[en] Sm³⁺ ions doped orange-red emitting AlN phosphors were successfully fabricated by a simple solid-state route at 880 °C. The phase analysis and crystal structure, symmetry, morphology, band gap width, elements analysis and photoluminescence properties are investigated detailly. The symmetry of the local environment for Sm³⁺ depends on the doping concentration of Sm³⁺ ions in AlN matrix. All the phosphors can exhibit orange-red emission by virtue of the ⁴G_5/2 → ⁶H_7/2 transition of Sm³⁺ ions. And all the phosphors display high color purity and low correlated color temperature. The best doping concentration of Sm³⁺ in AlN matrix is 1.0% mole fraction. Furthermore, in contrast to undoped AlN, AlN:xSm³⁺ semiconductors show excellent photocatalytic hydrogen evolution activity, and the maximum rate of H₂ evolution from water splitting is 98 μmol h⁻¹ g⁻¹ when the doping concentration of Sm³⁺ is 1.3% mole fraction. The study signifys bifunctional AlN:xSm³⁺ with luminescence and photocatalytic properties may be anticipated to apply in both white light-emitting diodes (WLEDs) and photocatalytic hydrogen evolution from water splitting.

[en] The Fe₃N nanoparticles with different Mn concentration were fabricated by a co-precipitation method. The structure and morphology of these as-prepared samples were carefully investigated. And we infer that the incorporation of Mn influence on the stability of Fe₃N. Moreover, we explore the magnetic properties of Fe₃N with different Mn concentration from vibrating sample magnetometer and analyze the reasons for the change of magnetic properties. The results demonstrate that our synthetic route provides a new way to explore the properties and structure of Fe₃N incorporated with different transition metals.

[en] Highlights: • Mn doped aluminum nitride (AlN) red phosphors were prepared by a simple solid-state reaction. • Their structure, morphology and photoluminescence were detailedly investigated. • The photoluminescence properties of the materials are affected by the Mn doped concentration. • The formation mechanism for AlN was briefly discussed. White light-emitting diodes (WLEDs), which have high luminous brightness, longevity, low energy consumption and friendliness of environment, could be employed in diverse fields. Nevertheless, commercial phosphors are short of red light component. New phosphors which can emit red light are required. Mn²⁺ doped aluminum nitride (marked as AlN) red phosphors were prepared by a simple solid-state reaction. X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS), as well as photoluminescence (PL) spectra are utilized to characterize the prepared samples. The preparing process of AlN phosphors, phase formation and crystal structure, morphology, and photoluminescence are detailedly investigated. For Mn²⁺ doped AlN phosphor(marked as AlN:Mn²⁺), it exhibits an intense red emission caused by the ⁴T₁(⁴G)-⁶A₁(⁶S) transition of Mn²⁺. The unusual red emission of Mn²⁺ is ascribed to the strong nephelauxetic and crystal field between Mn²⁺ and the tetrahedrally coordinated N³⁻. The oxygen-related defects in AlN have a great influence on the photoluminescence properties of the Mn²⁺ doped AlN. The AlN:Mn²⁺ phosphors exhibits a high brightness, high color purity, and lower saturation, which make it a great candidate of red phosphors for white light-emitting diodes (WLEDs).

[en] Transition metal dichalcogenides have unique physicochemical properties. Herein, a low-temperature facile method is demonstrated to synthesize ultrathin tungsten disulfide nanoflakes. They are loosely stacked between layers with highly exposed edges, which provide lots of active sites for electrochemical applications. The by-product of crystalline carbon improves their conductivity, which also enhances their performance in hydrogen evolution reaction. (paper)