Eu doped aluminum nitride phosphors were successfully synthesized by a novel gas-reduction-nitridation route with a reaction temperature of 1400 C and a soaking time of 3 h. The obtained AlN:Eu phosphors were analyzed to elucidate the location of the Eu luminescent center. High-resolution transmission electron microscopy and transmission electron microscopy-energy dispersive spectra proved that Eu was located in the crystal lattice of AlN, then EXAFS revealed that Eu occupied a highly distorted Al site coordinated by four nitrogen at about 2.30-2.40 Å , and the second nearest neighbors of Eu were 12 Al. This could be confirmed by the first-principles calculations based on the obtained local structure around the Eu luminescence center, where the theoretical absorption spectrum was similar to the experimental excitation spectrum. X-ray appearance near edge structure showed that Eu existed in terms of both Eu 3þ and Eu 2þ ions, which could be related to the limited location space of Eu. High temperature treatment could significantly increase the amount of Eu 2þ by the expansion of the crystal lattice, leading to an increased green luminescence of the obtained AlN:Eu phosphors. V

The luminance degradation of BaMgAl10O17:Eu2+(BAM) caused by baking at 600°C was studied. The dissolution of Si–N into BAM lattice lead to only a reduction in the lattice parameters. Under UV excitation, the Si–N codoping enhanced the luminescent intensity by a factor of 110% for the as‐received phosphors and by a factor of 122% for phosphors baked at 600°C for 1 h. This could be attributed to the stable local structure surrounding the Eu2+ ions and the lower electronegativity of nitrogen. The proposed method is expected to be potentially applicable to other aluminate phosphors with higher stability and photoluminescence.

Many strategies have been adopted to improve thermal degradation of phosphors. Because of the stability and high transmittance of graphene, here we report a novel method of carbon coating on BaMgAl 10 O 17 : Eu 2+ (BAM) phosphor particles through Chemical Vapor Deposition (CVD). The chemical composition, microstructure, and luminescence performance of carbon-coated BAM were characterized carefully. This coating can be controlled within 3-10 atomic layers, depending on the reaction time. Due to the decrease of surface defects and the effective weakening effect of oxidizing Eu 2+ to Eu 3+ after

Developing an economical, durable, and efficient electrode that performs well at high current densities and is capable of satisfying large-scale electrochemical hydrogen production is highly demanded. A self-supported electrocatalytic "Pt-like" WC porous electrode with open finger-like holes is produced through industrial processes, and a tightly bonded nitrogen-doped WC/W (WC-N/W) heterostructure is formed in situ on the WC grains. The obtained WC-N/W electrode manifests excellent durability and stability under multi-step current density in the range of 30-1000 mA cm −2 for more than 220 h in both acidic and alkaline media. Although WC is three orders of magnitude cheaper than Pt, the produced electrode demonstrates comparable hydrogen evolution reaction performance to the Pt electrode at high current density. Density functional theory calculations attribute its superior performance to the electrode structure and the modulated electronic structure at the WC-N/W interface.