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Doped CaZnOS materials show great potential for mechanoluminescence (ML) applications spanning the ultraviolet-visible-near infrared (UV-vis-NIR) range. However, conflicting reports regarding the generation and reproducibility of ML hinder the understanding and practical utilization of these materials. To address this issue, a comprehensive characterization strategy combining NIR laser-assisted de-trapping, UV irradiation-induced trap-filling, in situ mechanical stimulation, and continuous ML recording is proposed. Herein, the ML behaviors of four representative doped CaZnOS materials (Mn2+, Bi3+, Er3+, and Ce3+) are investigated using this approach. The results reveal that de-trapped materials exhibit non-trap-controlled ML, wherein ML intensity gradually weakens under successive mechanical stimuli without self-recovery. In contrast, trap-filled materials demonstrate both trap-controlled ML and non-trap-controlled ML, with the former predominantly contributing to the overall ML intensity. Notably, trap-controlled ML shows only partial recovery after trap filling. The non-trap-controlled ML is attributed to plastic ML and destructive ML phenomena, while explaining trap-controlled ML through the carrier de-trapping model. These results not only clarify conflicting reports but also provide clear insights into the ML properties and mechanisms of CaZnOS-based materials, facilitating advancements in practical applications. Furthermore, the developed characterization strategy is expected to serve as a valuable reference for establishing standardized protocols to evaluate ML performance. [ABSTRACT FROM AUTHOR]

Orange Eu2+‐doped phosphors are essential for light‐emitting diodes for cornering lights to prevent fatal road accidents at night, but such phosphors require features of high thermal, chemical stability and facile synthesis. This study reports a series of yellow‐orange‐red emitting SrAl2Si3ON6:Eu2+ oxynitride phosphors, derived from the SrAlSi4N7 nitride iso‐structure by replacing Si4+−N3− with Al3+−O2−. The introduction of a certain amount of oxygen enabled the facile synthesis under atmospheric pressure using the air‐stable raw materials SrCO3, Eu2O3, AlN and Si3N4. SrAl2Si3ON6 has a smaller band gap and lower structure rigidity than SrAlSi4N7 (5.19 eV vs 5.50 eV, Debye temperature 719 K vs 760 K), but exhibits higher thermal stability with 100 % of room temperature intensity remaining at 150 °C compared to 85 % for SrAlSi4N7. Electron paramagnetic resonance, thermoluminescence and density functional theory revealed that the oxygen vacancy electron traps compensated the thermal loss. Additionally, no decrease in emission intensity was found after either being heated at 500 °C for 2 hours or being immersed in water for 20 days, implying both of the thermal and chemical stability of SrAl2Si3ON6:Eu2+ phosphors. The strategy of oxynitride‐introduction from nitride promotes the development of low‐cost thermally and chemically stable luminescent materials. [ABSTRACT FROM AUTHOR]

Artificial light fishing technology has been used in marine fisheries for thousands of years. The light source with multi‐color adjustable output is expected to become a new generation of fish‐attracting lamps. Herein, a new method of crystal‐site engineering through reducing atmospheres is proposed for the development of Eu2+ doped single‐phase phosphor with multi‐excitation and multi‐emission properties. Following this approach, the distribution ratio of Eu2+ at Ca2+ and Sr2+ sites in CaSrSiO4 (CSO) can be modulated. Importantly, Eu2+ at both lattice sites exhibit non‐interfering optical properties, CSO:Eu2+ phosphor realizes multi‐color output from green to yellow and then to red when Eu2+ occupies the Sr2+ and Ca2+ sites in a relatively balanced ratio. Benefitting from the tunable color range covering the spectral sensitivity regions of most marine fishes, this phosphor may eventually be applied in futuristic innovative fish‐attracting lamps. [ABSTRACT FROM AUTHOR]

The minimization of thermal quenching, which leads to luminescence loss at high temperatures, is one of the most important issues for near‐infrared phosphors. In the present work, we investigated the properties of near‐infrared Ca(Sc,Mg)(Al, Si)O6 : Cr3+ phosphors with a pyroxene‐type structure under blue light excitation. The CaScAlSiO6 : Cr3+ end member of Ca(Sc,Mg)(Al,Si)O6 : Cr3+ phosphor led to broadband emission at a full‐width half maximum of 215 nm, whereas the CaMgSi2O6 : Cr3+ end member exhibited high thermal stability at 150 °C, with an intensity of 88.4 % of that at room temperature. The structural analysis and density functional theory calculations revealed the absence of soft conformations and local space confinement contributed to the high structural rigidity and weakened the thermal quenching effect. [ABSTRACT FROM AUTHOR]

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a central and acute demyelinating disease of the central nervous system with unusual clinical course. The development of novel biomarkers for NMOSD is critical for implementing effective clinical treatment. CD226 is known to be expressed on many types of peripheral lymphoid cells. However, the expression level and function of CD226 on type 1 T regulatory (Tr1) cells during NMOSD is unknown. Methods: Eighteen patients with NMOSD and 10 healthy volunteers were enrolled in the test group to probe the difference of CD226 expression on Tr1 cells using flow cytometric analysis. Results: The expression of CD226 on Tr1 cells exhibited significantly increased tendency in NMOSD patients. Additionally, methylprednisolone and rituximab treatment decreased the expression of CD226 on Tr1 cells. Furthermore, the expression of CD226 on Tr1 cells was correlated with disease severity. Conclusion: This study provides a new basic insight into CD226 expression pattern on Tr1 cells, which have great potential to be biomarkers for monitoring the development and treatment of NMOSD. [ABSTRACT FROM AUTHOR]

Improving the high‐rate performance of spinel lithium titanate (Li4Ti5O12, LTO) is one of the critical requirements to promote its practical application in Li‐ion batteries (LIBs). Herein, the possible Li+ ion diffusion routes in LTO are theoretically analyzed and compared by computational investigation. The calculations show that the most feasible diffusion path for Li+ ions is along the [110] direction indicated by the lowest energy barrier. Inspired by this prediction, ultrathin [110]‐confined LTO nanoflakes are rationally prepared through a function‐led targeted synthesis. The [110] orientation of the material sufficiently provides preferable transport channels which can promote the anisotropic diffusion of lithium ions within LTO nanoflakes. Furthermore, the ultrathin 2D nanostructure effectively shortens the diffusion length along the [110] direction, facilitating ion transport across the nanoflakes and thus improving the diffusion kinetics. Owing to these unique features, the LIB composed of optimized [110]‐confined LTO exhibits remarkable high rate capability and long‐term cycling stability, with a capacity of 146 mAh g‐1 at an ultrahigh rate of 100 C and a capacity retention of 88% even after 1500 cycles at 50 C. The as‐prepared [110]‐confined LTO nanoflakes have promising applications and show commercial viability for high‐power facilities. [ABSTRACT FROM AUTHOR]

A solvent‐vapor transport route produces centimeter‐sized single‐crystal red phosphors. The epitaxial growth route to yield its core–shell structure at ambient temperature was adopted. These red phosphors could be applied in all‐inorganic WLED devices. Cs2TiF6:Mn4+ (CTFM) single crystal provides enhancement of quantum efficiency, moisture resistance, and thermal stability compared to polycrystalline powders. The internal quantum efficiency can reach as high as 98.7 %. To further improve waterproof stability, the Cs2TiF6 (CTF) shell with tunable thickness has been epitaxially grown on the CTFM single crystal surface and a unique three‐step photoluminescence intensity evolution mechanism has been proposed. By combining as‐prepared CTFM@CTF core–shell structured single crystal, YAG:Ce single crystal and blue‐chip, warm WLEDs with excellent color rendition (Ra=90, R9=94), low correlated color temperature (CCT=3155 K), and high luminous efficacy were fabricated without any organic resins. [ABSTRACT FROM AUTHOR]

The practical applications of non‐aqueous lithium‐oxygen batteries are impeded by large overpotentials and unsatisfactory cycling durability. Reported here is that commonly encountered fatal problems can be efficiently solved by using a carbon‐ and binder‐free electrode of titanium coated with TiO2 nanotube arrays (TNAs) and gold nanoparticles (AuNPs). Ultraviolet irradiation of the TNAs generates positively charged holes, which efficiently decompose Li2O2 and Li2CO3 during recharging, thereby reducing the overpotential to one that is near the equilibrium potential for Li2O2 formation. The AuNPs promote Li2O2 formation, resulting in a large discharge capacity. The electrode exhibits excellent stability with about 100 % coulombic efficiency during continuous cycling of up to 200 cycles, which is due to the carbon‐ and binder‐free composition. This work reveals a new strategy towards the development of highly efficient oxygen electrode materials for lithium‐oxygen batteries. [ABSTRACT FROM AUTHOR]

The environmentally friendly and low‐priced CaYAlO4:Tb3+ nanophosphors are combined with good optically transparent materials for the application in 3D printing. For ultraviolet (UV) light‐emitting diode excitation, CaYAlO4:Tb0.07Cey and CaYAlO4:Ce0.05Tbx nanophosphors are prepared by a sol–gel route and systematically studied for optimal excitation at 380 nm to give strong green emission to which human and aquatic animals eyes are generally sensitive. This is benefited from the dipole and spin allowed transition of Ce3+ and the 92.5% efficient energy transfer from Ce3+ to Tb3+ in this host. Polydimethylsiloxane, with 92% transmittance in the visible spectral region, is a valid choice to make the shaped artwork by a templating method, combined with the nanoparticles to give a uniform distribution, as determined by X‐ray microcomputed tomography. Polylactic acid is also employed to create a frog artwork by the fused deposition modeling method. The final 3D‐printed colorful artwork is displayed herein together with that produced by the templating method under different light source excitation to suggest a novel expression of aesthetic concepts and a potential application in the future marine environment such as a lamp to attract aquatic animals or a buoy to guide ships. [ABSTRACT FROM AUTHOR]

The rational design of electrode structure with catalysts adequately utilized is of vital importance for future fuel cells. Herein, a novel 3D oriented wholly integrated electrode comprising core–shell Fe3O4@N‐doped‐C (Fe3O4@NC) nanoparticles embedded into N‐doped ordered interconnected hierarchical porous carbon (denoted as Fe3O4@NC/NHPC) is developed for the oxygen reduction reaction (ORR). The as‐prepared catalyst possesses novel structure and efficient active sites. In rotating disk electrode measurements, the Fe3O4@NC/NHPC exhibits almost identical ORR electrocatalytic activity, superior durability, and much better methanol tolerance compared with the commercial Pt/C in acidic media. To the authors' knowledge, this is among the best non‐precious‐metal ORR catalysts reported so far. Importantly, the Fe3O4@NC/NHPC is successfully in situ assembled onto carbon paper by the electrophoresis method to obtain a well‐designed 3D‐ordered electrode. With improved mass transfer and maximized active sites for ORR, the 3D‐oriented wholly integrated electrode shows superior performance to the one fabricated by the traditional method. [ABSTRACT FROM AUTHOR]

Crystal phosphors have many unique advantages compared with powdery ones. Herein, room‐temperature‐grown millimeter‐sized single‐crystal phosphors of Cs2XF6:Mn4+ (X = Ge, Si, and Ti) with remarkably higher external quantum efficiency than the corresponding powdery samples are reported. In addition, as compared with the powdery ones, the crystal samples exhibit much better stability toward water under different pH conditions. The red light‐emitting diodes (LEDs) based on Cs2XF6:Mn4+ crystals show significantly improved luminous efficiency than those based on their corresponding powders. An assembled white LED device composed of the two layers of phosphors, i.e., the crystal (such as Cs2GeF6:Mn4+) and commercial Y3Al5O12:Ce3+, on a blue chip exhibits intense warm white light with high luminous efficiency (up to 193 lm W−1), high color rendering indexes (88), and low correlated color temperatures (3107 K). Hence, these crystals with greatly improved efficiency and stability can be potentially applied in high‐quality LED backlighting display and white LED lighting, especially inside the micro‐LED devices. [ABSTRACT FROM AUTHOR]

Luminescence of monoclinic lithium metatitanate (Li2TiO3) powders activated with different quantities of Mn4+ is studied in detail. Its strong deep‐red emission arising from the Mn4+ 2Eg → 4A2g spin forbidden transition is centered at around 688 nm and is suitable for luminescence thermometry. Structural and electron paramagnetic resonance analyses show that Mn4+ ions are equally distributed in two almost identical Ti4+ sites in which they are octahedrally coordinated by six oxygen ions. Calculations based on the exchange charge model of the crystal field provided values of Racah parameters (B=760 cm−1, C= 2993 cm−1), crystal‐field splitting Dq= 2043 cm−1, and the nephelauxetic parameter β1=0.9775. The maximal quantum efficiency of 24.1% at room temperature is found for 0.126% Mn4+ concentration. Temperature quenching of emission occurs by a cross‐over via 4T2 excited state of the Mn4+ ions with T1/2=262 K and is quite favorable for the application in the lifetime‐based luminescence thermometry since relative changes in emission decay values are exceptionally‐large (around 3.21% at room temperature). We derived theoretical expressions for the temperature dependence of the absolute and relative sensitivities and discuss the influence of host material properties on lifetime sensitivities. [ABSTRACT FROM AUTHOR]

Abstract: Sn‐based materials can be potentially used as anode in lithium‐ion batteries (LIBs), though challenges still exist. Herein, SnO2/C composites with ultrafine SnO2 nanocrystals uniformly anchored to the carbon matrix are simply synthesized via a one‐pot solvothermal method. In this structure, the nano‐sized SnO2 can offer abundant electroactive sites and effectively shorten the lithium‐ion diffusion length. The interfacial structure between SnO2 and the carbon matrix restricts the particle within a specific space, allowing elastic buffering and alleviating the agglomeration and pulverization. Therefore, the capacity decay due to volume variation upon cycling can be refrained remarkably. Moreover, the unique interfaces facilitate electron transfer, as well as additional lithium storage (i. e., pseudocapacitance). Benefiting from these unique architectural merits, our optimized SnO2/C composite exhibits high specific capacity (600 mAh g−1 at 0.2 A g−1) and superior rate capability (185 mAh g−1 at 11.7 A g−1) when applied to LIBs anodes. Even without an additional conductive agent, the electrode can maintain its extremely stable performance. The strategy proposed here proves the feasibility to enhance electrochemical properties, utilizing the synergetic effect between SnO2 nanocrystals and the carbon base. Thus, the optimized SnO2/C is a promising candidate for applications as anode material in LIBs. [ABSTRACT FROM AUTHOR]

Samples of the Ca3Sc2Si3O12 (CSS) host singly doped with Eu2+ or Yb3+, doubly doped with Eu2+ and Yb3+, and triply doped with Ce3+, Eu2+ and Yb3+ were synthesized by a sol-gel combustion process under reducing conditions. Unlike previous reports of Eu2+→Yb3+ energy transfer in other systems, the energy transfer is resonant in the CSS host and the transfer efficiency reaches 100 % for lightly doped samples. The transfer mechanism is multipolar rather than electron transfer for the sample compositions employed herein. The emission intensity of Yb3+ is further enhanced by co-doping with Ce3+ in addition to Eu2+. The quantum efficiencies of the doped materials range between 9 % and 93 %. [ABSTRACT FROM AUTHOR]

The development of highly active and stable earth-abundant catalysts to reduce or eliminate the reliance on noble-metal based ones in green and sustainable (electro)chemical processes is nowadays of great interest. Here, N-, O-, and S-tridoped carbon-encapsulated Co9S8 (Co9S8@NOSC) nanomaterials are synthesized via simple pyrolysis of S- and Co(II)-containing polypyrrole solid precursors, and the materials are proven to serve as noble metal-free bifunctional electrocatalysts for water splitting in alkaline medium. The nanomaterials exhibit remarkable catalytic performances for oxygen evolution reaction in basic electrolyte, with small overpotentials, high anodic current densities, low Tafel slopes as well as very high (nearly 100%) Faradic efficiencies. Moreover, the materials are found to efficiently electrocatalyze hydrogen evolution reaction in acidic as well as basic solutions, showing high activity in both cases and maintaining good stability in alkaline medium. A two-electrode electrolyzer assembled using the material synthesized at 900 °C (Co9S8@NOSC-900) as an electrocatalyst at both electrodes gives current densities of 10 and 20 mA cm−2 at potentials of 1.60 and 1.74 V, respectively. The excellent electrocatalytic activity exhibited by the materials is proposed to be mainly due to the synergistic effects between the Co9S8 nanoparticles cores and the heteroatom-doped carbon shells in the materials. [ABSTRACT FROM AUTHOR]

The Mn4+ activated fluostannate Na2SnF6 red phosphor was synthesized from starting materials metallic tin shots, NaF, and K2MnF6 in HF solution at room temperature by a two-step method. The formation mechanism responsible for preparing Na2SnF6:Mn4+ ( NSF:Mn) has been investigated. The influences of synthetic parameters: such as concentrations of HF and K2MnF6 in reaction system, reaction time, and temperature on crystallinity, microstructure, and luminescence intensity of NSF:Mn have been investigated based on detailed experimental results. The actual doping concentration of Mn4+ in the NSF:Mn host lattice is less than 0.12 mol%. The most of K2MnF6 is decomposed in HF solution especially in hydrothermal system at elevated temperatures. The color of the as-prepared NSF:Mn samples changes from orange to white when the temperature is higher than 120°C, which indicates the lower concentration of luminescence centers in the crystals. A series of 'warm' white light-emitting diodes with color rendering index ( CRI) higher than 88 and correlated color temperatures between 3146 and 5172 K were obtained by encapsulating the as-prepared red phosphors NSF:Mn with yellow one Y3Al5O12:Ce3+ ( YAG:Ce) on 450 nm blue InGaN chips. The advantage of the synthetic strategy to obtain NSF:Mn can be extended to developing Mn4+-doped red phosphors from low-costing metals at room temperature for large-scale industrial applications. [ABSTRACT FROM AUTHOR]

Red phosphor BaSiF6:Mn4+ has been synthesized by a hydrothermal method at 120°C for 24 h, in which either Si or SiO2 is used as silicon source. HF as weak acid performs a complex agent for the formation of anion groups [SiF6]2− and [MnF6]2−. The luminescence properties of undoped BaSiF6 have been firstly observed. The dependence of luminescence intensities of BaSiF6:Mn4+ on the concentrations of HF and KMnO4 in precursory solution has been investigated. The as-prepared BaSiF6:Mn4+ exhibits high chemical stability even in deionized water. [ABSTRACT FROM AUTHOR]

Monodispersed hierarchically nanostructured yttrium-based materials including Y(OH)3, Y6O5F8, and H-NaYF4 were successfully synthesized from the same mesocrystal Y(OH) xF3- x precursor. It was found that there was a close crystallographic relationship between the precursor and the final products and all of the processes underwent an in situ topotactic transformation. [ABSTRACT FROM AUTHOR]

The article discusses the attainment of nanocrystals constructed anatase TiO 2 microcage using the hierarchical CaTiO 3 microcage. Topics include the formulation of hierarchical TiO 2 microcages by a hydrothermal treatment of CaTiO 3 precursor with an acetic acid solution, the crystalline construction of the product through a transmission electron microscopy (TEM) and high-resolution TEM (HRTEM), and the investigation of the lithium ion storage properties of TiO 2 microcages.

A new form of TiO2 microspheres comprised of anatase/TiO2-B ultrathin composite nanosheets has been synthesized successfully and used as Li-ion storage electrode material. By comparison between samples obtained with different annealing temperatures, it is demonstrated that the anatase/TiO2-B coherent interfaces may contribute additional lithium storage venues due to a favorable charge separation at the boundary between the two phases. The as-prepared hierarchical nanostructures show capacities of 180 and 110 mAh g−1 after 1000 cycles at current densities of 3400 and 8500 mA g−1. The ultrathin nanosheet structure which provides short lithium diffusion length and high electrode/electrolyte contact area also accounts for the high capacity and long-cycle stability. [ABSTRACT FROM AUTHOR]

A variety of hexagonal sodium yttrium fluoride (NYF) crystals with tunable shapes have been grown, and their up-conversion (UC) emission has been greatly improved after post-treatment in an aqueous solution of NH4HF2 and NaF. The enhancement has been attributed to topotactic ion insertion of sodium cations into the channels of Na3 xY2- xF6. As sodium-ion insertion continues to occur and the sodium content rises, the up-conversion emission intensity and green-to-red ratio increase up to the saturation level. However, the X-ray diffraction patterns and SEM images suggest that both the crystallographic structure and geometric morphology remain unchanged during this topotactic sodium ion insertion. This strategy is very different to previous reports on the use of ion exchange in the preparation of sodium yttrium fluoride crystals and improvement of UC emission. The results of this work demonstrate that sodium vacancy in the hexagonal Na3 xY2- xF6 crystal is the key to the clear reduction in the up-conversion photoluminescence properties of the crystals, but the topotactic sodium ion insertion can revive the up-conversion efficiency greatly. [ABSTRACT FROM AUTHOR]

Sluggish kinetics of photoexcited charge carriers in photocatalysts, slow hole transfer in oxidation half‐reaction, and consequent fast charge recombination on photocatalyst surface are the Achilles' heel limiting the efficiency of photocatalytic hydrogen evolution (PHE). Herein, the effectiveness of covalent binding alternating D‐A‐D organic small molecules (triphenylamine as the donor unit and benzothiadiazole as the acceptor unit) to Znln2S4 (ZIS) nanosheets in the design and development of highly efficient PHE photocatalysts is demonstrated. The covalent grafting of D‐A‐D molecules broadens the photo‐responsive range of ZIS nanosheets, significantly increasing the density of photogenerated charge carriers. More importantly, D‐A‐D organic small molecules can efficiently extract surface photogenerated holes and suppress the recombination of surface photogenerated electron‐hole pairs, thus facilitating the rapid consumption of retained photogenerated electrons for proton reduction to generate H2 with fast kinetics. Consequently, the optimized PHE rate of the ZIS@DAD hybrid catalyst reaches 28.25 mmol g−1 h−1, a 4.2‐fold improvement over that of ZnIn2S4 nanosheets. The covalent integration of D‐A‐D molecules onto inorganic semiconductor photocatalysts represents a novel and highly efficient strategy for optimizing the overall PHE process. This approach provides a fertile new ground for creating efficient solar‐to‐hydrogen systems. [ABSTRACT FROM AUTHOR]