One pot route to sponge-like Fe3N nanostructures

Iron nitride (Fe3N) is a promising material to replace scarce and costly noble metals in many catalytic applications. Here, we report the synthesis of Fe3N nanostructures by a simple sol-gel based route. This aqueous, one-pot method based on a self-expanding polypeptide foam represents a breakthrough in Fe3N nanostructure synthesis, which previously has only been achieved through ammonolysis. Through extensive X-ray diffraction and compositional analysis, a formation mechanism is proposed, based on in-situ nitridation by the decomposing gel matrix. The Fe3N nanoparticle sponge is shown to be a promising catalyst for ammonia decomposition, an easy process for CO2-free hydrogen supply and off-gas treatment.