Sunday, 29 May 2022: 17:20
West Meeting Room 205 (Vancouver Convention Center)
O. Hassan (Univ. Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, Grenoble, Fr-38000), G. F. Franklin (RS2E FR CNRS 3459, CIRIMAT, UMR CNRS 5085), P. Simon (Universite de Toulouse Paul Sabatier), L. Dubois (Univ. Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, Grenoble, Fr-38000), P. L. Taberna (Université Toulouse III Paul Sabatier - CIRIMAT, UMR CNRS 5085), and F. Duclairoir (Univ. Grenoble Alpes, CEA, CNRS, IRIG, SyMMES, Grenoble, Fr-38000)
Since the discovery of graphene in 2004 [1], it has been considered a “Wonder” material with lots of potential due to its attractive properties. However, due to the high cost and difficulty of producing and handling single sheets of graphene, the presence of graphene in the market has been hindered. Luckily, many methods have been devised to synthesize graphene-like materials that would be easier and cheaper to produce. Among such methods, the chemical exfoliation of graphite, yielding reduced Graphene Oxide (rGO), is one of the commonly used synthesis methods nowadays. Unfortunately, such a method, although efficient and low cost, is not a green one as it involves the use of hydrazine hydrate (Hz) as a reducing agent. Since hydrazine is a very toxic chemical, research has been conducted to find alternatives to its use. Many reducing agents have been experimented, yet Ascorbic Acid (AA) proved itself to be an efficient reducing agent, offering a mild green reduction process [2]. While many diverse protocols involving AA have been used, a rationalization of the correlation between important reaction condition parameters and RGO properties is lacking.
In this presentation, a full study on the reduction of graphene oxide using AA has been done including varying the reaction parameters such as the amount of AA, the reaction temperature and the reaction time. Various characterization techniques have been employed to analyze the structural and morphological differences of the rGO reduced with AA and Hz, including ssNMR, SEM, XPS, XRD, TGA, Elemental Analysis (EA) and conductivity measurements. The relationship between experimental and graphene intrinsic properties will hence be presented. Furthermore, being a material of high interest for supercapacitor applications, the electrochemical storage performances of the rGO samples reduced with those 2 reducing agents have been assessed. It will also be shown that the obtained results pave the road for the employment of AA as a mild green reduction method for, not only rGO, but also different rGO based materials, including pillared graphene materials that have been showing promising performances as supercapacitors [3].
References:
[1] S. Novoselov et al., Science, 306, (2004) 666.
[2] K. H. D. Silva et al., Carbon, 2017.
[3] Banda et al., ACS Nano, 13 (2019) 1143.
