Tuning the surface chemistry of graphene flakes: new strategies for selective oxidation

• Tipo: Artigo em Revista Científica Internacional
• Data: 2017

Autores

Araujo, MP (Autor) Outra; O.S.G.P. Soares (Autor) FEUP; Fernandes, AJS (Autor) Outra; Manuel Fernando R Pereira (Autor) FEUP; Cristina Freire (Autor) FCUP

Revista

Título: RSC Advances

Vol. 7

Páginas: 14290-14301

ISSN: 2046-2069

Editora: Royal Society of Chemistry

Indexação

ISI Web of Knowledge - 72 Citações

Scopus - 78 Citações

Outras Informações

ID Authenticus: P-00M-H2A

DOI: 10.1039/c6ra28868e

Abstract (EN): To accomplish a rational tuning of the surface chemistry of graphene flakes (GF), four different one-step protocols towards the selective oxidation of GF were performed, using different oxidants: nitric acid, potassium permanganate/sulfuric acid, ozone and 3-chloroperbenzoic acid. The characterization of the resulting materials confirmed the successful preparation of oxidized GF with C/O atomic ratios varying in the range of 21.2-4.9, with distinct types of oxygen functionalities. While the oxidation of GF with nitric acid exclusively promotes the introduction of carboxylic groups and carbonyl/quinones, 3-chloroperbenzoic acid is responsible for the introduction of epoxyl groups and carboxylic anhydrides, potassium permanganate favours the introduction of epoxyl and hydroxyl groups and some content of carboxylic anhydrides, and ozone promotes predominantly the introduction in graphene structure of epoxyl groups, carboxylic anhydrides, phenols, quinones and lactones, and in a lesser extension carbonyl groups in alpha-substituted ketones and aldehydes if the oxidation is performed in the solid phase, or hydroxyl groups and a moderate content of carbonyl groups and aldehydes if GF are in a water dispersion. Furthermore, this work highlighted the possibility of identifying and distinguishing labile groups, namely hydroxyl and epoxyl groups, which are predominant in the structure of GF oxidized with potassium permanganate/sulfuric acid, ozone and 3-chloroperbenzoic acid. This is the first comprehensive study on the fine tuning of the surface of oxidized GF and a major contribution for the rational design of graphene composites since the application of these specific strategies can be useful in the anchoring of other molecules or nanoparticles.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 12