Controllable Fabrication of Nano-NbN with Three-Dimensional Cotton like Structure for Oxygen Reduction Reaction

A facial method is demonstrated here for the controllable fabrication of nano-NbN with three-dimensional cotton like structure. It is composed of two-step synthesis strategy and uses ammonia as nitrogen source. The prepared NbN has three-dimensional cotton like structure formed by nanoparticles with a size of around 20[Formula: see text]nm. It is found that the temperature of nitriding has a great influence on the size of crystal grain. 800 ∘ C is the most appropriate temperature to form this special structure of nano-NbN. As a catalyst for oxygen reduction reaction, nano-NbN is discovered to have a significant property, which is much better than that of niobium nitride prepared from oxide precursor without any treatment. Inspired by this strategy, the electrocatalytic performance of transition metal nitrides in nanoscale can be better studied.