Chemical-Assisted Thermal Disproportionation of Porous Silicon Monoxide into Silicon-Based Multicomponent Systems

摘要

Commercially available silicon monoxide is an unstable material at high temperatures (>1000°C), at which point it disproportionates to silicon nanocrystals and amorphous silicon suboxides. The nanostructuring of SiO, or its conversion to Si, has been carried out using several approaches, such as mechanical milling,chemical vapor deposition and reduction by elemental metals at high temperatures (>900°C). However, these methods did not retain the original morphology of the SiO. Herein, we demonstrate a process for fabricating three-dimensional nanoporous SiO by metal-assisted chemical etching, without changing the chemical and physical properties of the original materials. Subsequent chemical-assisted thermal annealing led to the conversion of porous SiO into shape-preserving Si-based multicomponent systems that consisted of core (Si dispersed in amorphous silicon suboxides) and shell (crystalline silica).