Functionalized Graphene

Research

Ab-initio optical, electronic and magnetic properties of functionalized graphene derivatives

Graphene-based derivatives with covalent functionalization and well-defined stoichiometry are highly desirable in view of their application as functional surfaces.

This research has been performed to support the activities of the ENEA's labs for the synthesis and characterization of carbon-based nanomaterials, involving collaborations with Universities and other institutions.

Hydroxylated graphane. Hydroxylated graphane (i.e., fully functionalized graphene derivatives coordinated with -H and -OH groups) structures have been investigated to evaluate thermodynamic stability by ab initio calculations.

Thermodynamic stability of hydroxylated graphane. Stable phases of graphene derivatives coordinated with -OH and -H groups with low and high contents of hydrogen are found for high oxygen and hydrogen partial pressure, respectively.

(An ab initio study of hydroxylated graphane - F. Buonocore, A. Capasso and N. Lisi, Journal of Chemical Physics vol. 147, issue 11, (2017) )

Tuning the electronic properties of graphane. Within the density functional theory approach, we investigate the electronic property modifications of graphane by progressive hydroxylation, i.e., by progressively substituting –H with –OH groups. Hydroxylated graphane has two interfaces with vacuum, hence its electron affinity can be different on each interface, with the formation of an intrinsic dipole perpendicular to the monolayer. We envisage the possibility of using hydroxylated graphane allotropes with tuneable electronic affinity to serve as interfacial layers in 2D material-based heterojunctions.

(Tuning the electronic properties of graphane via hydroxylation: an ab-initio study - F. Buonocore, A. Capasso, M. Celino, N. Lisi, O. Pulci. J. Physical Chemistry C 2021, 125, 29, 16316–16323. DOI:10.1021/acs.jpcc.1c04397)

Tuning graphene optical properties by metal adsorption on pyridinic defects. We investigated by first principles calculations the tuning of graphene's optical properties by simultaneous: 1) carbon vacancy creation; 2) nitrogen doping and 3) metal decoration of pyridine-type vacancy defects used as anchoring sites. A tetramerized pyridinic defect (or TPD) is formed when a carbon dimer vacancy (di-vacancy) is created and each of the four carbon atoms two-fold coordinated left are substituted by nitrogen atom. We modified TPD by the chemisorption of Mg simple metal and Zn, Pd and Pt transition metals.

(Electronic and optical properties of metal decorated nitrogen-doped vacancy defects in graphene - F. Buonocore, N. Lisi, O. Pulci, J. Phys.: Condens. Matter 31 (2019) 235302.)

Magnetism of graphone. The magnetism of graphone, a single-side-hydrogenated graphene derivative, has been related to the localized and unpaired p-electrons associated with the unhydrogenated carbon atoms. The effects the adhesion to either Cu(111) or alpha-quartz (0001) surface on the magnetic properties of graphone have been investigated using an exchange-correlation functional corrected for long range interactions. The critical temperature has been investigated on the basis of the mean field theory to evaluate the stability of the magnetism at ordinary temperature.

(F. Buonocore, A.M. Conte and N. Lisi, Effects of the substrate on graphone magnetism: a density functional theory study Physica E: Low-dimensional Systems and Nanostructures, 78, pp. 65-72 (2016))

Adhesion of graphane to Copper.The study of the interface between hydrogen-functionalized graphene and catalyst metal surfaces can be pivotal to assess the feasibility of direct CVD growth methods for this material. We investigated the adhesion of graphane, a double-side-hydrogenated graphene derivative, to a Cu(111) surface by using ab initio calculations.

(Interface of graphane with copper: a van der Waals density-functional study - F Buonocore, A Capasso, N Lisi, Materials Research Express 1, 015608 (2014))

Other related publications:

Chemical Vapor Deposited Graphene-Based Derivative As High-Performance Hole Transport Material for Organic Photovoltaics - A. Capasso, L. Salamandra, G. Faggio, T. Dikonimos, F. Buonocore, V. Morandi, L. Ortolani, and Nicola Lisi , ACS Appl. Mater. Interfaces 8 (36), pp 23844-23853 (2016)
Interactions between Primary Neurons and Graphene Films with Different Structure and Electrical Conductivity - A. Capasso, J. Rodrigues, M. Moschetta, F. Buonocore, G. Faggio, G. Messina, M. J. Kim, J. Kwon, E. Placidi, F. Benfenati, M. Bramini, G‐H Lee, N. Lisi Advanced Functional Materials (2020) https://doi.org/10.1002/adfm.202005300
Ab Initio Study of Graphene/hBN Van der Waals Heterostructures: Effect of Electric Field, Twist Angles and pn Doping on the Electronic Properties - S Brozzesi, C Attaccalite, F Buonocore, G Giorgi, M Palummo, O Pulci Nanomaterials 12 (12), 2118 2022 DOI: 10.3390/nano121221
Nanocrystalline graphene for ultrasensitive surface-enhanced Raman spectroscopy - G Faggio, R Grillo, N Lisi, F Buonocore, R Chierchia, MJ Kim, GH Lee, ..., Applied Surface Science 599, 154035 2022 https://doi.org/10.1016/j.apsusc.2022.154035
The chimera of 2D- and 1D-graphene magnetization by hydrogenation or fluorination: critically revisiting old schemes and proposing new ones by ab initio methods - Albino, A., Buonocore, F., Celino, M. and Totti, F.. Nanoscale Advances, (2024) http://dx.doi.org/10.1039/D3NA01008B