Synthesis, microstructure, and catalytic properties of porous SiFeCO nanocomposites derived from MIL‐101(Fe)‐modified PCS

Abstract

SiFeCO ceramic nanocomposites with porous structure have been successfully prepared via pyrolysis of novel iron‐containing precursors, which were synthesized by modification of polycarbosilane with different contents of MIL‐101(Fe), a kind of metal‐organic framework made by our laboratory. Iron‐containing precursors were pyrolyzed at relatively low temperatures ranging from 500 to 900°C under nitrogen atmosphere, the polymer‐to‐ceramic conversion process were investigated by Fourier transform infrared spectroscopy, X‐ray diffraction (XRD), and thermo gravimetric analysis (TGA) measurements. SiFeCO ceramics with different iron contents were intensively studied with respect to their crystallization behavior, microstructure evolution, and porous morphology influenced by additive amount of MIL‐101(Fe). The results of XRD and Transmission electron microscopy revealed that MIL‐101(Fe)‐modified precursors converted into amorphous SiFeCO ceramics when pyrolyzed below 700°C under nitrogen, extremely small Fe3O4 and α‐Fe crystallites with grain size of only 2–5 nm were in situ generated and dispersed uniformly in the SiCO ceramic matrix. Simultaneously, interconnected porous structure was created in the matrix by the decomposition of MIL‐101(Fe). The as‐obtained SiFeCO ceramics could serve as heterogeneous Fenton‐like catalysts for the degradation of xylene orange and exhibit outstanding catalytic properties.