups, significant decrease was observed in glucose, insulin, C-peptide, and ghrelin. Homeostasis model assessment-insulin resistance and liver fat content was decreased. In diabetic group, MAGE and SD were decreased significantly, and the percent time-in-range was higher. The decrease in blood glucose was positively correlated with the decrease in ghrelin concentration in non-diabetic group. Within 1 week after SG, both glucose metabolism and glucose variability were improved significantly. Suppression of ghrelin secretion postoperatively might be a driver of this early improved glycemia homeostasis.

The detection of pH and water is of significance in natural and production processes. The ionothermal reactions of 4,4′-oxybisbenzoic acid (H2OBA) with Eu3+ and Tb3+ produced [M(OBA)(H2O)Cl] (M = Eu3+ (1) and Tb3+ (2)) and heteronuclear [Eu0.05Tb0.95(OBA)(H2O)Cl] (3). 3 emits the combined characteristic transitions of Eu3+ and Tb3+. Its energy transition processes can be disturbed by pH and water. The emission colors of 3 follow pH changes. It emits blue light when pH = 1–2, in which OBA2− turns into H2OBA based on the acid–base equilibrium. When pH = 3–11, the emission colors change from green to orange and ITb/IEu exhibits a linearity of ITb/IEu = 6.7482–0.5971·pH; the emissions are quenched at pH = 12–13, due to OH− destroying the delocalized conjugated system of 3. 3 shows a fluorescence response to water with a linearity of ITb/IEu = 0.30353 + 0.15042·VH2O% within 0–0.8% VH2O%. The green (G) and red (R) color intensities of the paper-based MOF sensor of 3 reveal a trinomial fitting equation of G/R = 4.16334 − 1.23014·pH + 0.14036·pH2 − 0.00551·pH3 when pH = 3–11. 3 can be used as a ratiometric fluorescent sensor to detect pH and water and the paper-based MOF sensor can also be used in on-site pH detection.

Through the review and summary of the 5th national clinical skill competition of acupuncture-moxibustion and

While soil erosion drives land degradation, the impact of erosion on soil microbial communities and multiple soil functions remains unclear. This hinders our ability to assess the true impact of erosion on soil ecosystem services and our ability to restore eroded environments. Here we examined the effect of erosion on microbial communities at two sites with contrasting soil texture and climates. Eroded plots had lower microbial network complexity, fewer microbial taxa, and fewer associations among microbial taxa, relative to non-eroded plots. Soil erosion also shifted microbial community composition, with decreased relative abundances of dominant phyla such as Proteobacteria, Bacteroidetes, and Gemmatimonadetes. In contrast, erosion led to an increase in the relative abundances of some bacterial families involved in N cycling, such as Acetobacteraceae and Beijerinckiaceae. Changes in microbiota characteristics were strongly related with erosion-induced changes in soil multifunctionality. Together, these results demonstrate that soil erosion has a significant negative impact on soil microbial diversity and functionality.

We present a strategy for selecting an optimal material in a particular temperature range by investigating the relationship between the absolute sensitivity ( Sa) and energy gap (Δ E), as well as the relationship between Sa and temperature on the basis of Yb3+/Ln3+ (Ln = Er3+, Ho3+)-codoped Ba2In2O5 phosphors. Through an investigation of optical performance, the phosphors exhibit near-infrared (NIR) downshifting and visible upconversion (UC) emissions under 980 nm excitation. The NIR spectral range from 700 to 1800 nm is referred to as the "biological window". The NIR emission peaks of Er3+ and Ho3+ are located at 1550 nm of the third biological window and 1192 nm of the second biological window, respectively. The temperature sensing behaviors based on the UC luminescence in Yb3+/Ln3+-codoped Ba2In2O5 phosphors are recorded by the fluorescence intensity ratio (FIR) technique in the temperature range from 303 to 573 K. The Ba2In2O5:Er3+/Yb3+ sample is usable at temperatures above 350 K, and the Ho3+/Yb3+-codoped Ba2In2O5 phosphor is suitable at temperatures below 350 K in our experimental region. The above results show that the Ba2In2O5:Ln3+/Yb3+ phosphors could be promising candidates for optical temperature sensors and applications in the biological imaging field.

We report a novel narrow-band blue emitting phosphor Sr7.92Mg7Si9N22:0.08Eu2+. The crystal structure of Sr8Mg7Si9N22 is composed of corner-sharing and edge-sharing [SiN4] tetrahedra and distorted square-pyramid [MgN5] polyhedra. Under 350 nm excitation, Eu2+ doped Sr8Mg7Si9N22 emits narrow-band blue light with maximum intensity at 450 nm and a fwhm of 38 nm.

Achieving tunable color and white light emission in a single phase phosphor is a challenging issue. Here, a series of Ce3+-Eu2+ co-doped Ca2Si5N8 phosphors were successfully synthesized by a high temperature solid state method. Luminescence properties, energy transfer (ET) and thermal quenching of the as-synthesized samples were investigated in detail. The emission color of as-prepared Ca1.94Na0.03Si5N8:0.03Ce3+,yEu2+ (0.0000 ≤ y ≤ 0.0035) could be tuned from blue to white light and eventually to orange via ET by changing the Ce3+/Eu2+ ratio. ET efficiency from Ce3+ to Eu2+ could reach up to 68.0% and the ET mechanism was demonstrated to be a non-radiative dipole-dipole interaction. More importantly, when y = 0.0012, approximate standard white light was generated with CIE coordinates of (0.335, 0.341). A photoluminescence (PL) mechanism was proposed to understand PL properties and thermal properties of the as-prepared phosphors. Additionally, the achieved white light phosphor Ca1.9388Na0.03Si5N8:0.03Ce3+,0.0012Eu2+ had good thermal stability, exhibiting about 75% at 150 °C and 64% at 200 °C of the emission intensity at 25 °C, respectively. The chromaticity shifts of Ca1.9388Na0.03Si5N8:0.03Ce3+,0.0012Eu2+ were 0.0032 at 150 °C and 0.0152 at 200 °C, respectively, which were only 27% and 42% of the commercial white-emitting phosphor mixture at the corresponding temperature. Furthermore, a proof-of-concept white LED was fabricated by combining the single component phosphor Ca1.9388Na0.03Si5N8:0.03Ce3+,0.0012Eu2+ with a near UV LED chip. All results demonstrate the promising application of the Ca2Si5N8:Ce3+,Eu2+ single phosphor for near-UV white LEDs.

Transition metal phosphides (TMPs) are considered to be highly-efficient electrochemical catalysts, which have extraordinary capabilities to relieve the energy crisis and have gradually become prime candidates for application in energy conversion and storage devices. In this contribution, we report the preparation of porous Ni2P nanosheets in a controllable manner using NiO–MOF-74 as precursors, followed by a conventional phosphorization strategy. The porous Ni2P nanosheets exhibit excellent electrocatalytic performance towards the hydrogen evolution reaction (HER) with a low overpotential of 168 mV at a current density of 10 mA cm−2 in 1.0 M KOH and a small Tafel slope of 63 mV dec−1. The overpotential and Tafel slope of porous Ni2P nanosheets for the oxygen evolution reaction (OER) are 320 mV (10 mA cm−2) and 105 mV dec−1, respectively. In addition, both the HER and OER measurements demonstrate that porous Ni2P nanosheets have superior electrochemical stability in alkaline solution. The desirable electrocatalytic properties of the porous Ni2P nanosheets may be due to their larger surface area and favorable electrical conductivity. The porous structures of the Ni2P nanosheets provide pathways for electron conduction, which facilitates electron transfer and accelerates bubble (H2 and O2) diffusion on the surface of the electrode.

Ce3+ or Yb3+ singly doped LaBO3 and Ce3+-Yb3+ co-doped LaBO3 were prepared by conventional solid state reactions at 1100 °C and their photoluminescence (PL) properties were investigated. The emission spectrum of LaBO3:Ce3+,Yb3+ contains both the Ce3+ ultraviolet (UV) emissions (355 nm and 380 nm) and the Yb3+ near infrared (NIR) emission (975 nm) when excited by the UV light at 270 nm. By using the data of the Ce3+ decay curves and the PL intensities of both Ce3+ and Yb3+, the energy transfer efficiency (η) from Ce3+ to Yb3+, the actual energy transfer efficiency (AE) and the quantum efficiency (Q) of the Yb3+ emission were calculated. In the Ce3+-Yb3+ co-doped LaBO3, Ce3+ can transfer its absorbed energy to Yb3+ efficiently (η can be over 60%), and Yb3+ shows the Q value over 50% when it accepts the energy from Ce3+, which results in the low AE value ∼30%. The energy transfer process from Ce3+ to Yb3+ may be understood by the charge transfer mechanism: Ce3+ + Yb3+ ↔ Ce4+ + Yb2+. Particularly the Ce3+-Yb3+ co-doped LaBO3 phosphor gives the emissions mainly in the UV range and the NIR range with a portion of visible emissions in eye-insensitive range. This unique property may be suitable for applications in anti-counterfeiting techniques and public security affairs.

Powder samples of Ba 3 Si 6 O 12 N 2 and Ba 3 Si 6 O 9 N 4 were synthesized by solid state reaction method at 1300–1400 °C in H 2 /N 2 (6:94) reductive atmosphere. The structural correlations between the two phases were analyzed based on X-ray diffraction data and neutron diffraction data. The results indicate that Ba 3 Si 6 O 12 N 2 can be converted into Ba 3 Si 6 O 9 N 4 when three O 2− are replaced by two N 3− , meanwhile, one trigeminal N(SiO 3 ) 3 group of two in the unit cell is transformed into (SiO 2 N) 3 ring. The luminescent properties of Eu 2+ doped Ba 3 Si 6 O 9 N 4 were investigated. Ba 3 Si 6 O 9 N 4 :Eu 2+ gives wide excitation and emission spectra since the dopant occupy three different Ba sites. The phosphor shows green luminescence color with three emission peaks at 370 nm, 405 nm and 520 nm excited in the range of 210 nm–470 nm. Both luminescence spectra and decay curves indicate that in the Eu 2+ doped Ba 3 Si 6 O 9 N 4 , the energy transfer occurs from the luminescence centers for the shorter wavelength emissions (Eu1 at 370 nm and Eu2 at 405 nm) to the center for the longer wavelength emissions (Eu3 at 520 nm). The Eu 2+ doped sample has potential application in white LEDs.

Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H3BTC) and Ni(NO3)2, Co(NO3)2 and Cu(NO3)2 gave two discrete 32-membered ring-like allomers, [M2(HBTC)2(NH2CONH2)2(H2O)4]·3H2O (M=Ni(1), Co(2)) and one layered [Cu2(BTC)Cl(H2O)4] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N2 absorption. Cu2+ has the highest N2 adsorbance when soaking with 1, and 1 can keep structure stable when Cu2+ below 0.16 mol L−1 and the soaking time within 24d. As Cu2+ beyond 0.16 mol L−1 and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu2+ amounts obtained Ni2+-Cu2+ hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu2+% increases with Cu2+ additions and close to 100% as Cu2+ being 1.6 mmol. It suggests that 3 is a controlled product and Cu2+ can transform discrete compound 1 into 2D compound 3.

Ionothermal reactions of 1,4-benzenedicarboxylic acid (H2BDC) and 4,4′-biphenyldicarboxylic (H2BPDC) with Mn(OAc)2 resulted in 12 compounds divided into four kinds of structural models: [RMI]2[Mn3(BDC)3X2] (1–5, type A), [EMI]2[Mn3(BPDC)4] (6, type B), [RMI]2[Mn2(BPDC)3(H2O)3] (7–9, type C) and [RMI]6[Mn9(BPDC)9(HBPDC)2(OAc)4] (10–12, type D). A combination effect of ligands and IL components can be observed in the structural construction, which also is reflected in the properties of thermal stability and fluorescence. The decomposition temperatures of Mn–BDC compounds are higher than those of Mn–BPDC compounds. The decomposition temperatures decrease with the alkyl chain in [RMI]+, due to a +I inductive effect. The maximum emissions of compounds 1–5 and 6–12 located at ca. 410 or 407 nm are assigned to ILCT of H2BDC and H2BPDC ligands, respectively.

Oxonitridoalumosilicates Y4Al2−2xSi2xO9−2xN2x (0.00 ≤ x ≤ 1.00) were prepared and the substitution effect of [Al3+O2−] pairs by [Si4+N3−] pairs in Y4Al2O9–Y4Si2O7N2 solid solutions on the structure and its corresponding influence on the Ce3+ activated luminescence properties are investigated. Y4Al2−2xSi2xO9−2xN2x (0.00 ≤ x ≤ 1.00) shows two solid solution regions, x = 0.00–0.40 for solid solution I, x = 0.50–1.00 for solid solution II from X-ray and neutron diffraction analysis. In the solid solution I, the Ce3+ emission is mainly in the UV range with the maximum wavelength at 350 nm, and the intensity decreases rapidly with the increase of the N content. In the solid solution II, the Ce3+ doped samples show blue-green luminescence with the maximum wavelength at ∼450 nm and the wide excitation bands extend from UV to 450 nm. The phosphors in the solid solution II are promising candidates for white-LED applications.

A novel ternary-alkaline red emitting fluoride phosphor K2NaGaF6:Mn4+ was successfully synthesized through co-precipitation method. The crystal structure, morphology, electronic band structure and luminescence properties of K2NaGaF6:Mn4+ phosphors were investigated in details by using Rietveld refinement of X-ray diffraction data, scanning electron microscopy (SEM), density functional theory (DFT) calculation and different reaction parameters. The K2NaGaF6 host has a cubic unit cell with the space group Fmm and lattice parameters of a = 8.2577 (4) A, Z = 4, Vcell = 563.08 (8) A3. Under blue light excitation, Mn4+ activated K2NaGaF6 exhibits a bright narrow-band red emission. The PL properties of the K2NaGaF6:Mn4+ red phosphors were optimized with different Mn4+ concentrations and aging times. A warm-white LED device was fabricated using a blue LED chip combined with commercial yellow YAG:Ce3+ phosphor and synthesized K2NaGaF6:Mn4+ red phosphor. The color rendering index (CRI, Ra = 81.6) and corresponding color temperature (CCT = 3643 K) easily reached the commercial warm white light LED standards (Ra > 80 and CCT < 4000 K). All these results indicate that K2NaGaF6:Mn4+ phosphor would be a suitable red phosphor candidate for warm-white LED applications.