Defect-free graphene metal oxide composites: formed by lithium mediated exfoliation of graphite

Abstract

In this work, defect-free graphene–metal oxide nanocomposites have been synthesized via direct reaction of Li–graphite alloy with an alcohol-based metal precursor solution. The intercalated Li atoms, within the graphitic galleries, are responsible for the reduction of the alcohol, which results in hydrogen evolution for direct exfoliation of defect-free graphene from the graphite. Meanwhile, the intercalated Li atoms serve as a strong reductant as well for reduction of metal ions, and act in the subsequent deposition of metal/metal oxide nanoparticles on the graphene layers. The resulting defect-free graphene sheets, with uniformly distributed nano-sized metal oxide particles on their surfaces, have excellent physical and electrochemical properties due to the synergistic effect between the active nanoparticles and the graphene sheets.