(414c) Synthesis and Electrochemical Characterization of Graphene-Metal and Metal Oxide Nanocomposites

The development of new electrodes with high specific capacity and excellent energy storage properties is very desirable. Graphene and derivative nanocomposites are new materials being investigated for such novel properties in energy storage and also as efficient electrocatalysts in oxygen and carbon dioxide reduction reactions. Graphene is a two-dimensional network in which sp²-hybrized carbon atoms packed into hexagonal structure and arranged into two different triangular sub-lattices (A and B). Chemically modified graphene nanoplalets have shown great promise in select applications due to their enhanced electrical properties. Chemical doping is an effective method to tune the electronic properties of graphene materials. The electrochemical properties of the aerogels are enhanced by adding nanosized select metals and metal oxides known to possess intrinsically high energy storage capacity. In this study, nanocomposite aerogels of reduced graphene oxide-platinum and reduced graphene oxide-nickel, as well as the nanocomposite aerogels reduced graphene aerogel/cobalt oxide and manganese oxide are synthesized in-situ using hydrothermal treatment of the precursors in aqueous solutions of urea or ammonia. With this approach, it is possible to synthesize a three-dimensional network reduced graphene oxide aerogel with metal or metal oxide nanoparticles trapped in therein. SEM characterization of the as-synthesized materials revealed a uniform distribution of nanospindles and nanocubes cobalt oxide and manganese oxide respectively in the aerogel. However, the composite materials consisting of platinum and nickel nanoparticles appeared agglomerated in the aerogel network. The synthesized materials are characterized using cyclic voltammetry and the electrochemical properties are discussed.