Speaker
Description
Carbon nanobuds - fullerenes covalently bonded to CNTs or to graphene [1] - are hybrid 0D/1D/2D carbons whose bud-substrate junction carries a topologically discrete sp3 defect set by Euler's theorem. In a forthcoming comprehensive survey [2], we critically evaluate the field and identify a persistent imbalance between theory and experiment. Density functional theory predicts Dirac-point modulation, room-temperature magnetism, visible-range nonlinear optical response (with the HOMO–LUMO gap reduced to ~1.70 eV upon C20→C60 fusion [3]), mode-selective phonon scattering, and hydrogen storage; however, most of these predictions remain unvalidated at the level of individual nanobuds.
We organise the outlook along three axes:
Synthesis & functionalisation: approaches including aerosol CVD, solution-phase cycloaddition, electrochemical in situ growth on graphene, and selective covalent chemistry are established, yet deterministic control over placement, size, and density remains elusive.
Characterisation: combined Raman and TEM measurements [4], alongside single-bud STM/STS, can resolve the junction structure, but studies targeting isolated nanobuds are scarce.
(iii) Devices: applications span from commercial transparent conductors (e.g., Canatu NanoBud films for flexible electronics [5]) to a wide range of laboratory-scale prototypes—including low-threshold field emitters (1–2 V μm⁻¹ [6]), Li-ion anodes, sensors, thermoelectrics, supercapacitors, and composites—yet lack a unifying materials platform.
Synthesis control emerges as the central bottleneck. We argue that advances in the 2D materials toolbox—such as patterned catalyst islands, van der Waals transfer techniques, and single-bud spectroscopies (STM/STS/PL/Raman)—combined with targeted DFT and molecular dynamics simulations, can bridge the theory–experiment gap. This integrated approach will enable validation of predicted electronic, magnetic, optical, and phononic properties, and support scalable fabrication of device-ready nanobud architectures. Ultimately, this could transform nanobuds from a niche material into a general platform for topology-engineered 2D carbons.
Refs:
[1] Nasibulin, A. G. et al. Nat. Nanotechnol. 2007, 2 (3), 156–161.
[2] Vandichel M.,et.al (2026) (in preparation)
[3] Rezaei, F.; Shamlouei, H. R. J. Mol. Struct. 2023, 1278, 134961.
[4] Tian, Y. et al. J. Am. Chem. Soc. 2008, 130 (23), 7188–7189.
[5] Mikladal, B. F. et al. SID Symp. Dig. Tech. Pap. 2013, 44 (1).
[6] Okotrub, A. V. et al. Fullerenes, Nanotubes Carbon Nanostruct. 2010, 18 (4–6), 551–557.