Synthesis of novel hierarchical SiC–SiO2 heterostructures via a catalyst free method

Abstract

Novel hierarchical SiC–SiO₂ heterostructures were synthesized on a graphite paper substrate via a catalyst free method. The morphology, microstructure and composition were characterized by SEM, HR-TEM, EDS and XRD. Results revealed that the hierarchy of SiC–SiO₂ heterostructures consisted of nanochain structures and nanoweb structures located in different layers of the graphite paper substrate. The nanochain structures were SiC–SiO₂ nanochains coated by an exterior SiO₂ shell, in which the SiO₂ beads were chained to the SiC nanostructure. The nanoweb structures showed that many intersecting SiC nanostructures were encapsulated in irregular SiO₂ agglomerates. The formation of hierarchical SiC–SiO₂ heterostructures was dependent on the synthesis temperature. The VS process followed by a modulation process was proposed to elucidate the formation mechanism of such hierarchical SiC–SiO₂ heterostructures.