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

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. (paper)