Synthesis of Si 3 N 4 nanowires by catalyst‐free nitridation of (Si + SiO 2 ) mixture

Recently nanowires, especially silicon nitride (Si3N4), have been the emphasis of recent researches, due to their potential application. In this work, the authors developed a catalyst-free method to prepare Si3N4 nanowires by heating the mixture of Si powder and SiO2 sol, coupled with carbon felt at 1500°C in a N2 atmosphere. The nanowires were composed of α-Si3N4 and β-Si3N4, with lengths of 1–2 mm and diameters of 1.5 μm. Meanwhile, the vapour–solid mechanism was employed to interpret the nanowires growth, and this method may be applied to synthesise other long nanowires.