Original scientific paper
https://doi.org/10.15255/CABEQ.2019.1609
Structural and Capacitive Properties of Graphene Obtained by a Green Method of Graphene Oxide Reduction
M. Raić
; Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
D. Sačer
; Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
M. Kraljić Roković
; Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 19, 10000 Zagreb, Croatia
Abstract
In this study, a green method was applied in order to reduce graphene oxide (GO). Reduction was carried out at 80 °C in the presence of phenolic compounds from olive leaf extract (OLE), and olive mill wastewater (OMW) as a reducing agent. Owning to the
natural origin of the reducing agent, this method is environmentally friendly. Reduction was carried out at pH=7 and pH=10 in the presence of OLE, and at pH=10 in the presence of OMW. The reduction process was monitored using UV/Vis spectroscopy. The
structural properties of the reduced graphene oxide (rGO) samples were characterized by Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Structural studies demonstrated that a part of the oxygen functionalities in the graphene
oxide structure had been removed, which resulted in increased electrical conductivity as proved by the four-point probe method. Better reduction efficiency, as well as better capacitive properties, were obtained at increased pH value. Capacitive properties of rGO
were determined using the cyclic voltammetry technique. The influence of the different reducing agents, OLE and OMW, on rGO capacitive properties is also shown in this work.
Keywords
graphene; graphene oxide; capacitive properties; olive leaf extract; olive mill wastewater
Hrčak ID:
225901
URI
Publication date:
7.10.2019.
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