Metal atoms at graphene edges are important because they can modify the structure and properties of graphene; however, there are very few reports on their direct observation. We performed electron microscopy to investigate the stability and dynamics of Cu and Pt atoms at graphene edges. We found that Cu atoms mended graphene edges, while Pt atoms etched them, and these transformations were promoted by electron irradiation. Cu and Pt atoms formed different atomic configurations at graphene edges.
Interaction between Pt or Cu atoms with the edge structure of graphene was observed and studied to determine the effect of different confirguration with the metal atoms. With atomic resolution imaging, evolution of defect as a function of time was also shown.