DFT study of graphene oxide reduction by a dopamine species

Abstract

Recently a large interest has arisen for using less active reducers of graphene oxide, GO, that are friendly with the environment. In the present work, a DFT theoretical study on the reduction process of GO model surfaces is performed taking into account zwitterionic dopamine, ZDA, as reducing agent. Several periodic models representing epoxy and hydroxyl patches on GO basal plane are proposed. As the number of oxide groups in a patch of epoxies or hydroxyls on the surface of graphene increases from 1 to 5, these systems become more stable. Whereas the adsorption of ZDA on patches of GO with 5 epoxy groups is non-dissociative, that of ZDA on patches of GO with 5 hydroxyl groups is fundamentally dissociative, reducing the surface of graphene oxide. The H₂O molecule produced in the GO reduction becomes trapped to ZDA through a hydrogen bond. The ZDA binding to GO was analysed by considering electrostatic effects and attractive non-covalent contributions due to vdW interactions.

GRAPHICAL ABSTRACT

KEYWORDS:

• Adsorption
• graphene oxide
• zwitterionic dopamine
• density functional theory
• Vasp

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina; Agencia Nacional de Promoción Científica y Tecnológica Argentina under [grant number PICT-2014-1778]; and Secretaría General de Ciencia y Tecnología, Universidad Nacional del Sur of Argentina under [grant number PGI 24/F063].