Spectroscopy and Microscopy of Graphene Oxide and Reduced Graphene Oxide

MATTHEW P. MCDONALD; YURII MOROZOV; JOSE H. HODAK; MASARU KUNO

Graphene Oxide

Springer International Publishing

Año: 2015; p. 1 - 33

Graphene oxide (GO) is an important material that provides a scalable approach for obtaining chemically derived graphene. Its optical and electrical properties are largely determined by the presence of oxygen-containing functionalities, which decorate its basal plane. This chemical derivatization results in useful properties such as the existence of a band gap as well as emission spanning both the visible and near infrared. Notably, GO?s optical and electrical properties can be altered through reduction, which proceeds through the removal of these oxygen-containing functional groups. However, widely variable behavior has been observed regarding the evolution of GO?s optical response during reduction. These discrepancies arise from the different reduction methods being used and, in part, from the fact that nearly all prior measurements have been ensemble studies. Consequently, detailed mechanistic studies of GO reduction are needed which can transcend the limitations of ensemble averaging. In this chapter, we show the spectroscopic evolution of GO?s optical properties during photoreduction at the single-sheet level. Laserinduced reduction, in particular, offers a unique and potentially controllable method for producing reduced GO (rGO), a material with properties similar to those of graphene. However, given the complexity of GO?s photoreduction mechanism, microscopic monitoring of the process is essential to understanding and ultimately exploiting this approach.