Graphene reduction dynamics unveiled. (6th August 2015)

• Record Type: Journal Article
• Authors: Tsai, Hung-Chieh; Shiu, Hung-Wei; Chuang, Min-Chiang; Chen, Chia-Hao; Su, Ching-Yuan; David White, Jonathon; Yen Woon, Wei
• Is Part Of: 2D materials. Volume 2:Number 3(2015)
• Publication Date: 2015-08-06
• Subjects: graphene -- defects -- scanning probe lithography -- reduction -- photoelectron spectroscopy; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/2/3/031003
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: The reduction dynamics of micron-sized defects created on chemical vapor deposition- (CVD) grown graphene through scanning probe lithography (SPL) is reported here. CVD-grown graphene was locally oxidized using SPL and subsequently reduced, making use of a focused beam of soft x-rays. During this whole process, the reduction dynamics was monitored using a combination of micro-Raman spectroscopy ( μ -RS) and micro-x-ray photoelectron spectroscopy ( μ -XPS). After x-ray reduction, the graphene film was found to be chemically identical ( μ -XPS) but structurally different ( μ -RS) from the original graphene. During reduction the population of C–C bonds was found to first increase dramatically and then decrease exponentially. By modeling the dynamics of the C=O → C–O → C–C → C=C reduction process with four coupled-rate equations and three rate constants, the conversion from C–C to C=C bonds was found to be the limiting rate.