Environmental-friendly synthesis of reduced graphene oxide (rGO) using gamma irradiation

Abstract

Graphene has drawn much attentions in recent years, mainly due to its excellences in their strength and thermal/electrical conductivity with various possible applications. However, some common graphene synthesis methods involve in using/producing poisonous chemicals and other production drawbacks, leading to attempts to adopt more efficient and more environmental-friendly synthesis methods. This work reported preliminary results in developing a method for graphene synthesis using gamma irradiation on graphene oxide (GO) with the accumulated doses of 14, 21, 28, 35, and 42 kGy, respectively. The results showed that gamma irradiation could successfully initiate the reduction of GO in water-ethanol mixture to reduced graphene oxide (rGO) with different efficiencies, which were confirmed by using SEM, SEM-EDS, UV-Vis spectroscopy, and FT-IR spectroscopy. In particular, SEM-EDS showed that irradiating GO with 35-kGy gamma dose led to the highest reduction of oxygen in GO as seen by the highest ratios of carbon and oxygen (C:O) content in rGO that increased by ~20% compared with the value from GO.

Radiation induced reduction of graphene oxide: a dose effect study

“…A modified approach, based on established literature procedures, was employed for the synthesis of rGO. 54 In a detailed account of the procedure, starting from commercial GO suspension, an aqueous solution with a concentration of 0.2 g L −1 of GO was prepared within a transparent glass vial (40 mL, 3 cm × 8 cm). This GO suspension was then further added with 0.2 mol L −1 isopropanol (IPA) or alternatively with 0.2 mol L −1 tert -butanol.…”

Features of structure and optical properties GO and a GO/PVA composite subjected to gamma irradiation

“…The addition of GO to PVA introduces new energy levels between the conduction and valence bands, leading to a decrease in the band gap value of the nanocomposite. 28 This decrease becomes more prominent with an increased concentration of GO. As observed in the table, the band gap value decreases with higher doses of gamma radiation.…”

“…Under the inuence of gamma radiation, the breaking of hydrogen and hydroxyl groups has occurred in the PVA polymer, while the GO/PVA composite lms undergo the disruption of hydrogen bonds. 28,29 Because of these structural modications, absorption increases, resulting in a decrease in the transmittance spectrum. The UV-Vis spectroscopy ndings enable the observation of changes in the band gap value of both gammairradiated and non-irradiated samples about the radiation dose.…”