UC Berkeley

The past decades have witnessed the exponential growth of studies utilizing optical techniques to characterize graphene functionalization. The promise and potential application of graphene and related materials are substantially expanded through chemical functionalization. However, due to the fact that graphene is a single layer of carbon atoms, it is difficult to study the in situ dynamics of graphene chemistry. Moreover, the inertness of the graphene basal plane has notably limited its viable chemical modification pathways. This dissertation describes efforts by the author and colleagues to overcome these limitations. Part I of this dissertation demonstrates the direct optical visualization of in situ dynamics of graphene chemistry through interference reflection microscopy. Specifically, we uncover the unique dynamics of the redox reaction, diazonium reaction and solution-enclosing blister generation process of substrate-supported graphene at high spatiotemporal resolution. Part II of this dissertation reports facile approaches to the chemical modifications of the inert graphene basal plane under ambient conditions. Optical characterizations techniques including interference reflection microscopy, transmission microscopy, fluorescence microscopy, and Raman spectroscopy are utilized here to help establish the successful modifications of graphene through our facile approaches. These approaches include direct azidation and chlorination of the graphene basal plane through the electrochemical oxidation of an aqueous sodium azide and sodium chloride solution as well as a photocatalytic approach for the facile azidation and chemical patterning of graphene surface.