Graphite oxide (GO) is a widely used precursor to make graphene and its composites. Studies have been conducted on graphene-based nanomaterials including modified graphene, graphene/semiconductor hybrids, graphene/metal nanoparticles composites, and graphene-complex oxide composites. These nanomaterials inherit the unique properties of graphene, and the addition of functional groups or the nanoparticles composites on their surfaces improves their performance. Reliable production of graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), offers a wide range of...