Apparent Roughness as Indicator of (Local) Deoxygenation of Graphene Oxide

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• 作者：Duncan den Boer ; Jonathan G. Weis ; Carlos A. Zuniga ; Stefanie A. Sydlik ; Timothy M. Swager
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：August 26, 2014
• 年：2014
• 卷：26
• 期：16
• 页码：4849-4855
• 全文大小：489K
• ISSN：1520-5002

文摘

Detailed characterization of graphene oxide (GO) and its reduced forms continues to be a challenge. We have employed scanning tunneling microscopy (STM) to examine GO samples with varying degrees of deoxygenation via controlled chemical reduction. Analysis of the roughness of the apparent height in STM topography measurements, i.e. the 鈥渁pparent roughness鈥? revealed a correlation between increasing deoxygenation and decreasing apparent roughness. This analysis can therefore be a useful supplement to the techniques currently available for the study of GO and related materials. The presence of a high electric field underneath the STM tip can locally induce a reaction on the GO basal plane that leads to local deoxygenation, and the restoration of the sp² hybridization of the carbons promotes increased planarity. These findings are in line with the apparent roughness values found for GO at varying levels of chemical reduction and illustrates the value of having a tool to gain structural/chemical insight on a local scale. This is the first example of employing an STM tip to locally reduce GO to reduced GO (rGO) and partially reduced GO (prGO) without locally destroying the graphene sample. Local manipulation on the nanoscale has utility for graphene nanoelectronics, and analysis employing the apparent roughness is an additional tool for the study of graphene oxide and related basal plane chemistry.