Emerging energy and environmental applications of vertically-oriented graphenes.

Graphene nanosheets arranged perpendicularly to the substrate surface, i.e., vertically-oriented graphenes (VGs), have many unique morphological and structural features that can lead to exciting properties. Plasma-enhanced chemical vapor deposition enables the growth of VGs on various substrates using gas, liquid, or solid precursors. Compared with conventional randomly-oriented graphenes, VGs' vertical orientation on the substrate, non-agglomerated morphology, controlled inter-sheet connectivity, as well as sharp and exposed edges make them very promising for a variety of applications. The focus of this tutorial review is on plasma-enabled simple yet efficient synthesis of VGs and their properties that lead to emerging energy and environmental applications, ranging from energy storage, energy conversion, sensing, to green corona discharges for pollution control.