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

Abstract

One-step selective oxidation strategies towards the rational tuning of the surface chemistry of graphene flakes are presented.

Co3O4 Nanoparticles Anchored on Selectively Oxidized Graphene Flakes as Bifunctional Electrocatalysts for Oxygen Reactions

“…The characterization of carbon supports, GF_KMnO 4 and GF_O 3 , by XPS, TPD, FTIR and Raman spectroscopy was previously reported . The reported XPS surface atomic percentages revealed that GF_KMnO 4 presents a higher content in oxygen with a C/O atomic ratio of 4.9, while that of GF_O 3 is 9.8 . The deconvolution of CO 2 and CO evolution TPD spectra showed that both GF_ox materials present a similar low content of carbonyl groups and moderate content of carboxylic acids, carboxylic anhydrides and phenols.…”

“…The characterization of carbon supports, GF_KMnO 4 and GF_O 3 , by XPS, TPD, FTIR and Raman spectroscopy was previously reported . The reported XPS surface atomic percentages revealed that GF_KMnO 4 presents a higher content in oxygen with a C/O atomic ratio of 4.9, while that of GF_O 3 is 9.8 .…”

“…The deconvolution of CO 2 and CO evolution TPD spectra showed that both GF_ox materials present a similar low content of carbonyl groups and moderate content of carboxylic acids, carboxylic anhydrides and phenols. Nevertheless, i) the epoxyl groups are predominant in GF_O 3 (relative percentage of 43% of total released CO 2 ), whereas in GF_KMnO 4 the relative percentage of these groups is diminished by half and similar to the relative percentage of hydroxyl groups (26% of epoxyl and 23% of hydroxyl of total released CO 2 ), and ii) quinones were identified in GF_O 3 , with a relative content of 25% of total released CO contrasting with the relative content of 6% for GF_KMnO 4 …”

“…In this work Co 3 O 4 @GF_ox nanocomposites were prepared using two types of oxidized graphene flakes with specific oxygen functionalities to promote the anchoring of Co 3 O 4 nanoparticles, which were synthesized in situ ; the variety of oxygen functional groups existing on the basal planes and at the edges of graphene flakes is expected to enhance the dispersion of Co 3 O 4 nanoparticles on graphene and also enable a more robust chemical and electrical coupling between the two components. Furthermore, we aimed to gain further insights into the importance of fine tuning of oxidized graphene supports and the role of specific oxygen functionalities on the anchoring of Co 3 O 4 nanoparticles and towards the electrocatalytic activity of the nanocomposites for oxygen evolution and reduction reactions.…”

Polyoxometalate‐graphene Electrocatalysts for the Hydrogen Evolution Reaction

“…The oxidized graphene was prepared using a method described by some of us in the literature . Typically 9 mol dm −3 H 2 SO 4 solution was slowly added to a mixture of GF (1.0 g) and KMnO 4 (1.0 g), and the mixture was cooled in an ice bath at 0 °C.…”