Yang Shen: Clarifying the GO reduction mechanism during thermal annealing

Yang Shen (1)*, Vittorio Boffa (2), Yuanzheng Yue (1,2) (1). Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark. *e-mail: ysh@bio.aau.dk (2). State Key Laboratory of Silicate Materials for Architecture. Wuhan University of Technology, 430070 Wuhan, P. R. China. Graphene Oxide (GO) is a promising intermediate material for preparation of graphene-like structure. Thus, it is important to be able to develop simple and reliable methods for the large-scale fabrication of reduced GO with desired structure and properties. However, the GO reduction mechanism during thermal annealing are still not fully clarified. In this work, we provide new insight into the chemical evolution of Hummer's GO during the low-temperature thermal reduction. Our results demonstrate that the reduction processes of Hummer’s GO could be divided into different steps. Differential scanning calorimetry (DSC) measurements shows a large exothermic response in GO upon heating from 160 to 300 degree centigrade, which is attributed to partial degradation of the oxygen functional groups. By analyzing several partially reduced Hummer’s GO samples, we identified some endothermic response besides the exothermic processes. Combined kinetic and structural measurements are used to analyze the structural evolution of Hummer’s GO during low-temperature reduction, thereby providing knowledge basis for the fabrication of desired structures of reduced-GO. Yang Shen is currently a PhD student at the Department of Chemistry and Bioscience, Aalborg University, Denmark. His primary research interests are order and disorder structures of graphene oxide and their applications. He received his B.S. (2012) and Master (2015) degrees in Materials Physics and Chemistry from Hainan University (P.R. China). Now he studying as a PhD at Aalborg University, where he involves in the project: structural evolution in graphene oxide and their impacts on functionalities.