Single-step, catalyst-free conversion of rice husk into one-dimensional core-shell nanocrystalline silicon...

Silicon carbide-silicon oxide (SiC-SiO₂) nanostructures have attracted considerable interest due to their exceptional electrical and thermal characteristics, making them suitable for field emission applications. However, achieving a scalable and catalyst-free synthesis of these materials remains a significant challenge. In this study, a novel single-step thermal plasma-assisted pyrolysis technique is introduced to transform rice husk into SiC-SiO₂ core-shell nanostructures. This method facilitates a very rapid production under controlled conditions, yielding core-shell structures with optimized shell thickness to enhance field emission properties. The synthesized core-shell nanostructures exhibit remarkable field emission properties, including a low turn-on filed of 1.8 V/μm and a high emission current density of 0.5 mA/cm² at an applied field of 2.9 V/μm. These findings highlight the effectiveness of a sustainable, agricultural waste-derived approach for fabricating SiC-SiO₂ core-shell nanostructures, paving the way for their application in next-generation electronic devices like low-power electron emitters and cold cathodes.