Highlights

• Studied the effects of reducing agents and CNTs on morphologies and properties of GAs

• Annealing and addition of CNTs enhances electrical conductivities of the GAs up to 5 times 

• The thermal conductivity of the GAs is measured to be ∼0.10 W/(m K) 

• Thermal stability of annealed GAs are higher than those of non-annealed GAs

Abstract

Graphene and carbon nanotube (CNT) aerogels provide combinations of mechanical, thermal, and electrical properties that are interesting for a variety of applications. In this work, the impact of three different reducing agents (L-ascorbic acid (LAA), HI and NaHSO3) and carbon nanotubes on the morphologies and properties of the graphene aerogels (GAs) are studied systematically. Additional, thermal annealing at 450°C for 5 h under Ar environment is also investigated. Annealing treatment and the addition CNTs enhance the electrical conductivities of the GAs up to a factor of 5. Thermal annealing impacts the surface area of the GAs. Specifically, the surface areas of those reduced by HI and NaHSO₃ decreased by 30%, while those reduced by LAA or dispersed with CNTs increased by 15%. The thermal conductivity of the highly porous GAs is measured using an improved infrared microscopy technique to be ∼0.10 W/(m K).

Full article available at http://www.sciencedirect.com/science/article/pii/S0927775714000284#