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1.
Molecules ; 29(20)2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39459255

RESUMEN

Excitation wavelength controllable lanthanide upconversion allows for real-time manipulation of luminescent color in a composition-fixed material, which has been proven to be conducive to a variety of applications, such as optical anti-counterfeiting and information security. However, current available materials highly rely on the elaborate core-shell structure in order to ensure efficient excitation-dependent energy transfer routes. Herein, multicolor upconversion luminescence in response to both near-infrared I and near-infrared II (NIR-I and NIR-II) excitations is realized in a novel but simple NaYGeO4:Yb3+/Er3+ phosphor. The remarkably enhanced red emission ratio under 1532 nm excitation, compared with that under 980 nm excitation, could be attributed to the Yb3+-mediated cross-relaxation energy transfers. Moreover, multi-wavelength excitable temperature-dependent (295-823 K) upconversion luminescence realizes a ratiometric thermometry relying on the thermally coupled levels (TCLs) of Er3+. Detailed investigations demonstrate that changing excitation wavelength makes little difference for the performances of TCL-based ratiometric thermometry of NaYGeO4:Yb3+/Er3+. These findings gain more insights to manipulate cross-relaxations for excitation controllable upconversion in single activator doped materials and benefit the cognition of the effect of excitation wavelength on ratiometric luminescence thermometry.

2.
Plants (Basel) ; 13(16)2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39204689

RESUMEN

Cadmium (Cd) pollution restricts the rice growth and poses a threat to human health. Nanosized selenium (NanoSe) is a new nano material. However, the effects of NanoSe application on aromatic rice performances under Cd pollution have not been reported. In this study, a pot experiment was conducted with two aromatic rice varieties and a soil Cd concentration of 30 mg/kg. Five NanoSe treatments were applied at distinct growth stages: (T1) at the initial panicle stage, (T2) at the heading stage, (T3) at the grain-filling stage, (T1+2) at both the panicle initial and heading stages, and (T1+3) at both the panicle initial and grain-filling stages. A control group (CK) was maintained without any application of Se. The results showed that, compared with CK, the T1+2 and T1+3 treatments significantly reduced the grain Cd content. All NanoSe treatments increased the grain Se content. The grain number per panicle, 1000-grain weight, and grain yield significantly increased due to NanoSe application under Cd pollution. The highest yield was recorded in T3 and T1+3 treatments. Compared with CK, all NanoSe treatments increased the grain 2-acetyl-1-pyrroline (2-AP) content and impacted the content of pyrroline-5-carboxylic acid and 1-pyrroline which are the precursors in 2-AP biosynthesis. In conclusion, the foliar application of NanoSe significantly reduced the Cd content, increased the Se content, and improved the grain yield and 2-AP content of aromatic rice. The best amendment was applying NanoSe at both the panicle initial and grain-filling stages.

3.
Materials (Basel) ; 17(9)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38730820

RESUMEN

Reflection cracks are one of the most common problems in semi-rigid base pavement. Setting a stress absorption layer can effectively delay the occurrence of reflection cracks, but further improvement is still needed in its interlayer bonding performance and anti-reflection crack performance. Considering the excellent crack resistance of basalt fibers and the good elastic recovery ability of rubber asphalt, it is considered worthwhile to incorporate them into traditional stress absorption layers to improve performance. To simulate the actual pavement layer effect, composite specimens consisting of a cement-stabilized macadam base + basalt fiber rubber asphalt stress-absorbing layer + AC-20 asphalt mixture surface layer were prepared to evaluate their performance through interlayer direct shear tests, interlayer tensile tests, three-point bending tests, and overlay tests (OTs). To determine the optimal fiber blending combination, four fiber lengths (3 cm, 6 cm, 9 cm, 12 cm) and four fiber proportions (120 g/m2, 140 g/m2, 160 g/m2, 180 g/m2) were selected respectively. The specific effects of basalt fibers with different lengths and dosages were analyzed. The results show that compared with the absence of fibers, the improvement of interlayer bonding performance of rubber asphalt with basalt fibers is not significant, and it has certain limitations; however, the improvement of anti-reflective crack performance is significant, with an increase of up to 305.5%. This indicates that the network structure formed by basalt fibers and rubber asphalt stress absorption layer can effectively absorb and disperse external loads, causing an excellent crack resistance effect. Meanwhile, the results indicate that the main factor affecting its interlayer bonding strength and anti-reflective crack performance is the fiber content. Based on the comprehensive analysis of the performance and economy of the stress absorption layer of basalt fiber rubber asphalt, the optimal fiber parameter combination recommended is as fiber length 9 cm and fiber content 160 g/m2. These results can provide a reference for the design and performance evaluation of basalt fiber rubber asphalt stress absorption layer, and have certain application value.

4.
Molecules ; 28(22)2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-38005346

RESUMEN

Efficient control over lanthanide luminescence by regulating excitations offers a real-time and reversible luminescence-managing strategy, which is of great importance and highly desirable for various applications, including multicolor display and information encryption. Herein, we studied the crystal structure, luminescence properties, and mechanisms of undoped and Tb3+/Eu3+-doped CaZrO3 in detail. The intrinsic purple-blue luminescence from host CaZrO3 and the introduced green/red luminescence from guest dopants Tb3+/Eu3+ were found to have different excitation mechanisms and, therefore, different excitation wavelength ranges. This enables the regulation of luminescent color through controlling the excitation wavelengths of Tb3+/Eu3+-doped CaZrO3. Furthermore, preliminary applications for information encryption with these materials were demonstrated using portable UV lamps of 254 and 302 nm. This study not only promotes the development of multicolor luminescence regulation in fixed-composition materials, but also advances the practical applications of lanthanide luminescent materials in visually readable, high-level anti-counterfeiting and information encryption.

5.
Materials (Basel) ; 15(21)2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36363272

RESUMEN

Upconversion materials have numerous potential applications in light energy utilization due to their unique optical properties. The use of visible light excitation to obtain ultraviolet emission is a promising technology with broad application prospects, while relevant research is absent. A series of Pr3+, Gd3+ doped Y7O6F9 phosphors were synthesized by traditional solid-state reaction. X-ray diffraction, scanning electronic microscopy, steady-state photoluminescence spectra, a decay dynamic, and upconversion emission spectra of the samples were studied. Under the excitation of 238 nm, the energy transfer from Pr3+ to Gd3+ was realized and a strong ultraviolet B emission due to the 6P7/2→8S7/2 transition of the Gd3+ ions was achieved. Under the excitation of a 450 nm blue laser, Pr3+ absorbed two blue photons to realize the upconversion process and then transferred the energy to Gd3+ to obtain the ultraviolet B emission.

6.
Dalton Trans ; 51(4): 1423-1433, 2022 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-34951612

RESUMEN

The electron and ion conductivities of anode materials such as MnOx affect critically the properties of anodes in Li-ion batteries. Herein, a three-dimensional (3D) nanofiber network (MnOx-MXene/CNFs) for high-speed electron and ion transport with a MnOx surface anchored and embedded inside is designed via electrospinning manganese ion-modified MXene nanosheets and subsequent carbonization. Ion transport analysis reveals improved Li+ transport on the MnOx-MXene/CNF electrode and first-principles density functional theory (DFT) calculation elucidates the Li+ adsorption and storage mechanism. The surface-anchored MnOx nanoparticles form extremely strong bonds with the nanofibers, and the internally embedded MnOx nanoparticles, due to the fiber confinement effect, ensure the structural stability during charging and discharging, achieving the so-called dual stabilization strategies for cyclic fluctuation. By electrospinning, self-restacking of MXene flakes can be prevented, thereby giving rise to a larger surface area and more accessible active sites on the flexible anode. Benefiting from the 3D network with excellent conductivity and stability, at high current densities, the MnOx-MXene/CNF anode exhibits outstanding electrochemical characteristics. Even after 2000 cycles, a reversible capacity of 1098 mA h g-1 can be obtained at 2 A g-1 with only 0.007208% decay rate. The MnOx-MXene/CNF anode also shows a significant rate performance such as 1268 mA h g-1 at 2 A g-1 and 1137 mA h g-1 at 5 A g-1 corresponding to an area specific capacity of 2.536 mA h cm-2 at 4 mA cm-2 and 2.274 mA h cm-2 at 10 mA cm-2, respectively. The results indicate that the MnOx-MXene/CNF anode has excellent Li-ion storage properties and great commercial potential.

7.
Nanoscale ; 13(8): 4624-4633, 2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33605964

RESUMEN

Fe3O4 is one of the promising anode materials in Li-ion batteries and a potential alternative to graphite due to the high specific capacity, natural abundance, environmental benignity, non-flammability, and better safety. Nevertheless, the sluggish intrinsic reaction kinetics and huge volume variation severely limit the reversible capacity and cycling life. In order to overcome these hurdles and enhance the cycling life of Fe3O4, a one-dimensional (1D) nanochain structure composed of 2D Ti3C2-encapsulated hollow Fe3O4 nanospheres homogeneously embedded in N-doped carbon nanofibers (Fe3O4@MXene/CNFs) is designed and demonstrated as a high-performance anode in Li-ion batteries. The distinctive 1D nanochain structure not only inherits the high electrochemical activity of Fe3O4, but also exhibits excellent electron and ion conductivity. The Ti3C2 layer on the Fe3O4 hollow nanospheres forms the primary electron transport pathway and the N-doped carbon nanofiber network provides the secondary transport pathway. At the same time, Ti3C2 flakes partially accommodate the large volume change of Fe3O4 during Li+ insertion/extraction. Density functional theory (DFT) calculations demonstrate that the Fe3O4@MXene/CNFs electrode can efficiently enhance the adsorption of Li+ to promote Li+ storage. As a result of the electrospinning process, self-restacking of Ti3C2 flakes and aggregation of Fe3O4 nanospheres can be prevented resulting in a larger surface area and more accessible active sites on the flexible anode. The Fe3O4@MXene/CNFs anode has remarkable electrochemical properties at high current densities. For example, a reversible capacity of 806 mA h g-1 can be achieved at 2 A g-1 even after 500 cycles, corresponding to an area specific capacity of 1.612 mA h cm-2 at 4 mA cm-2 and a capacity as high as 613 mA h g-1 is retained at 5 A g-1, corresponding to an area capacity of 1.226 mA h cm-2 at 10 mA cm-2. The results indicate that the Fe3O4@MXene/CNFs anode has excellent properties for Li-ion storage.

8.
Nanoscale Horiz ; 5(7): 1127-1135, 2020 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-32458873

RESUMEN

As a two-dimensional layered material with a structure analogous to that of graphene, molybdenum disulfide (MoS2) holds great promise in sodium-ion batteries (SIBs). However, recent research findings have revealed some disadvantages in two-dimensional (2D) materials such as poor interlayer conductivity and structural instability, resulting in poor rate performance and short cycle life for SIBs. Herein, we designed MoS2 nanoflowers with an ultra-wide spacing interlayer (W-MoS2/C) anchored on special double carbon tubes to construct three-dimensional (3D) nanostructures. When tested as an anode material in a SIB, the as-prepared CNT@NCT@W-MoS2/C sample achieves high capacities (530 and 230 mA h g-1 at current densities of 0.1 and 2 A g-1, respectively). Density functional theory (DFT) calculations demonstrate that the ultra-wide spacing MoS2/C structure is beneficial for the chemical adsorption of sodium ions and facilitates redox reactions. The wide interlayer spacing and the presence of an intermediate carbon layer provide a rapid diffusion channel for ions and offer a free space for volume expansion of the electrode material.

9.
RSC Adv ; 10(15): 8760-8765, 2020 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-35496539

RESUMEN

Low energy density of supercapacitors is one of the major downsides for their practical applications. Here, a simple hydrothermal method was developed to synthesize NiS nanosheets on Ni foam. NiS nanosheets with a rough surface promise large electroactive surface area for energy storage, and show an ultra-high capacitance of 2587 F g-1 at a scan rate of 0.2 A g-1 (corresponding to the discharge time of 5563 s). The NiS nanosheets also present an outstanding cycling stability of 95.8% after 4000 cycles. As a positive electrode material for hybrid supercapacitors (HSC), NiS nanostructures provide a broad voltage window of 1.7 V. Our device also shows a high energy density of 38 W h kg-1 at a power density of 1.5 kW kg-1.

10.
Nanoscale Res Lett ; 14(1): 326, 2019 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-31624928

RESUMEN

The reasonable design of nanostructure is the key to solving the inherent defects and realizing a high performance of Li2FeSiO4 cathode materials. In this work, a novel heterostructure CNT@Li2FeSiO4@C has been designed and synthesized and used as a cathode material for lithium-ion battery. It is revealed that the product has a uniform core-shell structure, and the thickness of the Li2FeSiO4 layer and the outer carbon layer is about 19 nm and 2 nm, respectively. The rational design effectively accelerates the diffusion of lithium ions, improves the electric conductivity, and relieves the volume change during the charging/discharging process. With the advantages of its specific structure, CNT@Li2FeSiO4@C has successfully overcome the inherent shortcomings of Li2FeSiO4 and shown good reversible capacity and cycle properties.

11.
Nanoscale ; 11(35): 16562-16570, 2019 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-31460546

RESUMEN

The modulation of luminescence via external stimuli such as temperature, mechanical stress, hydrostatic pressure, as well as electric and/or magnetic fields, has witnessed great progress, enabled the disclosure of new principles and energy transfer pathways, and widened applications. However, investigations on the luminescence modulation of lanthanide ions doped in semiconductors via an applied electric field are still absent. Herein, for the first time, we have demonstrated the in situ, real-time, and reversible modulation of the luminescence of Eu3+ doped in SnO2 nanocrystals by manipulating the recombination rate of photo-generated electrons and holes, and the accompanied energy transfer mode in terms of linear and quasi-sinusoidal, from semiconductor to lanthanide ions. Following the same principle, the modulation of near infrared responsive Er3+ in SnO2 and the visible luminescence of perovskite nanocrystals is further realized. This study offers extra methodologies for luminescence modulation, in addition to those already reported for ferro- and/or piezoelectric-hosted luminescent materials.

12.
J Proteomics ; 205: 103419, 2019 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-31212084

RESUMEN

Protein lysine acetylation is a major post-translational modification and plays a critical regulatory role in almost every aspect in both eukaryotes and prokaryotes, yet there have been no data on Shewanella baltica, which is one of the specific spoilage organism (SSO) of aquatic products. Here, we performed the first global acetylproteome analysis of S. baltica. 2929 lysine acetylation sites were identified in 1103 proteins, accounting for 26.1% of the total proteins which participate in a wide variety of biological processes, especially in the constituent of ribosome, the biosynthesis of aminoacyl-tRNA, the amino acids and fatty acid metabolism. Besides, 14 conserved acetylation motifs were detected in S. baltica. Notably, various directly or indirectly spoilage-related proteins were prevalently acetylated, including enzymes involved in the unsaturated fatty acids biosynthesis closely related to the cold adaptability, cold shock proteins, pivotal enzymes involved in the putrescine biosynthesis, and a LuxR-type protein in quorum sensing system. The acetylome analysis in Shewanella can supplement the database and provide new insight into uncovering the spoilage mechanisms of S. baltica. The provided dataset illuminates the potential role of reversible acetylation in S. baltica, and serves as an important resource for exploring the physiological role of lysine acetylation in prokaryotes. SIGNIFICANCE: The psychrotrophic nature and the ability of S. baltica to make good use of "habitat" nutrients explain its importance in spoilage of seafood stored at low temperatures. However, the underlying mechanism of spoilage potential from the perspective of protein post-translational modification was rarely studied. This work identifies the first comprehensive survey of a lysine acetylome in S. baltica and uncovers the involvement of lysine acetylation in the diverse biological processes, especially in the closely spoilage-related pathways. This study provides a resource for functional analysis of acetylated proteins and creates opportunities for in-depth elucidation of the physiological role of protein acetylation in Shewanella spp.


Asunto(s)
Proteínas Bacterianas/metabolismo , Lisina Acetiltransferasas/metabolismo , Lisina/metabolismo , Procesamiento Proteico-Postraduccional/fisiología , Shewanella/metabolismo , Acetilación , Animales , Organismos Acuáticos/microbiología , Contaminación de Alimentos , Metabolismo de los Lípidos/fisiología , Redes y Vías Metabólicas/fisiología , Proteoma/análisis , Proteoma/metabolismo , Putrescina/metabolismo , Alimentos Marinos/microbiología , Shewanella/química , Shewanella/aislamiento & purificación , Shewanella/patogenicidad
13.
Nanoscale ; 11(22): 11025-11032, 2019 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-31140522

RESUMEN

As a promising energy storage device, sodium ion batteries (SIBs) have attracted more and more attention. Nevertheless, the radius of a sodium ion is much larger than that of a lithium ion, and it is still a significant challenge to solve the problem of volume expansion. In order to solve the problem of volume expansion, a rational nanostructure consisting of CNTs as a carbon matrix, and were sequentially coated with mesoporous SnO2 and N-doped porous carbon tube (NCT). Mesoporous SnO2 can alleviate the volume expansion caused by charge and discharge, and the N-doped porous carbon layer can further inhibit the volume expansion of SnO2. When used as an anode material in sodium ion batteries, the CNT@SnO2@NCT heterostructure achieves efficient capabilities (350 and 150 mA h g-1 at current densities of 0.1 and 2 A g-1, respectively).

14.
Nanoscale Res Lett ; 13(1): 389, 2018 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-30511189

RESUMEN

Structure pulverization and poor electrical conductivity of metal dichalcogenides result in serious capacity decay both in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). To resolve the above problems, a combination of metal dichalcogenides with conductive scaffolds as high-performance electrode materials has aroused tremendous interest recently. Herein, we synthesize a 3D honeycomb-like rGO anchored with SnS2 quantum dots (3D SnS2 QDs/rGO) composite via spray-drying and sulfidation. The unique 3D-ordered honeycomb-like structure can confine the volume change of SnS2 QDs in the lithiation/delithiation and sodiation/desodiation processes, provide enough space for electrolyte reservoirs, promote the conductivity of the SnS2 QDs, and improve the electron transfer. As a result, the 3D SnS2 QDs/rGO composite electrode delivers a high capacity and long cycling stability (862 mAh/g for LIB at 0.1 A/g after 200 cycles, 233 mAh/g for SIB at 0.5 A/g after 200 cycles). This study provides a feasible synthesis route for preparing 3D-ordered porous networks in varied materials for the development of high-performance LIBs and SIBs in future.

15.
Dalton Trans ; 47(37): 12868-12872, 2018 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-30159561

RESUMEN

A series of lanthanide-based metal-organic frameworks (Ln-MOFs) with significantly improved and tunable upconversion emissions were prepared. Y-MOFs co-doped with Yb3+/Er3+ ions have exhibited characteristic upconversion emissions at 520, 545, and 658 nm under 980 nm laser excitation, the intensities of which vary with Yb3+/Er3+ concentrations. In addition, experimental results have indicated that an excited state absorption mechanism is responsible for the upconversion process of Y-MOF:Yb/Er materials. This study has provided a novel design principle and experimental basis for the preparation of luminescent Ln-MOF materials.

16.
Nat Commun ; 9(1): 2593, 2018 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-29955059

RESUMEN

In the originally published version of this Article, the affiliation details for Yan Wang, Yingwei Gao, Qi Deng, Yangbo Wang, Tian Zhou, Yingping Wang, Huiqing Liu, Ruining Ma, Jinke Cheng and Yong Li incorrectly omitted 'Shanghai Jiao Tong University'. This has now been corrected in both the PDF and HTML versions of the Article.' Furthermore, the Supplementary Information file originally associated with this Article inadvertently omitted Supplementary Figure 9. The error has now been fixed and the corrected version Supplementary Information PDF is available to download from the HTML version of the Article.

17.
Nat Commun ; 9(1): 1529, 2018 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-29670121

RESUMEN

Although TRPV1 channels represent a key player of noxious heat sensation, the precise mechanisms for thermal hyperalgesia remain unknown. We report here that conditional knockout of deSUMOylation enzyme, SENP1, in mouse dorsal root ganglion (DRG) neurons exacerbated thermal hyperalgesia in both carrageenan- and Complete Freund's adjuvant-induced inflammation models. TRPV1 is SUMOylated at a C-terminal Lys residue (K822), which specifically enhances the channel sensitivity to stimulation by heat, but not capsaicin, protons or voltage. TRPV1 SUMOylation is decreased by SENP1 but upregulated upon peripheral inflammation. More importantly, the reduced ability of TRPV1 knockout mice to develop inflammatory thermal hyperalgesia was rescued by viral infection of lumbar 3/4 DRG neurons of wild-type TRPV1, but not its SUMOylation-deficient mutant, K822R. These data suggest that TRPV1 SUMOylation is essential for the development of inflammatory thermal hyperalgesia, through a mechanism that involves sensitization of the channel response specifically to thermal stimulation.


Asunto(s)
Endopeptidasas/metabolismo , Ganglios Espinales/metabolismo , Inflamación , Nocicepción , Dolor/metabolismo , Canales Catiónicos TRPV/metabolismo , Animales , Calcio/metabolismo , Cricetinae , Cisteína Endopeptidasas , Genotipo , Células HEK293 , Calor , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación , Neuronas/metabolismo , Reacción en Cadena de la Polimerasa , Dominios Proteicos , Transducción de Señal , Canales Catiónicos TRPV/genética
18.
Dalton Trans ; 47(14): 4950-4958, 2018 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-29553152

RESUMEN

Scandium (Sc) sits at a unique position in the periodic table, i.e., the junction of the top of the rare earth column and the beginning of the transition metal row. Studies have shown that Sc-based nanomaterials are very sensitive to the surrounding chemical environment. A simple adjustment of the chemical reaction conditions such as temperature, surfactant molecules, and solvents (e.g., oleic acid (OA) or 1-octadecene (OD)) can easily lead to different products in terms of chemical composition and phase structure. Herein, under purposely adjusted reaction conditions, we have investigated the interconversion process between two representative Sc-based nanomaterials, that is, nanocrystals of orthorhombic KSc2F7:Yb/Er and cubic K2NaScF6:Yb/Er, both of which have characteristic red upconversion luminescence and high similarity in chemical composition and phase structure. Experimental results have indicated that conversion from KSc2F7:Yb/Er to K2NaScF6:Yb/Er may start from the edge of the nanocrystal where K+ in KSc2F7:Yb/Er was gradually substituted by the post-introduced Na+ in the solution and finally KSc2F7:Yb/Er nanorods were broken and K2NaScF6:Yb/Er nanocubes were formed. On the other hand, a simple variation of the OA : OD ratio facilitates the dissolution of K2NaScF6:Yb/Er and subsequent crystallization of KSc2F7:Yb/Er during the opposite conversion process. Possible chemical reaction mechanisms were further developed to elucidate the interconversion details. Meanwhile, the variation of the upconversion luminescence such as emission intensity, red to green ratio, and lifetime is interpreted to monitor the conversion progress at corresponding stages, which is highly consistent with the scenario discussed above.

19.
Phys Chem Chem Phys ; 20(14): 9516-9522, 2018 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-29570204

RESUMEN

Recent years have witnessed the progress of lanthanide-doped materials from fundamental material synthesis to targeted practical applications such as optical applications in photodetection, anti-counterfeiting, volumetric display, optical communication, as well as biological imaging. The unique compositions and structures of well-designed lanthanide ion-doped materials could expand and strengthen their application performances. Herein, we report dual-mode luminescent crystalline microrods that spatially confine upconversion and downconversion photophysical process within defined regions using the specially designed heterogeneous structure. Through an epitaxial growth procedure, downconversion tips have been conjugated with the parent upconversion microrods in oriented directions. This spatially confined structure can effectively depress the deleterious energy depletion in lanthanide ions homogeneously doped materials, and as a result, the red, green, and blue upconversion intensities have been enhanced by 334, 225, and 22 times, respectively. Moreover, the induced tips hardly disturb the upconversion process of the microrod seeds. Upon 980 nm laser or ultraviolet lamp excitation, tunable emission colors were realized in the single tip-modified microrod, indicating potential applications of these microrods for high-level dual-mode anti-counterfeiting.

20.
Adv Mater ; 30(14): e1705256, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29430797

RESUMEN

Luminescent nanothermometers have shown competitive superiority for contactless and noninvasive temperature probing especially at the nanoscale. Herein, we report the inherently Eu2+ /Eu3+ codoped Sc2 O3 nanoparticles synthesized via a one-step and controllable thermolysis reaction where Eu3+ is in-situ reduced to Eu2+ by oleylamine. The stable luminescence emission of Eu3+ as internal standard and the sensitive response of Eu2+ emission to temperature as probe comprise a perfect ratiometric nanothermometer with wide-range temperature probing (77-267 K), high repeatability (>99.94%), and high relative sensitivity (3.06% K-1 at 267 K). The in situ reduction of Eu3+ to Eu2+ ensures both uniform distribution in the crystal lattice and simultaneous response upon light excitation of Eu2+ /Eu3+ . To widen this concept, Tb3+ is codoped as additional internal reference for tunable temperature probing range.

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