(Invited) From Carbon Nanotubes to Graphene, a Versatile Building Block in the Nanoscale World
Authors: Kittrell Carter , Tour James M. 
Published: February 2020

Carbon nanotubes (CNT) can be turned into graphene, CNT and graphene can be fused to gain beneficial properties of both, and graphene is branching out into a number of new applications. It is used both in its pure form, and as a host for many other elements in the periodic table. As Bob Hauge demonstrated, carbon nanotubes can be fused with graphene to add "rebar" to the single atom layer of graphene when greater structural strength is needed, adding a three-dimensional aspect to the 2D structure of graphene. Carbon nanotubes can be "unzipped" to make graphene nanoribbons (GNRs). These have been used to make resistively heated de-icing films. On the biomedical side, GNRs derived from CNT have shown to be successful as a scaffold in guiding nerve growth and restoring muscle function after a spinal cord is severed. Graphene can be extracted from natural sources such as coal, and produced in many ways, as quick as a sub-millisecond flash of a focused carbon dioxide laser to an hour of slow-roasting over a copper foil. The laser prints 2D graphene for electrodes and superhydrophobic films; adding more precursor leads to 3D printing. Almost any source of carbon is suitable for making graphene, hence the precursors can be of low cost or no cost if it is a waste material containing carbon. Suitable examples range from the single carbon atom in methane to such complex precursors as the leg of a cockroach. Bulk sources like asphalt can be rendered nanoporous for capturing carbon dioxide. Graphene oxide is selective in adsorbing trace amounts of radionuclides from water in the presence of common ions like sodium. Addition of metals to graphene produces a "single atom catalyst", and atomic cobalt is suitable for electrolytic water-splitting. And the reverse process of producing water and electricity from a fuel cell uses a single atom catalyst of ruthenium, which has the advantage of a fuel cell catalyst that is about 1/30th the cost of platinum.	Carbon nanotubes (CNT) can be turned into graphene, CNT and graphene can be fused to gain beneficial properties of both, and graphene is branching out into a number of new applications. It is used both in its pure form, and as a host for many other elements in the periodic table. As Bob Hauge demonstrated, carbon nanotubes can be fused with graphene to add "rebar" to the single atom layer of graphene when greater structural strength is needed, adding a three-dimensional aspect to the 2D structure of graphene. Carbon nanotubes can be "unzipped" to make graphene nanoribbons (GNRs). These have been used to make resistively heated de-icing films. On the biomedical side, GNRs derived from CNT have shown to be successful as a scaffold in guiding nerve growth and restoring muscle function after a spinal cord is severed. Graphene can be extracted from natural sources such as coal, and produced in many ways, as quick as a sub-millisecond flash of a focused carbon dioxide laser to an hour of slow-roasting over a copper foil. The laser prints 2D graphene for electrodes and superhydrophobic films; adding more precursor leads to 3D printing. Almost any source of carbon is suitable for making graphene, hence the precursors can be of low cost or no cost if it is a waste material containing carbon. Suitable examples range from the single carbon atom in methane to such complex precursors as the leg of a cockroach. Bulk sources like asphalt can be rendered nanoporous for capturing carbon dioxide. Graphene oxide is selective in adsorbing trace amounts of radionuclides from water in the presence of common ions like sodium. Addition of metals to graphene produces a "single atom catalyst", and atomic cobalt is suitable for electrolytic water-splitting. And the reverse process of producing water and electricity from a fuel cell uses a single atom catalyst of ruthenium, which has the advantage of a fuel cell catalyst that is about 1/30th the cost of platinum.