title: A New Member of the Graphene Family: Graphene Acid.
abstract: A new member of the family of graphene derivatives, namely, graphene acid with a composition close to C1(COOH)1, was prepared by oxidation of graphene oxide. The synthetic procedure is based on repeated oxidation of graphite with potassium permanganate in an acidic environment. The oxidation process was studied in detail after each step. The multiple oxidations led to oxidative removal of other oxygen functional groups formed in the first oxidation step. Detailed chemical analysis showed only a minor amount of other oxygen-containing functional groups such as hydroxyl and the dominant presence of carboxyl groups in a concentration of about 30 wt %. Further oxidation led to complete decomposition of graphene acid. The obtained material exhibits unique sorption capacity towards metal ions and carbon dioxide. The highly hydrophilic nature of graphene acid allowed the assembly of ultrathin free-standing membranes with high transparency.
authors.affiliation: Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 16628, Prague 6, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Jankovský
authors.affiliation: Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 16628, Prague 6, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Nováček
authors.affiliation: Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 16628, Prague 6, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Luxa
authors.affiliation: Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 16628, Prague 6, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Sedmidubský
authors.affiliation: Department of Inorganic Technology, University of Chemistry and Technology Prague, Technická 5, 16628, Prague 6, Czech Republic.
authors.forename: Vlastimil
authors.initials: V
authors.lastname: Fila
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371.
authors.forename: Martin
authors.initials: M
authors.lastname: Pumera
authors.affiliation: Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technická 5, 16628, Prague 6, Czech Republic.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Sofer
keywords: carboxylic acids; graphene; graphene derivatives; membranes; oxidation