Accelerating global energy consumption makes the development of clean and renewable alternative energy sources indispensable. Nanotechnology opens up new frontiers in materials science and engineering to meet this energy challenge by creating new materials, particularly carbon nanomaterials, for efficient energy conversion and storage. Since the Nobel Prize winning research on graphene by Geim and Novoselov, considerable efforts have been made to exploit graphene as an energy material, and tremendous progress has been achieved in developing high-performance devices for energy conversion and energy storage. This article reviews recent progress in the research and development of graphene materials for advanced energy-conversion devices, including solar cells and fuel cells, and energy-storage devices, including supercapacitors and lithium-ion batteries, and discusses some challenges in this exciting field.

As graphene technologies progress to commercialization and large-scale manufacturing, issues of material and processing safety will need to be more seriously considered. The single word “graphene” actually represents a family of related materials with large variations in number of layers, surface area, lateral dimensions, stiffness, and surface chemistry. Many of these materials have aerodynamic diameters below 5 μm and can potentially be inhaled into the human lung. Graphene materials show several unique modes of interaction with biological molecules, tissues, and cells. The limited literature suggests that graphene materials can be either benign or harmful and that the biological response varies according to a material’s physicochemical properties and biologically effective dose. The present article reviews the current literature on the graphene–biological interface with an emphasis on the mechanisms and fundamental biological responses relevant to material safety and also to potential biomedical applications