Synthetic approaches to carbon nanomaterials

On-surface synthesis is a useful approach for the construction of nanoporous graphene materials, which are in turn of interest for various electronic applications. Here, the authors review the latest developments in the on-surface synthesis of atomically precise pristine and hetero-atom doped nanoporous graphene materials.

‘Molecular surgery’ is a useful method through which to create endohedral fullerenes that aren’t accessible by conventional physical methods of trapping small atoms and molecules. Here, the authors review the organic chemistry behind molecular surgery, describing the methods to access open-cage intermediates alongside the cage-closing chemistry.

Liquid phase exfoliation (LPE) is a common technology used for graphene synthesis, however, the optimization of liquid suspension medium remains challenging. Here, the authors report a combination of ammonia (NH₃) as an easily removable additive together with low boiling point organic-water co-solvent mixtures as suspension media to achieve high-concentration and long-term stable graphene suspensions by LPE, reaching current benchmark graphene concentration values of ~180 mg·L^-1.

Carbon quantum dots are of interest for a range of applications thanks to their unique physical and eco-friendly properties, and facile bottom-up methods to synthesize these are thus in demand. Here, the authors report the bottom-up synthesis of carbon quantum dots and microparticles via the thermal decomposition of supercritical acetone, in the absence of any external precursors/starting materials

The transformation of CO₂ to oxygen and graphene nanocarbons using lithium carbonate as an electrolyte is a promising, large-scale process for CO₂ removal and valorization, but lithium carbonate is already in high demand as an important battery material. Here, the authors report the use of strontium carbonate as an alternative electrolyte in the electrochemical reduction of CO₂ to carbon nanotubes.

Using metal coordination to assemble carbon nanodots (CND) into clusters can enhance their photophysical properties for applications in sensing and biomedicine. Here, carboxylate groups on the surface of carbon nanodots serve as ligands for the coordination of manganese ions, enabling the assembly of optically and magnetically active CND clusters in a one-step microwave-assisted synthesis in water.

Transition-metal-graphene nanoribbons (TM-GNR) exhibit unusual optoelectronic properties, however, synthetic access to such materials remains highly challenging. Here, the authors report a quantum chemical substrate design via DFT to access TM-GNR hybrid semiconductors using zwitterionic Bergman cyclization-triggered cascade polymerization.

Incommensurate double-wall carbon nanotubes give rise to unique stereochemistry originating from twisted stacks of hexagon arrays, but atomic-level studies of molecular analogues are hindered by the challenges in designing and synthesizing pairs of chiral cylindrical molecules. Here, a molecular version of incommensurate double-wall carbon nanotubes is designed by development of a roadmap of synthetically accessible chiral indices.