Structures formed by passage of current through graphite: flat or three-dimensional?

Publication date: January 2020Source: Carbon, Volume 156Author(s): Peter J.F. HarrisAbstractThe passage of an electric current, or the application of an electrostatic charge through graphite at high temperatures can produce dramatic structural transformations. These involve the formation of carbon structures made up of few-layer graphene with highly irregular morphologies, displaying many unusual features, including nanotube–graphene junctions. A number of studies of the transformed carbon have been carried out, but many aspects of its structure are still not understood. Here, transmission electron microscopy is used to image regions of the transformed carbon at a series of tilt angles, in order to determine their overall shapes. It is found that both flat regions and three-dimensional structures are present. Along the edges of the flat regions, hollow strips are observed, due to the separation of graphene layers. These sometimes contain encapsulated nanotubes or nanoparticles. As well as describing the experimental results, I discuss the possible mechanisms whereby these interesting structures form.Graphical abstract
Source: Carbon - Category: Materials Science Source Type: research