Thermodynamic, electronic, and optical properties of graphene oxide: A statistical ab initio approach

Autor(es)

Guilhon, I. ; Bechstedt, F. ; Botti, Silvana ; Marques, M. ; Teles, L. K.

• Tipo de documento: Artigo Científico
• Fonte: PHYSICAL REVIEW B; v. 95, n. 24, p. 14-pg., 2017-06-23.

Resumo

We study the incomplete oxidation of graphene or reduction of graphene oxide for hydroxyl and epoxy oxidant groups. While in wet oxidation hydroxyl groups are favorable, in a drier environment an oxygen atom can bridge two neighboring carbon atoms. We model composition variations and structural disorder within a statistical theory, the generalized quasichemical approximation, combined with density functional theory calculations of the local atomic geometries. A generalization of the statistical approach is developed to account for the antiparallel orientation of hydroxyl groups and a fourfold coordination of C atoms. The theoretical framework enables a thermodynamic treatment of graphene oxide as a function of oxygen content, allowing us to derive temperature-composition phase diagrams and investigate possible clustering and segregation. The resulting geometries, local and average electronic structures, and optical absorption spectra are discussed and compared with available experimental data. (AU)

• Processo FAPESP: 12/50738-3 - Estudo de pontos quânticos através de cálculos de primeiros princípios
• Beneficiário: Ronaldo Rodrigues Pelá
• Modalidade de apoio: Auxílio à Pesquisa - Regular