Chemical Synthesis of Niobium Diboride Nanosheets by a Solid-State Reaction Route

Abstract

Chemical synthesis of niobium diboride nanosheets by a solid-state reaction routeA new process was developed to synthesize niobium diboride (NbB 2 ) nanosheets with the dimension of about 500 nm and thickness of about 10 nm by using metal niobium, iodine and sodium borohydride as starting materials in an stainless steel autoclave at 700 °C. Iodine was used to facilitate the exothermic reaction between metal niobium and sodium borohydride and the formation of NbB 2 . X-ray powder diffraction pattern indicated that the obtained product is hexagonal phase NbB 2 with the calculated lattice constants a = 110 Å and c = 3.2929 Å. The obtained product was also studied by thermogravimetric analysis. It had good oxidation resistance below 400 °C in air.

Low‐temperature synthesis of CrB nanoparticles and nanosheets by a solid‐state reaction

“…All the above methods need high reaction temperatures. Recently, the reported synthesis method in the “autoclave route” is an effective method for preparation of borides, carbides, and nitrides at low temperatures 11‐21 . As an effective boron source, sodium borohydride has high reactivity in the preparation of borides, 11,19,22 while chromium trioxide is a strong oxidizing reagent.…”

“…Recently, the reported synthesis method in the “autoclave route” is an effective method for preparation of borides, carbides, and nitrides at low temperatures 11‐21 . As an effective boron source, sodium borohydride has high reactivity in the preparation of borides, 11,19,22 while chromium trioxide is a strong oxidizing reagent. The chemical reaction between chromium trioxide (strong oxidizing reagent) and sodium borohydride (strong reducing agent) is used to prepare chromium boride, which can reduce the temperature required for the reaction, so that chromium boride can be prepared at a lower reaction temperature.…”