学术报告：Catalysts, Etchants and Magnetic Fields: How can Carbon Nanostructure Growth be Controlled?
报告人：Dr. Alister J. Page, University of Newcastle, Australia
I present recent quantum chemical and non-equilibrium MD simulations1-7 showing how 1D and 2D carbon nanomaterials nucleate and "grow" during chemical vapor deposition (CVD). Graphene and carbon nanotube growth begin with the precipitation/aggregation of carbon atoms on a catalyst surface to form extended carbon chains, which quickly combine and oligomerise to form “islands” of sp2-hybridized carbon. Larger nanostructures then form via the coalescence of these structures on the catalyst surface, which are stabilised through strong carbon-catalyst σ-bonding. I will discuss how these processes are influenced by three key experimental parameters: (1) the type of catalyst used; (2) the presence of chemical "etchants", such as H2, NH3 and H2O, on the catalyst surface; and (3) the presence of applied magnetic fields. I will also discuss recent advances in chirality-controlled carbon nanotube growth based on molecular templates. Our simulations demonstrate how each of these parameters can potentially be exploited towards controlling the growth of graphene and carbon nanotubes. Importantly, we demonstrate that chemical etchants are an important aspect of carbon nanotube growth kinetics that have so far been overlooked in popular growth models.
1 A. J. Page, Y. Ohta, et al., Acc. Chem. Res. 2009, 43, 1375-1385
2 Y. Wang, A. J. Page, et al., J. Am. Chem. Soc., 2011, 133, 18837-18842.
3 H.-B. Li, A. J. Page, et al., J. Am. Chem. Soc., 2012, 134, 15887-15896
4 A. J. Page, Y. Wang, et al., J. Phys. Chem. C, 2013, 117, 14858-14864.
5 B. Liu, J. Liu, et al., Nano Lett. 2015, 15, 1530-6984
6 A. J. Page, S. Saha, et al. J. Am Chem. Soc., 2015, 137, 9281-9288.
7 A. J. Page, F. Ding, et al. Rep. Prog. Phys., 2015, 78, 036501.
Alister Page is a Senior Lecturer in the Newcastle Institute for Energy and Resources at the University of Newcastle, Australia. Alister received degrees in chemistry and mathematics from The University of Newcastle, Australia in 2005, and a PhD in 2008 under the supervision of Prof. Ellak I. von Nagy-Felsobuki. Between 2009-2012 he undertook a Fukui Fellowship in the group of Prof. Keiji Morokuma at the Fukui Institute for Fundamental Chemistry, Kyoto University. In 2012 he was awarded a University Fellowship at The University of Newcastle. Since 2013 he has been a lecturer in physical chemistry at Newcastle since 2013. His research focuses on understanding nanoscale self-assembly mechanisms related to graphene and carbon nanotubes, and characterising the structure and dynamics in ionic liquids, and ionic liquid - solid interfaces, using computational chemistry. Since 2006 he has published 1 book, 2 book chapters, and more than 50 peer-reviewed articles.