We have studied the electronic characteristics of covalently functionalized graphene by nitrene chemistry using first-principles density functional calculations. The perfluorophenylazide functionalization leads to a band-gap opening in graphene and transition from a semimetallic to a semiconducting state. The [2 + 1] cycloaddition-induced gap is shown to be attributed to the modification of the π conjugation that depends on the concentration of aziridine adducts. The implications of tailoring the band structure of functionalized graphene for future graphene-based device applications are discussed.

We first explore negative-ion formation in fullerenes C44 to C136 through low-energy electron elastic scattering total cross sections calculations using our Regge-pole methodology. Then, the formed negative ions C44ˉ to C136ˉ are used to investigate the catalysis of water oxidation to peroxide and water synthesis from H2 and O2. The exploited fundamental mechanism underlying negative-ion catalysis involves hydrogen bond strength-weakening/breaking in the transition state. Density Functional Theory transition state calculations found C60ˉ optimal for both water and peroxide synthesis, C100ˉ increases the energy barrier the most, and C136ˉ the most effective catalyst in both water synthesis and oxidation to H2O2.

The electronic characteristics of a planar covalent organic framework (COF) on graphene are investigated by means of dispersion-corrected density functional theory. The aromatic central molecule of the COF acts as an electron donor to graphene, while the linker of the COF acts as an electron acceptor. The concerted interaction between the filled orbitals of the central molecule and empty orbitals of the linker promotes the formation of planar COF networks on graphene. The calculation results are in very good agreement with experimental findings of an ordered hexagonal and square COF planar on graphene, which sheds light on the supermolecular assembly mechanism.

Graphene's adhesive properties owing to inherent van der Waals interactions become increasingly relevant in the nanoscale regime. Polymer self-assembly via graphene-mediated noncovalent interactions offers a powerful tool for the creation of anisotropic nanopatterned systems. Here, we report the supramolecular self-assembly of biofunctional-modified poly(2-methoxystyrene) on graphene nanoribbons prepared by unzipping multiwalled carbon nanotubes. This approach promotes the glycol-modified polymer to self-assemble into structured nanopatterns with preserved bioactivity. The self-assembly is attributed to enhanced van der Waals interactions and the associated charge transfer from polymer to graphene. These findings demonstrate that the assembly yields a prospective route to novel nanomaterial systems.

We have studied the electronic characteristics of chemically modified single-walled carbon nanotubes by oxygen doping using first-principles density-functional calculations. The oxygen doping, a controlled [2 + 1] cycloaddition scheme, is shown to modify the π-conjugation and impact on the near-infrared band gaps. The implications of tailoring the electronic structure of oxygen doped carbon nanomaterials for future device applications are discussed.