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

Abstract In this work, we report the synthesis and characterization of hierarchical MgAl 2 O 4 spinel/carbon fiber composites via the sol–gel, in situ growth and calcination processes. The Al 2 O 3 /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 Al 2 O 3 as aluminum source. The MgAl 2 O 4 spinel was finally obtained by thermal decomposition of LDHs on the surface of carbon fiber forming spinel/carbon fiber composites. The as-prepared MgAl 2 O 4 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.