Nanofabrication of Three-Dimensional Graphene with Controlled Shape

Michigan Technological University, Houghton MI

Investigators

Abstract

Graphene is a very promising material for many applications. The current mass production of graphene is focused on two-dimensional graphene sheets. However, the attractive forces between graphene sheets can cause two-dimensional graphene to restack into graphite-like powders, decreasing their specific surface area and deteriorating graphene's unique properties. Three-dimensional graphene, which is a graphene sheet that possesses a curved non-planar shape can inhibit the restacking. This award advances knowledge in scalable nano-scale processing of three-dimensional shape-controlled graphene. In this process, three-dimensional graphene sheets are produced from the exothermic reaction of carbon monoxide and alkali metal oxides, followed by an acid treatment. The three-dimensional graphene are explored as materials for energy devices. Project plans are to have a strong impact on education and outreach by inspiring to engage Native American students in science and engineering. Graduate and undergraduate students involved in this project receive advanced training, which will build a firm foundation for their future careers. Current techniques for three-dimensional (3D) graphene synthesis are limited by the difficulty of controlling graphene shapes and the requirement for high energy need. To overcome these limits, a scalable process is investigated based on a previously invented method involving a reaction between CO and alkali metal oxides. In this approach, graphene sheets are formed simultaneously with alkali metal carbonate nano-particles. Consequently, the generated carbonate nano-particles do not only play a role in determining the locally curved shape of the 3D graphene sheets, but also isolate the graphene sheets from each other to prevent graphite formation during synthesis. After removing the carbonate nano-particles with acid, 3D shape-controlled graphene sheets are obtained. The specific aims of this research are to synthesize various controlled shapes, understand the kinetics of reactions for 3D graphene production, evaluate structure-property relationships, and explore the 3D graphene sheets as electrode materials for solar cells, ion batteries, and supercapacitors. This research advances a new concept in the synthesis of 3D graphene. It involves the understanding of fundamental chemistry, physics, and material science at nanoscale. Furthermore, the resulting kinetic relationships provide a scientific and engineering basis to scale-up the manufacturing process for commercialization.