Nanocarbons, such as carbon nanotubes and graphene, have had a remarkable history and impact on current applications. We briefly review the genesis and development of nanocarbons over the last 50 years, referencing key articles, including the role of catalysts in their formation. This issue focuses on the formation mechanisms and controlled growth of carbon nanotubes and graphene on substrates through catalytic processes. The five contributions in this issue review the mechanisms and theory of catalytic growth of nanocarbons (carbon nanotube forests, superaligned arrays, single-wall carbon nanotubes), the growth of large-quantity, high-quality graphene on metal substrates, and the unique and excellent properties for current and potential commercial applications.

Nanocarbons have been catalytically grown since 1993. However, even today, the formation mechanisms of carbon nanotubes (CNTs) and graphene are not sufficiently understood. This sustained challenge has been an engine for the development in theory concepts and computational methods, tackling the problem of well-controlled production of these nanomaterials. This article discusses how experimental discoveries and theoretical approaches evolved hand-in-hand for the successful understanding of challenging issues, highlighting parallels and distinctions between graphene and CNTs. Key aspects include the mechanisms of nucleation and CNT-liftoff, chiral symmetry selection and control, rates of growth and island shapes, mechanisms defining single chirality of the nanotubes, and ways to suppress grain boundaries in the quest for ever larger and faster growing single-crystal graphene, or longest defect-free CNTs. The theme of catalyst chemistry and structure, either as a nanoparticle or a planar substrate, is traced through the stages of nanocarbon formation, with focus on theoretically generalizable findings.

When the size and spacing of catalyst nanoparticles are well controlled on a substrate, carbon nanotubes (CNTs) can grow and assemble into a unique, vertically aligned structure frequently called a “forest.” Long, aligned, and pure CNTs can easily be synthesized in simple or highly complex configurations. First reported in 1996, CNT forests have been shown to be unique and useful forms of CNTs, as they have spurred the development of novel processes and applications and in addition, served as test beds for investigations into CNT growth mechanisms. This article provides an overview of two decades of research in this area.

Catalysts play essential roles in the chemical vapor deposition of single-wall carbon nanotubes (SWCNTs). In this article, we summarize studies on catalysts for the structure-controlled growth and mass production of SWCNTs, discussing the main progress and the remaining challenges.

Because of its unique properties and promising applications, graphene has attracted great interest from both academia and industry in the last decade. For studies on graphene as well as for applications, it is essential to develop techniques to prepare graphene in a controllable way. Graphene can be produced in the form of nano-/microflakes using a top-down method by the exfoliation of graphite or the reduction of graphene oxide, or in the form of a film or foam in a bottom-up method, predominantly by chemical vapor deposition of carbon precursors on catalytic substrates. This article focuses on the catalytic substrates, especially metals, used for graphene growth. We also discuss graphene growth mechanisms and kinetics, control of the number of graphene layers and their stacking order, engineering of large-area graphene single crystals, as well as low-temperature growth.

High-quality carbon nanotubes (CNTs) and graphene synthesized by chemical vapor deposition (CVD) have unique one- and two-dimensional structures made up of sp2-hybridized carbon atoms and excellent physical and chemical properties. They have shown potential for use in electronics, optoelectronics, energy-storage devices, composites, and sensors. In this article, we review important milestones in these uses of CNTs and graphene produced by CVD, with special emphasis on the latest advances and remaining challenges. The key characteristics and advantages of CNTs and graphene synthesized by CVD for different applications are compared, and future trends in the use of these nanocarbons are discussed.

Scanning tunneling microscopy (STM) is an excellent technique to image the surfaces of materials with extreme spatial resolution. However, it is difficult to maintain its imaging quality when applying the technique under the conditions used in many practical processes, such as chemical vapor deposition and catalysis. In this article, we describe two special classes of STM instruments that are capable of maintaining good imaging quality under “difficult” conditions, namely, one for high and variable temperatures and the other for the combination of high temperatures and high gas pressures. In both cases, we discuss the special design features that make these instruments robust with respect to the challenging imaging conditions and provide examples to illustrate how they are applied.