Получение покрытий гексагонального нитрида бора из концентрированных растворов боратов щелочных металлов

The continuous hexagonal boron nitride (h-BN) coating with the ~100-350 nm thickness was produced from the aqueous solutions of the lithium and sodium borates. The saturated solution was applied on the silicon support by the spin coating, dried under the normal conditions and treated in the ammonia atmosphere under 1300 °C. Such method is a promising way for the fabrication of protection coating. For example, for the protection of the carbon products from an oxidation under high temperature atmosphere.

Nitridated Ca2NaMg2V3O12: Eu3+ Vanadate Garnet Phosphor-in-Glass

In this study, Ca2NaMg2V3O12 coordination compound undoped and doped with Eu3+ obtained in the air and ammonia atmosphere by solid-state reaction was investigated. Ca2NaMg2V3O12: Eu3+ obtained in the ammonia atmosphere was then investigated as a phosphor-in-glass (PiG). Annealed Ca2NaMg2V3O12: Eu3+ phosphor forms a single phase with the cubic garnet structure and Ia3d space group. Nitridation in ammonia causes a widening of a VO43− group emission band on the low energy side and it red-shifts by 20 nm. The emission of Eu3+ is extended as compared to the non-nitridated phosphor. Ca2NaMg2V3O12: Eu3+ after nitridation shows higher emission quantum yield (QY): 49 vs. 45 and lower correlated color temperature (CCT) and 4179 vs. 4998 as compared to phosphor without nitridation. The QY for PiG is 55. The thermal stability of nitridated phosphors is superior to phosphor obtained in the air atmosphere and is further enhanced for PiG.

Co nanoparticles decorated on N-doped rGO carbon aerogel as a highly efficient electrocatalyst for oxygen reduction

With sodium alginate and graphene oxide (GO) as raw materials, cobalt alginate/GO aerogel was prepared by ion-exchange reaction and subsequent freeze-drying technique. The aerogel was transported into a Co/N-rGO composite material through high-temperature carbonization at ammonia atmosphere. The Co/N-rGO composite material was then used for catalyzing oxygen reduction reaction in fuel cell and showed excellent catalytic activity and stability.