Synthesis and Structural Analysis of Graphene Oxide (GO) and reduced Graphene Oxide (rGO)

Around the world, research institutions are trying to develop ways to revolutionise the production of graphene sheets of the highest quality through the synthesis of reduced graphene oxide (rGO). The aim of this study is to synthesize graphene oxide (GO) and reduced graphene oxide by using an improved Hummer’s method. The synthesis was carried out using natural graphite, sulphuric acid, phosphorous pentoxide and potassium permanganate instead of sodium nitrate that emits toxic gases into the environment. Graphene oxide was reduced by using sodium borohydrate as a reducing agent. This makes the reduced graphene oxide (rGO) formed similar to graphene but it contains residual oxygen as well as structural defects. The prepared Samples were analyzed by FT-IR and Raman analysis. FTIR spectroscopy showed the characteristic peak at ~3200 cm−1 attributed to O–H stretching of hydroxyl and carboxyl groups, characteristic peak of ~1510 cm−1 is attributed to benzene functional group (C=C), and the characteristic peak at ~1060 cm−1 (sp3 C–O), and ~1200 cm−1 (sp2 C–O) are believed to be attributed to carboxylic acid and carbonyl groups. These oxygen functional groups indicated that the flake graphite powder has been oxidized to GO. The D and G bands of GO are situated at Raman shift of 1290 and 1600 cm−1 respectively, whereas the D and G band of rGO slightly shifted towards lower wavenumber in the Raman shift and are respectively located at 1300 and 1570 cm−1. The values of ID/IG ratio for GO and rGO were found to be 0.81 and 0.83 respectively. The increase in the value of ID/IG ratio of rGO compared with that of GO is an indication that rGO has been obtained after reduction of GO.