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The influence of a graphene/silver (G/A) nanocomposite coating layer on the microstructural evolution and surface oxidation of a Mg–Ni–La hydride is investigated systematically by XRD, SEM, EDS and HRTEM in detail. SEM and EDS reveal that the existence of the G/A composite prevents the electrode from pulverizing and oxidizing. The oxygen content in the surface of the electrode is reduced from 21% to 10% after 50 cycles for a Mg-Ni-La electrode with 0.2 mass fraction of G/A. The crystallization process of the amorphous electrodes coated by G/A is reduced compared to the uncoated electrode and the stable Mg 2 NiH 4 , α-Mg, MgH 2 and La oxihydroxide phases are present with the grain size about 40–60 nm after 50 charge/discharge cycles. The G/A coating reduces the corrosion and oxidation of the electrode alloy and provides both a pathway for hydrogen diffusion and active sites for the redox reaction of hydrogen. All of these factors result in a significant improvement of the discharge capacity by about 200 mAh g −1 in each cycle (after activation) for Mg-Ni-La electrodes with 0.2 mass fraction of G/A nanocomposites. [ABSTRACT FROM AUTHOR]

2-Thenoyltrifluoroacetone (Tta) and 1,10-Phenanthroline hydrate (Phen) were used as ligands for Eu 3+ ions to prepare graphene oxide (GO)/rare-earth (RE) complex hybrid luminescent materials by a new method. The as-prepared products are characterized via fluorescence microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV–Vis absorption spectroscopy, X-ray diffraction, fluorescence spectroscopy, and thermogravimetric analysis. The hybrid materials exhibit good solubility, long luminescent lifetime, high fluorescence quantum yield, good thermal and photo stability. Moreover, their fluorescence properties in sodium acetate/acetic acid buffer solution over the pH range from 3.6 to 5.4 are also studied. These properties of hybrid materials provide an important basis for their application in medicine, as potential biological markers, and as drug delivery vehicles. [ABSTRACT FROM AUTHOR]

Reversible bright-dark luminescence nanomaterials have been developed for information storage and anti-counterfeiting in recent years, however, their monochrome characteristic and 2D patterning impose limits on the effective information storage density. In this work, a new strategy for producing ultraviolet switchable and stable luminescent patterns is proposed, based on Ln3+ (Eu3+/Tb3+) induced-polyelectrolyte aggregates (LIPAs) with sharp multi-color optical properties. Under 365 nm excitation, a multicolor pattern can be observed using both red and green, which is not visible when this excitation light source is off. The LIPAs enable the luminescent lanthanide complexes to be compatibilized with poly(lactic acid) (PLA). Functional anti-counterfeiting patterns were prepared by 3D printing using luminescent PLA containing by Ln3+ (Eu3+/Tb3+) LIPAs. Invisible, adjustable and ultra-stable multicolor luminescent patterns well enable information storage and enhance information security for anti-counterfeiting applications. ● Novel nanocomposite based on Ln3+-induced polyelectrolyte aggregates (LIPAs) is synthesized. ● Novel luminescent polylactic acid (PLA) composite fiber based on LIPAs is successfully fabricated. ● The functional anti-counterfeiting pattern is prepared by 3D printing using luminescent LIPAs/PLA fiber. ● Multicolor luminescent patterns are invisible, adjustable and ultra-stable. [ABSTRACT FROM AUTHOR]