▎ 摘　　要

Graphene has emerged as an intriguing and attractive functional material for a wide range of applications, owing to its unique physical, chemical and mechanical properties. Herein, we report large-scale production of high quality single crystalline graphene sheets based on the ambient pressure chemical vapor deposition (APCVD) method using acetylene (C2H2) as the carbon source and coral-like iron with body-centered-cubic structure as the catalyst. The process can be scaled up for large quantity production at a low cost. The optimum APCVD temperature has been identified to be 850 degrees C, which is much lower than that catalyzed by other metals. Transmission electron microscopy (TEM), atomic force microscopy, Raman spectroscopy and X-ray photoemission spectroscopy characterizations show the single crystalline and high quality nature of the as-prepared graphene produced by the bottom-up APCVD approach. A new horizontal "dissolution-deposition-growth" mechanism is proposed and verified by high resolution TEM. When applied as anode materials in lithium ion batteries, graphene sheets exhibited a high lithium storage capacity and an excellent cyclability. The capability of preparing crystalline graphene on a large scale with low cost opens an avenue for technological applications of graphene in many fields. (C) 2013 Elsevier Ltd. All rights reserved.