Carbon Scaffolds for Stiff and Highly Conductive Monolithic Oxide–Carbon Nanotube Composites

Abstract

The ultra low density, high electrical conductivity, and mechanical robustness of carbon nanotube aerogels (SWNT-CA) make them ideal scaffolds around which to create novel composites. Here we report on the synthesis and characterization of oxide/carbon nanotube composites fabricated through the sol–gel deposition of oxide coatings (SiO2, SnO2 or TiO2) on SWNT-CA. The porous network of the SWNT-CA scaffold is retained after the deposition and drying process. In each case, the deposited oxide appears to form a uniform coating on the surfaces of aerogel ligaments. The composite materials exhibit high electrical conductivity (∼100 S/m) and enhanced mechanical properties relative to the uncoated SWNT-CA support. In addition, the oxide/SWNT-CA composites possess high surface areas (as high as 742 m2/g) and large mesopore volumes (as high as 2.2 cm3/g). This approach offers viability in engineering new oxide/CNT composites for applications such as energy storage, sensing, and catalysis.