Controlled fabrication of hierarchical MgAl2O4 spinel/carbon fiber composites by crystal growth and calcination processes

In this work, we report the synthesis and characterization of hierarchical MgAl2O4 spinel/carbon fiber composites via the sol-gel, in situ growth and calcination processes. The Al2O3/carbon fiber composites were prepared through a ultrasound-assisted sol-gel method by coating an alumina sol layer on the surface of carbon fiber, followed by a subsequent calcination process. Then, the layered double hydroxides (LDHs)/carbon fiber composites with hierarchical morphologies were fabricated by in situ growth of LDHs nanoplatelets on the surface of carbon fiber using Al2O3 as aluminum source. The MgAl2O4 spinel was finally obtained by thermal decomposition of LDHs on the surface of carbon fiber forming spinel/carbon fiber composites. The as-prepared MgAl2O4 spinel/carbon fiber composites and corresponding design strategies developed herein are expected to be applicable to the synthesis of other hierarchical spinel/carbon composites for various applications. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.